Subject: RE: GraGraph home earthquake meter From: "Kareem of Heyjoojoo" system98765@............. Date: Sun, 30 Sep 2007 13:13:00 -0700 I thought it was $85 but that link shows $159... (american dollars) -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of JimT Sent: Sunday, September 30, 2007 8:40 AM To: psn-l@.............. Subject: Re: GraGraph home earthquake meter There is more info on this page: http://www.kilian-nakamura.com/catalog/gragraph-home-earthquake-seismograph- p-176.html Here is what it says: The Gragraph is a home seismograph that warns you as an earthquake is occurring, measures the intensity, and records the data in its calendar. The verbal warnings are in Japanese, but the digital data can be easily accessed in any language. In normal mode, the Gragraph serves as a tabletop calendar/clock and a reference for past activity. Gragraph features: .. Perceives shaking, and indicates on display . Warns of shaking with sound and voice . Indicates level from 3-10 . Keeps record of previous seismic activity . During the night, it activates a safety light . Calendar/Clock function Jim Turner On 9/29/07, psn-l-digest-request@.............. wrote: > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 1 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: GraGraph home earthquake meter > From: "David Saum" > Date: Sat, 29 Sep 2007 18:40:00 -0400 > > Japanese > http://www.gragraph.jp/ > > English > http://blog.scifi.com/tech/archives/2007/09/28/gragraph_home_e.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fast Moment Ternsor List??? From: Dave Nelson davenn@............... Date: Mon, 01 Oct 2007 09:47:23 +1000 Hi Stephen, yeah damn annoying, some weeks ago I emailed Madelene Zirbies who is one of the ones looking after the www site. She was aware of it and seemed to indicate that it wasnt going to get fixed any time soon. the other data available under the Scientific & Technical tab just isnt the same :( for one it doesnt have the nice world map image with the "beachball" on it that I had saved on puter for many years. also the data is in a different format. also the "Global CMT Project Moment Tensor Solution" info now being supplied lists events Mw6.0 and higher and some times only the high events eg M6.6 up cheers Dave N Sydney At 11:27 AM 9/30/2007 -0700, you wrote: >Question,, anyone know why the FM Tensor List is stuck at 14 Aug 2007? >I know that I can get the info in a few days under the Scientific & >Technical tab of the individual quakes at NEIC, but was wondering what >happened to their FM Tensor list at the following link??? >http://neic.usgs.gov/neis/FM/ > Stephen > PSN #55 -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: 269.13.35/1039 - Release Date: 9/29/2007 9:46 PM __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fast Moment Ternsor List??? From: John Lahr johnjan@........ Date: Mon, 01 Oct 2007 14:29:38 -0700 Here's the word from the USGS. Cheers, John Because of Department of Interior security requirements, we had to install a number of new routers in our internal network. At that point some of our processes that depended on communication between different subnets stopped working. In other words, some of our programs broke. Most of the problems were fixed on the first day, but we are still unable to compute the moment tensors. We have been working on a new, faster experimental system, with an improved user interface, for generating the moment tensors. Since this is the direction we were already committed to, we have decided to accelerate implementation of the new system. In the near future we hope to be computing moment tensors again, using the new system. You may want to take a look at the USGS Earthquake Notification Service (ENS) at http://earthquake.usgs.gov/eqcenter/ens/. These notifications, at this time, will not include the "beachball", but will be A LOT faster. They are also very easy to customize in terms of geographic region(s) of interest and magnitude threshold. You may end up preferring these to the moment tensor solutions. At 04:47 PM 9/30/2007, you wrote: >Hi Stephen, > yeah damn annoying, some weeks ago I emailed > Madelene Zirbies > who is one of the ones looking after the www site. She was aware of it and >seemed to indicate that it wasnt going to get fixed any time soon. > > the other data available under the Scientific & Technical tab just >isnt the same :( for one it doesnt have the nice world map image with the >"beachball" on it that I had saved on puter for many years. also >the data is in >a different format. also the "Global CMT Project Moment Tensor >Solution" info >now being supplied lists events Mw6.0 and higher and some times >only the high >events eg M6.6 up > >cheers >Dave N >Sydney > > > >At 11:27 AM 9/30/2007 -0700, you wrote: >>Question,, anyone know why the FM Tensor List is stuck at 14 Aug 2007? >>I know that I can get the info in a few days under the Scientific & >>Technical tab of the individual quakes at NEIC, but was wondering >>what happened to their FM Tensor list at the following link??? >>http://neic.usgs.gov/neis/FM/ >> Stephen >> PSN #55 > > >-- >No virus found in this outgoing message. >Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: >269.13.35/1039 - Release Date: 9/29/2007 9:46 PM > > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with the body >of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fast Moment Ternsor List??? From: Dave Nelson davenn@............... Date: Tue, 02 Oct 2007 07:53:09 +1000 Thanks John nice to have an official explanation, hopefully we will see the "beachball maps again one day soon. Yes I have been logged onto the ENS for some years and it is a good fast notification of new events. cheers Dave At 02:29 PM 10/1/2007 -0700, you wrote: >Here's the word from the USGS. Cheers, John > Because of Department of Interior security requirements, we had to > install a number of new routers in our internal network. At that point > some of our processes that depended on communication between different > subnets stopped working. In other words, some of our programs broke. > Most of the problems were fixed on the first day, but we are still > unable to compute the moment tensors. > We have been working on a new, faster experimental system, with an > improved user interface, for generating the moment tensors. Since this > is the direction we were already committed to, we have decided to > accelerate implementation of the new system. In the near future we hope > to be computing moment tensors again, using the new system. > You may want to take a look at the USGS Earthquake Notification Service > (ENS) at http://earthquake.usgs.gov/eqcenter/ens/. These notifications, > at this time, will not include the "beachball", but will be A LOT > faster. They are also very easy to customize in terms of geographic > region(s) of interest and magnitude threshold. You may end up preferring > these to the moment tensor solutions. > -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: 269.13.35/1040 - Release Date: 9/30/2007 9:01 PM __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fast Moment Ternsor List??? Working!!! From: Stephen & Kathy skmort@............ Date: Mon, 01 Oct 2007 18:57:49 -0700 Wouldn't you know,, we must have jarred something loose,, ha,, I just checked and today it is working,,, thanks to all. Stephen PSN #55 John Lahr wrote: > Here's the word from the USGS. Cheers, John > > Because of Department of Interior security requirements, we had to > install a number of new routers in our internal network. At that point > some of our processes that depended on communication between different > subnets stopped working. In other words, some of our programs broke. > Most of the problems were fixed on the first day, but we are still > unable to compute the moment tensors. > > > We have been working on a new, faster experimental system, with an > improved user interface, for generating the moment tensors. Since this > is the direction we were already committed to, we have decided to > accelerate implementation of the new system. In the near future we > hope > to be computing moment tensors again, using the new system. > > > You may want to take a look at the USGS Earthquake Notification > Service > (ENS) at http://earthquake.usgs.gov/eqcenter/ens/. These > notifications, > at this time, will not include the "beachball", but will be A LOT > faster. They are also very easy to customize in terms of geographic > region(s) of interest and magnitude threshold. You may end up > preferring > these to the moment tensor solutions. > > > > > > > At 04:47 PM 9/30/2007, you wrote: >> Hi Stephen, >> yeah damn annoying, some weeks ago I emailed >> Madelene Zirbies >> who is one of the ones looking after the www site. She was aware >> of it and >> seemed to indicate that it wasnt going to get fixed any time soon. >> >> the other data available under the Scientific & Technical tab just >> isnt the same :( for one it doesnt have the nice world map image >> with the >> "beachball" on it that I had saved on puter for many years. also >> the data is in >> a different format. also the "Global CMT Project Moment Tensor >> Solution" info >> now being supplied lists events Mw6.0 and higher and some times >> only the high >> events eg M6.6 up >> >> cheers >> Dave N >> Sydney >> >> >> >> At 11:27 AM 9/30/2007 -0700, you wrote: >>> Question,, anyone know why the FM Tensor List is stuck at 14 Aug 2007? >>> I know that I can get the info in a few days under the Scientific & >>> Technical tab of the individual quakes at NEIC, but was wondering >>> what happened to their FM Tensor list at the following link??? >>> http://neic.usgs.gov/neis/FM/ >>> Stephen >>> PSN #55 >> >> >> -- >> No virus found in this outgoing message. >> Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: >> 269.13.35/1039 - Release Date: 9/29/2007 9:46 PM >> >> >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with the body >> of the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. >> > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of > the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > Wouldn't you know,,  we must have jarred something loose,, ha,,  I just checked and today it is working,,,   thanks to all.
  Stephen
  PSN #55

John Lahr wrote:
Here's the word from the USGS.  Cheers, John

   Because of Department of Interior security requirements, we had to
   install a number of new routers in our internal network. At that point
   some of our processes that depended on communication between different
   subnets stopped working. In other words, some of our programs broke.
   Most of the problems were fixed on the first day, but we are still
   unable to compute the moment tensors.


   We have been working on a new, faster experimental system, with an
   improved user interface, for generating the moment tensors. Since this
   is the direction we were already committed to, we have decided to
   accelerate implementation of the new system. In the near future we hope
   to be computing moment tensors again, using the new system.


   You may want to take a look at the USGS Earthquake Notification Service
   (ENS) at http://earthquake.usgs.gov/eqcenter/ens/. These notifications,
   at this time, will not include the "beachball", but will be A LOT
   faster. They are also very easy to customize in terms of geographic
   region(s) of interest and magnitude threshold. You may end up preferring
   these to the moment tensor solutions.






At 04:47 PM 9/30/2007, you wrote:
Hi Stephen,
                  yeah damn annoying,   some weeks ago I emailed Madelene Zirbies
 who is one of the ones looking after the www site.   She was aware of it and
seemed to indicate that it wasnt going to get fixed any time soon.

 the other data available  under the Scientific & Technical tab  just
isnt the same  :(  for one  it doesnt have the nice world map  image with the
"beachball" on it that I had saved on puter for many years.   also the data is in
a different format.  also the  "Global CMT Project Moment Tensor Solution"  info
now being supplied  lists events Mw6.0 and higher  and some times only the high
events  eg  M6.6 up

cheers
Dave N
Sydney



At 11:27 AM 9/30/2007 -0700, you wrote:
Question,, anyone know why the FM Tensor List is stuck at 14 Aug 2007?
I know that I can get the info in a few days under the Scientific & Technical tab of the individual quakes at NEIC, but was wondering what happened to their FM Tensor list at the following link???
<http://neic.usgs.gov/neis/FM/>http://neic.usgs.gov/neis/FM/
 Stephen
 PSN #55


--
No virus found in this outgoing message.
Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: 269.13.35/1039 - Release Date: 9/29/2007 9:46 PM


__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

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See http://www.seismicnet.com/maillist.html for more information.



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Subject: San Andreas drilling From: ian ian@........... Date: Sat, 06 Oct 2007 09:05:08 +0100 interesting story about recovering rocks from deep inside the fault: http://news.bbc.co.uk/2/hi/science/nature/7030660.stm Ian __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: WinQuake Display Question From: "Jerry Payton" gpayton880@....... Date: Tue, 9 Oct 2007 14:01:05 -0500 (Question 1): On a WinQuake event display are the P and S arrival times showning the ACTUAL arrival times or shown according to what the table says they should be? (Question 2): Is the distance from the event to your seismograph computed "through the earth" or "around the surface?" Thank you, Jerry Payton
(Question 1):    On a WinQuake event display = are the=20 P and S arrival times showning the ACTUAL arrival times = or=20 shown according to what the table says they should be?
 
(Question 2):    Is the distance from the event to=20 your seismograph computed "through the earth" or "around the=20 surface?"
 
Thank you,
Jerry Payton
 
 
 
 
Subject: Re: WinQuake Display Question From: tchannel1@............ Date: Tue, 9 Oct 2007 14:55:46 -0600 Hi Jerry, "I Think"................Q 1 The p and s and other = phases if you use them are all based on (time theory) =20 The math program knows where you are and where the event took place, it = converts that info to Miles, also to Degrees. It then uses one of several formulas, I use the default formula, to = place the p and s on a time line, which is on the bottom of the Winquake = screen. Q2.........The distance is "around the surface" like a string on a = globe. This is all "great circle" math. So the program is simple for this part, because, it take the event Long. = and Lat, your Long. and Lat, the time of the event, does the math (the = p travels about 10km per second), I calculate it is about 28,000 miles = per hour, and figure it would take the P, say 12.002 minute to reach = you, add that, to the event time, and places the P on your screen = accordingly. It does not read you recording, you could have recorded a truck or a = train and if the event matched your train in would place the p and s, on = the time line. Is this clear??????????????????? Ted ----- Original Message -----=20 From: Jerry Payton=20 To: psn-l@................. Sent: Tuesday, October 09, 2007 1:01 PM Subject: WinQuake Display Question (Question 1): On a WinQuake event display are the P and S arrival = times showning the ACTUAL arrival times or shown according to what the = table says they should be? (Question 2): Is the distance from the event to your seismograph = computed "through the earth" or "around the surface?" Thank you, Jerry Payton
Hi Jerry,  "I = Think"................Q=20 1        The p and s and other phases = if you=20 use them are all based on (time theory)  
The math program knows where you are = and where the=20 event took place, it converts that info to Miles, also to = Degrees.
It then uses one of several = formulas, I use=20 the default formula, to place the p and s on a time line, which is = on the=20 bottom of the Winquake screen.
 
Q2.........The distance is "around the = surface"=20 like a string on a globe.   This is all "great circle"=20 math.
 
So the program is simple for this part, = because, it=20 take the event Long. and Lat,  your Long. and Lat, the time of the = event,=20 does the math (the p travels about 10km per second), I calculate it is = about=20 28,000 miles per hour, and figure it would take the P, say  12.002 = minute=20 to reach you, add that, to the event time, and places the P on your = screen=20 accordingly.
 
It does not read you recording,  = you could=20 have recorded a truck or a train and if the event matched your train in = would=20 place the p and s, on the time line.
 
Is this = clear???????????????????  =20 Ted
----- Original Message -----
From:=20 Jerry = Payton=20
Sent: Tuesday, October 09, 2007 = 1:01=20 PM
Subject: WinQuake Display = Question

(Question 1):    On a WinQuake event display = are the=20 P and S arrival times showning the ACTUAL arrival = times or=20 shown according to what the table says they should be?
 
(Question 2):    Is the distance from the event to = your seismograph computed "through the earth" or "around the=20 surface?"
 
Thank you,
Jerry Payton
 
 
 
 
Subject: Re: WinQuake Display Question From: "Jerry Payton" gpayton880@....... Date: Tue, 9 Oct 2007 16:46:17 -0500 Yes, you answer IS clear. I suspected that it was a "Great Circle" measurement, but wanted verification. However, I was curious about the phase-time travel. Wave propagation through the earth is a highly variable thing depending upon the materials it travels through, reflections, refractions and etc. I guess that the "tables" are basically averages taken from measurements over the years and reasonably accurate. What prompted my question was reading about the construction of the "beachball" Focal Mechanism Solution. They look at the P wave arrival and depending upon whether it goes up or down determines one of the factors of the final solution. Thus, exact timing is needed. If the P wave is arbitrarily identified, the solution would be false. (I think???) Thank you, Jerry ----- Original Message ----- From: tchannel1@............ To: psn-l@.............. Sent: Tuesday, October 09, 2007 3:55 PM Subject: Re: WinQuake Display Question Hi Jerry, "I Think"................Q 1 The p and s and other phases if you use them are all based on (time theory) The math program knows where you are and where the event took place, it converts that info to Miles, also to Degrees. It then uses one of several formulas, I use the default formula, to place the p and s on a time line, which is on the bottom of the Winquake screen. Q2.........The distance is "around the surface" like a string on a globe. This is all "great circle" math. So the program is simple for this part, because, it take the event Long. and Lat, your Long. and Lat, the time of the event, does the math (the p travels about 10km per second), I calculate it is about 28,000 miles per hour, and figure it would take the P, say 12.002 minute to reach you, add that, to the event time, and places the P on your screen accordingly. It does not read you recording, you could have recorded a truck or a train and if the event matched your train in would place the p and s, on the time line. Is this clear??????????????????? Ted ----- Original Message ----- From: Jerry Payton To: psn-l@.............. Sent: Tuesday, October 09, 2007 1:01 PM Subject: WinQuake Display Question (Question 1): On a WinQuake event display are the P and S arrival times showning the ACTUAL arrival times or shown according to what the table says they should be? (Question 2): Is the distance from the event to your seismograph computed "through the earth" or "around the surface?" Thank you, Jerry Payton
Yes, you answer IS clear.  I suspected that it was a "Great = Circle"=20 measurement, but wanted verification.
 
However, I was curious about the phase-time travel.  Wave = propagation=20 through the earth is a highly variable thing depending upon the = materials it=20 travels through, reflections, refractions and etc.  I guess that = the=20 "tables" are basically averages taken from measurements over the years = and=20 reasonably accurate.
 
What prompted my question was reading about the construction = of the=20 "beachball" Focal Mechanism Solution.  They look at the P wave = arrival and=20 depending upon whether it goes up or down determines one of the factors = of the=20 final solution.  Thus, exact timing is needed.  If the P wave = is=20 arbitrarily identified, the solution would be false.  (I = think???)
 
Thank you,
Jerry
 
 
----- Original Message -----=20
From: tchannel1@............
Sent: Tuesday, October 09, 2007 3:55 PM
Subject: Re: WinQuake Display Question

Hi Jerry,  "I = Think"................Q=20 1        The p and s and other phases = if you=20 use them are all based on (time theory)  
The math program knows where you are = and where the=20 event took place, it converts that info to Miles, also to = Degrees.
It then uses one of several = formulas, I use=20 the default formula, to place the p and s on a time line, which is = on the=20 bottom of the Winquake screen.
 
Q2.........The distance is "around the = surface"=20 like a string on a globe.   This is all "great circle"=20 math.
 
So the program is simple for this part, = because, it=20 take the event Long. and Lat,  your Long. and Lat, the time of the = event,=20 does the math (the p travels about 10km per second), I calculate it is = about=20 28,000 miles per hour, and figure it would take the P, say  12.002 = minute=20 to reach you, add that, to the event time, and places the P on your = screen=20 accordingly.
 
It does not read you recording,  = you could=20 have recorded a truck or a train and if the event matched your train in = would=20 place the p and s, on the time line.
 
Is this = clear???????????????????  =20 Ted
----- Original Message -----
From:=20 Jerry = Payton=20
Sent: Tuesday, October 09, 2007 = 1:01=20 PM
Subject: WinQuake Display = Question

(Question 1):    On a WinQuake event display = are the=20 P and S arrival times showning the ACTUAL arrival = times or=20 shown according to what the table says they should be?
 
(Question 2):    Is the distance from the event to = your seismograph computed "through the earth" or "around the=20 surface?"
 
Thank you,
Jerry Payton
 
 
 
 
Subject: Re: WinQuake Display Question From: Bob Hancock carpediem1@......... Date: Tue, 09 Oct 2007 17:24:42 -0700 There are both body waves which travel through the earth=B9s mantel and core, and surface waves which follow the crust. The P & S waves and their variations are body waves. The LQ and LR waves are surface waves and follo= w the surface of the earth. These waves also have different dissipation rates.=20 Alan Jones program Seismic Waves gives a good presentation of the major waves. You can download it from the following link: http://www.geol.binghamton.edu/faculty/jones/ Using WinQuake, the wave arrival times are computed based upon standard wav= e speeds depending upon the route the waves take, and the depth of the event. The data is computed using the latitude and longitude of the event and the station recording the event. Bob Hancock On 10/9/07 2:46 PM, "Jerry Payton" wrote: > Yes, you answer IS clear. I suspected that it was a "Great Circle" > measurement, but wanted verification. > =20 > However, I was curious about the phase-time travel. Wave propagation thr= ough > the earth is a highly variable thing depending upon the materials it trav= els > through, reflections, refractions and etc. I guess that the "tables" are > basically averages taken from measurements over the years and reasonably > accurate. > =20 > What prompted my question was reading about the construction of the > "beachball" Focal Mechanism Solution. They look at the P wave arrival an= d > depending upon whether it goes up or down determines one of the factors o= f the > final solution. Thus, exact timing is needed. If the P wave is arbitrar= ily > identified, the solution would be false. (I think???) > =20 > Thank you, > Jerry > =20 > =20 > ----- Original Message ----- > From: tchannel1@............ > To: psn-l@.............. > Sent: Tuesday, October 09, 2007 3:55 PM > Subject: Re: WinQuake Display Question >=20 > Hi Jerry, "I Think"................Q 1 The p and s and other phas= es if > you use them are all based on (time theory) > The math program knows where you are and where the event took place, it > converts that info to Miles, also to Degrees. > It then uses one of several formulas, I use the default formula, to place= the > p and s on a time line, which is on the bottom of the Winquake screen. > =20 > Q2.........The distance is "around the surface" like a string on a globe. > This is all "great circle" math. > =20 > So the program is simple for this part, because, it take the event Long. = and > Lat, your Long. and Lat, the time of the event, does the math (the p tra= vels > about 10km per second), I calculate it is about 28,000 miles per hour, an= d > figure it would take the P, say 12.002 minute to reach you, add that, to= the > event time, and places the P on your screen accordingly. > =20 > It does not read you recording, you could have recorded a truck or a tra= in > and if the event matched your train in would place the p and s, on the ti= me > line. > =20 > Is this clear??????????????????? Ted >> =20 >> ----- Original Message ----- >> =20 >> From: Jerry Payton >> =20 >> To: psn-l@.............. >> =20 >> Sent: Tuesday, October 09, 2007 1:01 PM >> =20 >> Subject: WinQuake Display Question >> =20 >>=20 >> =20 >> (Question 1): On a WinQuake event display are the P and S arrival ti= mes >> showning the ACTUAL arrival times or shown according to what the table = says >> they should be? >> =20 >> =20 >> =20 >> (Question 2): Is the distance from the event to your seismograph com= puted >> "through the earth" or "around the surface?" >> =20 >> =20 >> =20 >> Thank you, >> =20 >> Jerry Payton >> =20 >> =20 >> =20 >> =20 >> =20 >> =20 >> =20 >> =20 >=20 Re: WinQuake Display Question There= are both body waves which travel through the earth’s mantel and core,= and surface waves which follow the crust.  The P & S waves and the= ir variations are body waves.  The LQ and LR waves are surface waves an= d follow the surface of the earth.  These waves also have different dis= sipation rates.

Alan Jones program Seismic Waves gives a good presentation of the major wav= es.  You can download it from the following link:

        http://www.geol.binghamton.edu/faculty/jones/

Using WinQuake, the wave arrival times are computed based upon standard wav= e speeds depending upon the route the waves take, and the depth of the event= ..

The data is computed using the latitude and longitude of the event and the = station recording the event.

Bob Hancock


On 10/9/07 2:46 PM, "Jerry Payton" <gpayton880@.......> wro= te:

Yes, you answer IS clear.  I suspected that it was= a "Great Circle" measurement, but wanted verification.
 
However, I was curious about the phase-time travel.  Wave propagation = through the earth is a highly variable thing depending upon the materials it= travels through, reflections, refractions and etc.  I guess that the &= quot;tables" are basically averages taken from measurements over the ye= ars and reasonably accurate.
 
What prompted my question was reading about the construction of the "b= eachball" Focal Mechanism Solution.  They look at the P wave arriv= al and depending upon whether it goes up or down determines one of the facto= rs of the final solution.  Thus, exact timing is needed.  If the P= wave is arbitrarily identified, the solution would be false.  (I think= ???)
 
Thank you,
Jerry
 
 
----- Original Message -----
From: tchannel1@............
To: psn-l@..............
Sent: Tuesday, October 09, 2007 3:55 PM
Subject: Re: WinQuake Display Question

Hi Jerry, &= nbsp;"I Think"................Q 1      &n= bsp; The p and s and other phases if you use them are all based on (tim= e theory)   
The math program knows where you are and where the event took place, it con= verts that info to Miles, also to Degrees.
It then uses one of several formulas, I use the default formula, to place t= he p and s on a time line, which is on the bottom of the Winquake screen.
Q2.........The distance is "around the surfa= ce" like a string on a globe.   This is all "great circl= e" math.
So the program is simple for this part, because, = it take the event Long. and Lat,  your Long. and Lat, the time of the e= vent, does the math (the p travels about 10km per second), I calculate it is= about 28,000 miles per hour, and figure it would take the P, say  12.0= 02 minute to reach you, add that, to the event time, and places the P on you= r screen accordingly.
It does not read you recording,  you could h= ave recorded a truck or a train and if the event matched your train in would= place the p and s, on the time line.
Is this clear???????????????????   Ted<= BR>

----- Original Message -----
 
From:  Jerry Payton <mai= lto:gpayton880@.......>   
 
To: psn-l@..............
 
Sent: Tuesday, October 09, 2007 1:01  PM
 
Subject: WinQuake Display Question
 

 
(Question 1):    On a WinQuake event display are the  P= and S arrival times showning the ACTUAL arrival times or  shown= according to what the table says they should be?
 
 
 
(Question 2):    Is the distance from the event to  you= r seismograph computed "through the earth" or "around the &nb= sp;surface?"
 
 
 
Thank you,
 
Jerry Payton
 
 
 
 
 
 
 
 


 Subject: Re: WinQuake Display Question From: ChrisAtUpw@....... Date: Tue, 9 Oct 2007 20:50:59 EDT In a message dated 09/10/2007 22:46:38 GMT Daylight Time, gpayton880@....... writes: Wave propagation through the earth is a highly variable thing depending upon the materials it travels through, reflections, refractions and etc. I guess that the "tables" are basically averages taken from measurements over the years and reasonably accurate. The wave velocities are mostly determined by depth, so it is possible to plot average curves for the time travel along the curved ray paths. You may also have to allow for the depth of the quake. Seismic Waves and Seismic Eruptions give good visualisation of the principle waves. See Alan Jones website at _http://www.geol.binghamton.edu/faculty/jones/_ (http://www.geol.binghamton.edu/faculty/jones/) Regards, Chris Chapman
In a message dated 09/10/2007 22:46:38 GMT Daylight Time,=20 gpayton880@....... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000>Wave=20 propagation through the earth is a highly variable thing depending upon th= e=20 materials it travels through, reflections, refractions and etc.  I gu= ess=20 that the "tables" are basically averages taken from measurements over the=20 years and reasonably accurate.
    The wave velocities are mostly determined by de= pth,=20 so it is possible to plot average curves for the time travel along the curve= d=20 ray paths. You may also have to allow for the depth of the quake.
 
    Seismic Waves and Seismic=20 Eruptions give good visualisation of the principle waves.  See Alan Jon= es=20 website at http://www.geol.binghamton.edu/faculty/jones/
    Regards,
 
    Chris Chapman
Subject: Mystery item and its potential seismometry uses/s? From: "meredith lamb" paleoartifact@......... Date: Tue, 9 Oct 2007 19:28:02 -0600 Hi all, I think it might be fun for those of you who are amateur or real "engineers"; to come up with their own thoughts and use/s for acouple pictures of a item at: http://home.earthlink.net/~meredithlamb/ I have my own (surprising) and varied uses in mind; whats yours? Meredith Lamb
Hi all,
 
I think it might be fun for those of you who are amateur or real "engineers";
to come up with their own thoughts and use/s for acouple pictures of a item at:
 
 
I have my own (surprising) and varied uses in mind; whats yours?
 
Meredith Lamb
 
 
Subject: Travel times From: "Randy Pratt" rpratt@............. Date: Wed, 10 Oct 2007 17:28:44 -0500 Hi All, I saw the question on travel times and had just come across this page a couple nights back showing some plots of times and locations. http://aslwww.cr.usgs.gov/Seismic_Data/ttdata.shtml Randy
Hi=20 All,
 
I saw = the question=20 on travel times and had just come across this page a couple nights back = showing=20 some plots of times and locations.
 
http://aslww= w.cr.usgs.gov/Seismic_Data/ttdata.shtml
 
Randy
Subject: seismometer/site sensitivity From: Jan Froom JDarwin@............. Date: Thu, 11 Oct 2007 12:35:32 -0700 I'm curious how many of you have come up with a "rule of thumb" for the general sensitivity of your seismometers. For instance I have sensed a 3.0 sixty miles out from my seismometer, and have seen 5s within 300 miles. And I understand we should be able to sense a 7 anywhere in the world. But just now, I did not see a 1.3 seven miles out. So my question.... is this good, bad, average? I'm sure there are lots of variables such as type of instrument, orientation, ambient noise, etc.. but still, shouldn't there be a general feeling or rule of thumb. Jan in Gilroy I'm curious how many of you have come up with a "rule of thumb" for the general sensitivity of your seismometers.

For instance I have sensed a 3.0 sixty miles out from my seismometer, and have seen 5s within 300 miles.
And I understand we should be able to sense a 7 anywhere in the world.
But just now, I did not see a 1.3  seven miles out.
So my question.... is this good, bad, average?
I'm sure there are lots of variables such as type of instrument, orientation, ambient noise, etc..
but still, shouldn't there be a general feeling or rule of thumb.

Jan in Gilroy
Subject: Re: seismometer/site sensitivity From: Pete Rowe ptrowe@......... Date: Thu, 11 Oct 2007 12:45:49 -0700 (PDT) Hi Jan I'd say that you are doing just fine. With my 3 second period horizontal I see 5s down in Mexico, 7s anywhere, but a 1.3 needs to be with in 3 or 4 miles. I have never gone to the trouble of actually trying to calibrate mine because I really don't know how to do it and haven't taken the time to learn. The gain numbers that I use in Larry's program are just guesses. 73, Pete --- Jan Froom wrote: > I'm curious how many of you have come up with a > "rule of thumb" for the > general sensitivity of your seismometers. > > For instance I have sensed a 3.0 sixty miles out > from my seismometer, > and have seen 5s within 300 miles. > And I understand we should be able to sense a 7 > anywhere in the world. > But just now, I did not see a 1.3 seven miles out. > So my question.... is this good, bad, average? > I'm sure there are lots of variables such as type of > instrument, > orientation, ambient noise, etc.. > but still, shouldn't there be a general feeling or > rule of thumb. > > Jan in Gilroy > ____________________________________________________________________________________ Tonight's top picks. What will you watch tonight? Preview the hottest shows on Yahoo! TV. http://tv.yahoo.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismometer/site sensitivity From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 11 Oct 2007 20:46:58 +0000 Hi Small earthquakes can be difficault to detect. But for me the general rule is that the less background noise there is, the bigger the chance of seeing small earthquake is. More background noise, less chance. I have seen earthquakes down to 1.0 or smaller up to a distance of ~55 km. After that, it is really a hard to see small earthquakes. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismometer/site sensitivity From: Larry Conklin lconklin@............ Date: Thu, 11 Oct 2007 17:28:01 -0400 I have a spreadsheet that I have been using for several years to log the events that I've been able to record. It includes a scatterplot of magnitude versus distance. In addition, I assign a rough "quality" score to the events (A - D) that is used to determine the color of the points plotted. I live in central NY, so the vast majority of events that I see are at teleseismic distances, and frustratingly, a very high percentage of the stuff I see is at distances that put me in the shadow zone. I am very definitely limited by some mix of environmental noise and very possibly some sort of spruious system noise that I don't really understand. If anyone is interested in seeing my accumulated results, I would be happy to send them a copy of the spreadsheet. Larry Conklin Liverpool, NY lconklin@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismometer/site sensitivity From: "Geoff" gmvoeth@........... Date: Fri, 12 Oct 2007 02:15:00 -0700 I have a vertical setup with a sensor that seems to have a sensitivity of 1.5 to 2 volts per inches per second and I can see a magnitude 4 about 6 degrees away. or so it seems. I am using heavy damping to allow me to use a single bandpass filter to equalize the freq response of a one hertz geophone somewhere between 4 seconds and 2 Hz. The geophone is buried underground on a granite tile with the base of the geophone maybe 24 inches below ground. Sealed to the best of my abilities against temp and moisture and electro/magnetic fields. My area here is extremely noisy from vehicular traffic as well as electrical disturbances. My station is not a very good one but will at least let me know when a major event happens. The USGS was not interested in signals from this station unless my times were the very first and that is so very rare. Commonly the local signals are mine blasts which they seem to have no interest in also. The USGS seems to have there own setup that does not seem to miss anything at all. You need a friend there to look for signals you might see at your amature station that are not earth quakes. They are busy people there i believe with no lower level help doing any analysis. You most probably shall have troubles identifying small stuff since you need several signatures to compare. You got to compare your signals with the USGS to get an idea what your MDL ( minimum dicernable level) really is. It will take time. ----- Original Message ----- From: "Jan Froom" To: Sent: Thursday, October 11, 2007 12:35 PM Subject: seismometer/site sensitivity > I'm curious how many of you have come up with a "rule of thumb" for the > general sensitivity of your seismometers. > > For instance I have sensed a 3.0 sixty miles out from my seismometer, > and have seen 5s within 300 miles. > And I understand we should be able to sense a 7 anywhere in the world. > But just now, I did not see a 1.3 seven miles out. > So my question.... is this good, bad, average? > I'm sure there are lots of variables such as type of instrument, > orientation, ambient noise, etc.. > but still, shouldn't there be a general feeling or rule of thumb. > > Jan in Gilroy > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismometer/site sensitivity From: ChrisAtUpw@....... Date: Fri, 12 Oct 2007 07:07:11 EDT In a message dated 12/10/2007, gmvoeth@........... writes: I have a vertical setup with a sensor that seems to have a sensitivity of 1.5 to 2 volts per inches per second and I can see a magnitude 4 about 6 degrees away. or so it seems. I am using heavy damping to allow me to use a single bandpass filter to equalize the freq response of a one hertz geophone somewhere between 4 seconds and 2 Hz. Hi Geoff, You need to use negative impedance input to get broad band response from a geophone by heavy damping to mostly cancel out the internal resistance. You then need a very low noise 1/f amplifier to give you a flat to velocity response. The technique is dscribed with references at _http://www.lennartz-electronic.de/MamboV4.5.2/downloads/Seismometers.pdf_ (http://www.lennartz-electronic.de/MamboV4.5.2/downloads/Seismometers.pdf) Regards, Chris Chapman
In a message dated 12/10/2007, gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I have a=20 vertical setup with a sensor that seems to have a sensitivity of 1.5 to 2=20 volts per inches per second and I can see a magnitude 4 about 6 degrees aw= ay.=20 or so it seems. I am using heavy damping to allow me to use a single bandp= ass=20 filter to equalize the freq response of a one hertz geophone somewher= e=20 between 4 seconds and 2 Hz.
 
Hi Geoff,
 
    You need to use negative impedance input to get= =20 broad band response from a geophone by heavy damping to mostly cancel out th= e=20 internal resistance. You then need a very low noise 1/f amplifier to give yo= u a=20 flat to velocity response.
    The technique is dscribed with references at http://www.lennartz-electronic.de/MamboV4.5.2/downloads/Seismometers.p= df
 
    Regards,
 
    Chris Chapman
Subject: Re: seismometer/site sensitivity From: "Connie and Jim Lehman" lehmancj@........... Date: Fri, 12 Oct 2007 11:27:14 -0400 Jan. I believe your system is in the "ball-park" in performance. I = don't know what design you are working with, or your exact location. = With our experience with a long-period cantilever (l8 sec) period, we = generally read 3.0 events --here in Virginia, some quarry blasts, not = many natural events here!. Anything Mag. 5 and above in the U.S. = Alaska, and much of Central and South America. Anything Mag.. 6 or more = worldwide. Of course events in South Pacific outnumbered the rest of = the World for us. The ideal was when we ran two identical sensors = broadside N-S and E-W. We generally let microseisms decide the = amplitude setting. In our summertime here in VA. the microseisms are = lower (for whatever reasons??) and we could crank up the daily gains, = and for a two month summer recording with two sensors we received our = record of 62 events in 60 days. That was years ago, and I haven't tried = a repeat. Best wishes, Jim Lehman ----- Original Message -----=20 From: Jan Froom=20 To: psn-l@................. Sent: Thursday, October 11, 2007 3:35 PM Subject: seismometer/site sensitivity I'm curious how many of you have come up with a "rule of thumb" for = the general sensitivity of your seismometers. For instance I have sensed a 3.0 sixty miles out from my seismometer, = and have seen 5s within 300 miles. And I understand we should be able to sense a 7 anywhere in the world. But just now, I did not see a 1.3 seven miles out. So my question.... is this good, bad, average?=20 I'm sure there are lots of variables such as type of instrument, = orientation, ambient noise, etc..=20 but still, shouldn't there be a general feeling or rule of thumb. Jan in Gilroy
Jan.  I believe your system is in = the=20 "ball-park" in performance.  I don't know what design you are = working with,=20 or your exact location.  With our experience with a long-period = cantilever=20 (l8 sec) period, we generally read 3.0 events --here in Virginia, some = quarry=20 blasts, not many natural events here!.  Anything Mag. 5 and above = in the=20 U.S. Alaska, and much of Central and South America.  = Anything=20 Mag.. 6 or more worldwide.   Of course events in South Pacific = outnumbered the rest of the World for us.  The ideal was when = we=20 ran two identical sensors broadside N-S and E-W.  We generally = let=20 microseisms decide the amplitude setting.  In our summertime here = in VA.=20 the microseisms are lower (for whatever reasons??) and we could crank up = the=20 daily gains, and for a two month summer recording with two sensors we = received=20 our record of 62 events in 60 days.  That was years ago, and I = haven't=20 tried a repeat.
        =20 Best wishes,    Jim Lehman
----- Original Message -----
From:=20 Jan=20 Froom
Sent: Thursday, October 11, = 2007 3:35=20 PM
Subject: seismometer/site=20 sensitivity

I'm curious how many = of you=20 have come up with a "rule of thumb" for the general sensitivity of = your=20 seismometers.

For instance I have sensed a 3.0 sixty miles out = from my=20 seismometer, and have seen 5s within 300 miles.
And I understand we = should=20 be able to sense a 7 anywhere in the world.
But just now, I did not = see a=20 1.3  seven miles out.
So my question.... is this good, bad, = average?=20
I'm sure there are lots of variables such as type of instrument,=20 orientation, ambient noise, etc..
but still, shouldn't there be a = general=20 feeling or rule of thumb.

Jan in=20 Gilroy
Subject: Re: seismometer/site sensitivity From: Bobhelenmcclure@....... Date: Sat, 13 Oct 2007 21:29:59 EDT Hi Geoff, There is a better way to extend the response of a 1 Hz geophone, or any open loop sensor. Try the period extending filter in WQFilter.exe. Use normal damping. The filter can extend the period by a factor of 8 or more on major events. This is a digital inverse filter, whose gain is shaped to preserve normal gain at high frequencies and to supply the gain needed at frequencies below the natural frequency of the sensor. The utility can be downloaded from _http://www.jclahr.com/science/psn/mcclure/sac/index.html_ (http://www.jclahr.com/science/psn/mcclure/sac/index.html) This program includes high-pass and low-pass Butterworth filters which perform better than those supposedly IIR BW filters in WinQuake. I have learned never to use WinQuake's filters. I use the lowest order, order 2, both directions for high-pass filtering. Extended period filtering works best if you select the option "LONG PERIOD plus HPF". Additional high-pass filtering is usually unnecessary if you use that option. Even long period period Lehman sensors can benefit from proper use of WQFilter, as it can compensate for over- or under-damping. It can make the filtered long period response either longer or shorter than the actual sensor period. On an unrelated note, those of you who use HP calculators with Reverse Polish Notation will like the following freeware calculator for your PC desktop: _http://www.tordivel.no/xcalc/_ (http://www.tordivel.no/xcalc/) Bob In a message dated 12/10/2007, gmvoeth@.... writes: I have a vertical setup with a sensor that seems to have a sensitivity of 1.5 to 2 volts per inches per second and I can see a magnitude 4 about 6 degrees away. or so it seems. I am using heavy damping to allow me to use a single bandpass filter to equalize the freq response of a one hertz geophone somewhere between 4 seconds and 2 Hz. ************************************** See what's new at http://www.aol.com
Hi Geoff,
 
  There is a better way to extend the response of a 1 Hz geophone,= or=20 any open loop sensor. Try the period extending filter in WQFilter.exe. Use=20 normal damping. The filter can extend the period by a factor of 8 or more on= =20 major events. This is a digital inverse filter, whose gain is shaped to pres= erve=20 normal gain at high frequencies and to supply the gain needed at frequencies= =20 below the natural frequency of the sensor. The utility can be downloaded=20 from
 
   http://www= ..jclahr.com/science/psn/mcclure/sac/index.html
 
  This program includes high-pass and low-pass Butterworth filters= =20 which perform better than those supposedly IIR BW filters in WinQuake. I hav= e=20 learned never to use WinQuake's filters. I use the lowest order, order 2, bo= th=20 directions for high-pass filtering. Extended period filtering works bes= t if=20 you select the option "LONG PERIOD plus HPF". Additional high-pass filtering= is=20 usually unnecessary if you use that option. Even long period period Lehman=20 sensors can benefit from proper use of WQFilter, as it can compensate for ov= er-=20 or under-damping. It can make the filtered long period response either longe= r or=20 shorter than the actual sensor period.
 
  On an unrelated note, those of you who use HP calculators with=20 Reverse Polish Notation will like the following freeware calculator for your= PC=20 desktop:
 
 http://www.tordivel.no/xcalc/
 
Bob
 
In a message dated 12/10/2007, gmvoeth@.... writes:
 
I have a  vertical setup with a sensor that seems to have a=20 sensitivity of
1.5 to 2  volts per inches per second and I can see=20= a=20 magnitude 4 about 6
degrees away.  or so it seems. I am using heavy= =20 damping to allow me to use a single
bandpass  filter to equalize th= e=20 freq response of a one hertz geophone
somewhere  between 4 seconds=20= and=20 2 Hz.



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= Subject: Earthquake near Albany, NY, U.S ? From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Sun, 14 Oct 2007 14:36:34 +0000 Hi all I have a friend how lives in Albany, N.Y in the U.S. He tells me that he felt two earthquake like shocks around 2 am local time, they where each with about five min, intervals. I did look for earthquakes on the usgs web page but I didn't find anything there. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake near Albany, NY, U.S ? From: Stephen & Kathy skmort@............ Date: Sun, 14 Oct 2007 08:24:59 -0700 If we are talking about this morning, about 6:00 UTC, I see nothing on = the N/E USA webicorders??? http://aslwww.cr.usgs.gov/Seismic_Data/heli2_us.shtml Stephen J=F3n Fr=EDmann wrote: > Hi all > > I have a friend how lives in Albany, N.Y in the U.S. He tells me that h= e > felt two earthquake like shocks around 2 am local time, they where each= > with about five min, intervals. > > I did look for earthquakes on the usgs web page but I didn't find > anything there. > > Regards. > =20 If we are talking about this morning,=A0 about 6:00= UTC,=A0 I see nothing on the N/E USA webicorders???

http://aslwww.cr.usgs.gov/Seismic_Data/heli2_us.= shtml
=A0 Stephen

J=F3n Fr=EDmann wrote: 
Hi all

I have a friend how lives in Albany, N.Y in the U.S. He tells me that he
felt two earthquake like shocks around 2 am local time, they where each
with about five min, intervals.

I did look for earthquakes on the usgs web page but I didn't find
anything there.

Regards.
Subject: Re: Earthquake near Albany, NY, U.S ? From: Bob Hancock carpediem1@......... Date: Sun, 14 Oct 2007 08:43:02 -0700 Hi Jon - Here is a link to the other stations at Lamont-Daugherty. Click on station HCNY. It is located about 30 miles west of Albany, NY, and UTC time is located on the right side of the chart. http://www.ldeo.columbia.edu/LCSN/view_pal.html Bob Hancock On 10/14/07 7:36 AM, "J=F3n Fr=EDmann" wrote: > Hi all >=20 > I have a friend how lives in Albany, N.Y in the U.S. He tells me that he > felt two earthquake like shocks around 2 am local time, they where each > with about five min, intervals. >=20 > I did look for earthquakes on the usgs web page but I didn't find > anything there. >=20 > Regards. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake near Albany, NY, U.S ? From: "Thomas Dick" dickthomas01@............. Date: Mon, 15 Oct 2007 07:00:15 -0500 Midwest network indicates a 1.5 mag at Tupper Lake NY see at ----- Original Message ----- From: "Bob Hancock" To: Sent: Sunday, October 14, 2007 10:43 AM Subject: Re: Earthquake near Albany, NY, U.S ? Hi Jon - Here is a link to the other stations at Lamont-Daugherty. Click on station HCNY. It is located about 30 miles west of Albany, NY, and UTC time is located on the right side of the chart. http://www.ldeo.columbia.edu/LCSN/view_pal.html Bob Hancock On 10/14/07 7:36 AM, "Jón Frímann" wrote: > Hi all > > I have a friend how lives in Albany, N.Y in the U.S. He tells me that he > felt two earthquake like shocks around 2 am local time, they where each > with about five min, intervals. > > I did look for earthquakes on the usgs web page but I didn't find > anything there. > > Regards. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake near Albany, NY, U.S ? From: "Thomas Dick" dickthomas01@............. Date: Mon, 15 Oct 2007 07:03:37 -0500 Midwest network shows a 1.5 meg earthquake at Tupper Lake, NY see details at http://folkworm.ceri.memphis.edu/recenteqs/Quakes/quakes0.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: seismometer/site sensitivity From: "Chuck Boudreaux" chuckbou@............. Date: Mon, 15 Oct 2007 10:36:53 -0500 Larry, I would like a copy of the spreadsheet when you get a chance. Chuck Boudreaux Berwick, LA chuckbou@............. -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Larry Conklin Sent: Thursday, October 11, 2007 16:28 To: PSN List Subject: Re: seismometer/site sensitivity I have a spreadsheet that I have been using for several years to log the events that I've been able to record. It includes a scatterplot of magnitude versus distance. In addition, I assign a rough "quality" score to the events (A - D) that is used to determine the color of the points plotted. I live in central NY, so the vast majority of events that I see are at teleseismic distances, and frustratingly, a very high percentage of the stuff I see is at distances that put me in the shadow zone. I am very definitely limited by some mix of environmental noise and very possibly some sort of spruious system noise that I don't really understand. If anyone is interested in seeing my accumulated results, I would be happy to send them a copy of the spreadsheet. Larry Conklin Liverpool, NY lconklin@............ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake near Albany, NY, U.S ? From: "Thomas Dick" dickthomas01@............. Date: Mon, 15 Oct 2007 14:23:38 -0500 Midwest area recorded two quakes this weekend see http://folkworm.ceri.memphis.edu/recenteqs/Quakes/quakes0.html __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Octorber From: tchannel1@............ Date: Thu, 18 Oct 2007 09:24:38 -0600 Hi Folks, By my counts, the next two weeks could be very active, or the = month of October is going to be the quietest month this year. Obviously no one can look into the future, but I am convinced the counts = of events do form totals which seem to repeat, month after month. I sure wish I knew more about probabilities, perhaps I could qualify my = observation. My equipment does not record many of the smaller events. = Discounting those smaller events, here are my notes. My monthly average is 16 Lowest month.............12 Highest month............19 October.......................3 If the month of October, DOES play = catch up, the next two weeks are going to be very active. If the month = of October DOESN'T, then please dismiss all of the above as the ranting = of a grumpy old man. Cheers, Ted
Hi Folks,  By my counts, the next = two=20 weeks could be very active, or the month of October is going to be = the=20 quietest month this year.
Obviously no one can look into the = future, but I am=20 convinced the counts of events do form totals which seem to repeat, = month after=20 month.
I sure wish I knew more about = probabilities,=20 perhaps I could qualify my observation.   My equipment does = not record=20 many of the smaller events.  Discounting those smaller events, here = are my notes.
 
My monthly average is 16
Lowest = month.............12
Highest = month............19
October.......................3      = If the=20 month of October, DOES play catch up, the next two weeks are going to be = very=20 active.  If the month of October DOESN'T, then please dismiss all = of the=20 above as the ranting of a grumpy old man.
 
Cheers,
Ted
Subject: Re: Octorber From: Dave Nelson davenn@............... Date: Fri, 19 Oct 2007 06:53:42 +1000 Depends on where you have been living Ted, ;) Down in this part of the world its been VERY active so far this month .... definately the busiest for a long long time. The New Zealand region has truely lived up to its name of " The Shakey Isles" Here's a brief list of the M5+ events.... M5.6 upper Sth Is M5.7 upper Nth Is M5.1 upper Nth Is M54 offshr SW of Sth Is ashk of the M7+ and M6+ events on the last day of the previous month M6.7 Fiordland, Sth Is M6.2 Fiordland, Sth Is M5.8 Fiordland, Sth Is M6.2 Fiordland, Sth Is M5.1 Fiordland, Sth Is M6.5 NW of Raoul Is, to the nth of NZ but well felt in Nth Is. of NZ not to mention the dozens of good aftershocks and other 4.0-4.9 events around the country At 01:24 AM 10/19/2007, you wrote: >Hi Folks, By my counts, the next two weeks could be very active, or the >month of October is going to be the quietest month this year. >Obviously no one can look into the future, but I am convinced the counts >of events do form totals which seem to repeat, month after month. >I sure wish I knew more about probabilities, perhaps I could qualify my >observation. My equipment does not record many of the smaller >events. Discounting those smaller events, here are my notes. > >My monthly average is 16 >Lowest month.............12 >Highest month............19 >October.......................3 If the month of October, DOES play >catch up, the next two weeks are going to be very active. If the month of >October DOESN'T, then please dismiss all of the above as the ranting of a >grumpy old man. > >Cheers, >Ted > > >No virus found in this incoming message. >Checked by AVG Free Edition. >Version: 7.5.488 / Virus Database: 269.15.0/1077 - Release Date: >10/18/2007 9:54 AM -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: 269.15.0/1077 - Release Date: 10/18/2007 9:54 AM __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Octorber From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Fri, 19 Oct 2007 02:57:27 +0000 Hi all In my part of the world, the whole year has been quiet on the earthquake front. Some weeks I don't even record a single earthquake. Regards. -- J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mystery item and its potential seismometry uses/s? From: "Jerry Payton" gpayton880@....... Date: Wed, 24 Oct 2007 10:56:15 -0500 OK, Meredith. I give up and curiosity has got this cat. It reminds me of an oar-lock, but what was you idea? I've seen no replies to your question and there seems to be a lull right now in EQ's. Let's stir up some discussion! Regards, Jerry Payton ----- Original Message ----- From: meredith lamb To: psn-l@.............. Sent: Tuesday, October 09, 2007 8:28 PM Subject: Mystery item and its potential seismometry uses/s? Hi all, I think it might be fun for those of you who are amateur or real "engineers"; to come up with their own thoughts and use/s for a couple pictures of a item at: http://home.earthlink.net/~meredithlamb/ I have my own (surprising) and varied uses in mind; what's yours? Meredith Lamb
OK, Meredith.  I give up and curiosity has got this = cat. =20 It reminds me of an oar-lock, but what was you idea?  I've seen no = replies=20 to your question and there seems to be a lull right now in EQ's.  = Let's=20 stir up some discussion!
Regards,
Jerry Payton
 
----- Original Message -----=20
From: meredith=20 lamb
Sent: Tuesday, October 09, 2007 8:28 PM
Subject: Mystery item and its potential seismometry=20 uses/s?

Hi all,
 
I think it might be fun for those of you who are amateur or real=20 "engineers";
to come up with their own thoughts and use/s for a couple pictures = of a=20 item at:
 
http://home.earthlink.n= et/~meredithlamb/
 
I have my own (surprising) and varied uses in mind; what's = yours?
 
Meredith Lamb
 
 
Subject: Re: Mystery item and its potential seismometry uses/s? From: tchannel1@............ Date: Wed, 24 Oct 2007 11:11:04 -0600 Jerry, You've got that right................This is my slowest month = for a year, day after day very uninteresting screens. Maybe tomorrow? Since I have no earthquakes to discuss...........Could this device be a = support for a large dia. pipe? As a part of a Seismic device, here is my suggestion: Get a large piece of white butcher paper 48" x 48" Draw a center point = on the piece of paper, using a black #2 pencil, connecting two opposite = diagonal corners. Carefully position one corner of the paper facing true north and the = opposite corner south. Place this device in the center of the paper and align it's support = shaft along the N/S axis. Trace the profile of the entire device on to the paper using the black = #2 pencil. Wait for a large earthquake, >7 M, closer than 100 miles. After the large event, retrace the new position of the device's profile, = using a red #2 Pencil. Comparing the original position profile with the new position profile, = one may be able to plot the general direction of the epicenter, and = estimate the magnitude. Unless it move greater than 24" from center. Thanks,=20 Ted ----- Original Message -----=20 From: Jerry Payton=20 To: psn-l@................. Sent: Wednesday, October 24, 2007 9:56 AM Subject: Re: Mystery item and its potential seismometry uses/s? OK, Meredith. I give up and curiosity has got this cat. It reminds = me of an oar-lock, but what was you idea? I've seen no replies to your = question and there seems to be a lull right now in EQ's. Let's stir up = some discussion! Regards, Jerry Payton ----- Original Message -----=20 From: meredith lamb=20 To: psn-l@................. Sent: Tuesday, October 09, 2007 8:28 PM Subject: Mystery item and its potential seismometry uses/s? Hi all, I think it might be fun for those of you who are amateur or real = "engineers";=20 to come up with their own thoughts and use/s for a couple pictures of = a item at: http://home.earthlink.net/~meredithlamb/ I have my own (surprising) and varied uses in mind; what's yours? Meredith Lamb
Jerry,  You've got that=20 right................This is my slowest month for a year, day after day = very=20 uninteresting screens.   Maybe tomorrow?
Since I have no earthquakes to=20 discuss...........Could this device be a support for a large dia.=20 pipe?
 
As a part of a Seismic device, here is = my=20 suggestion:
Get a large piece of white butcher = paper 48" x 48"=20 Draw a center point on the piece of paper, using a black #2 pencil, = connecting=20 two opposite diagonal corners.
Carefully position one corner of the = paper facing=20 true north and the opposite corner south.
Place this device in the center of the = paper and=20 align it's support shaft along the N/S axis.
Trace the profile of the entire device = on to the=20 paper using the black #2 pencil.
 
Wait for a large earthquake, >7 M, = closer than=20 100 miles.
After the large event, retrace the new = position of=20 the device's profile, using a red #2 Pencil.
Comparing the original = position profile with=20 the new position profile, one may be able to plot the general = direction of=20 the epicenter, and estimate the magnitude.  Unless it move greater = than 24"=20 from center.
Thanks,
Ted
 
 
----- Original Message -----
From:=20 Jerry = Payton=20
Sent: Wednesday, October 24, = 2007 9:56=20 AM
Subject: Re: Mystery item and = its=20 potential seismometry uses/s?

OK, Meredith.  I give up and curiosity has got this=20 cat.  It reminds me of an oar-lock, but what was you idea?  = I've=20 seen no replies to your question and there seems to be a lull right = now in=20 EQ's.  Let's stir up some discussion!
Regards,
Jerry Payton
 
----- Original Message -----=20
From: meredith=20 lamb
Sent: Tuesday, October 09, 2007 8:28 PM
Subject: Mystery item and its potential seismometry=20 uses/s?

Hi all,
 
I think it might be fun for those of you who are amateur or real=20 "engineers";
to come up with their own thoughts and use/s for a couple = pictures of a=20 item at:
 
http://home.earthlink.n= et/~meredithlamb/
 
I have my own (surprising) and varied uses in mind; what's = yours?
 
Meredith Lamb
 
 
Subject: Re: Mystery item and its potential seismometry uses/s? From: "meredith lamb" paleoartifact@......... Date: Wed, 24 Oct 2007 20:09:43 -0600 Hi Jerry and all, I put up some text and 3 more pictures of a rather unusual pendulum (horizontal sensing), on the web, and some very brief text relating to its other vertical sensing use/s. The pendulum is essentially a hanging mass or "S-G" type. The aluminum looks to be quite useful for a variety of seismometer setups....without...as much material being used. Fun stuff! See: http://home.earthlink.net/~meredithlamb/ Take care, Meredith Lamb On 10/24/07, Jerry Payton wrote: > > *OK, Meredith. I give up and curiosity has got this cat. It reminds me > of an oar-lock, but what was you idea? I've seen no replies to your > question and there seems to be a lull right now in EQ's. Let's stir up some > discussion!* > *Regards,* > *Jerry Payton* > ** >
Hi Jerry and all,
 
I put up some text and 3 more pictures of a rather unusual pendulum (horizontal
sensing), on the web, and some very brief text relating to its other vertical sensing
use/s.  The pendulum is essentially a hanging mass or "S-G" type.  The aluminum
looks to be quite useful for a variety of seismometer setups....without...as much
material being used.  Fun stuff!  See:
 
 
Take care, Meredith Lamb

 
On 10/24/07, Jerry Payton <gpayton880@.......> wrote:
OK, Meredith.  I give up and curiosity has got this cat.  It reminds me of an oar-lock, but what was you idea?  I've seen no replies to your question and there seems to be a lull right now in EQ's.  Let's stir up some discussion!
Regards,
Jerry Payton
 
Subject: RE: Mystery item and its potential seismometry uses/s? From: "Steve Hammond" shammon1@............. Date: Wed, 24 Oct 2007 23:24:27 -0700 Hi, The design suggests to me that it may have been connected to a round object such as a sailboat's mast. I once read about a counter balance = device that reduced the port/starboard sway when a boat is at anchor buy using = a counterbalance pendulum to create an apposing force that reduces the = wave energy. The rollers in the top photo suggest to me that they would allow = the base object to be hoisted to the upper portion of a mast increasing the effect of the pendulum. Here is a link to some patents that describe = this idea. www.freepatentsonline.com/CCL-114-122.html=20 =20 My guess, Steve Hammond -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of meredith lamb Sent: Wednesday, October 24, 2007 7:10 PM To: psn-l@.............. Subject: Re: Mystery item and its potential seismometry uses/s? Hi Jerry and all, =20 I put up some text and 3 more pictures of a rather unusual pendulum (horizontal sensing), on the web, and some very brief text relating to its other vertical sensing use/s. The pendulum is essentially a hanging mass or "S-G" type. The aluminum looks to be quite useful for a variety of seismometer = setups....without...as much material being used. Fun stuff! See: =20 http://home.earthlink.net/~meredithlamb/ =20 Take care, Meredith Lamb =20 On 10/24/07, Jerry Payton wrote:=20 OK, Meredith. I give up and curiosity has got this cat. It reminds me = of an oar-lock, but what was you idea? I've seen no replies to your = question and there seems to be a lull right now in EQ's. Let's stir up some discussion!=20 Regards, Jerry Payton =20 Message
Hi,=20 The design suggests to me that it may have been connected to a = round object=20 such as a sailboat's mast. I once read about a counter balance device = that=20 reduced the port/starboard sway when a boat is at anchor buy using a=20 counterbalance pendulum to create an apposing force that reduces the = wave=20 energy. The rollers in the top photo suggest to me that they would allow = the=20 base object to be hoisted to the upper portion of a mast = increasing=20 the effect of the pendulum. Here is a link to some = patents that=20 describe this idea. www.freepatent= sonline.com/CCL-114-122.html=20
 
 My guess, Steve Hammond
-----Original Message-----
From:=20 psn-l-request@.............. [mailto:psn-l-request@............... = On=20 Behalf Of meredith lamb
Sent: Wednesday, October 24, = 2007 7:10=20 PM
To: psn-l@..............
Subject: Re: Mystery = item and=20 its potential seismometry uses/s?

Hi Jerry and all,
 
I put up some text and 3 more pictures of a rather unusual = pendulum=20 (horizontal
sensing), on the web, and some very brief text relating to = its other=20 vertical sensing
use/s.  The pendulum is essentially a hanging mass or "S-G"=20 type.  The aluminum
looks to be quite useful for a variety of seismometer=20 setups....without...as much
material being used.  Fun stuff!  See:
 
http://home.earthlink.n= et/~meredithlamb/
 
Take care, Meredith Lamb

 
On 10/24/07, Jerry=20 Payton <gpayton880@.......>=20 wrote:=20
OK, Meredith.  I give up and curiosity has got = this=20 cat.  It reminds me of an oar-lock, but what was you = idea?  I've=20 seen no replies to your question and there seems to be a lull right = now in=20 EQ's.  Let's stir up some discussion!
Regards,
Jerry Payton
=
 
Subject: Re: Digest from 10/24/2007 00:00:50 From: Randall Peters PETERS_RD@.......... Date: Thu, 25 Oct 2007 08:59:01 -0400 It's a neat piece , Meredith; however, I see a serious problem with bearing friction when it comes to use in a seismometer. Rolling friction is really complex, as evidenced by the paper I wrote at http://arxiv.org/abs/physics/0506143 My expectation is that you will find challenges due to `stiction' since the decay of your system (independent of damping that you supply to the instrument by design) is more in the category of Coulomb friction than forms that result in exponential decay. As is well known for Coulomb friction, the static coefficient is greater than the kinetic coefficient. Consequently, you would probably need to provide some way to dither your instrument to have much in the way of sensitivity. Randall Peters psn-l-digest-request@.............. wrote: > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 1 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Re: Mystery item and its potential seismometry uses/s? > From: "Jerry Payton" > Date: Wed, 24 Oct 2007 10:56:15 -0500 > > This is a multi-part message in MIME format. > > ------=_NextPart_000_0055_01C8162C.7F61FF40 > Content-Type: text/plain; > charset="Windows-1252" > Content-Transfer-Encoding: 7bit > > OK, Meredith. I give up and curiosity has got this cat. It reminds me of > an oar-lock, but what was you idea? I've seen no replies to your question > and there seems to be a lull right now in EQ's. Let's stir up some > discussion! > Regards, > Jerry Payton > > ----- Original Message ----- > From: meredith lamb > To: psn-l@.............. > Sent: Tuesday, October 09, 2007 8:28 PM > Subject: Mystery item and its potential seismometry uses/s? > > Hi all, > > I think it might be fun for those of you who are amateur or real > "engineers"; > to come up with their own thoughts and use/s for a couple pictures of a item > at: > > http://home.earthlink.net/~meredithlamb/ > > I have my own (surprising) and varied uses in mind; what's yours? > > Meredith Lamb > > ------=_NextPart_000_0055_01C8162C.7F61FF40 > Content-Type: text/html; > charset="Windows-1252" > Content-Transfer-Encoding: quoted-printable > > > > charset=3Dwindows-1252"> > > > > >
OK, Meredith.  I give up and curiosity has got this = > cat. =20 > It reminds me of an oar-lock, but what was you idea?  I've seen no = > replies=20 > to your question and there seems to be a lull right now in EQ's.  = > Let's=20 > stir up some discussion!
>
Regards,
>
Jerry Payton
>
 
>
----- Original Message -----=20 >
From: title=3Dpaleoartifact@......... = > href=3D"mailto:paleoartifact@.........">meredith=20 > lamb
> >
Sent: Tuesday, October 09, 2007 8:28 PM
>
Subject: Mystery item and its potential seismometry=20 > uses/s?
>

>
Hi all,
>
 
>
I think it might be fun for those of you who are amateur or real=20 > "engineers";
>
to come up with their own thoughts and use/s for a couple pictures = > of a=20 > item at:
>
 
>
href=3D"http://home.earthlink.net/~meredithlamb/">http://home.earthlink.n= > et/~meredithlamb/
>
 
>
I have my own (surprising) and varied uses in mind; what's = > yours?
>
 
>
Meredith Lamb
>
 
>
 
> > ------=_NextPart_000_0055_01C8162C.7F61FF40-- > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 2 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Re: Mystery item and its potential seismometry uses/s? > From: > Date: Wed, 24 Oct 2007 11:11:04 -0600 > > This is a multi-part message in MIME format. > > ------=_NextPart_000_000C_01C8162E.914B0A60 > Content-Type: text/plain; > charset="Windows-1252" > Content-Transfer-Encoding: quoted-printable > > Jerry, You've got that right................This is my slowest month = > for a year, day after day very uninteresting screens. Maybe tomorrow? > Since I have no earthquakes to discuss...........Could this device be a = > support for a large dia. pipe? > > As a part of a Seismic device, here is my suggestion: > Get a large piece of white butcher paper 48" x 48" Draw a center point = > on the piece of paper, using a black #2 pencil, connecting two opposite = > diagonal corners. > Carefully position one corner of the paper facing true north and the = > opposite corner south. > Place this device in the center of the paper and align it's support = > shaft along the N/S axis. > Trace the profile of the entire device on to the paper using the black = > #2 pencil. > > Wait for a large earthquake, >7 M, closer than 100 miles. > After the large event, retrace the new position of the device's profile, = > using a red #2 Pencil. > Comparing the original position profile with the new position profile, = > one may be able to plot the general direction of the epicenter, and = > estimate the magnitude. Unless it move greater than 24" from center. > Thanks,=20 > Ted > > ----- Original Message -----=20 > From: Jerry Payton=20 > To: psn-l@................. > Sent: Wednesday, October 24, 2007 9:56 AM > Subject: Re: Mystery item and its potential seismometry uses/s? > > OK, Meredith. I give up and curiosity has got this cat. It reminds = > me of an oar-lock, but what was you idea? I've seen no replies to your = > question and there seems to be a lull right now in EQ's. Let's stir up = > some discussion! > Regards, > Jerry Payton > > ----- Original Message -----=20 > From: meredith lamb=20 > To: psn-l@................. > Sent: Tuesday, October 09, 2007 8:28 PM > Subject: Mystery item and its potential seismometry uses/s? > > Hi all, > > I think it might be fun for those of you who are amateur or real = > "engineers";=20 > to come up with their own thoughts and use/s for a couple pictures of = > a item at: > > http://home.earthlink.net/~meredithlamb/ > > I have my own (surprising) and varied uses in mind; what's yours? > > Meredith Lamb > > ------=_NextPart_000_000C_01C8162E.914B0A60 > Content-Type: text/html; > charset="Windows-1252" > Content-Transfer-Encoding: quoted-printable > > > > charset=3Dwindows-1252"> > > > > >
Jerry,  You've got that=20 > right................This is my slowest month for a year, day after day = > very=20 > uninteresting screens.   Maybe tomorrow?
>
Since I have no earthquakes to=20 > discuss...........Could this device be a support for a large dia.=20 > pipe?
>
 
>
As a part of a Seismic device, here is = > my=20 > suggestion:
>
Get a large piece of white butcher = > paper 48" x 48"=20 > Draw a center point on the piece of paper, using a black #2 pencil, = > connecting=20 > two opposite diagonal corners.
>
Carefully position one corner of the = > paper facing=20 > true north and the opposite corner south.
>
Place this device in the center of the = > paper and=20 > align it's support shaft along the N/S axis.
>
Trace the profile of the entire device = > on to the=20 > paper using the black #2 pencil.
>
 
>
Wait for a large earthquake, >7 M, = > closer than=20 > 100 miles.
>
After the large event, retrace the new = > position of=20 > the device's profile, using a red #2 Pencil.
>
Comparing the original = > position profile with=20 > the new position profile, one may be able to plot the general = > direction of=20 > the epicenter, and estimate the magnitude.  Unless it move greater = > than 24"=20 > from center.
>
Thanks,
>
Ted
>
 
>
 
>
----- Original Message -----
>
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = > BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> > style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = > black">From:=20 > Jerry = > Payton=20 > > >
Sent: Wednesday, October 24, = > 2007 9:56=20 > AM
>
Subject: Re: Mystery item and = > its=20 > potential seismometry uses/s?
>

>
OK, Meredith.  I give up and curiosity has got this=20 > cat.  It reminds me of an oar-lock, but what was you idea?  = > I've=20 > seen no replies to your question and there seems to be a lull right = > now in=20 > EQ's.  Let's stir up some discussion!
>
Regards,
>
Jerry Payton
>
 
>
----- Original Message -----=20 >
From: title=3Dpaleoartifact@......... = > href=3D"mailto:paleoartifact@.........">meredith=20 > lamb
> >
Sent: Tuesday, October 09, 2007 8:28 PM
>
Subject: Mystery item and its potential seismometry=20 > uses/s?
>

>
Hi all,
>
 
>
I think it might be fun for those of you who are amateur or real=20 > "engineers";
>
to come up with their own thoughts and use/s for a couple = > pictures of a=20 > item at:
>
 
>
= > href=3D"http://home.earthlink.net/~meredithlamb/">http://home.earthlink.n= > et/~meredithlamb/
>
 
>
I have my own (surprising) and varied uses in mind; what's = > yours?
>
 
>
Meredith Lamb
>
 
>
 
> > ------=_NextPart_000_000C_01C8162E.914B0A60-- > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 3 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Re: Mystery item and its potential seismometry uses/s? > From: "meredith lamb" > Date: Wed, 24 Oct 2007 20:09:43 -0600 > > ------=_Part_9710_24185849.1193278183386 > Content-Type: text/plain; charset=ISO-8859-1 > Content-Transfer-Encoding: 7bit > Content-Disposition: inline > > Hi Jerry and all, > > I put up some text and 3 more pictures of a rather unusual pendulum > (horizontal > sensing), on the web, and some very brief text relating to its other > vertical sensing > use/s. The pendulum is essentially a hanging mass or "S-G" type. The > aluminum > looks to be quite useful for a variety of seismometer setups....without...as > much > material being used. Fun stuff! See: > > http://home.earthlink.net/~meredithlamb/ > > Take care, Meredith Lamb > > On 10/24/07, Jerry Payton wrote: > > > > *OK, Meredith. I give up and curiosity has got this cat. It reminds me > > of an oar-lock, but what was you idea? I've seen no replies to your > > question and there seems to be a lull right now in EQ's. Let's stir up some > > discussion!* > > *Regards,* > > *Jerry Payton* > > ** > > > > ------=_Part_9710_24185849.1193278183386 > Content-Type: text/html; charset=ISO-8859-1 > Content-Transfer-Encoding: 7bit > Content-Disposition: inline > >
Hi Jerry and all,
>
 
>
I put up some text and 3 more pictures of a rather unusual pendulum (horizontal
>
sensing), on the web, and some very brief text relating to its other vertical sensing
>
use/s.  The pendulum is essentially a hanging mass or "S-G" type.  The aluminum
>
looks to be quite useful for a variety of seismometer setups....without...as much
>
material being used.  Fun stuff!  See:
>
 
> >
 
>
Take care, Meredith Lamb

 
>
On 10/24/07, Jerry Payton <gpayton880@.......> wrote: >
>
>
OK, Meredith.  I give up and curiosity has got this cat.  It reminds me of an oar-lock, but what was you idea?  I've seen no replies to your question and there seems to be a lull right now in EQ's.  Let's stir up some discussion! >
>
Regards,
>
Jerry Payton
>
 
> > ------=_Part_9710_24185849.1193278183386-- > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 4 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: RE: Mystery item and its potential seismometry uses/s? > From: "Steve Hammond" > Date: Wed, 24 Oct 2007 23:24:27 -0700 > > This is a multi-part message in MIME format. > > ------=_NextPart_000_0001_01C81695.060A0FC0 > Content-Type: text/plain; > charset="us-ascii" > Content-Transfer-Encoding: quoted-printable > > Hi, The design suggests to me that it may have been connected to a round > object such as a sailboat's mast. I once read about a counter balance = > device > that reduced the port/starboard sway when a boat is at anchor buy using = > a > counterbalance pendulum to create an apposing force that reduces the = > wave > energy. The rollers in the top photo suggest to me that they would allow = > the > base object to be hoisted to the upper portion of a mast increasing the > effect of the pendulum. Here is a link to some patents that describe = > this > idea. www.freepatentsonline.com/CCL-114-122.html=20 > =20 > My guess, Steve Hammond > > -----Original Message----- > From: psn-l-request@.............. [mailto:psn-l-request@............... = > On > Behalf Of meredith lamb > Sent: Wednesday, October 24, 2007 7:10 PM > To: psn-l@.............. > Subject: Re: Mystery item and its potential seismometry uses/s? > > Hi Jerry and all, > =20 > I put up some text and 3 more pictures of a rather unusual pendulum > (horizontal > sensing), on the web, and some very brief text relating to its other > vertical sensing > use/s. The pendulum is essentially a hanging mass or "S-G" type. The > aluminum > looks to be quite useful for a variety of seismometer = > setups....without...as > much > material being used. Fun stuff! See: > =20 > http://home.earthlink.net/~meredithlamb/ > =20 > Take care, Meredith Lamb > > =20 > On 10/24/07, Jerry Payton wrote:=20 > > OK, Meredith. I give up and curiosity has got this cat. It reminds me = > of > an oar-lock, but what was you idea? I've seen no replies to your = > question > and there seems to be a lull right now in EQ's. Let's stir up some > discussion!=20 > Regards, > Jerry Payton > > =20 > > ------=_NextPart_000_0001_01C81695.060A0FC0 > Content-Type: text/html; > charset="us-ascii" > Content-Transfer-Encoding: quoted-printable > > > > charset=3Dus-ascii"> > Message > > > >
size=3D2>Hi,=20 > The design suggests to me that it may have been connected to a = > round object=20 > such as a sailboat's mast. I once read about a counter balance device = > that=20 > reduced the port/starboard sway when a boat is at anchor buy using a=20 > counterbalance pendulum to create an apposing force that reduces the = > wave=20 > energy. The rollers in the top photo suggest to me that they would allow = > the=20 > base object to be hoisted to the upper portion of a mast = > increasing=20 > the effect of the pendulum. Here is a link to some = > patents that=20 > describe this idea.  href=3D"http://www.freepatentsonline.com/CCL-114-122.html">www.freepatent= > sonline.com/CCL-114-122.html=20 >
>
size=3D2> class=3Da> 
>
> size=3D2> My guess, Steve Hammond
>
>
>
align=3Dleft> face=3DTahoma size=3D2>-----Original Message-----
From:=20 > psn-l-request@.............. [mailto:psn-l-request@............... = > On=20 > Behalf Of meredith lamb
Sent: Wednesday, October 24, = > 2007 7:10=20 > PM
To: psn-l@..............
Subject: Re: Mystery = > item and=20 > its potential seismometry uses/s?

>
Hi Jerry and all,
>
 
>
I put up some text and 3 more pictures of a rather unusual = > pendulum=20 > (horizontal
>
sensing), on the web, and some very brief text relating to = > its other=20 > vertical sensing
>
use/s.  The pendulum is essentially a hanging mass or "S-G"=20 > type.  The aluminum
>
looks to be quite useful for a variety of seismometer=20 > setups....without...as much
>
material being used.  Fun stuff!  See:
>
 
>
= > href=3D"http://home.earthlink.net/~meredithlamb/">http://home.earthlink.n= > et/~meredithlamb/
>
 
>
Take care, Meredith Lamb

 
>
On 10/24/07, class=3Dgmail_sendername>Jerry=20 > Payton < href=3D"mailto:gpayton880@.......">gpayton880@.......>=20 > wrote:=20 >
style=3D"PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: = > #ccc 1px solid"> >
>
OK, Meredith.  I give up and curiosity has got = > this=20 > cat.  It reminds me of an oar-lock, but what was you = > idea?  I've=20 > seen no replies to your question and there seems to be a lull right = > now in=20 > EQ's.  Let's stir up some discussion!
>
Regards,
>
Jerry Payton
> = >
 
QUOTE> > > ------=_NextPart_000_0001_01C81695.060A0FC0-- > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-DIGEST-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. Subject: Peters study of complex friction From: John Lahr johnjan@........ Date: Thu, 25 Oct 2007 07:57:02 -0700 This is an interesting point that Randall makes. I suppose if there is always some movement due to microseisms, then the static friction will not come into play... but maybe not .... at the end of each swing it may be a factor anyway, causing the response to be nonlinear. I wonder if there are also complexities of this sort in other types of hinge that involve flexure of a material? John >Date: Thu, 25 Oct 2007 08:59:01 -0400 >From: Randall Peters >It's a neat piece , Meredith; however, I see a serious problem with >bearing friction when it comes to use in >a seismometer. Rolling friction is really complex, as evidenced by >the paper I wrote at >http://arxiv.org/abs/physics/0506143 > My expectation is that you will find challenges due to `stiction' > since the decay of your system (independent >of damping that you supply to the instrument by design) is more in >the category of Coulomb friction than >forms that result in exponential decay. As is well known for >Coulomb friction, the static coefficient is greater than the kinetic >coefficient. Consequently, you would probably need to provide some >way to dither your instrument to have much in the way of sensitivity. > >Randall Peters __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mystery item and its potential seismometry uses/s? From: "meredith lamb" paleoartifact@......... Date: Thu, 25 Oct 2007 11:52:49 -0600 Hi Steve and all, I don't really know what the item was originally used for. The "wear" pattern only suggests a horizontal load use for this particular item. There is indeed likely a wide variety of use variations as you web referenced. Meanwhile...I've added another 6th picture and text for a crude "crossed rod" pivot using the same item. The "crossed rod" type of pivot is in my opinion much better than using ball bearings, as from past table top edge experiments; its resulting visual low level small movement response (less than 1/16") seems to be quite abit more responsive....i.e., its undampened visual movement has been known to continue for ~ 2 hours more than using a variety of ball bearings. In this picture however, it is different as the 90 degree rods serve to limit unitentional assembly displacement in the lateral axis...which is a improvement over a simple straight rod riding atop the two extended table top rods. http://home.earthlink.net/~meredithlamb/ On 10/25/07, Steve Hammond wrote: > > Hi, The design suggests to me that it may have been connected to a round > object such as a sailboat's mast. I once read about a counter balance device > that reduced the port/starboard sway when a boat is at anchor buy using a > counterbalance pendulum to create an apposing force that reduces the wave > energy. The rollers in the top photo suggest to me that they would allow the > base object to be hoisted to the upper portion of a mast increasing the > effect of the pendulum. Here is a link to some patents that describe this > idea. www.freepatentsonline.com/CCL-114-122.html > > My guess, Steve Hammond > >
Hi Steve and all,
 
I don't really know what the item was originally used for.  The "wear" pattern
only suggests a horizontal load use for this particular item.  There is indeed likely a
wide variety of use variations as you web referenced.
 
Meanwhile...I've added another 6th picture and text for a crude "crossed rod" pivot using
the same item.  The "crossed rod" type of pivot is in my opinion much better
than using ball bearings, as from past table top edge experiments; its resulting visual
low level small movement response (less than 1/16") seems to be quite abit more responsive....i.e.,
its undampened visual movement has been known to continue for ~ 2 hours more than
using a variety of ball bearings.  In this picture however, it is different as the 90 degree rods serve
to limit unitentional assembly displacement in the lateral axis...which is a improvement over
a simple straight rod riding atop the two extended table top rods.   
 
 
 


 
On 10/25/07, Steve Hammond <shammon1@............. > wrote:
Hi, The design suggests to me that it may have been connected to a round object such as a sailboat's mast. I once read about a counter balance device that reduced the port/starboard sway when a boat is at anchor buy using a counterbalance pendulum to create an apposing force that reduces the wave energy. The rollers in the top photo suggest to me that they would allow the base object to be hoisted to the upper portion of a mast increasing the effect of the pendulum. Here is a link to some patents that describe this idea.  www.freepatentsonline.com/CCL-114-122.html
 
 My guess, Steve Hammond
Subject: Re: Digest from 10/24/2007 00:00:50 From: "meredith lamb" paleoartifact@......... Date: Thu, 25 Oct 2007 12:13:35 -0600 Hi Randall, Thanks for the email and notes. I agree that ball bearings aren't a very good pivot point as I've seen a comparison of ball bearings to a "crossed rod" pivot; i.e., the low level mass pivot response of the ball bearings was outright "locked" compared to the crossed rod pivot where mass movement is less than 1/16"....right in the neighborhood range where most seismic response occurs. I won't pretend to grasp totally all you've wrote of. I do appreciate your contributions! Take care, Meredith Lamb On 10/25/07, Randall Peters wrote: > > It's a neat piece , Meredith; however, I see a serious problem with > bearing friction when it comes to use in > a seismometer. Rolling friction is really complex, as evidenced by the > paper I wrote at > http://arxiv.org/abs/physics/0506143 > My expectation is that you will find challenges due to `stiction' since > the decay of your system (independent > of damping that you supply to the instrument by design) is more in the > category of Coulomb friction than > forms that result in exponential decay. As is well known for Coulomb > friction, the static coefficient is greater than the kinetic > coefficient. Consequently, you would probably need to provide some way to > dither your instrument to have much in the way of sensitivity. > > Randall Peters > > >
Hi Randall,
 
Thanks for the email and notes.  I agree that ball bearings aren't a very good pivot point as I've seen
a comparison of ball bearings to a "crossed rod" pivot; i.e., the low level mass pivot response of the ball
bearings was outright "locked" compared to the crossed rod pivot where mass movement is less than
1/16"....right in the neighborhood range where most seismic response occurs.
 
I won't pretend to grasp totally all you've wrote of.  I do appreciate your contributions!
 
Take care, Meredith Lamb    

 
On 10/25/07, Randall Peters <PETERS_RD@..........> wrote:
It's a neat piece , Meredith; however, I see a serious problem with bearing friction when it comes to use in
a seismometer.  Rolling friction is really complex, as evidenced by the paper I wrote at
http://arxiv.org/abs/physics/0506143
My expectation is that you will find challenges due to `stiction' since the decay of your system (independent
of damping that you supply to the instrument by design) is more in the category of Coulomb friction than
forms that result in exponential decay.  As is well known for Coulomb friction, the static coefficient is greater than the kinetic coefficient.  Consequently, you would probably need to provide some way to dither your instrument to have much in the way of sensitivity.

Randall Peters


Subject: Re: Mystery item and its potential seismometry uses/s? From: John Lahr johnjan@........ Date: Thu, 25 Oct 2007 13:07:55 -0700 At 10:52 AM 10/25/2007, you wrote: >...I've added another 6th picture and text for a crude "crossed rod" >pivot using >the same item. Meredith, It would be interesting to test this arrangement of rods. I think that due to the angles, the pivot point will need to rub rather than roll. If that's the case there will be much greater friction. John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mystery item and its potential seismometry uses/s? From: "Geoff" gmvoeth@........... Date: Thu, 25 Oct 2007 13:37:27 -0700 Interesting, I would think if you get a natural damping from frictional forces of possibly 1.4 ( Q = 0.7) you would not need any magnetic or other damping ? ----- Original Message ----- From: "John Lahr" To: Sent: Thursday, October 25, 2007 1:07 PM Subject: Re: Mystery item and its potential seismometry uses/s? > At 10:52 AM 10/25/2007, you wrote: >>...I've added another 6th picture and text for a crude "crossed rod" >>pivot using >>the same item. > > Meredith, > > It would be interesting to test this arrangement of rods. I think > that due to the angles, > the pivot point will need to rub rather than roll. If that's the > case there will be much > greater friction. > > John > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Peters study of complex friction From: ChrisAtUpw@....... Date: Thu, 25 Oct 2007 16:53:08 EDT In a message dated 25/10/2007, johnjan@........ writes: This is an interesting point that Randall makes. I suppose if there is always some movement due to microseisms, then the static friction will not come into play... but maybe not .... at the end of each swing it may be a factor anyway, causing the response to be nonlinear. Hi All, If you have simple rolling of a hard cylinder / sphere on another hard surface, no direct friction will be involved, although a small loss will occur as the rolling surfaces are elastically compressed. If you have any sliding, the movement will alternate from one stick / slip situation to another in small jerky steps. I wonder if there are also complexities of this sort in other types of hinge that involve flexure of a material? In the V suspension shown, vibrations will tend to flex the rods and will probably markedly increase the loss in the suspension due to sliding friction. _http://home.earthlink.net/~meredithlamb/id1.html_ (http://home.earthlink.net/~meredithlamb/id1.html) Regards, Chris Chapman
In a message dated 25/10/2007, johnjan@........ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>This is=20 an interesting point that Randall makes.  I suppose if there
is=20 always some movement due to microseisms, then the static friction
will= not=20 come into play...  but maybe not .... at the end of each
swing it= may=20 be a factor anyway, causing the response to be nonlinear.
Hi All,
 
    If you have simple rolling of a hard cylinder /= =20 sphere on another hard surface, no direct friction will be involved, althoug= h a=20 small loss will occur as the rolling surfaces are elastically compressed. If= you=20 have any sliding, the movement will alternate from one stick / sli= p=20 situation to another in small jerky steps. 
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I wonder=20 if there are also complexities of this sort in other types of hinge that=20 involve flexure of a material?
    In the V suspension shown, vibrations will tend= to=20 flex the rods and will probably markedly increase the loss in the suspension= due=20 to sliding friction. http://home.earthl= ink.net/~meredithlamb/id1.html
 
    Regards,
 
    Chris Chapman
Subject: Re: Mystery item and its potential seismometry uses/s? From: "meredith lamb" paleoartifact@......... Date: Thu, 25 Oct 2007 16:24:23 -0600 Hi John, Yes.... you are correct...the rod would twist sideways (rub), rather than roll as a crossed rod pivot should. All is not lost however with the aluminum; it does have another pair of holes that can accomodate a rod through it. Yes....(ha), I also put up yet another photo (bottom of the web page) of a more correct crossed rod pivot and denoted my error. http://home.earthlink.net/~meredithlamb/ Meredith On 10/25/07, John Lahr wrote: > > At 10:52 AM 10/25/2007, you wrote: > >...I've added another 6th picture and text for a crude "crossed rod" > >pivot using > >the same item. > > Meredith, > > It would be interesting to test this arrangement of rods. I think > that due to the angles, > the pivot point will need to rub rather than roll. If that's the > case there will be much > greater friction. > > John > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >
Hi John,
 
Yes.... you are correct...the rod would twist sideways (rub), rather than roll
as a crossed rod pivot should. 
 
All is not lost however with the aluminum; it does have another pair of holes
that can accomodate a rod through it.
 
Yes....(ha), I also put up yet another photo (bottom of the web page) of a more
correct crossed rod pivot and denoted my error.
 

Meredith
 
On 10/25/07, John Lahr <johnjan@........> wrote:
At 10:52 AM 10/25/2007, you wrote:
>...I've added another 6th picture and text for a crude "crossed rod"
>pivot using
>the same item.

Meredith,

It would be interesting to test this arrangement of rods.  I think
that due to the angles,
the pivot point will need to rub rather than roll.  If that's the
case there will be much
greater friction.

John


__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with
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Subject: Question regarding two seismometers From: "Kay Wyatt" kwyatt@............. Date: Fri, 26 Oct 2007 11:01:48 -0700 Greetings fellow PSN enthusiasts, My name is Kay Wyatt and I am the Director of the Oregon Shakes Program = (www.OregonShakes.com) which is trying to put seismograph in all public = schools in Oregon starting in Lincoln County. We have funding to = purchase three AS-1 seismographs, but I am looking at alternatives = before we make the purchase. I currently run an AS-1 at my house and = maintain an AS-1 at our local after school enrichment program in Depoe = Bay Oregon. Does anybody have the VolksMeter II which is made by RLL Instruments, a = division of Zoltech Corp. Their website is at = http://www.rllinstruments.com/. If anybody has any experience with this = system (good or bad) I would be most interested in hearing from you. I was also looking at the SEP Seismometer System which is sold by MUTR = in the UK. Their website is at = http://www.mutr.co.uk/catalog/product_info.php?cPath=3D18_412&products_id= =3D9047. Again, if anybody has any experience with this, good or bad, I = am most interested. Also, if you have suggestions on other educational seismometers, I would = be very interested. Our Lincoln County kids are incredibly excited = about this program. We may have a few budding PSN'rs. Perhaps a PSN = Junior listserver might be in order ;-) Thanks, Kay Wyatt
Greetings fellow PSN enthusiasts,
 
My name is Kay Wyatt and I am the Director of = the Oregon=20 Shakes Program (www.OregonShakes.com)=20 which is trying to put seismograph in all public schools in Oregon = starting in=20 Lincoln County.  We have funding to purchase three AS-1 = seismographs, but I=20 am looking at alternatives before we make the purchase.  I = currently run an=20 AS-1 at my house and maintain an AS-1 at our local after school = enrichment=20 program in Depoe Bay Oregon.
 
Does anybody have the VolksMeter II which is = made by RLL=20 Instruments, a division of Zoltech Corp.  Their website is at http://www.rllinstruments.com/. =20 If anybody has any experience with this system (good or bad) I would be = most=20 interested in hearing from you.
 
I was also looking at the SEP Seismometer System = which is=20 sold by MUTR in the UK.  Their website is at http://www.mutr.co.uk/catalog/product_info.php?cPath= =3D18_412&products_id=3D9047. =20 Again, if anybody has any experience with this, good or bad, I am most=20 interested.
 
Also, if you have suggestions on other = educational=20 seismometers, I would be very interested.  Our Lincoln County kids = are=20 incredibly excited about this program.  We may have a few budding=20 PSN'rs.  Perhaps a PSN Junior listserver might be in=20 order    ;-)
 
Thanks,
Kay Wyatt
 
Subject: A rough trial HD pivot vertical From: "meredith lamb" paleoartifact@......... Date: Sat, 27 Oct 2007 13:03:58 -0600 Hi all, Just for fun, I put a web site with pictures of a rough trial vertical using hard drive hole inner surface disks with a 1/4" rod as the pivot. The "base" layout is roughly similar to that of the Georgia Tech vertical; which does not use a mast. The perforated steel tubing (Ace Hardware) helped make it easy to construct. I have not extensively "played" with it, so the period is only a fraction over 1 second. Perhaps....the main points of it all, are the HD disks and the rolling rod as the pivot; and the extreme ease of assembly with the Ace Hardware perforated steel tubing, that served as the "base plate", that was utilized. http://home.earthlink.net/~meredithlamb/hdpivotvertical/ Take care, Meredith Lamb
Hi all,
 
Just for fun, I put a web site with pictures of a rough trial vertical using hard drive
hole inner surface disks with a 1/4" rod as the pivot.  The "base" layout is roughly
similar to that of the Georgia Tech vertical; which does not use a mast.  The
perforated steel tubing (Ace Hardware) helped make it easy to construct.  I have
not extensively "played" with it, so the period is only a fraction over 1 second.
 
Perhaps....the main points of it all, are the HD disks and the rolling rod as the
pivot; and the extreme ease of assembly with the Ace Hardware perforated steel
tubing, that served as the "base plate", that was utilized.
 
 
 
Take care, Meredith Lamb
 
  
Subject: Different types of Pendulums From: tchannel1@............ Date: Sat, 27 Oct 2007 15:23:56 -0600 Hi Folks, Sometime in the past I saw a web site describing different = type of pendulums used in sensors. I don't remember their names, but 1. one was a long vertical rod, with a center pivot, it contained a = mass at the top of the rod and a mass at the bottom of the rod. 2. Another pendulum was a horz rod which had a short vertical rod = pointing up from the center of the long horz rod. The pivot point was = at the top of this short vertical. There may have been two or so more pendulum illustrated. My question has to do with 1. I thought this pendulum (positioned like = an airplane propeller) was able to adjust it's period by moving the top = and or bottom mass, up or down the rod? I made a simply mock up of this illustration, but was not successful in = any way as the mock up was too crude. To me it was similar to the = folded pendulum, as it had a normal and inverted pendulum, one apposing = the other? Can one adjust this arrangement to result in an extended period???????? = Does anyone know of this wed site or one similar? Thanks, Ted
Hi Folks, Sometime in the past I saw a = web site=20 describing different type of pendulums used in sensors.  I don't = remember=20 their names, but
 
1.  one was a long vertical = rod, with a=20 center pivot, it contained a mass at the top of the rod and a mass at = the bottom=20 of the rod.
 
 
2. Another pendulum was a horz rod = which had a=20 short vertical rod pointing up from the center of the long horz = rod.  The=20 pivot point was at the top of this short vertical.
 
There may have been two or so more = pendulum=20 illustrated.
 
My question has to do with 1.  I = thought this=20 pendulum (positioned like an airplane propeller) was able to adjust it's = period=20 by moving the top and or bottom mass, up or down the rod?
I made a simply mock up of this = illustration, but=20 was not successful in any way as the mock up was too crude.  To me = it was=20 similar to the folded pendulum, as it had a normal and inverted = pendulum, one=20 apposing the other?
Can one adjust this arrangement to = result in an=20 extended period????????   Does anyone know of this wed site or = one=20 similar?
 
Thanks, Ted
Subject: Re: Different types of Pendulums From: ChrisAtUpw@....... Date: Sat, 27 Oct 2007 17:44:22 EDT In a message dated 27/10/2007 22:23:56 GMT Daylight Time, tchannel1@............ writes: Hi Folks, Sometime in the past I saw a web site describing different types of pendulums used in sensors. I don't remember their names, but 1. one was a long vertical rod, with a center pivot, it contained a mass at the top of the rod and a mass at the bottom of the rod. My question has to do with 1. I thought this pendulum (positioned like an airplane propeller) was able to adjust it's period by moving the top and or bottom mass, up or down the rod? I made a simply mock up of this illustration, but was not successful in any way. Can one adjust this arrangement to result in an extended period? Does anyone know of this web site or one similar? Hi Ted, There are several possible systems, but you need to suspend the pendulum near the middle, a small height above the centre of gravity. This gives a high moment of inertia due to the masses at the ends and the small restoring force due to 2x mass operating just below the suspension axis. It should work fine. You can also vary the position of one of the masses. Regards, Chris Chapman
In a message dated 27/10/2007 22:23:56 GMT Daylight Time,=20 tchannel1@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Hi Folks, Sometime in the past I saw a we= b site=20 describing different types of pendulums used in sensors.  I don't=20 remember their names, but
 
1.  one was a long vertical rod= , with a=20 center pivot, it contained a mass at the top of the rod and a mass at the=20 bottom of the rod.
 
My question has to do with 1.  I tho= ught=20 this pendulum (positioned like an airplane propeller) was able to adjust i= t's=20 period by moving the top and or bottom mass, up or down the rod?
I made a simply mock up of this illustrat= ion, but=20 was not successful in any way. Can one=20= adjust=20 this arrangement to result in an extended period? Does anyone know of this= web=20 site or one similar?
Hi Ted,
 
    There are several possible systems, but you nee= d to=20 suspend the pendulum near the middle, a small height above the centre=20 of gravity. This gives a high moment of inertia due to the masses=20= at=20 the ends and the small restoring force due to 2x mass operating just below t= he=20 suspension axis. It should work fine. You can also vary the position of= one=20 of the masses.
 
    Regards,
 
    Chris Chapman
Subject: Re: Different types of Pendulums From: John Lahr johnjan@........ Date: Sat, 27 Oct 2007 15:04:59 -0700 The "airplane-type" design is basically a "solid pendulum." Although the period can be made very long, the sensitivity becomes correspondingly low. I don't recommend this design. Cheers, John At 02:44 PM 10/27/2007, you wrote: >In a message dated 27/10/2007 22:23:56 GMT Daylight Time, >tchannel1@............ writes: >Hi Folks, Sometime in the past I saw a web site describing different >types of pendulums used in sensors. I don't remember their names, but > >1. one was a long vertical rod, with a center pivot, it contained a >mass at the top of the rod and a mass at the bottom of the rod. > >My question has to do with 1. I thought this pendulum (positioned >like an airplane propeller) was able to adjust it's period by moving >the top and or bottom mass, up or down the rod? >I made a simply mock up of this illustration, but was not successful >in any way. Can one adjust this arrangement to result in an extended >period? Does anyone know of this web site or one similar? > >Hi Ted, > > There are several possible systems, but you need to suspend the > pendulum near the middle, a small height above the centre of > gravity. This gives a high moment of inertia due to the masses at > the ends and the small restoring force due to 2x mass operating > just below the suspension axis. It should work fine. You can also > vary the position of one of the masses. > > Regards, > > Chris Chapman __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Different types of Pendulums From: tchannel1@............ Date: Sat, 27 Oct 2007 16:58:42 -0600 Hi Chris, What you described below, I think, was one of the = illustration, Let me describe it this way........... Lets say a 36" horz rod.............from the balance point 18" connect a = short 2" x 4" (L) shape rod, the 2" leg is welded to the balance point = of the horz rod. Now the 4" leg is inserted into some sort of bearing, and the whole = thing swings back and forth from this 4" axle. You have two equal = masses, one on the left and one on the right of the 36" horz. rod. NOW = CAN one extend the period of the device by relocating one or other of = the masses? Thanks, Ted ----- Original Message -----=20 From: ChrisAtUpw@.......... To: psn-l@................. Sent: Saturday, October 27, 2007 3:44 PM Subject: Re: Different types of Pendulums In a message dated 27/10/2007 22:23:56 GMT Daylight Time, = tchannel1@............ writes: Hi Folks, Sometime in the past I saw a web site describing different = types of pendulums used in sensors. I don't remember their names, but 1. one was a long vertical rod, with a center pivot, it contained a = mass at the top of the rod and a mass at the bottom of the rod. My question has to do with 1. I thought this pendulum (positioned = like an airplane propeller) was able to adjust it's period by moving the = top and or bottom mass, up or down the rod? I made a simply mock up of this illustration, but was not successful = in any way. Can one adjust this arrangement to result in an extended = period? Does anyone know of this web site or one similar? Hi Ted, There are several possible systems, but you need to suspend the = pendulum near the middle, a small height above the centre of gravity. = This gives a high moment of inertia due to the masses at the ends and = the small restoring force due to 2x mass operating just below the = suspension axis. It should work fine. You can also vary the position of = one of the masses.=20 Regards, Chris Chapman
Hi Chris,  What you described below, I think, was one of the=20 illustration,  Let me describe it this way...........
Lets say a 36" horz rod.............from the balance point 18" = connect a=20 short 2" x 4"  (L) shape rod, the 2" leg is welded to the balance = point of=20 the horz rod.
Now the 4" leg is inserted into some sort of bearing, and the whole = thing=20 swings back and forth from this 4" axle.   You have two equal = masses,=20 one on the left and one on the right of the 36" horz. rod.   = NOW=20 CAN  one extend the period of the device by relocating one or other = of the=20 masses?
 
Thanks, Ted
----- Original Message -----
From:=20 ChrisAtUpw@.......
Sent: Saturday, October 27, = 2007 3:44=20 PM
Subject: Re: Different types of = Pendulums

In a message dated 27/10/2007 22:23:56 GMT Daylight Time, tchannel1@............ = writes:
Hi Folks, Sometime in the past I = saw a web site=20 describing different types of pendulums used in sensors.  I = don't=20 remember their names, but
 
1.  one was a long = vertical rod, with=20 a center pivot, it contained a mass at the top of the rod and a mass = at the=20 bottom of the rod.
 
My question has to do with 1.  = I thought=20 this pendulum (positioned like an airplane propeller) was able to = adjust=20 it's period by moving the top and or bottom mass, up or down the=20 rod?
I made a simply mock up of this = illustration,=20 but was not successful in any way. Can one=20 adjust this arrangement to result in an extended period? Does anyone = know of=20 this web site or one similar?
Hi Ted,
 
    There are several possible systems, but = you need=20 to suspend the pendulum near the middle, a small height above the = centre=20 of gravity. This gives a high moment of inertia due to the = masses at=20 the ends and the small restoring force due to 2x mass operating just = below the=20 suspension axis. It should work fine. You can also vary the = position of=20 one of the masses.
 
    Regards,
 
    Chris=20 Chapman
Subject: Re: Different types of Pendulums From: tchannel1@............ Date: Sat, 27 Oct 2007 17:20:04 -0600 Hi Folks, I found the wed site again. http://www.phy.mtu.edu/~suits/PH3110/pendulums.html The two I mentioned are called "Balanced-Like" and "Nearly Balanced" Just wondering if anyone has worked with them. As I said I made a mock up, with no luck. But maybe my mock up was not done correctly. Ted ----- Original Message ----- From: "John Lahr" To: Sent: Saturday, October 27, 2007 4:04 PM Subject: Re: Different types of Pendulums > The "airplane-type" design is basically a "solid pendulum." Although the > period can be made > very long, the sensitivity becomes correspondingly low. I don't recommend > this design. > > Cheers, > John > > At 02:44 PM 10/27/2007, you wrote: >>In a message dated 27/10/2007 22:23:56 GMT Daylight Time, >>tchannel1@............ writes: >>Hi Folks, Sometime in the past I saw a web site describing different types >>of pendulums used in sensors. I don't remember their names, but >> >>1. one was a long vertical rod, with a center pivot, it contained a mass >>at the top of the rod and a mass at the bottom of the rod. >> >>My question has to do with 1. I thought this pendulum (positioned like an >>airplane propeller) was able to adjust it's period by moving the top and >>or bottom mass, up or down the rod? >>I made a simply mock up of this illustration, but was not successful in >>any way. Can one adjust this arrangement to result in an extended period? >>Does anyone know of this web site or one similar? >> >>Hi Ted, >> >> There are several possible systems, but you need to suspend the >> pendulum near the middle, a small height above the centre of gravity. >> This gives a high moment of inertia due to the masses at the ends and the >> small restoring force due to 2x mass operating just below the suspension >> axis. It should work fine. You can also vary the position of one of the >> masses. >> >> Regards, >> >> Chris Chapman > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Different types of Pendulums From: ChrisAtUpw@....... Date: Sat, 27 Oct 2007 20:38:04 EDT In a message dated 27/10/2007, tchannel1@............ writes: Hi Chris, What you described below, I think, was one of the illustration, Let me describe it this way........... Lets say a 36" horz rod.............from the balance point 18" connect a short 2" x 4" (L) shape rod, the 2" leg is welded to the balance point of the horz rod. Now the 4" leg is inserted into some sort of bearing, and the whole thing swings back and forth from this 4" axle. You have two equal masses, one on the left and one on the right of the 36" horz. rod. NOW CAN one extend the period of the device by relocating one or other of the masses? Hi Ted, You would need to move both masses equally, or they would not balace. If the rod is of low weight and the masses are K from the centre, the moment of inertia is roughly 2MK^2. The restoring force is roughly 2Mg x 4" x dTheta. Changes in the length of the 4" rod will make a big contribution to the period. As John has mentioned, the sensitivity to seismic motion is low, but if you use a quad NdFeB magnet + coil sensor, you can get 10x the output of a U Alnico magnet design. If you also design your amplifier for low noise, you can get maybe 1/10 the noise of available amplifiers. Referring to _http://jclahr.com/science/psn/cochrane/index.html_ (http://jclahr.com/science/psn/cochrane/index.html) if you reduce R29 from 400 K to 12 K and R10 from 5.1 K to 150 Ohm you will reduce the shot noise by ~x5 and also reduce the 1/f current noise. Using discreet low noise input transistors can give a further noise reduction of x5, or more. Using such a system as part of a chopper amplifier will dramatically reduce the 1/f voltage and current noise. See _http://www.linear.com.cn/pc/downloadDocument.do?navId=H0,C1,C1010,C1203,P1248,D4136_ (http://www.linear.com.cn/pc/downloadDocument.do?navId=H0,C1,C1010,C1203,P1248,D4136) I like the reference _http://www.phy.mtu.edu/~suits/PH3110/pendulums.html_ (http://www.phy.mtu.edu/~suits/PH3110/pendulums.html) The wide angle crossed wire suspension system is very interesting. But crossed foils might be more robust. You can also extend the period of Lehman and vertical pendulums up to x10 by magnetic repulsion. This modifies the force / position relationship, but you may then be very sensitive to local magnetic field noise. Regards, Chris Chapman
In a message dated 27/10/2007, tchannel1@............ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Hi Chris,  What you described below, I think, was one of the=20 illustration,  Let me describe it this way...........
Lets say a 36" horz rod.............from the balance point 18" connec= t a=20 short 2" x 4"  (L) shape rod, the 2" leg is welded to the balance poi= nt=20 of the horz rod.
Now the 4" leg is inserted into some sort of bearing, and the whole t= hing=20 swings back and forth from this 4" axle.   You have two equal=20 masses, one on the left and one on the right of the 36" horz. rod. &n= bsp;=20 NOW CAN  one extend the period of the device by relocating one or oth= er=20 of the masses?
Hi Ted,
 
    You would need to move both masses equally, or=20= they=20 would not balace. If the rod is of low weight and the masses are K from the=20 centre, the moment of inertia is roughly 2MK^2. The restoring force is rough= ly=20 2Mg x 4" x dTheta. Changes in the length of the 4" rod will make a big=20 contribution to the period.
 
    As John has mentioned, the sensitivity to seism= ic=20 motion is low, but if you use a quad NdFeB magnet + coil sensor, you can get= 10x=20 the output of a U Alnico magnet design. If you also design your amplifier fo= r=20 low noise, you can get maybe 1/10 the noise of available amplifiers.
    Referring to http://jclahr.com= /science/psn/cochrane/index.html if=20 you reduce R29 from 400 K to 12 K and R10 from 5.1 K to 150 Ohm you will red= uce=20 the shot noise by ~x5 and also reduce the 1/f current noise. Using= =20 discreet low noise input transistors can give a further noise reduction of x= 5,=20 or more. Using such a system as part of a chopper amplifier will dramaticall= y=20 reduce the 1/f voltage and current noise. See http://www.linear.com.cn/pc/downloadDocument.do?navId=3DH= 0,C1,C1010,C1203,P1248,D4136
 
    I like the reference http://www.phy.= mtu.edu/~suits/PH3110/pendulums.html The=20 wide angle crossed wire suspension system is very interesting. But crossed f= oils=20 might be more robust. You can also extend the period of Lehman and vertical=20 pendulums up to x10 by magnetic repulsion. This modifies the force /=20 position relationship, but you may then be very sensitive to local magnetic=20 field noise.
 
    Regards,
 
    Chris Chapman
Subject: Re: Different types of Pendulums From: "Geoff" gmvoeth@........... Date: Sat, 27 Oct 2007 17:40:37 -0700 Hello All; This Is All quite Interesting but no one seems to concentrate on the real devil your fighting which is gravity. In order to lengthen the period of a pendulum you must find some way of lowering the pull of gravity which is 32.17fpss that means you need to effectively reduce it to like 3.217fpss if you want a decent period. At least that is how I understand it. All these fancy things we do are essentially to reduce gravitational effects on the mass. You might use bouyancy to help you if you can find a fluid with high specific gravity like 5g/cm3 or more then use a small spring to do the rest on the mass. Whatever you can get to oppose gravity is in the game. If only someone could find a cheap way to oppose gravity ?? Light ( EM ) waves are themselves like a pendulum in that they oscillate seemingly between the potential ( E ) and the Kenetic ( B ) and who is to say there is nothing to dampen an EM wave since we simply can not ride with one till it dies out ??? Just a thought stimulated by this thread. Regards; geoff ----- Original Message ----- From: To: Sent: Saturday, October 27, 2007 4:20 PM Subject: Re: Different types of Pendulums > Hi Folks, I found the wed site again. > http://www.phy.mtu.edu/~suits/PH3110/pendulums.html The two I mentioned are > called "Balanced-Like" and "Nearly Balanced" > Just wondering if anyone has worked with them. As I said I made a mock up, > with no luck. But maybe my mock up was not done correctly. > Ted > > > > > > > ----- Original Message ----- > From: "John Lahr" > To: > Sent: Saturday, October 27, 2007 4:04 PM > Subject: Re: Different types of Pendulums > > >> The "airplane-type" design is basically a "solid pendulum." Although the >> period can be made >> very long, the sensitivity becomes correspondingly low. I don't recommend >> this design. >> >> Cheers, >> John >> >> At 02:44 PM 10/27/2007, you wrote: >>>In a message dated 27/10/2007 22:23:56 GMT Daylight Time, >>>tchannel1@............ writes: >>>Hi Folks, Sometime in the past I saw a web site describing different types >>>of pendulums used in sensors. I don't remember their names, but >>> >>>1. one was a long vertical rod, with a center pivot, it contained a mass >>>at the top of the rod and a mass at the bottom of the rod. >>> >>>My question has to do with 1. I thought this pendulum (positioned like an >>>airplane propeller) was able to adjust it's period by moving the top and >>>or bottom mass, up or down the rod? >>>I made a simply mock up of this illustration, but was not successful in >>>any way. Can one adjust this arrangement to result in an extended period? >>>Does anyone know of this web site or one similar? >>> >>>Hi Ted, >>> >>> There are several possible systems, but you need to suspend the >>> pendulum near the middle, a small height above the centre of gravity. >>> This gives a high moment of inertia due to the masses at the ends and the >>> small restoring force due to 2x mass operating just below the suspension >>> axis. It should work fine. You can also vary the position of one of the >>> masses. >>> >>> Regards, >>> >>> Chris Chapman >> >> >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with the body of the >> message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. >> > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: VolksMeter II From: "Jerry Payton" gpayton880@....... Date: Tue, 30 Oct 2007 08:28:17 -0500 After reading Kay Wyatt's email on the 26th, I have been looking at the VolkMeter II. It is something else, but the price = OUCH. I printed out their manual and am reading it now. I believe that it will be educational, especially about the WinSDR and WinQuake software settings. I am a real fuddy-duddy about HELP files. I don't like it when one just tell me, "This is the gas pedal", and stops at that. I want it to tell me that when I press it, you will go, and when you press harder you go faster! I like for help files to explain WHAT THEY DO, not simply what they are named. Off my soapbox now. I liked what Mrs. Wyatt was trying to do, similar to what you are doing, but larger scale, I think. I wanted remind you that I bought those fifty used tungsten drill bits. I have a lot left, if you should want to try the cross-roller method. Let me know and I send you what you need. I am not progressing very fast on my building. First, I am no much of a "tinkerer" and have to get my lazy bones out in the garage to work on it. Second, I keep changing my mind about the configuration of things. Chris had suggested, before he stopped helping, that I use a 3/4" x 6" cross bar, and connect two wire suspension cables. I tried that, but didn't like it. So, I am going back to something like John Cole used for suspension of the arm. I've got a little challenge in vertical alignment of the two pivot points too. I'm experimenting with that too. Annnnnnnnnd, it is getting cooler out in the garage. I broke down and bought an inexpensive drill press from Harbor Freight. It sure is handy. I've always wanted one for those special times that you need one. Regards, Jerry
After reading Kay Wyatt's email on the 26th, I have been looking at = the=20 VolkMeter II.  It is something else, but the price =3D OUCH.
 
I printed out their manual and am reading it now.  I believe = that it=20 will be educational, especially about the WinSDR and WinQuake software=20 settings.  I am a real fuddy-duddy about HELP files.  I don't = like it=20 when one just tell me, "This is the gas pedal", and stops at that.  = I want=20 it to tell me that when I press it, you will go, and when you press = harder you=20 go faster!  I like for help files to explain WHAT THEY DO, not = simply what=20 they are named.
 
Off my soapbox now.  I liked what Mrs. Wyatt was trying to do, = similar=20 to what you are doing, but larger scale, I think. 
 
I wanted remind you that I bought those fifty used tungsten drill=20 bits.  I have a lot left, if you should want to try the = cross-roller=20 method.  Let me know and I send you what you need.
 
I am not progressing very fast on my building.  First, I am no = much of=20 a "tinkerer" and have to get my lazy bones out in the garage to work on=20 it.  Second, I keep changing my mind about the configuration of=20 things.  Chris had suggested, before he stopped helping, that I use = a 3/4"=20 x 6" cross bar, and connect two wire suspension cables.  I tried = that, but=20 didn't like it.  So, I am going back to something like John Cole = used for=20 suspension of the arm. 
 
I've got a little challenge in vertical alignment of the two pivot = points=20 too.  I'm experimenting with that too.
 
Annnnnnnnnd, it is getting cooler out in the garage.  I broke = down and=20 bought an inexpensive drill press from Harbor Freight.  It sure is=20 handy.  I've always wanted one for those special times that you = need=20 one.
 
Regards,
Jerry
Subject: I GOOFED From: "Jerry Payton" gpayton880@....... Date: Tue, 30 Oct 2007 08:33:29 -0500 My apologies to the PSN Net. My last email was supposed to go to Ted Channel and not the Net. Sorry! Jerry
My apologies to the PSN Net. 
 
My last email was supposed to go to Ted Channel and not the = Net. =20 Sorry!
 
Jerry
Subject: Hardware failure From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Wed, 31 Oct 2007 02:46:53 +0000 Hi all My earthquake computer did suffer a huge hardware failure. The motherboard in the computer did fail and I am unable to start the computer. So my sensor net is going to be partical offline for the next two days or so. My Borgarnes sensor is still online, far as I can tell, but the web page is not going to get updated while the computer is down. Now I hope it stays quiet while I am fixing this. Last time I had a hardware failure, I missed a mag 4.6 earthquake in Iceland. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: tchannel1@............ Date: Tue, 30 Oct 2007 20:59:11 -0600 Hi Jon, Well, we know what happens when someone's sensor is down for equipment failure! Good luck with your repairs. Ted ----- Original Message ----- From: "Jón Frímann" To: "PSN-Postlist" Sent: Tuesday, October 30, 2007 8:46 PM Subject: Hardware failure Hi all My earthquake computer did suffer a huge hardware failure. The motherboard in the computer did fail and I am unable to start the computer. So my sensor net is going to be partical offline for the next two days or so. My Borgarnes sensor is still online, far as I can tell, but the web page is not going to get updated while the computer is down. Now I hope it stays quiet while I am fixing this. Last time I had a hardware failure, I missed a mag 4.6 earthquake in Iceland. Regards. -- Jón Frímann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: "Rudy Norvelle" rudy43norvelle@........... Date: Tue, 30 Oct 2007 20:10:12 -0700 Just had a nice one here East of San Jose. I don't have a seismograph. It lasted about 6-7 seconds. ----- Original Message ----- From: To: Sent: Tuesday, October 30, 2007 7:59 PM Subject: Re: Hardware failure > Hi Jon, Well, we know what happens when someone's sensor is down for > equipment failure! Good luck with your repairs. > Ted > > > ----- Original Message ----- > From: "Jón Frímann" > To: "PSN-Postlist" > Sent: Tuesday, October 30, 2007 8:46 PM > Subject: Hardware failure > > > Hi all > > My earthquake computer did suffer a huge hardware failure. The > motherboard in the computer did fail and I am unable to start the > computer. So my sensor net is going to be partical offline for the next > two days or so. My Borgarnes sensor is still online, far as I can tell, > but the web page is not going to get updated while the computer is down. > > Now I hope it stays quiet while I am fixing this. Last time I had a > hardware failure, I missed a mag 4.6 earthquake in Iceland. > > Regards. > -- > Jón Frímann > http://www.jonfr.com > http://earthquakes.jonfr.com > http://www.net303.net > http://www.mobile-coverage.com/ > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Hardware failure From: "Stephen Hammond" shammon1@............. Date: Tue, 30 Oct 2007 20:46:18 -0700 Email From a friend --=20 I am now living in North San Jose, just a few hundred yards from Milpitas. As you know by now, that is 11 miles from the epicenter. It was a sharp quake, with a lot of lateral motion, lasting 15-20 seconds. Since we were close and it was fairly shallow (5.5 miles), it was not a roller, but a long series of sharp jolts. The doors opened on the china hutch, some stuff fell of the desk, but nothing broke. After the major motion was over, it felt like we were on a boat on the ocean with a long series of rolling waves. Steve Hammond PSN Aptos CA. -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Rudy Norvelle Sent: Tuesday, October 30, 2007 8:10 PM To: psn-l@.............. Subject: Re: Hardware failure Just had a nice one here East of San Jose. I don't have a seismograph. It=20 lasted about 6-7 seconds. ----- Original Message -----=20 From: To: Sent: Tuesday, October 30, 2007 7:59 PM Subject: Re: Hardware failure > Hi Jon, Well, we know what happens when someone's sensor is down for > equipment failure! Good luck with your repairs. > Ted > > > ----- Original Message -----=20 > From: "J=F3n Fr=EDmann" > To: "PSN-Postlist" > Sent: Tuesday, October 30, 2007 8:46 PM > Subject: Hardware failure > > > Hi all > > My earthquake computer did suffer a huge hardware failure. The > motherboard in the computer did fail and I am unable to start the > computer. So my sensor net is going to be partical offline for the next > two days or so. My Borgarnes sensor is still online, far as I can tell, > but the web page is not going to get updated while the computer is down. > > Now I hope it stays quiet while I am fixing this. Last time I had a > hardware failure, I missed a mag 4.6 earthquake in Iceland. > > Regards. > --=20 > J=F3n Fr=EDmann > http://www.jonfr.com > http://earthquakes.jonfr.com > http://www.net303.net > http://www.mobile-coverage.com/ > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the=20 > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >=20 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Hardware failure From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Wed, 31 Oct 2007 03:54:11 +0000 Hi all EMSC says that the San Fransico earthquake was mb5.2. I am still hopeing that Iceland gets a quiet time until I am able to fix my earthquake computer, that is going to take at least two days. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: Brad Douglas rez@.................. Date: Wed, 31 Oct 2007 04:01:32 +0000 Yup! Initial M5.6 (9km) near the Hayward Step-over on the Calaveras fault. Strong rolling for a good 10 seconds, here in Fremont, but no real damage...Amazing for such the magnitude. I noticed that all of the telemetry frequencies stopped after the quake. On Tue, 2007-10-30 at 20:10 -0700, Rudy Norvelle wrote: > Just had a nice one here East of San Jose. I don't have a seismograph. It > lasted about 6-7 seconds. > > ----- Original Message ----- > From: > Subject: Re: Hardware failure > > > Hi Jon, Well, we know what happens when someone's sensor is down for > > equipment failure! Good luck with your repairs. > > Ted -- 73, de Brad KB8UYR/6 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Wed, 31 Oct 2007 04:05:08 +0000 Hi all There was also a Mw7.0 earthquake at PAGAN REG., N. MARIANA ISLANDS at 03:30 (sorry for caps). I still hope that Iceland stays quiet until I can fix my computer. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Hardware failure From: Pete Rowe ptrowe@......... Date: Tue, 30 Oct 2007 21:44:01 -0700 (PDT) I had lots of shaking here near Alum Rock. I was looking at my seismograph when it hit. I've seen about 10 aftershocks. None that I've felt. I have some broken glass to clean up but nothing major. Like John Muir once said: "earthquakes are grand and glorious things" Pete --- Stephen Hammond wrote: > Email From a friend -- > I am now living in North San Jose, just a few > hundred yards from > Milpitas. As you know by now, that is 11 miles from > the epicenter. It > was a sharp quake, with a lot of lateral motion, > lasting 15-20 seconds. > Since we were close and it was fairly shallow (5.5 > miles), it was not a > roller, but a long series of sharp jolts. The doors > opened on the china > hutch, some stuff fell of the desk, but nothing > broke. After the major > motion was over, it felt like we were on a boat on > the ocean with a long > series of rolling waves. > Steve Hammond PSN Aptos CA. > > -----Original Message----- > From: psn-l-request@.............. > [mailto:psn-l-request@............... > On Behalf Of Rudy Norvelle > Sent: Tuesday, October 30, 2007 8:10 PM > To: psn-l@.............. > Subject: Re: Hardware failure > > Just had a nice one here East of San Jose. I don't > have a seismograph. > It > lasted about 6-7 seconds. > > > ----- Original Message ----- > From: > To: > Sent: Tuesday, October 30, 2007 7:59 PM > Subject: Re: Hardware failure > > > > Hi Jon, Well, we know what happens when > someone's sensor is down for > > > equipment failure! Good luck with your repairs. > > Ted > > > > > > ----- Original Message ----- > > From: "Jón Frímann" > > To: "PSN-Postlist" > > Sent: Tuesday, October 30, 2007 8:46 PM > > Subject: Hardware failure > > > > > > Hi all > > > > My earthquake computer did suffer a huge hardware > failure. The > > motherboard in the computer did fail and I am > unable to start the > > computer. So my sensor net is going to be partical > offline for the > next > > two days or so. My Borgarnes sensor is still > online, far as I can > tell, > > but the web page is not going to get updated while > the computer is > down. > > > > Now I hope it stays quiet while I am fixing this. > Last time I had a > > hardware failure, I missed a mag 4.6 earthquake in > Iceland. > > > > Regards. > > -- > > Jón Frímann > > http://www.jonfr.com > > http://earthquakes.jonfr.com > > http://www.net303.net > > http://www.mobile-coverage.com/ > > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email > PSN-L-REQUEST@.............. with > > the body of the message (first line only): > unsubscribe > > See http://www.seismicnet.com/maillist.html for > more information. > > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email > PSN-L-REQUEST@.............. with the body of > the > > message (first line only): unsubscribe > > See http://www.seismicnet.com/maillist.html for > more information. > > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email > PSN-L-REQUEST@.............. with > the body of the message (first line only): > unsubscribe > See http://www.seismicnet.com/maillist.html for more > information. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email > PSN-L-REQUEST@.............. with > the body of the message (first line only): > unsubscribe > See http://www.seismicnet.com/maillist.html for more > information. > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: RE: Hardware failure From: "Kareem of Heyjoojoo.com" system98765@............. Date: Tue, 30 Oct 2007 22:39:46 -0700 felt it in my Xterra in Walnut Creek, Ca while stopped at a signal = light. I initially thought it was the wind but was unable to locate any branches being jostled by wind. But I did see the signal light bobbing up and = down. It did seem to last for quite some time in my vehicle, clear distinct jostling with several sharp pushes. My first such experience in a car. =20 -----Original Message----- From: psn-l-request@.............. [mailto:psn-l-request@............... = On Behalf Of Pete Rowe Sent: Tuesday, October 30, 2007 9:44 PM To: psn-l@.............. Subject: RE: Hardware failure I had lots of shaking here near Alum Rock. I was looking at my = seismograph when it hit. I've seen about 10 aftershocks. None that I've felt. I have some broken glass to clean up but nothing major. Like John Muir once said: "earthquakes are grand and glorious things" Pete --- Stephen Hammond wrote: > Email From a friend -- > I am now living in North San Jose, just a few hundred yards from=20 > Milpitas. As you know by now, that is 11 miles from the epicenter. =20 > It was a sharp quake, with a lot of lateral motion, lasting 15-20=20 > seconds. > Since we were close and it was fairly shallow (5.5 miles), it was not=20 > a roller, but a long series of sharp jolts. The doors opened on the=20 > china hutch, some stuff fell of the desk, but nothing broke. After the = > major motion was over, it felt like we were on a boat on the ocean=20 > with a long series of rolling waves. > Steve Hammond PSN Aptos CA. >=20 > -----Original Message----- > From: psn-l-request@.............. > [mailto:psn-l-request@............... > On Behalf Of Rudy Norvelle > Sent: Tuesday, October 30, 2007 8:10 PM > To: psn-l@.............. > Subject: Re: Hardware failure >=20 > Just had a nice one here East of San Jose. I don't have a=20 > seismograph. > It > lasted about 6-7 seconds. >=20 >=20 > ----- Original Message ----- > From: > To: > Sent: Tuesday, October 30, 2007 7:59 PM > Subject: Re: Hardware failure >=20 >=20 > > Hi Jon, Well, we know what happens when > someone's sensor is down for >=20 > > equipment failure! Good luck with your repairs. > > Ted > > > > > > ----- Original Message ----- > > From: "J=F3n Fr=EDmann" > > To: "PSN-Postlist" > > Sent: Tuesday, October 30, 2007 8:46 PM > > Subject: Hardware failure > > > > > > Hi all > > > > My earthquake computer did suffer a huge hardware > failure. The > > motherboard in the computer did fail and I am > unable to start the > > computer. So my sensor net is going to be partical > offline for the > next > > two days or so. My Borgarnes sensor is still > online, far as I can > tell, > > but the web page is not going to get updated while > the computer is > down. > > > > Now I hope it stays quiet while I am fixing this. > Last time I had a > > hardware failure, I missed a mag 4.6 earthquake in > Iceland. > > > > Regards. > > -- > > J=F3n Fr=EDmann > > http://www.jonfr.com > > http://earthquakes.jonfr.com > > http://www.net303.net > > http://www.mobile-coverage.com/ > > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email > PSN-L-REQUEST@.............. with > > the body of the message (first line only): > unsubscribe > > See http://www.seismicnet.com/maillist.html for > more information. > > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email > PSN-L-REQUEST@.............. with the body of the > > message (first line only): unsubscribe See=20 > > http://www.seismicnet.com/maillist.html for > more information. > >=20 >=20 >=20 > __________________________________________________________ >=20 > Public Seismic Network Mailing List (PSN-L) >=20 > To leave this list email > PSN-L-REQUEST@.............. with > the body of the message (first line only): > unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >=20 > __________________________________________________________ >=20 > Public Seismic Network Mailing List (PSN-L) >=20 > To leave this list email > PSN-L-REQUEST@.............. with > the body of the message (first line only): > unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >=20 __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com __________________________________________________________ Public Seismic Network Mailing List (PSN-L) http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: tchannel1@............ Date: Wed, 31 Oct 2007 07:36:25 -0600 Hi Rudy, Let build one for you together. This is a great hobby. Many resources here at PSN. Happy to help you. Ted ----- Original Message ----- From: "Rudy Norvelle" To: Sent: Tuesday, October 30, 2007 9:10 PM Subject: Re: Hardware failure > Just had a nice one here East of San Jose. I don't have a seismograph. > It lasted about 6-7 seconds. > > > ----- Original Message ----- > From: > To: > Sent: Tuesday, October 30, 2007 7:59 PM > Subject: Re: Hardware failure > > >> Hi Jon, Well, we know what happens when someone's sensor is down for >> equipment failure! Good luck with your repairs. >> Ted >> >> >> ----- Original Message ----- >> From: "Jón Frímann" >> To: "PSN-Postlist" >> Sent: Tuesday, October 30, 2007 8:46 PM >> Subject: Hardware failure >> >> >> Hi all >> >> My earthquake computer did suffer a huge hardware failure. The >> motherboard in the computer did fail and I am unable to start the >> computer. So my sensor net is going to be partical offline for the next >> two days or so. My Borgarnes sensor is still online, far as I can tell, >> but the web page is not going to get updated while the computer is down. >> >> Now I hope it stays quiet while I am fixing this. Last time I had a >> hardware failure, I missed a mag 4.6 earthquake in Iceland. >> >> Regards. >> -- >> Jón Frímann >> http://www.jonfr.com >> http://earthquakes.jonfr.com >> http://www.net303.net >> http://www.mobile-coverage.com/ >> >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with >> the body of the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. >> >> __________________________________________________________ >> >> Public Seismic Network Mailing List (PSN-L) >> >> To leave this list email PSN-L-REQUEST@.............. with the body of >> the message (first line only): unsubscribe >> See http://www.seismicnet.com/maillist.html for more information. >> > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of the > message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: USGS seems to be one hour off From: George Bush ke6pxp@....... Date: Wed, 31 Oct 2007 11:16:41 -0700 In processing the 5.6 Ml quake from Alum Rock yesterday I noticed while working in Winquake that the quake information download from USGS was one hour off. I had to go to the heading info and change the time from 04 UT to 03 UT??? This is the information from http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html (N. Cal Events) that Winquake uses. The main USGS web site has the correct time as does the automatic email notices they send me of new quakes. Could USGS REALLY be off one hour in the UT time listed? Or am I just doing something wrong??? George __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: USGS seems to be one hour off From: "Jerry Payton" gpayton880@....... Date: Wed, 31 Oct 2007 13:26:49 -0500 I've heard some people saying that their electronic devices (DVD player, VCR's & Etc.)have already done the "Fall Back" thing which is later this year than previously. Could that be you problem? regards, Jerry ----- Original Message ----- From: George Bush To: psn-l@.............. Sent: Wednesday, October 31, 2007 1:16 PM Subject: USGS seems to be one hour off In processing the 5.6 Ml quake from Alum Rock yesterday I noticed while working in Winquake that the quake information download from USGS was one hour off. I had to go to the heading info and change the time from 04 UT to 03 UT??? This is the information from http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html (N. Cal Events) that Winquake uses. The main USGS web site has the correct time as does the automatic email notices they send me of new quakes. Could USGS REALLY be off one hour in the UT time listed? Or am I just doing something wrong??? George __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
I've heard some people saying that their electronic devices (DVD = player,=20 VCR's & Etc.)have already done the "Fall Back" thing which is later = this=20 year than previously.  Could that be you problem?
 
regards,
Jerry
 
 
----- Original Message -----=20
From: George Bush =
Sent: Wednesday, October 31, 2007 1:16 PM
Subject: USGS seems to be one hour off

In processing the 5.6 Ml quake from Alum Rock yesterday I = noticed=20 while
working in Winquake that the quake information download from = USGS was=20 one
hour off. I had to go to the heading info and change the time = from 04 UT=20 to
03 UT??? This is the information from
http://qu= ake.wr.usgs.gov/recenteqs/Quakes/quakes0.html=20 (N. Cal Events) that
Winquake uses. The main USGS web site has the = correct=20 time as does the
automatic email notices they send me of new=20 quakes.

Could USGS REALLY be off one hour in the UT time listed? = Or am I=20 just doing
something=20 wrong???
George
___________________________________________________= _______

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: USGS seems to be one hour off From: George Bush ke6pxp@....... Date: Wed, 31 Oct 2007 12:02:36 -0700 I don't think so, it is the UTC from USGS that is wrong, not local time. At 01:26 PM 10/31/2007 -0500, you wrote: >>>> I've heard some people saying that their electronic devices (DVD player, VCR's & Etc.)have already done the "Fall Back" thing which is later this year than previously. Could that be you problem? regards, Jerry ----- Original Message ----- From: <George Bush To: <psn-l@.............. Sent: Wednesday, October 31, 2007 1:16 PM Subject: USGS seems to be one hour off In processing the 5.6 Ml quake from Alum Rock yesterday I noticed while working in Winquake that the quake information download from USGS was one hour off. I had to go to the heading info and change the time from 04 UT to 03 UT??? This is the information from <http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html (N. Cal Events) that Winquake uses. The main USGS web site has the correct time as does the automatic email notices they send me of new quakes. Could USGS REALLY be off one hour in the UT time listed? Or am I just doing something wrong??? George __________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email <PSN-L-REQUEST@.............. with the body of the message (first line only): unsubscribe See <http://www.seismicnet.com/maillist.html for more information. <<<<<<<< George Subject: Mass deflection weight test From: "meredith lamb" paleoartifact@......... Date: Wed, 31 Oct 2007 15:57:20 -0600 Hi all, Quite some time back, their was a reference (text) regarding a rough "deflection" test; where a small item (feather or something similar), was placed upon the mass of a vertical seismometer, and that displacement was a rough measure of (I think) of its crude sensitivity? Anybody have a knowledge of such; or a exact PSN email reference...or their experiences? Thanks, Meredith Lamb
Hi all,
 
Quite some time back, their was a reference (text) regarding a rough "deflection" test;
where a small item (feather or something similar), was placed upon the mass of a
vertical seismometer, and that displacement was a rough measure of (I think) of its
crude sensitivity?
 
Anybody have a knowledge of such; or a exact PSN email reference...or their
experiences?
 
Thanks, Meredith Lamb
 
 
 
 
Subject: Re: Mass deflection weight test From: "Bob Hammond" propgrinder@......... Date: Wed, 31 Oct 2007 14:06:44 -0800 http://www.geophys.uni-stuttgart.de/oldwww/seismometry/man_html/node41.html Bob PSN-Alaska http://wulik.com On Oct 31, 2007 1:57 PM, meredith lamb wrote: > Hi all, > > Quite some time back, their was a reference (text) regarding a rough > "deflection" test; > where a small item (feather or something similar), was placed upon the > mass of a > vertical seismometer, and that displacement was a rough measure of (I > think) of its > crude sensitivity? > > Anybody have a knowledge of such; or a exact PSN email reference...or > their > experiences? > > Thanks, Meredith Lamb > > > > >
 
Bob
PSN-Alaska
On Oct 31, 2007 1:57 PM, meredith lamb <paleoartifact@.........> wrote:
Hi all,
 
Quite some time back, their was a reference (text) regarding a rough "deflection" test;
where a small item (feather or something similar), was placed upon the mass of a
vertical seismometer, and that displacement was a rough measure of (I think) of its
crude sensitivity?
 
Anybody have a knowledge of such; or a exact PSN email reference...or their
experiences?
 
Thanks, Meredith Lamb
 
 
 
 

Subject: Re: Mass deflection weight test From: tchannel1@............ Date: Wed, 31 Oct 2007 16:16:03 -0600 Hi Meredith, I have seen a similar test, using a small folded piece of = paper on a thread. The thread was pulled which removed the small piece = of paper from the pendulum arm. This was one of the AS1 wed sites, I think. Ted ----- Original Message -----=20 From: meredith lamb=20 To: psn-l@................. Sent: Wednesday, October 31, 2007 3:57 PM Subject: Mass deflection weight test Hi all, Quite some time back, their was a reference (text) regarding a rough = "deflection" test;=20 where a small item (feather or something similar), was placed upon the = mass of a vertical seismometer, and that displacement was a rough measure of (I = think) of its crude sensitivity? Anybody have a knowledge of such; or a exact PSN email reference...or = their experiences? Thanks, Meredith Lamb
Hi Meredith,  I have seen a = similar test,=20 using a small folded piece of paper on a thread.  The thread was = pulled=20 which removed the small piece of paper from the pendulum = arm.
This was one of the AS1 wed sites, I=20 think.
Ted
----- Original Message -----
From:=20 meredith lamb
Sent: Wednesday, October 31, = 2007 3:57=20 PM
Subject: Mass deflection weight = test

Hi all,
 
Quite some time back, their was a reference (text) regarding a = rough=20 "deflection" test;
where a small item (feather or something similar), was placed = upon the=20 mass of a
vertical seismometer, and that displacement was a rough measure = of (I=20 think) of its
crude sensitivity?
 
Anybody have a knowledge of such; or a exact PSN email = reference...or=20 their
experiences?
 
Thanks, Meredith Lamb
 
 
 
 
Subject: Re: Mass deflection weight test From: ChrisAtUpw@....... Date: Wed, 31 Oct 2007 20:01:30 EDT In a message dated 31/10/2007, paleoartifact@......... writes: Quite some time back, their was a reference (text) regarding a rough "deflection" test; where a small item (feather or something similar), was placed upon the mass of a vertical seismometer, and that displacement was a rough measure of (I think) of its crude sensitivity? Hi Meredith, Weight lift calibration is used on AS-1 seismometers. See links from _http://jclahr.com/science/psn/as1/_ (http://jclahr.com/science/psn/as1/) Far from being crude, it should be accurate at least to a few%. I favour using weights made from known lengths and diameters of copper wire, bent to give three point contacts. You can use fine nylon fishing line to lift the weight. Sewing thread tends to twist. You can also calibrate horizontal seismometers using a wire weight suspended on a 90 deg V silk / cotton thread. Having set the system up, you release the mass by burning the thread. Regards, Chris
In a message dated 31/10/2007, paleoartifact@......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Quite some time back, their was a reference (text) regarding a rough=20 "deflection" test;
where a small item (feather or something similar), was placed upon th= e=20 mass of a
vertical seismometer, and that displacement was a rough measure of (I= =20 think) of its
crude sensitivity?
Hi Meredith,
 
    Weight lift calibration is used on AS-1=20 seismometers. See links from  http://jclahr.com/science/psn/as= 1/
    Far from being crude, it should be accurate at=20 least to a few%. I favour using weights made from known lengths and diameter= s of=20 copper wire, bent to give three point contacts. You can use fine nylon fishi= ng=20 line to lift the weight. Sewing thread tends to twist.
    You can also calibrate horizontal seismometers=20 using a wire weight suspended on a 90 deg V silk / cotton thread. Having set= the=20 system up, you release the mass by burning the thread.  
 
    Regards,
 
    Chris
Subject: Earthquake experiences From: "Kay Wyatt" kwyatt@............. Date: Wed, 31 Oct 2007 19:37:47 -0700 Folks, I confess that I enjoyed hearing about experiences that many of you = shared regarding yesterday's earthquakes. One question that I am asked = time after time by our young budding students is "what does an = earthquake feel like". Having come from Oklahoma and recently retired = to Oregon, being in an earthquake is not one of my personal experiences. If any of you would like to share your personal experiences with my = students, I would be delighted to hear from you. You can email me = directly at kwyatt@............. if you wish. Thanks, also, to all of you who have provided feedback regarding = seismometers suitable in an educational environment. Kay Wyatt
Folks,
 
I confess that I enjoyed hearing about experiences = that many=20 of you shared regarding yesterday's earthquakes.  One question that = I am=20 asked time after time by our young budding students is "what does an = earthquake=20 feel like".  Having come from Oklahoma and recently retired to = Oregon,=20 being in an earthquake is not one of my personal = experiences.
 
If any of you would like to share your personal = experiences=20 with my students, I would be delighted to hear from you.  You can = email me=20 directly at kwyatt@............. if=20 you wish.
 
Thanks, also, to all of you who have provided = feedback=20 regarding seismometers suitable in an educational = environment.
 
Kay Wyatt
 
Subject: Re: Earthquake experiences From: "Bob Hammond" propgrinder@......... Date: Wed, 31 Oct 2007 18:53:43 -0800 Kay, Here's a link to my web page and personal accounts of people feeling the M 7.9 (revised to M 8.2, I think) earthquake of November 3, 2002. The first one is my wife's personal account of the quake in our house in Fairbanks. The rest of the felt reports were compiled by a friend who was the Denali National Park Geologist at the time of the quake. http://wulik.com/descript.htm This might be of interest and use to your students. Regards, Bob Hammond PSN-Alaska http://wulik.com On Oct 31, 2007 6:37 PM, Kay Wyatt wrote: > Folks, > > I confess that I enjoyed hearing about experiences that many of you shared > regarding yesterday's earthquakes. One question that I am asked time after > time by our young budding students is "what does an earthquake feel like". > Having come from Oklahoma and recently retired to Oregon, being in an > earthquake is not one of my personal experiences. > > If any of you would like to share your personal experiences with my > students, I would be delighted to hear from you. You can email me directly > at kwyatt@............. if you wish. > > Thanks, also, to all of you who have provided feedback regarding > seismometers suitable in an educational environment. > > Kay Wyatt > > Kay,

Here's a link to my web page and personal accounts of people feeling the M 7.9 (revised to M 8.2, I think) earthquake of November 3, 2002.  The first one is my wife's personal account of the quake in our house in Fairbanks.  The rest of the felt reports were compiled by a friend who was the Denali National Park Geologist at the time of the quake.

http://wulik.com/descript.htm

This might be of interest and use to your students.

Regards,

Bob Hammond
PSN-Alaska
http://wulik.com



On Oct 31, 2007 6:37 PM, Kay Wyatt <kwyatt@.............> wrote:
Folks,
 
I confess that I enjoyed hearing about experiences that many of you shared regarding yesterday's earthquakes.  One question that I am asked time after time by our young budding students is "what does an earthquake feel like".  Having come from Oklahoma and recently retired to Oregon, being in an earthquake is not one of my personal experiences.
 
If any of you would like to share your personal experiences with my students, I would be delighted to hear from you.  You can email me directly at kwyatt@............. if you wish.
 
Thanks, also, to all of you who have provided feedback regarding seismometers suitable in an educational environment.
 
Kay Wyatt
 

Subject: Re: Mass deflection weight test From: "meredith lamb" paleoartifact@......... Date: Wed, 31 Oct 2007 22:00:19 -0600 Hi Chris and all, Thanks for all the helpful references! I was looking for a test that would roughly indicate pivot sensitivity; but where, there is no pickup coil (electronics), dampening etc....i.e., a "base" test of the instruments pivot/boom/mass in its unfinished state, just to evaluate whether the setup is worth further pursuing. After going through John Lahr's web site...I "gather" that if; say a bond paper item of about ~2" x 1/2" is laid atop the mass, and one can VISUALLY see a immediate deflection of the mass; then the sensitivity must be quite good. Does this sound logical; or maybe I'am missing something? The test vertical instrument here is using acouple hard drive disk/s inner hole circle surfaces with the axis being a 1/4" rod...i.e, a rolling pivot; laid out somewhat like the Georgia Tech vertical "demonstrator" seismometer...but not using flexure strips as the pivot. I could see roughly a initial 1/16" deflection. Meredith Lamb On 10/31/07, ChrisAtUpw@....... wrote: > > In a message dated 31/10/2007, paleoartifact@......... writes: > > Quite some time back, their was a reference (text) regarding a rough > "deflection" test; > where a small item (feather or something similar), was placed upon the > mass of a > vertical seismometer, and that displacement was a rough measure of (I > think) of its > crude sensitivity? > > Hi Meredith, > > Weight lift calibration is used on AS-1 seismometers. See links from > http://jclahr.com/science/psn/as1/ > Far from being crude, it should be accurate at least to a few%. I > favour using weights made from known lengths and diameters of copper wire, > bent to give three point contacts. You can use fine nylon fishing line to > lift the weight. Sewing thread tends to twist. > You can also calibrate horizontal seismometers using a wire weight > suspended on a 90 deg V silk / cotton thread. Having set the system up, you > release the mass by burning the thread. > > Regards, > > Chris >
Hi Chris and all,
 
Thanks for all the helpful references!  I was looking for a test that would roughly indicate
pivot sensitivity; but where, there is no pickup coil (electronics), dampening etc....i.e.,
a "base" test of the instruments pivot/boom/mass in its unfinished state, just to
evaluate whether the setup is worth further pursuing.
 
After going through John Lahr's web site...I "gather" that if; say a bond paper item of
about ~2" x 1/2" is laid atop the mass, and one can VISUALLY see a immediate
deflection of the mass; then the sensitivity must be quite good.  Does this sound
logical; or maybe I'am missing something?
 
The test vertical instrument here is using acouple hard drive disk/s inner hole circle surfaces
with the axis being a 1/4" rod...i.e, a rolling pivot; laid out somewhat like the Georgia
Tech vertical "demonstrator" seismometer...but not using flexure strips as the pivot.
I could see roughly a initial 1/16" deflection. 
 
Meredith Lamb

 
On 10/31/07, ChrisAtUpw@....... <ChrisAtUpw@.......> wrote:
In a message dated 31/10/2007, paleoartifact@......... writes:
Quite some time back, their was a reference (text) regarding a rough "deflection" test;
where a small item (feather or something similar), was placed upon the mass of a
vertical seismometer, and that displacement was a rough measure of (I think) of its
crude sensitivity?
Hi Meredith,
 
    Weight lift calibration is used on AS-1 seismometers. See links from  http://jclahr.com/science/psn/as1/
    Far from being crude, it should be accurate at least to a few%. I favour using weights made from known lengths and diameters of copper wire, bent to give three point contacts. You can use fine nylon fishing line to lift the weight. Sewing thread tends to twist.
    You can also calibrate horizontal seismometers using a wire weight suspended on a 90 deg V silk / cotton thread. Having set the system up, you release the mass by burning the thread.  
 
    Regards,
 
    Chris

Subject: Re: Mass deflection weight test From: John Lahr johnjan@........ Date: Wed, 31 Oct 2007 22:24:01 -0700 Meredith, The paper I use is 2 cm by 1 cm, with an estimated weight of 0.0338 gm. I don't think the deflection of the boom could be seen with the eye, but I haven't tried. John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 01 Nov 2007 12:45:36 +0000 Hi all I am almost done with my repairs. Now I just have to re-install windows 2000 and setup the computer. On a side note, the serial port (Com1 & 2) are dissapearing from the motherboard. The new motherboard that I got dosen't even have a Com port, I needed to get a extra plug for that. I do however have usb to serial converter, but in the future I guess earthquake hardware needs to have usb ports also. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: ian ian@........... Date: Thu, 01 Nov 2007 13:13:37 +0000 you just missed a mag 3.6 in your back yard at 12:47 gmt! To replace com ports, you could look at terminal servers, ie: http://www.perle.com/ They come with software that makes them look like com ports. Might be a bit pricey though. Cheers Ian Jón Frímann wrote: >Hi all > >I am almost done with my repairs. Now I just have to re-install windows >2000 and setup the computer. > >On a side note, the serial port (Com1 & 2) are dissapearing from the >motherboard. The new motherboard that I got dosen't even have a Com >port, I needed to get a extra plug for that. I do however have usb to >serial converter, but in the future I guess earthquake hardware needs to >have usb ports also. > >Regards. > > -- you just missed a mag 3.6 in your back yard at 12:47 gmt!

To replace com ports, you could look at terminal servers, ie: http://www.perle.com/  They come with software that makes them look like com ports.  Might be a bit pricey though.

Cheers

Ian

Jón Frímann wrote:
Hi all

I am almost done with my repairs. Now I just have to re-install windows
2000 and setup the computer.

On a side note, the serial port (Com1 & 2) are dissapearing from the
motherboard. The new motherboard that I got dosen't even have a Com
port, I needed to get a extra plug for that. I do however have usb to
serial converter, but in the future I guess earthquake hardware needs to
have usb ports also.

Regards.

--

Subject: Re: Hardware failure From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 01 Nov 2007 13:18:29 +0000 Hi I just noticed the ML3.6 earthquake, only my hvt station did miss it. My Borgarnes station is still working even if it is not online, it did record it. I will get the earthquake manually later today. But this always happens when something fails.... Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Earthquake experiences From: "Jerry Payton" gpayton880@....... Date: Thu, 1 Nov 2007 08:48:33 -0500 Thanks, also, to all of you who have provided feedback regarding seismometers suitable in an educational environment. Dr. Wyatt, please share any other sources of seismometers give to you, other those already mentioned: AS-1, VM II and etc., to us low budgeted "Amateur Nerds" out here. Thanks for your devotion to the children. Regards, Jerry
Thanks, also, to all of you who have provided = feedback=20 regarding seismometers suitable in an educational = environment.
 
Dr. Wyatt, please share any other sources of = seismometers give to you, other those already mentioned: AS-1, VM II and = etc.,=20 to us low budgeted "Amateur Nerds" out here.  Thanks for your = devotion to=20 the children. 
 
Regards,
Jerry
Subject: Re: Mass deflection weight test From: "meredith lamb" paleoartifact@......... Date: Thu, 1 Nov 2007 09:26:53 -0600 Hi John, OK on the correction. Per your web site, that particular "item" had more to it, than what we've texted here of course. I used a mass head reference object and eyeballed it when putting the paper size I used down on the mass. Suspect one might see the deflection of the AS-1 mass also if they "look" for it as described, but without dampening or the coil hooked up; in free mass response. Its rather tough to gauge any verticals sensitivity without further completing the whole assembly....they are much more difficult to adjust and maintain overall. Meredith On 10/31/07, John Lahr wrote: > > Meredith, > > The paper I use is 2 cm by 1 cm, with an estimated weight of 0.0338 > gm. I don't think the > deflection of the boom could be seen with the eye, but I haven't tried. > > John > > >
Hi John,
 
OK on the correction.  Per your web site, that particular "item" had more to it, than
what we've texted here of course.  I used a mass head reference object and eyeballed it
when putting the paper size I used down on the mass.  Suspect one might see the
deflection of the AS-1 mass also if they "look" for it as described, but without 
dampening or the coil hooked up; in free mass response.  Its rather tough to
gauge any verticals sensitivity without further completing the whole assembly....they
are much more difficult to adjust and maintain overall. 
 
Meredith             

 
On 10/31/07, John Lahr <johnjan@........> wrote:
Meredith,

The paper I use is 2 cm by 1 cm, with an estimated weight of 0.0338
gm.  I don't think the
deflection of the boom could be seen with the eye, but I haven't tried.

John


Subject: Fwd: RE: Re: USGS seems to be one hour off From: John Lahr johnjan@........ Date: Thu, 01 Nov 2007 08:39:58 -0700 Here's the word that I received from Menlo Park on the timing error. There seems to be no error at all on the web site. If the events from this page: http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html which shows the time in PDT is imported into WinQuake and converted by WinQuake into UT, then the conversion could be in error if the computer has already switched from PDT to PST. I'm running some computers with Win98SE and have yet to figure out how to change the switch over time from PDT to PST. Cheers, John >Hi John, > >I don't understand the problem. The link he references >http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html >shows time in PDT, which is correct. The page >http://quake.wr.usgs.gov/recenteqs/Quakes/nc40204628.htm >shows both UTC and PDT, which are both correct. > >-David > >------------------------------------------------------- > >-----Original Message----- >From: John Lahr [mailto:johnjan@......... >Sent: Wednesday, October 31, 2007 3:09 PM >To: David O >Subject: Fwd: Re: USGS seems to be one hour off > >FYI, > >John > > >X-Original-To: jclahr > >Delivered-To: jclahr@.................. > >From: "Jerry Payton" > >To: > >Subject: Re: USGS seems to be one hour off > >Date: Wed, 31 Oct 2007 13:26:49 -0500 > >X-Mailer: Microsoft Outlook Express 6.00.2900.3138 > >Reply-To: psn-l@.............. > >Sender: psn-l-request@.............. > >X-RCPT-TO: > >X-SA-Poll-Id: 1193855489617..428290727..1..1193855209000 > >X-SA-USERIDNR: 3394894 > >X-SA-MPREASON: sender enabled (gpayton880@........ > > > >I've heard some people saying that their electronic devices (DVD > >player, VCR's & Etc.)have already done the "Fall Back" thing which > >is later this year than previously. Could that be you problem? > > > >regards, > >Jerry > > > > > >----- Original Message ----- > >From: George Bush > >To: psn-l@.............. > >Sent: Wednesday, October 31, 2007 1:16 PM > >Subject: USGS seems to be one hour off > > > >In processing the 5.6 Ml quake from Alum Rock yesterday I noticed while > >working in Winquake that the quake information download from USGS was one > >hour off. I had to go to the heading info and change the time from 04 UT to > >03 UT??? This is the information from > >http://quak > e.wr.usgs.gov/recenteqs/Quakes/quakes0.html > >(N. Cal Events) that > >Winquake uses. The main USGS web site has the correct time as does the > >automatic email notices they send me of new quakes. > > > >Could USGS REALLY be off one hour in the UT time listed? Or am I just doing > >something wrong??? > >George > >__________________________________________________________ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: RE: Re: USGS seems to be one hour off From: "Erich Kern" efkern@............. Date: Thu, 1 Nov 2007 09:00:43 -0700 Another possibility is that the UK switched from BST (British Summer = Time) to standard time (GMT) this past Sunday. If someone was looking at = the UK domestic clock instead of the UTC / GMT clock, that may account = for it. Not saying that's what happened, just a possibility. Erich ----- Original Message -----=20 From: John Lahr=20 To: psn-l@................. Sent: Thursday, November 01, 2007 8:39 AM Subject: Fwd: RE: Re: USGS seems to be one hour off Here's the word that I received from Menlo Park on the timing error. There seems to be no error at all on the web site. If the events from this page: http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html which shows the time in PDT is imported into WinQuake and converted by WinQuake into UT, then the conversion could be in error if the computer has already switched from PDT to PST. I'm running some computers with Win98SE and have yet to figure out how to change the switch over time from PDT to PST. Cheers, John >Hi John, > >I don't understand the problem. The link he references >http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html >shows time in PDT, which is correct. The page >http://quake.wr.usgs.gov/recenteqs/Quakes/nc40204628.htm >shows both UTC and PDT, which are both correct. > >-David > >------------------------------------------------------- > >-----Original Message----- >From: John Lahr [mailto:johnjan@......... >Sent: Wednesday, October 31, 2007 3:09 PM >To: David O >Subject: Fwd: Re: USGS seems to be one hour off > >FYI, > >John > > >X-Original-To: jclahr > >Delivered-To: jclahr@.................. > >From: "Jerry Payton" > >To: > >Subject: Re: USGS seems to be one hour off > >Date: Wed, 31 Oct 2007 13:26:49 -0500 > >X-Mailer: Microsoft Outlook Express 6.00.2900.3138 > >Reply-To: psn-l@.............. > >Sender: psn-l-request@.............. > >X-RCPT-TO: > >X-SA-Poll-Id: 1193855489617..428290727..1..1193855209000 > >X-SA-USERIDNR: 3394894 > >X-SA-MPREASON: sender enabled (gpayton880@........ > > > >I've heard some people saying that their electronic devices (DVD > >player, VCR's & Etc.)have already done the "Fall Back" thing which > >is later this year than previously. Could that be you problem? > > > >regards, > >Jerry > > > > > >----- Original Message ----- > >From: George Bush > >To: psn-l@.............. > >Sent: Wednesday, October 31, 2007 1:16 PM > >Subject: USGS seems to be one hour off > > > >In processing the 5.6 Ml quake from Alum Rock yesterday I noticed = while > >working in Winquake that the quake information download from USGS was = one > >hour off. I had to go to the heading info and change the time from 04 = UT to > >03 UT??? This is the information from > >http://quak=20 > e.wr.usgs.gov/recenteqs/Quakes/quakes0.html > >(N. Cal Events) that > >Winquake uses. The main USGS web site has the correct time as does = the > >automatic email notices they send me of new quakes. > > > >Could USGS REALLY be off one hour in the UT time listed? Or am I just = doing > >something wrong??? > >George > >__________________________________________________________ __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
 
Another possibility is that the UK switched from = BST=20 (British Summer Time) to standard time (GMT) this past Sunday. If = someone was=20 looking at the UK domestic clock instead of the UTC / GMT clock, that = may=20 account for it.
 
Not saying that's what happened, just a=20 possibility.
 
Erich
 
 
----- Original Message -----=20
From: John Lahr =
Sent: Thursday, November 01, 2007 8:39 AM
Subject: Fwd: RE: Re: USGS seems to be one hour = off

Here's the word that I received from Menlo Park on the = timing=20 error.

There seems to be no error at all on the web = site.

If the=20 events from this page:
http://qu= ake.wr.usgs.gov/recenteqs/Quakes/quakes0.html
which=20 shows the time in PDT is imported into WinQuake and converted
by = WinQuake=20 into UT, then the conversion could be in error if the
computer has = already=20 switched from PDT to PST.  I'm running some
computers with = Win98SE and=20 have yet to figure out how to change the
switch over time from PDT to = PST.

Cheers,
John

>Hi John,
>
>I don't=20 understand the problem. The link he=20 references
>http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html<= BR>>shows=20 time in PDT, which is correct.  The=20 page
>http://quake.wr.usgs.gov/recenteqs/Quakes/nc40204628.htm
&= gt;shows=20 both UTC and PDT, which are both=20 correct.
>
>-David
>
>---------------------------= ----------------------------
>
>-----Original=20 Message-----
>From: John Lahr = [mailto:johnjan@.........
>Sent:=20 Wednesday, October 31, 2007 3:09 PM
>To: David O
>Subject: = Fwd: Re:=20 USGS seems to be one hour=20 off
>
>FYI,
>
>John
>
> = >X-Original-To:=20 jclahr
> >Delivered-To: jclahr@..................>=20 >From: "Jerry Payton" <gpayton880@.......>
> = >To:=20 <psn-l@..............>
>= =20 >Subject: Re: USGS seems to be one hour off
> >Date: Wed, 31 = Oct=20 2007 13:26:49 -0500
> >X-Mailer: Microsoft Outlook Express=20 6.00.2900.3138
> >Reply-To: psn-l@..............
> = >Sender:=20 psn-l-request@...............
>=20 >X-RCPT-TO: <johnjan@........>
>=20 >X-SA-Poll-Id: 1193855489617..428290727..1..1193855209000
>=20 >X-SA-USERIDNR: 3394894
> >X-SA-MPREASON: sender enabled (gpayton880@.......)
> = >
>=20 >I've heard some people saying that their electronic devices = (DVD
>=20 >player, VCR's & Etc.)have already done the "Fall Back" thing=20 which
> >is later this year than previously.  Could that = be you=20 problem?
> >
> >regards,
> >Jerry
>=20 >
> >
> >----- Original Message -----
> = >From:=20 <George">mailto:ke6pxp@.......>George= =20 Bush
> >To: <psn-l@..............">mailto:psn-l@we= btronics.com>psn-l@..............
>=20 >Sent: Wednesday, October 31, 2007 1:16 PM
> >Subject: USGS = seems to=20 be one hour off
> >
> >In processing the 5.6 Ml quake = from=20 Alum Rock yesterday I noticed while
> >working in Winquake that = the=20 quake information download from USGS was one
> >hour off. I had = to go=20 to the heading info and change the time from 04 UT to
> >03 = UT??? This=20 is the information from
> ><http://qua= k">http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html>http://quak<= /A>=20
> e.wr.usgs.gov/recenteqs/Quakes/quakes0.html
> >(N. Cal = Events)=20 that
> >Winquake uses. The main USGS web site has the correct = time as=20 does the
> >automatic email notices they send me of new = quakes.
>=20 >
> >Could USGS REALLY be off one hour in the UT time = listed? Or am=20 I just doing
> >something wrong???
> >George
>=20 >__________________________________________________________

__________________________________________________________

Public= =20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information. Subject: Re: Fwd: RE: Re: USGS seems to be one hour off From: George Bush ke6pxp@....... Date: Thu, 01 Nov 2007 09:51:25 -0700 I agree, there is no error on the web site. Also I know about the PDT time problem, but this is a USGS file and it reports time in UT and it was wrong when downloaded into Winquake???? At 08:39 AM 11/1/2007 -0700, you wrote: >Here's the word that I received from Menlo Park on the timing error. > >There seems to be no error at all on the web site. > >If the events from this page: >http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html >which shows the time in PDT is imported into WinQuake and converted >by WinQuake into UT, then the conversion could be in error if the >computer has already switched from PDT to PST. I'm running some >computers with Win98SE and have yet to figure out how to change the >switch over time from PDT to PST. > >Cheers, >John > >>Hi John, >> >>I don't understand the problem. The link he references >>http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html >>shows time in PDT, which is correct. The page >>http://quake.wr.usgs.gov/recenteqs/Quakes/nc40204628.htm >>shows both UTC and PDT, which are both correct. >> >>-David >> >>------------------------------------------------------- >> >>-----Original Message----- >>From: John Lahr [mailto:johnjan@......... >>Sent: Wednesday, October 31, 2007 3:09 PM >>To: David O >>Subject: Fwd: Re: USGS seems to be one hour off >> >>FYI, >> >>John >> >> >X-Original-To: jclahr >> >Delivered-To: jclahr@.................. >> >From: "Jerry Payton" >> >To: >> >Subject: Re: USGS seems to be one hour off >> >Date: Wed, 31 Oct 2007 13:26:49 -0500 >> >X-Mailer: Microsoft Outlook Express 6.00.2900.3138 >> >Reply-To: psn-l@.............. >> >Sender: psn-l-request@.............. >> >X-RCPT-TO: >> >X-SA-Poll-Id: 1193855489617..428290727..1..1193855209000 >> >X-SA-USERIDNR: 3394894 >> >X-SA-MPREASON: sender enabled (gpayton880@........ >> > >> >I've heard some people saying that their electronic devices (DVD >> >player, VCR's & Etc.)have already done the "Fall Back" thing which >> >is later this year than previously. Could that be you problem? >> > >> >regards, >> >Jerry >> > >> > >> >----- Original Message ----- >> >From: George Bush >> >To: psn-l@.............. >> >Sent: Wednesday, October 31, 2007 1:16 PM >> >Subject: USGS seems to be one hour off >> > >> >In processing the 5.6 Ml quake from Alum Rock yesterday I noticed while >> >working in Winquake that the quake information download from USGS was one >> >hour off. I had to go to the heading info and change the time from 04 UT to >> >03 UT??? This is the information from >> >http://quak >> e.wr.usgs.gov/recenteqs/Quakes/quakes0.html >> >(N. Cal Events) that >> >Winquake uses. The main USGS web site has the correct time as does the >> >automatic email notices they send me of new quakes. >> > >> >Could USGS REALLY be off one hour in the UT time listed? Or am I just doing >> >something wrong??? >> >George >> >__________________________________________________________ > > >__________________________________________________________ > >Public Seismic Network Mailing List (PSN-L) > >To leave this list email PSN-L-REQUEST@.............. with >the body of the message (first line only): unsubscribe >See http://www.seismicnet.com/maillist.html for more information. > George __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Hardware failure From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Thu, 01 Nov 2007 17:36:36 +0000 Hi all My earthquake computer is back in action. More powerful then ever, it now r= uns AMD 64bit 1.8Ghz CPU with 1GB ram. I did record the M3.6 earthquake on the Borgarnes station, I have send in t= he data now. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Fwd: RE: Re: USGS seems to be one hour off From: Stephen & Kathy skmort@............ Date: Thu, 01 Nov 2007 11:12:30 -0700 Here is a link to a win98 daylight savings patch that worked for me! http://www.intelliadmin.com/DaylightSavingNotice.asp?File=DaylightSavingFix98.exe Stephen PSN Station # 55 John Lahr wrote: > Here's the word that I received from Menlo Park on the timing error. > > There seems to be no error at all on the web site. > > If the events from this page: > http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html > which shows the time in PDT is imported into WinQuake and converted > by WinQuake into UT, then the conversion could be in error if the > computer has already switched from PDT to PST. I'm running some > computers with Win98SE and have yet to figure out how to change the > switch over time from PDT to PST. > > Cheers, > John > >> Hi John, >> >> I don't understand the problem. The link he references >> http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html >> shows time in PDT, which is correct. The page >> http://quake.wr.usgs.gov/recenteqs/Quakes/nc40204628.htm >> shows both UTC and PDT, which are both correct. >> >> -David >> >> ------------------------------------------------------- >> >> -----Original Message----- >> From: John Lahr [mailto:johnjan@......... >> Sent: Wednesday, October 31, 2007 3:09 PM >> To: David O >> Subject: Fwd: Re: USGS seems to be one hour off >> >> FYI, >> >> John >> >> >X-Original-To: jclahr >> >Delivered-To: jclahr@.................. >> >From: "Jerry Payton" >> >To: >> >Subject: Re: USGS seems to be one hour off >> >Date: Wed, 31 Oct 2007 13:26:49 -0500 >> >X-Mailer: Microsoft Outlook Express 6.00.2900.3138 >> >Reply-To: psn-l@.............. >> >Sender: psn-l-request@.............. >> >X-RCPT-TO: >> >X-SA-Poll-Id: 1193855489617..428290727..1..1193855209000 >> >X-SA-USERIDNR: 3394894 >> >X-SA-MPREASON: sender enabled (gpayton880@........ >> > >> >I've heard some people saying that their electronic devices (DVD >> >player, VCR's & Etc.)have already done the "Fall Back" thing which >> >is later this year than previously. Could that be you problem? >> > >> >regards, >> >Jerry >> > >> > >> >----- Original Message ----- >> >From: George Bush >> >To: psn-l@.............. >> >Sent: Wednesday, October 31, 2007 1:16 PM >> >Subject: USGS seems to be one hour off >> > >> >In processing the 5.6 Ml quake from Alum Rock yesterday I noticed while >> >working in Winquake that the quake information download from USGS >> was one >> >hour off. I had to go to the heading info and change the time from >> 04 UT to >> >03 UT??? This is the information from >> >http://quak >> e.wr.usgs.gov/recenteqs/Quakes/quakes0.html >> >(N. Cal Events) that >> >Winquake uses. The main USGS web site has the correct time as does the >> >automatic email notices they send me of new quakes. >> > >> >Could USGS REALLY be off one hour in the UT time listed? Or am I >> just doing >> >something wrong??? >> >George >> >__________________________________________________________ > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of > the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > Here is a link to a win98 daylight savings patch that worked for me!

http://www.intelliadmin.com/DaylightSavingNotice.asp?File=DaylightSavingFix98.exe

   Stephen
   PSN Station # 55

John Lahr wrote:
Here's the word that I received from Menlo Park on the timing error.

There seems to be no error at all on the web site.

If the events from this page:
http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html
which shows the time in PDT is imported into WinQuake and converted
by WinQuake into UT, then the conversion could be in error if the
computer has already switched from PDT to PST.  I'm running some
computers with Win98SE and have yet to figure out how to change the
switch over time from PDT to PST.

Cheers,
John

Hi John,

I don't understand the problem. The link he references
http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html
shows time in PDT, which is correct.  The page
http://quake.wr.usgs.gov/recenteqs/Quakes/nc40204628.htm
shows both UTC and PDT, which are both correct.

-David

-------------------------------------------------------

-----Original Message-----
From: John Lahr [mailto:johnjan@........]
Sent: Wednesday, October 31, 2007 3:09 PM
To: David O
Subject: Fwd: Re: USGS seems to be one hour off

FYI,

John

>X-Original-To: jclahr
>Delivered-To: jclahr@..................
>From: "Jerry Payton" <gpayton880@.......>
>To: <psn-l@..............>
>Subject: Re: USGS seems to be one hour off
>Date: Wed, 31 Oct 2007 13:26:49 -0500
>X-Mailer: Microsoft Outlook Express 6.00.2900.3138
>Reply-To: psn-l@..............
>Sender: psn-l-request@..............
>X-RCPT-TO: <johnjan@........>
>X-SA-Poll-Id: 1193855489617..428290727..1..1193855209000
>X-SA-USERIDNR: 3394894
>X-SA-MPREASON: sender enabled (gpayton880@.......)
>
>I've heard some people saying that their electronic devices (DVD
>player, VCR's & Etc.)have already done the "Fall Back" thing which
>is later this year than previously.  Could that be you problem?
>
>regards,
>Jerry
>
>
>----- Original Message -----
>From: <mailto:ke6pxp@.......>George Bush
>To: <mailto:psn-l@..............>psn-l@..............
>Sent: Wednesday, October 31, 2007 1:16 PM
>Subject: USGS seems to be one hour off
>
>In processing the 5.6 Ml quake from Alum Rock yesterday I noticed while
>working in Winquake that the quake information download from USGS was one
>hour off. I had to go to the heading info and change the time from 04 UT to
>03 UT??? This is the information from
><http://quake.wr.usgs.gov/recenteqs/Quakes/quakes0.html>http://quak e.wr.usgs.gov/recenteqs/Quakes/quakes0.html
>(N. Cal Events) that
>Winquake uses. The main USGS web site has the correct time as does the
>automatic email notices they send me of new quakes.
>
>Could USGS REALLY be off one hour in the UT time listed? Or am I just doing
>something wrong???
>George
>__________________________________________________________


__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.


Subject: Re: Mass deflection weight test From: John Lahr johnjan@........ Date: Thu, 01 Nov 2007 11:46:23 -0700 Hi Meredith, There are two issues involved. One is the absolute deflection due to adding a weight and the other is the electronic response, once some motion sensor has been applied. The absolute deflection when a weight is added is equivalent to changing the acceleration of gravity, which is also equivalent to applying a constant acceleration. The deflection will be a function of the free period; the greater the period the greater the deflection. This assumes that there is no friction at the hinge. To test various hinges, one would want a very long period pendulum. Then a very small weight should cause a known, specific deflection. If there is less deflection, then the cause must be friction. Usually the term sensitivity relates to the electronic output per unit of motion, measured as displacement or velocity or acceleration at a given period. Cheers, John At 08:26 AM 11/1/2007, you wrote: >Hi John, > >OK on the correction. Per your web site, that particular "item" had >more to it, than >what we've texted here of course. I used a mass head reference >object and eyeballed it >when putting the paper size I used down on the mass. Suspect one >might see the >deflection of the AS-1 mass also if they "look" for it as described, >but without >dampening or the coil hooked up; in free mass response. Its rather tough to >gauge any verticals sensitivity without further completing the whole >assembly....they >are much more difficult to adjust and maintain overall. > >Meredith > > >On 10/31/07, John Lahr <johnjan@........> wrote: >Meredith, > >The paper I use is 2 cm by 1 cm, with an estimated weight of 0.0338 >gm. I don't think the >deflection of the boom could be seen with the eye, but I haven't tried. > >John > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mass deflection weight test From: ChrisAtUpw@....... Date: Thu, 1 Nov 2007 15:03:20 EDT In a message dated 01/11/2007, johnjan@........ writes: There are two issues involved. One is the absolute deflection due to adding a weight and the other is the electronic response, once some motion sensor has been applied. Hi John, I find it easier to cut a measured length of Copper wire and bend it so that it gives a three point contact - a small U loop and a larger U loop at right angles to it. You can look up the weight either in wire tables or by the diameter for that gauge and the density of Copper. Regards, Chris
In a message dated 01/11/2007, johnjan@........ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>There=20 are two issues involved.  One is the absolute deflection due to=20
adding a weight and the other is the electronic response, once some=20
motion sensor has been applied.
Hi John,
 
    I find it easier to cut a measured length of Co= pper=20 wire and bend it so that it gives a three point contact - a small U loop and= a=20 larger U loop at right angles to it. You can look up the weight either in wi= re=20 tables or by the diameter for that gauge and the density of Copper.
 
    Regards,
 
    Chris
Subject: Re: Mass deflection weight test From: John Lahr johnjan@........ Date: Thu, 01 Nov 2007 12:49:36 -0700 That's a good idea. Is there a good wire table on line that can be used? John At 12:03 PM 11/1/2007, you wrote: >In a message dated 01/11/2007, johnjan@........ writes: >There are two issues involved. One is the absolute deflection due to >adding a weight and the other is the electronic response, once some >motion sensor has been applied. > >Hi John, > > I find it easier to cut a measured length of Copper wire and > bend it so that it gives a three point contact - a small U loop and > a larger U loop at right angles to it. You can look up the weight > either in wire tables or by the diameter for that gauge and the > density of Copper. > > Regards, > > Chris __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mass deflection weight test From: "meredith lamb" paleoartifact@......... Date: Thu, 1 Nov 2007 16:19:19 -0600 Hi John, OK on the email. In a "maintenance" sense, it would seem appropriate to use the known test results, per each seismometer; to check on the pivot wear sporadically. I would think that if would be helpful. I would guess that knife edge, razor edge pivots would show the most wear/friction, followed by perhaps ball bearings....with my test hinge having its own particular potential problems, like lint/dirt getting in the rolling path etc. Perhaps the best would be a true crossed rod pivot....but as far as a vertical seismo...I've yet to "find" the "common" material to be able to do that. Meredith On 11/1/07, John Lahr wrote: > > Hi Meredith, > > There are two issues involved. One is the absolute deflection due to > adding a weight and the other is the electronic response, once some > motion sensor has been applied. > > The absolute deflection when a weight is added is equivalent to > changing the acceleration of gravity, which is also equivalent to > applying a constant acceleration. The deflection will be a function > of the free period; the greater the period the greater the > deflection. This assumes that there is no friction at the hinge. To > test various hinges, one would want a very long period > pendulum. Then a very small weight should cause a known, specific > deflection. If there is less deflection, then the cause must be friction. > > Usually the term sensitivity relates to the electronic output per > unit of motion, measured as displacement or velocity or acceleration > at a given period. > > Cheers, > John > > >
Hi John,
 
OK on the email.  In a "maintenance" sense, it would seem appropriate to
use the known test results, per each seismometer; to check on the pivot
wear sporadically.  I would think that if would be helpful.  I would guess that
knife edge, razor edge pivots would show the most wear/friction, followed by
perhaps ball bearings....with my test hinge having its own particular potential
problems, like lint/dirt getting in the rolling path etc.  Perhaps the best would
be a true crossed rod pivot....but as far as a vertical seismo...I've yet to "find" the
"common" material to be able to do that.
 
Meredith
 
 
On 11/1/07, John Lahr <johnjan@........> wrote:
Hi Meredith,

There are two issues involved.  One is the absolute deflection due to
adding a weight and the other is the electronic response, once some
motion sensor has been applied.

The absolute deflection when a weight is added is equivalent to
changing the acceleration of gravity, which is also equivalent to
applying a constant acceleration.  The deflection will be a function
of the free period; the greater the period the greater the
deflection.  This assumes that there is no friction at the hinge.  To
test various hinges, one would want a very long period
pendulum.  Then a very small weight should cause a known, specific
deflection.  If there is less deflection, then the cause must be friction.

Usually the term sensitivity relates to the electronic output per
unit of motion, measured as displacement or velocity or acceleration
at a given period.

Cheers,
John


Subject: Re: Mass deflection weight test From: "Geoff" gmvoeth@........... Date: Thu, 1 Nov 2007 16:29:55 -0700 Yes, there is this very large OLD geospace ( Texas I think ) Seismometer that weighs about 500 lbs avodupoise and you test it by taking a known weight ( 1gm ( metric ) ball bearing ) on a string ( dental floss ). using the string you place the weight upon an adjusting screw mounted to the suspended mass then let it rest till all motion ceases then you yank on the string to instantly remove the small weight. This will simulate an impules of a one way acceleration relating directly to the mass removed. You can then look at the trace and see if free period and damping and sensitivity are ok or adjustments or repairs are necessary. This barontosaurous of geophones is actually quite good but need a special home underground or dampness ( exposure ) will destroy it. It is also extremely difficult to move around being 500lbs. sort of like one of those mystical magical squeegee sharpening machines you boss sometimes wants you to find. If it happens to weigh 500 lbs and is bolted down it might take all day to deal with. I have the best way to simulate this with smaller geophones is to pulse it with a battery limiting the current flow ( resistor ) to whatever produces 100 or so microvolts across the geophone. You just need to be consistant with the chosen form of testing. If you really want to get it ringing with minimal damping zap ( momentarily not continuous ) it with a 9V battery. ( magnet spring type only ) Regards; geoff ----- Original Message ----- From: "meredith lamb" To: Sent: Wednesday, October 31, 2007 2:57 PM Subject: Mass deflection weight test > Hi all, > > Quite some time back, their was a reference (text) regarding a rough > "deflection" test; > where a small item (feather or something similar), was placed upon the mass > of a > vertical seismometer, and that displacement was a rough measure of (I think) > of its > crude sensitivity? > > Anybody have a knowledge of such; or a exact PSN email reference...or their > experiences? > > Thanks, Meredith Lamb > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mass deflection weight test From: "Geoff" gmvoeth@........... Date: Thu, 1 Nov 2007 16:33:14 -0700 CRC handbook from the library or possibly arrl. ----- Original Message ----- From: "John Lahr" To: Sent: Thursday, November 01, 2007 12:49 PM Subject: Re: Mass deflection weight test > That's a good idea. Is there a good wire table on line that can be used? > > John > > At 12:03 PM 11/1/2007, you wrote: >>In a message dated 01/11/2007, johnjan@........ writes: >>There are two issues involved. One is the absolute deflection due to >>adding a weight and the other is the electronic response, once some >>motion sensor has been applied. >> >>Hi John, >> >> I find it easier to cut a measured length of Copper wire and >> bend it so that it gives a three point contact - a small U loop and >> a larger U loop at right angles to it. You can look up the weight >> either in wire tables or by the diameter for that gauge and the >> density of Copper. >> >> Regards, >> >> Chris > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mass deflection weight test From: "Jerry Payton" gpayton880@....... Date: Thu, 1 Nov 2007 18:48:55 -0500 http://www.powerstream.com/Wire_Size.htm http://en.wikipedia.org/wiki/American_wire_gauge These site may help also. Regards, Jerry ----- Original Message ----- From: Geoff To: psn-l@.............. Sent: Thursday, November 01, 2007 6:33 PM Subject: Re: Mass deflection weight test CRC handbook from the library or possibly arrl. ----- Original Message ----- From: "John Lahr" To: Sent: Thursday, November 01, 2007 12:49 PM Subject: Re: Mass deflection weight test > That's a good idea. Is there a good wire table on line that can be used? > > John > > At 12:03 PM 11/1/2007, you wrote: >>In a message dated 01/11/2007, johnjan@........ writes: >>There are two issues involved. One is the absolute deflection due to >>adding a weight and the other is the electronic response, once some >>motion sensor has been applied. >> >>Hi John, >> >> I find it easier to cut a measured length of Copper wire and >> bend it so that it gives a three point contact - a small U loop and >> a larger U loop at right angles to it. You can look up the weight >> either in wire tables or by the diameter for that gauge and the >> density of Copper. >> >> Regards, >> >> Chris > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
http://www.powerstream.= com/Wire_Size.htm
 
http://en.wikip= edia.org/wiki/American_wire_gauge
 
These site may help also.
 
Regards,
Jerry
 
 
----- Original Message -----=20
From: Geoff
Sent: Thursday, November 01, 2007 6:33 PM
Subject: Re: Mass deflection weight test

CRC handbook from the library or possibly = arrl.

-----=20 Original Message -----
From: "John Lahr" <johnjan@........>
To: <psn-l@..............>
Sent= :=20 Thursday, November 01, 2007 12:49 PM
Subject: Re: Mass deflection = weight=20 test


> That's a good idea.  Is there a good wire = table on=20 line that can be used?
>
> John
>
> At 12:03 = PM=20 11/1/2007, you wrote:
>>In a message dated 01/11/2007, johnjan@........ = writes:
>>There are=20 two issues involved.  One is the absolute deflection due=20 to
>>adding a weight and the other is the electronic response, = once=20 some
>>motion sensor has been = applied.
>>
>>Hi=20 John,
>>
>>     I find it easier = to cut a=20 measured length of Copper wire and
>> bend it so that it gives = a three=20 point contact - a small U loop and
>> a larger U loop at right = angles=20 to it. You can look up the weight
>> either in wire tables or = by the=20 diameter for that gauge and the
>> density of=20 Copper.
>>
>>    =20 Regards,
>>
>>     Chris
> =
>=20
> = __________________________________________________________
>=20
> Public Seismic Network Mailing List (PSN-L)
>
> To = leave=20 this list email PSN-L-REQUEST@............... with=20
> the body of the message (first line only): unsubscribe
> = See http://www.seismicnet.co= m/maillist.html=20 for more=20 information.
>
_________________________________________________= _________

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: Mass deflection weight test From: ChrisAtUpw@....... Date: Thu, 1 Nov 2007 19:50:44 EDT In a message dated 01/11/2007, gmvoeth@........... writes: I have the best way to simulate this with smaller geophones is to pulse it with a battery limiting the current flow ( resistor ) to whatever produces 100 or so microvolts across the geophone. Hi Geoff, One other way to do it is to use a capacitor with a resistor in series. You charge up the capacitor to a known voltage and simply short it across the geophone, seismometer etc. This supplies a known charge I x T to the system and the resistor damps any oscillations. Regards, Chris Chapman
In a message dated 01/11/2007, gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I have=20 the best way to simulate this with smaller geophones is to pulse it with a= =20 battery limiting
the current flow ( resistor ) to whatever produces 100= or=20 so microvolts across the geophone.
Hi Geoff,
 
    One other way to do it is to use a capacitor wi= th a=20 resistor in series. You charge up the capacitor to a known voltage and simpl= y=20 short it across the geophone, seismometer etc. This supplies a known charge=20= I x=20 T to the system and the resistor damps any oscillations. 
 
    Regards,
 
    Chris Chapman
Subject: Re: Mass deflection weight test From: Mark Robinson mark.robinson@............... Date: Fri, 02 Nov 2007 13:34:18 +1300 ChrisAtUpw@....... wrote: > In a message dated 01/11/2007, johnjan@........ writes: > > There are two issues involved. One is the absolute deflection due to > adding a weight and the other is the electronic response, once some > motion sensor has been applied. > I find it easier to cut a measured length of Copper wire and bend it > so that it gives a three point contact - a small U loop and a larger U > loop at right angles to it. You can look up the weight either in wire > tables or by the diameter for that gauge and the density of Copper. Pharmacists usually have a good accurate scale and will weigh things for me if I provide them with some conversation which goes beyond their daily fare of pills and potions. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mass deflection weight test From: ChrisAtUpw@....... Date: Thu, 1 Nov 2007 22:13:54 EDT In a message dated 01/11/2007, johnjan@........ writes: That's a good idea. Is there a good wire table on line that can be used? > I find it easier to cut a measured length of Copper wire and > bend it so that it gives a three point contact - a small U loop and > a larger U loop at right angles to it. You can look up the weight > either in wire tables or by the diameter for that gauge and the > density of Copper. Hi John, The density of Copper is 8.933 gm / ml. A wire table is at _http://en.wikipedia.org/wiki/American_wire_gauge_ (http://en.wikipedia.org/wiki/American_wire_gauge) Regards, Chris Chapman
In a message dated 01/11/2007, johnjan@........ writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>That's a=20 good idea.  Is there a good wire table on line that can be=20 used?

>     I find it easier to cut a measured le= ngth=20 of Copper wire and
> bend it so that it gives a three point contact= - a=20 small U loop and
> a larger U loop at right angles to it. You can l= ook=20 up the weight
> either in wire tables or by the diameter for that g= auge=20 and the
> density of Copper.
Hi John,
 
    The density of Copper is 8.933 gm / ml.
 
    A wire table is at http://en.wikipedi= a.org/wiki/American_wire_gauge
 
    Regards,
 
    Chris Chapman
Subject: Re: Mass deflection weight test From: "Geoff" gmvoeth@........... Date: Thu, 1 Nov 2007 22:45:15 -0700 Hello Chris; Affirmative, I like that idea. I just found while playing with different configurations what I thought to be a bad geophone. Nothing I would do would get me a good signal from the geophone. After a couple days of considering digging it up I decided to run the signal straight through from the geophone to the A/D converter. I found there to be in the ground a high frequency > 10 Hz that was overdriving my preamplifier essentially "jamming" the amplifier. I solved this problem simply by filtering harshly with a LPF at about 3 seconds 0.3333... Hz. This will allow me to equalize the signal down to this freq. Conquering the noise also has allowed me to achieve a stable baseline something I have been fretting over the past several years :-( Now I have at a gain of 10,000 and down to DC the ability to see signals between DC and 3 or 4 Hz. If I can ever get back to playing around with that positive feedback arrangement I will let you know what happens. At the moment I had to go back to using the Diff amp to solve the noise problem and get back online. I cant tell you how terribly noisy my location is. With a gain of only about X1000 the geophone was putting out a human artifact that drove the amplifier way beyond its limits. When I put the N=4 LPF with 2.0 Hz Fc The noise was greatly reduced indicating it was above that. When A high freq does this all other signals become distorted or so I found. It seems solving the noise makes everything behave in a more predictable fashion. That was how i spent Halloween between the amplifier and monster shows on tv. Hope you had a nicer holiday. One Other Thing, I have found there to be a common mode capacitance between the shield and wires to the geophone of about 6.74 e-9 farads and would like to hear your comments about proper grounding to the amplifier as it relates to this common mode figure. By common mode i mean if you short the two geophone wires together then measure between the two wires and the shield between the geophone and the house this 6.74nf is what i get after subtracting maybe 0.04nf of meter ( DMM ) capacitance. I know this is important but have no idea the proper way to deal with it. The geophone cable is about 35 to 40 feet long and is 100% shielded with copper foil and infused wuth what looks to be silicone grease for underground buriel. Regards; geoff ----- Original Message ----- From: To: Sent: Thursday, November 01, 2007 4:50 PM Subject: Re: Mass deflection weight test > > In a message dated 01/11/2007, gmvoeth@........... writes: > > I have the best way to simulate this with smaller geophones is to pulse it > with a battery limiting > the current flow ( resistor ) to whatever produces 100 or so microvolts > across the geophone. > > > > Hi Geoff, > > One other way to do it is to use a capacitor with a resistor in series. > You charge up the capacitor to a known voltage and simply short it across the > geophone, seismometer etc. This supplies a known charge I x T to the system > and the resistor damps any oscillations. > > Regards, > > Chris Chapman > > > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Mass deflection weight test From: "Geoff" gmvoeth@........... Date: Thu, 1 Nov 2007 23:03:18 -0700 Hello Cruel World; My geophone here at GVA is buried underground so I can do no direct testing. It seems that Chris's Capacitor test may very well one of the best. But i would not use any resistors I would simply short it across the geophone as it sits attached to the amplifier, let the circuit do whatever so you can see its normal response to the stimulus. Here I am plagued by static electricity so I would be careful there. You might damage the amplifier or geophone insulation if you present somehow 100,000V static charge instead of only the 1 or so volts desired depending upon the value of the capacitor. I used to work in FAT on DEC ( Digital Equipment Corp now owned by HP ) Digital Data comm boards (1980s :-( ) and would see field service people get returns that had a dendrite of chips fail due to static discharges like lightning. Not just the input chip but fanning out several chips deep. I see these computers with big plexiglass holes in the sides. It seems to me any kind of EMP like lightning can get in there and do some damage. You really need a faraday shield to protect anything today. regards geoff ----- Original Message ----- From: "Mark Robinson" To: Sent: Thursday, November 01, 2007 5:34 PM Subject: Re: Mass deflection weight test > ChrisAtUpw@....... wrote: >> In a message dated 01/11/2007, johnjan@........ writes: >> >> There are two issues involved. One is the absolute deflection due to >> adding a weight and the other is the electronic response, once some >> motion sensor has been applied. >> I find it easier to cut a measured length of Copper wire and bend it >> so that it gives a three point contact - a small U loop and a larger U >> loop at right angles to it. You can look up the weight either in wire >> tables or by the diameter for that gauge and the density of Copper. > > Pharmacists usually have a good accurate scale and will weigh things for me if > I provide them with some conversation which goes beyond their daily fare of > pills and potions. > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Signal To Noise Ratio From: Bob Hancock carpediem1@......... Date: Sat, 03 Nov 2007 13:16:50 -0700 When downloading events through IRIS =AD Wilber II, I noticed that they liste= d the signal to noise ratio. Most of the time the number was =AD1; however, there were other numbers listed. I have some questions and hopefully someone can answer them. 1. What is the significance of signal to noise ratio when looking at earthquakes? 2. How is signal to noise ratio computed? 3. What are the ideal numbers to look for and at what point does the data become unusable? Thanks Bob Hancock Signal To Noise Ratio When = downloading events through IRIS – Wilber II, I noticed that they liste= d the signal to noise ratio.  Most of the time the number was –1;= however, there were other numbers listed.  I have some questions and h= opefully someone can answer them.


1.  What is the significance of signal to noise ratio when looking at = earthquakes?

2.  How is signal to noise ratio computed?

3.  What are the ideal numbers to look for and at what point does the = data become unusable?

Thanks

Bob Hancock

 Subject: Re: Signal To Noise Ratio From: "Geoff" gmvoeth@........... Date: Sat, 3 Nov 2007 16:26:09 -0700 All I know is signal to noise ratio is one of the most important characteristics of any sensor. You want the sensor noise and electronic noise to reside lower than the ground noise in the most quiet of areas. I think a supercooled sensor is the only way to do this unless the natural noises are great. Pioneer had this thing called a supertuner which would let me see radio waves bouncing off ion trails left by meteors. Built a 3 element yagi-uda adjustable so it could be tuned anywhere in the FM band and between that antenna and the supertuner I had great fun listening into FM stations over 1000 miles away when certain meteors streaked below about 45deg elevation normal to my location. I think the supertuner used the then newly built gallium arsinide front ends that were the best signal to noise ratio of the time 1990 ?? That is the kind of hardware we need too. I think there exists the possibility of somehow demodulating the noise to witness a general increase in its overall amplitude to receive signals lower then the noise yet since it sums with the noise will present itself as an increase in the noise but you can not see the actual signal doing this. They do this in signal analysis by integrating signals over long periods of time like 24 hours just to look for one kind of signal or other. It seems you can see signals up to -40Db below the background??? To me that is a level 0.01 the actual noise itself. ??? Wish i knew more but when the USA lables one mentally ill the relm of meaningful technical research and development can only be learned through the process of educational/informational osmosis. :-) geoff ----- Original Message ----- From: "Bob Hancock" To: "PSN" Sent: Saturday, November 03, 2007 1:16 PM Subject: Signal To Noise Ratio When downloading events through IRIS ­ Wilber II, I noticed that they listed the signal to noise ratio. Most of the time the number was ­1; however, there were other numbers listed. I have some questions and hopefully someone can answer them. 1. What is the significance of signal to noise ratio when looking at earthquakes? 2. How is signal to noise ratio computed? 3. What are the ideal numbers to look for and at what point does the data become unusable? Thanks Bob Hancock __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Signal To Noise Ratio From: "Geoff" gmvoeth@........... Date: Sat, 3 Nov 2007 16:50:57 -0700 Hello Bob; Have you ever heard of a low noise GaAs op amp that is designed to work like a op177G (typical opamp) or ?? Signal to noise ratio should be easily found in google I think it simply is like Expectided MDL signal power / Ubiquitous Noise Power The higher the ratio the better the whatever. Possibly expressed in db. For power thats 10Log(Sig/Noi). The noise would be the reference point. If you can get a 120db (coopers) I think youd be in fat city. The higher the overall s/n ratio the smaller signals they can see. Like someone sneezing next door. :-) geoff ----- Original Message ----- From: "Bob Hancock" To: "PSN" Sent: Saturday, November 03, 2007 1:16 PM Subject: Signal To Noise Ratio When downloading events through IRIS ­ Wilber II, I noticed that they listed the signal to noise ratio. Most of the time the number was ­1; however, there were other numbers listed. I have some questions and hopefully someone can answer them. 1. What is the significance of signal to noise ratio when looking at earthquakes? 2. How is signal to noise ratio computed? 3. What are the ideal numbers to look for and at what point does the data become unusable? Thanks Bob Hancock __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Signal To Noise Ratio From: Bob Hancock carpediem1@......... Date: Sat, 03 Nov 2007 17:06:31 -0700 Hi Geoff - Unfortunately, my knowledge of electronics is less than stellar. I am working at understanding concepts of seismology. As for electronics.....well, I'll leave that for someone else. I was hoping to find an answer that would allow me to apply the SNR numbers I see to the practical side of seismology. I understand the simple concept of an amplifier (boosting a signal), but unfortunately, I have no working knowledge of their innards or how the individual parts work by themselves and in concert with each other. Bob H On 11/3/07 4:50 PM, "Geoff" wrote: > Hello Bob; >=20 > Have you ever heard of a low noise > GaAs op amp that is designed to work > like a op177G (typical opamp) or ?? >=20 > Signal to noise ratio should be easily found > in google I think it simply is like > Expectided MDL signal power / Ubiquitous Noise Power > The higher the ratio the better the whatever. > Possibly expressed in db. > For power thats 10Log(Sig/Noi). > The noise would be the reference point. > If you can get a 120db (coopers) > I think youd be in fat city. > The higher the overall s/n ratio > the smaller signals they can see. > Like someone sneezing next door. >=20 > :-) > geoff >=20 > ----- Original Message ----- > From: "Bob Hancock" > To: "PSN" > Sent: Saturday, November 03, 2007 1:16 PM > Subject: Signal To Noise Ratio >=20 >=20 > When downloading events through IRIS =AD Wilber II, I noticed that they lis= ted > the signal to noise ratio. Most of the time the number was =AD1; however, > there were other numbers listed. I have some questions and hopefully > someone can answer them. >=20 >=20 > 1. What is the significance of signal to noise ratio when looking at > earthquakes? >=20 > 2. How is signal to noise ratio computed? >=20 > 3. What are the ideal numbers to look for and at what point does the dat= a > become unusable? >=20 > Thanks >=20 > Bob Hancock >=20 >=20 >=20 > __________________________________________________________ >=20 > Public Seismic Network Mailing List (PSN-L) >=20 > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. >=20 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Signal To Noise Ratio From: Brad Douglas rez@.................. Date: Sat, 03 Nov 2007 17:48:29 -0700 On Sat, 2007-11-03 at 16:50 -0700, Geoff wrote: > Hello Bob; > > Have you ever heard of a low noise > GaAs op amp that is designed to work > like a op177G (typical opamp) or ?? GaAs FETs go that low in frequency and still yield gain and stability? Lowest I've ever done is 144MHz and that was straining the chip, yielding decreased gain (but still higher than any non-GaAs FET). If my understanding is correct, GaAs is "saturated" above 2GHz, making them ideal for microwave LNAs. Or have I entirely missed the point? :-) > Signal to noise ratio should be easily found > in google I think it simply is like > Expectided MDL signal power / Ubiquitous Noise Power > The higher the ratio the better the whatever. > Possibly expressed in db. > For power thats 10Log(Sig/Noi). That's mostly accurate: http://en.wikipedia.org/wiki/Signal-to-noise_ratio -- 73, de Brad KB8UYR/6 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Mag 5.8 earthquake in Antarctica From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Sun, 04 Nov 2007 21:04:12 +0000 Hi all There was an unusual earthquake in Antartica at 20:35, the earthquake was mb5.8 (early resaults) and the depth is 40 km according to the same early resaults. This is quite unusual, since there isn't any known faults there, I think. This might be volcano related, but I don't have any way to confirm it. Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Signal To Noise Ratio From: "Geoff" gmvoeth@........... Date: Tue, 6 Nov 2007 02:26:21 -0700 Interesting Mr. Brad Douglas; Im not sure about any of this but it would be nice to understand what is in the front end of the first PIONEER SUPERTUNERS. I think there are very low noise devices out there but it would be useless to use them in any high noise environment like ShortWave radio. All one really needs is to keep the combined circuit noise below the ambient noise or you will have a hard time seeing the those signals riding near the natural grass. The astronomers will supercool their preamps to eliminate noise and do any broadband shifting right in the front end. I think i would like to have an Astronomical expert making the electronics for my geophone but fear I would not be able to afford the liquid helium to keep it in operation. :-) Regards; geoff ----- Original Message ----- From: "Brad Douglas" To: Sent: Saturday, November 03, 2007 5:48 PM Subject: Re: Signal To Noise Ratio > On Sat, 2007-11-03 at 16:50 -0700, Geoff wrote: >> Hello Bob; >> >> Have you ever heard of a low noise >> GaAs op amp that is designed to work >> like a op177G (typical opamp) or ?? > > GaAs FETs go that low in frequency and still yield gain and stability? > Lowest I've ever done is 144MHz and that was straining the chip, > yielding decreased gain (but still higher than any non-GaAs FET). If my > understanding is correct, GaAs is "saturated" above 2GHz, making them > ideal for microwave LNAs. > > Or have I entirely missed the point? :-) > >> Signal to noise ratio should be easily found >> in google I think it simply is like >> Expectided MDL signal power / Ubiquitous Noise Power >> The higher the ratio the better the whatever. >> Possibly expressed in db. >> For power thats 10Log(Sig/Noi). > > That's mostly accurate: > http://en.wikipedia.org/wiki/Signal-to-noise_ratio > > > -- > 73, de Brad KB8UYR/6 > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: Signal To Noise Ratio From: "Geoff" gmvoeth@........... Date: Tue, 6 Nov 2007 02:44:42 -0700 Hello Bob; I guess I am no scientist because the basic idea seems so simple to me that the signal to noise ratio can be somewhat arbitrary in your selection of reference points. You pick a signal level of interest and make sure your S/N ratio is such you will actually see the signal of interest. Any signal with like 6dbv X2 above the noise should be visible. One that is 120db is a million times the noise. It all depends upon what noise you mean and to me that is overall "S" noise. White Noise. Like on an "S" meter. As any bubblehead should know ( Sub-Sailor ) S/N is one of the sinle most important facets of any sensor device. I am amazed that an NMR machine can rattle a mole of atoms in a strong magnetic gradient and listen to them ring With various frequencies in response. They must have a receiver unlike anything I am familiar with. I would start by looking at the USGS noise levels then figure out what S/N ratio needs to be before designing a serious device. The place i live in here is so terribly noisy I need to filter right at the preamp to keep my electronics from being jammed by higher vehicular frequencies. It probably would do me little good to invest in high class low noise amplifiers at my current location. The overall noise of your system needs to be lower than the grass. To the point of diminishing returns. The grass being the noise in the ground at whatever bandwidth during a quiet sunday morning like 3am local time. Most people do not build their own devices and do not concern themselves with this thought. There are many types of noise but the only one of interest is the overall results. I cant wait until Universal Entropy Reaches Maximum That will be the quietist time of all. Regards geoff ----- Original Message ----- From: "Bob Hancock" To: Sent: Saturday, November 03, 2007 5:06 PM Subject: Re: Signal To Noise Ratio Hi Geoff - Unfortunately, my knowledge of electronics is less than stellar. I am working at understanding concepts of seismology. As for electronics.....well, I'll leave that for someone else. I was hoping to find an answer that would allow me to apply the SNR numbers I see to the practical side of seismology. I understand the simple concept of an amplifier (boosting a signal), but unfortunately, I have no working knowledge of their innards or how the individual parts work by themselves and in concert with each other. Bob H On 11/3/07 4:50 PM, "Geoff" wrote: > Hello Bob; > > Have you ever heard of a low noise > GaAs op amp that is designed to work > like a op177G (typical opamp) or ?? > > Signal to noise ratio should be easily found > in google I think it simply is like > Expectided MDL signal power / Ubiquitous Noise Power > The higher the ratio the better the whatever. > Possibly expressed in db. > For power thats 10Log(Sig/Noi). > The noise would be the reference point. > If you can get a 120db (coopers) > I think youd be in fat city. > The higher the overall s/n ratio > the smaller signals they can see. > Like someone sneezing next door. > > :-) > geoff > > ----- Original Message ----- > From: "Bob Hancock" > To: "PSN" > Sent: Saturday, November 03, 2007 1:16 PM > Subject: Signal To Noise Ratio > > > When downloading events through IRIS ­ Wilber II, I noticed that they listed > the signal to noise ratio. Most of the time the number was ­1; however, > there were other numbers listed. I have some questions and hopefully > someone can answer them. > > > 1. What is the significance of signal to noise ratio when looking at > earthquakes? > > 2. How is signal to noise ratio computed? > > 3. What are the ideal numbers to look for and at what point does the data > become unusable? > > Thanks > > Bob Hancock > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Unknown event From: tchannel1@............ Date: Tue, 6 Nov 2007 11:19:29 -0700 Hi Folks, I got the 5.4 Guerrero, Mexico, here in Boise, at about = 06:42, It was followed be another one, at about 06:52 UTC. I can't = identify this one? =20 Thanks, Ted
Hi Folks,  I got the 5.4 Guerrero, = Mexico,=20 here in Boise, at about 06:42,  It was followed be another one, at = about=20 06:52 UTC.   I can't identify this one? 
 
Thanks, Ted
Subject: Re: Unknown event From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= jonfr@......... Date: Tue, 06 Nov 2007 18:31:27 +0000 Hi There was a ML4.3 earthquake at 06:41 in SERAM, INDONESIA (sorry for the caps). Maybe it was that one ? More details. http://www.emsc-csem.org/index.php?page=3Dcurrent&sub=3Ddetail&id=3D69262 Regards. --=20 J=F3n Fr=EDmann http://www.jonfr.com http://earthquakes.jonfr.com http://www.net303.net http://www.mobile-coverage.com/ __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Guerrero Mexico 5.4M From: tchannel1@............ Date: Tue, 6 Nov 2007 13:48:56 -0700 Hi Folks, I now think my unidentified event was just the remainder of = the 5.4, not a separate event. Thanks, Ted
Hi Folks,  I now think my = unidentified event=20 was just the remainder of the 5.4,  not a separate = event.  =20 Thanks,
Ted
Subject: noise and seismometer performance From: Randall Peters PETERS_RD@.......... Date: Wed, 07 Nov 2007 08:38:31 -0500 Various of the latest list-serve comments are concerned with SNR of instruments, so I've decided to describe a few of the things I've learned after about two decades of intense research on the non-ideal properties of mechanical oscillators. To the extent that linear approximations are meaningful (not really true at low frequencies and small amplitudes), the theoretical description of a seismometer's performance is straightforward, and treated in the paper I wrote, titled "Seismometer performance based on a simple theory of instrument-generated noise equivalent power", online at http://physics.mercer.edu/hpage/inep/inep.html If you look at this paper, pay close attention to the difference between conventional instruments that output the time derivative of mass position (velocity) and the VolksMeter (position). Because every seismometer (as Einstein well understood, because of inertia) responds only to acceleration (tilt being a special case), the conventional instruments measure the 'jerk' of the earth, whereas the VolksMeter measures its acceleration. The two systems offer synergetic possibilities--jerk sensors better for the high frequency range and acceleration sensors better for the low frequency range. Some of the recent comments are concerned wtih noise equivalent power generated by electronic devices. Such noise is inevitable and temperature plays a dominant role in the electronics. It has been understood for decades from the time of Johnson, and its treatment is straightforward. Insofar as temperature dependence of the mass/spring of a seismometer is concerned, this is an entirely different issue. A common calculation of the Brownian motion of the seismic mass (which suggests a simple advanatage to operating at lower temperatures) is meaningless. The equation employed is based on the equipartition theorem, which does not apply because the number of 'degrees of freedom' in the non-ideal spring is much greater than the number two that is assumed; i.e., one term for the potential energy and one term for the kinetic energy (each contribution one-half kT of thermal energy), naively assuming a harmonic potential (based on Hooke's law which is known to be not-obeyed). For those interested in some of the foundation physics responsible for seismometer difficulties due to mesoanelastic complexity, I wrote the article "Anharmonic Oscillator" for the the 10th Ed. of McGraw Hill's Encyclopedia of Science and Technology. Typing into Google the expression damping anharmonicity -- will return the Access Science quote of the first part of this article. To read the whole article you will have to either (i) pay something to McGraw Hill or (ii) contact me and I will return a copy by email attachment. Internal friction is intimately related to the instrument-generated noise equivalent power and readers may find interesting the following paper: "Harmonic oscillator potential to describe internal dissipation", online at http://arxiv.org/html/physics/0307016 Seismometer theory is hard enough to understand, even when based on linear (overly idealized) approximations. Even the professional seismologists, along with myself, have been guilty of erroneous assumptions. I believe, after more than a decade of trying to acquire self-consistency in at least the linear descriptions--that I'm getting close to a first-order approximate description that is valid for the first-cut of instrument design. A full understanding of the real-world properties of seismometers is truly impossible at this point in time, because we don't understand internal friction from first principles. In the article that I wrote, titled "Friction at the mesoscale", Contemporary Physics vol. 45, no. 6, pp. 475-490 (2004), I included a quote from a Nature article (Kessler) that speaks to the matter; i.e., "It is one of the dirty little secrets of physics that while we physicists can tell you a lot about quarks, quasars, and other exotica; there still is no universally accepted explanation of the basic laws of friction". As noted in the paper, I had actually contemplated a title "Friction, friction everywhere but in our understanding". Randall psn-l-digest-request@.............. wrote: > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 1 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Re: Signal To Noise Ratio > From: "Geoff" > Date: Tue, 6 Nov 2007 02:26:21 -0700 > > Interesting Mr. Brad Douglas; > > Im not sure about any of this > but it would be nice to understand > what is in the front end of the > first PIONEER SUPERTUNERS. > > I think there are very low noise devices out there > but it would be useless to use them > in any high noise environment like > ShortWave radio. > > All one really needs is to keep the > combined circuit noise below the > ambient noise or you will have > a hard time seeing the those signals > riding near the natural grass. > > The astronomers will supercool > their preamps to eliminate noise and > do any broadband shifting right in > the front end. > > I think i would like to have > an Astronomical expert making the > electronics for my geophone > but fear I would not be able to > afford the liquid helium to > keep it in operation. > :-) > > Regards; > geoff > ----- Original Message ----- > From: "Brad Douglas" > To: > Sent: Saturday, November 03, 2007 5:48 PM > Subject: Re: Signal To Noise Ratio > > > On Sat, 2007-11-03 at 16:50 -0700, Geoff wrote: > >> Hello Bob; > >> > >> Have you ever heard of a low noise > >> GaAs op amp that is designed to work > >> like a op177G (typical opamp) or ?? > > > > GaAs FETs go that low in frequency and still yield gain and stability? > > Lowest I've ever done is 144MHz and that was straining the chip, > > yielding decreased gain (but still higher than any non-GaAs FET). If my > > understanding is correct, GaAs is "saturated" above 2GHz, making them > > ideal for microwave LNAs. > > > > Or have I entirely missed the point? :-) > > > >> Signal to noise ratio should be easily found > >> in google I think it simply is like > >> Expectided MDL signal power / Ubiquitous Noise Power > >> The higher the ratio the better the whatever. > >> Possibly expressed in db. > >> For power thats 10Log(Sig/Noi). > > > > That's mostly accurate: > > http://en.wikipedia.org/wiki/Signal-to-noise_ratio > > > > > > -- > > 73, de Brad KB8UYR/6 > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email PSN-L-REQUEST@.............. with > > the body of the message (first line only): unsubscribe > > See http://www.seismicnet.com/maillist.html for more information. > > > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 2 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Re: Signal To Noise Ratio > From: "Geoff" > Date: Tue, 6 Nov 2007 02:44:42 -0700 > > Hello Bob; > > I guess I am no scientist because the basic > idea seems so simple to me that the signal to noise > ratio can be somewhat arbitrary in your selection > of reference points. > > You pick a signal level of interest > and make sure your S/N ratio is such > you will actually see the signal of interest. > > Any signal with like 6dbv X2 above the noise > should be visible. One that is 120db > is a million times the noise. > > It all depends upon what noise you mean > and to me that is overall "S" noise. > White Noise. Like on an "S" meter. > > As any bubblehead should know ( Sub-Sailor ) > S/N is one of the sinle most important facets > of any sensor device. > > I am amazed that an NMR machine can > rattle a mole of atoms in a strong > magnetic gradient and listen > to them ring With various frequencies > in response. > > They must have a receiver unlike anything > I am familiar with. > > I would start by looking at the USGS noise levels > then figure out what S/N ratio needs to be > before designing a serious device. > The place i live in here is so terribly > noisy I need to filter right at the > preamp to keep my electronics from > being jammed by higher vehicular frequencies. > > It probably would do me little good > to invest in high class low noise > amplifiers at my current location. > > The overall noise of your system > needs to be lower than the grass. > To the point of diminishing returns. > The grass being the noise in the ground > at whatever bandwidth during a quiet > sunday morning like 3am local time. > > Most people do not build their own > devices and do not concern themselves > with this thought. > There are many types of noise but the only > one of interest is the overall results. > I cant wait until Universal Entropy Reaches Maximum > That will be the quietist time of all. > > Regards > geoff > > ----- Original Message ----- > From: "Bob Hancock" > To: > Sent: Saturday, November 03, 2007 5:06 PM > Subject: Re: Signal To Noise Ratio > > Hi Geoff - > > Unfortunately, my knowledge of electronics is less than stellar. I am > working at understanding concepts of seismology. As for > electronics.....well, I'll leave that for someone else. I was hoping to > find an answer that would allow me to apply the SNR numbers I see to the > practical side of seismology. I understand the simple concept of an > amplifier (boosting a signal), but unfortunately, I have no working > knowledge of their innards or how the individual parts work by themselves > and in concert with each other. > > Bob H > > On 11/3/07 4:50 PM, "Geoff" wrote: > > > Hello Bob; > > > > Have you ever heard of a low noise > > GaAs op amp that is designed to work > > like a op177G (typical opamp) or ?? > > > > Signal to noise ratio should be easily found > > in google I think it simply is like > > Expectided MDL signal power / Ubiquitous Noise Power > > The higher the ratio the better the whatever. > > Possibly expressed in db. > > For power thats 10Log(Sig/Noi). > > The noise would be the reference point. > > If you can get a 120db (coopers) > > I think youd be in fat city. > > The higher the overall s/n ratio > > the smaller signals they can see. > > Like someone sneezing next door. > > > > :-) > > geoff > > > > ----- Original Message ----- > > From: "Bob Hancock" > > To: "PSN" > > Sent: Saturday, November 03, 2007 1:16 PM > > Subject: Signal To Noise Ratio > > > > > > When downloading events through IRIS ­ Wilber II, I noticed that they listed > > the signal to noise ratio. Most of the time the number was ­1; however, > > there were other numbers listed. I have some questions and hopefully > > someone can answer them. > > > > > > 1. What is the significance of signal to noise ratio when looking at > > earthquakes? > > > > 2. How is signal to noise ratio computed? > > > > 3. What are the ideal numbers to look for and at what point does the data > > become unusable? > > > > Thanks > > > > Bob Hancock > > > > > > > > __________________________________________________________ > > > > Public Seismic Network Mailing List (PSN-L) > > > > To leave this list email PSN-L-REQUEST@.............. with > > the body of the message (first line only): unsubscribe > > See http://www.seismicnet.com/maillist.html for more information. > > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 3 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Unknown event > From: > Date: Tue, 6 Nov 2007 11:19:29 -0700 > > This is a multi-part message in MIME format. > > ------=_NextPart_000_0007_01C82066.E5EE6CA0 > Content-Type: text/plain; > charset="iso-8859-1" > Content-Transfer-Encoding: quoted-printable > > Hi Folks, I got the 5.4 Guerrero, Mexico, here in Boise, at about = > 06:42, It was followed be another one, at about 06:52 UTC. I can't = > identify this one? =20 > > Thanks, Ted > ------=_NextPart_000_0007_01C82066.E5EE6CA0 > Content-Type: text/html; > charset="iso-8859-1" > Content-Transfer-Encoding: quoted-printable > > > > charset=3Diso-8859-1"> > > > > >
Hi Folks,  I got the 5.4 Guerrero, = > Mexico,=20 > here in Boise, at about 06:42,  It was followed be another one, at = > about=20 > 06:52 UTC.   I can't identify this one? 
>
 
>
Thanks, Ted
> > ------=_NextPart_000_0007_01C82066.E5EE6CA0-- > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 4 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Re: Unknown event > From: =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= > Date: Tue, 06 Nov 2007 18:31:27 +0000 > > Hi > > There was a ML4.3 earthquake at 06:41 in SERAM, INDONESIA (sorry for the > caps). Maybe it was that one ? > > More details. > > http://www.emsc-csem.org/index.php?page=3Dcurrent&sub=3Ddetail&id=3D69262 > > Regards. > --=20 > J=F3n Fr=EDmann > http://www.jonfr.com > http://earthquakes.jonfr.com > http://www.net303.net > http://www.mobile-coverage.com/ > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. > | Message 5 | > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' > Subject: Guerrero Mexico 5.4M > From: > Date: Tue, 6 Nov 2007 13:48:56 -0700 > > This is a multi-part message in MIME format. > > ------=_NextPart_000_0005_01C8207B.C6AAFCE0 > Content-Type: text/plain; > charset="iso-8859-1" > Content-Transfer-Encoding: quoted-printable > > Hi Folks, I now think my unidentified event was just the remainder of = > the 5.4, not a separate event. Thanks, > Ted > ------=_NextPart_000_0005_01C8207B.C6AAFCE0 > Content-Type: text/html; > charset="iso-8859-1" > Content-Transfer-Encoding: quoted-printable > > > > charset=3Diso-8859-1"> > > > > >
Hi Folks,  I now think my = > unidentified event=20 > was just the remainder of the 5.4,  not a separate = > event.  =20 > Thanks,
>
Ted
> > ------=_NextPart_000_0005_01C8207B.C6AAFCE0-- > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-DIGEST-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. Various of the latest list-serve comments are concerned with SNR of instruments, so I've decided to describe a few of the things I've learned after about two decades of intense research on the non-ideal properties of mechanical oscillators.
    To the extent that linear approximations are meaningful (not really true at low frequencies and small
amplitudes), the theoretical description of a seismometer's performance is straightforward, and treated
in the paper I wrote, titled "Seismometer performance based on a simple theory of instrument-generated
noise equivalent power", online at
http://physics.mercer.edu/hpage/inep/inep.html
  If you look at this paper, pay close attention to the difference between conventional instruments that output the time derivative of mass position (velocity) and the VolksMeter (position).  Because every seismometer (as Einstein well understood, because of inertia) responds only to acceleration (tilt being a special case), the conventional instruments measure the 'jerk' of the earth, whereas the VolksMeter measures its acceleration.  The two systems offer synergetic
possibilities--jerk sensors better for the high frequency range and acceleration sensors better for the low frequency
range.
    Some of the recent comments are concerned wtih noise equivalent power generated by electronic devices.  Such
noise is inevitable and temperature plays a dominant role in the electronics. It has been understood for decades
from the time of Johnson, and its treatment is straightforward.  Insofar as temperature dependence
of the mass/spring of a seismometer is concerned, this is an entirely different issue.  A common calculation of the Brownian motion of the seismic mass (which suggests a simple advanatage to operating at lower temperatures) is
meaningless.  The equation employed is based on the equipartition theorem, which does not apply because the
number of 'degrees of freedom' in the non-ideal spring is much greater than the number two that  is assumed;
i.e., one term for the potential energy and one term for the kinetic energy (each contribution one-half kT of thermal
energy), naively assuming a harmonic potential (based on Hooke's law which is known to be not-obeyed).
    For those interested in some of the foundation physics responsible for seismometer difficulties due to mesoanelastic complexity, I wrote the article "Anharmonic Oscillator" for the the 10th Ed. of McGraw Hill's
Encyclopedia of Science and Technology.  Typing into Google the expression damping anharmonicity -- will return the Access Science quote of the first part of this article.  To read the whole article you will have to either (i) pay something to McGraw Hill or (ii) contact me and I will return a copy by email attachment.
    Internal friction is intimately related to the instrument-generated noise equivalent power and readers may find
interesting the following paper:  "Harmonic oscillator potential to describe internal dissipation", online at
http://arxiv.org/html/physics/0307016
     Seismometer theory is hard enough to understand, even when based on linear (overly idealized) approximations.
Even the professional seismologists, along with myself, have been guilty of erroneous assumptions.  I believe, after
more than a decade of trying to acquire self-consistency in at least the linear descriptions--that I'm getting close
to a first-order approximate description that is valid for the first-cut of instrument design.  A full understanding of the real-world properties of seismometers is truly impossible at this point in time, because we don't
understand internal friction from first principles.  In the article that I wrote, titled
"Friction at the mesoscale",  Contemporary Physics vol. 45, no. 6, pp. 475-490 (2004),
I included a quote from a Nature article (Kessler) that speaks to the matter; i.e., "It is one of the dirty little secrets of physics that while we physicists can tell you a lot about quarks, quasars, and other exotica; there still is no universally
accepted explanation of the basic laws of friction".  As noted in the paper, I had actually contemplated
a title "Friction, friction everywhere but in our understanding".

Randall
 
 

psn-l-digest-request@.............. wrote:

.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 1                                                           |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: Signal To Noise Ratio
From:    "Geoff" <gmvoeth@...........>
Date:    Tue, 6 Nov 2007 02:26:21 -0700

Interesting Mr. Brad Douglas;

Im not sure about any of this
but it would be nice to understand
what is in the front end of the
first PIONEER SUPERTUNERS.

I think there are very low noise devices out there
but it would be useless to use them
in any high noise environment like
ShortWave radio.

All one really needs is to keep the
combined circuit noise below the
ambient noise or you will have
a hard time seeing the those signals
riding near the natural grass.

The astronomers will supercool
their preamps to eliminate noise and
do any broadband shifting right in
the front end.

I think i would like to have
an Astronomical expert making the
electronics for my geophone
but fear I would not be able to
afford the liquid helium to
keep it in operation.
:-)

Regards;
geoff
----- Original Message -----
From: "Brad Douglas" <rez@..................>
To: <psn-l@..............>
Sent: Saturday, November 03, 2007 5:48 PM
Subject: Re: Signal To Noise Ratio

> On Sat, 2007-11-03 at 16:50 -0700, Geoff wrote:
>> Hello Bob;
>>
>> Have you ever heard of a low noise
>> GaAs op amp that is designed to work
>> like a op177G (typical opamp) or ??
>
> GaAs FETs go that low in frequency and still yield gain and stability?
> Lowest I've ever done is 144MHz and that was straining the chip,
> yielding decreased gain (but still higher than any non-GaAs FET).  If my
> understanding is correct, GaAs is "saturated" above 2GHz, making them
> ideal for microwave LNAs.
>
> Or have I entirely missed the point? :-)
>
>> Signal to noise ratio should be easily found
>> in google I think it simply is like
>> Expectided MDL signal power / Ubiquitous Noise Power
>> The higher the ratio the better the whatever.
>> Possibly expressed in db.
>> For power thats 10Log(Sig/Noi).
>
> That's mostly accurate:
> http://en.wikipedia.org/wiki/Signal-to-noise_ratio
>
>
> --
> 73, de Brad KB8UYR/6 <rez touchofmadness com>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>

.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 2                                                           |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: Signal To Noise Ratio
From:    "Geoff" <gmvoeth@...........>
Date:    Tue, 6 Nov 2007 02:44:42 -0700

Hello Bob;

I guess I am no scientist because the basic
idea seems so simple to me that the signal to noise
ratio can be somewhat arbitrary in your selection
of reference points.

You pick a signal level of interest
and make sure your S/N ratio is such
you will actually see the signal of interest.

Any signal with like 6dbv X2 above the noise
should be visible. One that is 120db
is a million times the noise.

It all depends upon what noise you mean
and to me that is overall "S" noise.
White Noise. Like on an "S" meter.

As any bubblehead should know ( Sub-Sailor )
S/N is one of the sinle most important facets
of any sensor device.

I am amazed that an NMR machine can
rattle a mole of atoms in a strong
magnetic gradient and listen
to them ring With various frequencies
in response.

They must have a receiver unlike anything
I am familiar with.

I would start by looking at the USGS noise levels
then figure out what S/N ratio needs to be
before designing a serious device.
The place i live in here is so terribly
noisy I need to filter right at the
preamp to keep my electronics from
being jammed by higher vehicular frequencies.

It probably would do me little good
to invest in high class low noise
amplifiers at my current location.

The overall noise of your system
needs to be lower than the grass.
To the point of diminishing returns.
The grass being the noise in the ground
at whatever bandwidth during a quiet
sunday morning like 3am local time.

Most people do not build their own
devices and do not concern themselves
with this thought.
There are many types of noise but the only
one of interest is the overall results.
I cant wait until Universal Entropy Reaches Maximum
That will be the quietist time of all.

Regards
geoff

----- Original Message -----
From: "Bob Hancock" <carpediem1@.........>
To: <psn-l@..............>
Sent: Saturday, November 03, 2007 5:06 PM
Subject: Re: Signal To Noise Ratio

Hi Geoff -

Unfortunately, my knowledge of electronics is less than stellar.  I am
working at understanding concepts of seismology.  As for
electronics.....well, I'll leave that for someone else.  I was hoping to
find an answer that would allow me to apply the SNR numbers I see to the
practical side of seismology.  I understand the simple concept of an
amplifier (boosting a signal), but unfortunately, I have no working
knowledge of their innards or how the individual parts work by themselves
and in concert with each other.

Bob H

On 11/3/07 4:50 PM, "Geoff" <gmvoeth@...........> wrote:

> Hello Bob;
>
> Have you ever heard of a low noise
> GaAs op amp that is designed to work
> like a op177G (typical opamp) or ??
>
> Signal to noise ratio should be easily found
> in google I think it simply is like
> Expectided MDL signal power / Ubiquitous Noise Power
> The higher the ratio the better the whatever.
> Possibly expressed in db.
> For power thats 10Log(Sig/Noi).
> The noise would be the reference point.
> If you can get a 120db (coopers)
> I think youd be in fat city.
> The higher the overall s/n ratio
> the smaller signals they can see.
> Like someone sneezing next door.
>
> :-)
> geoff
>
> ----- Original Message -----
> From: "Bob Hancock" <carpediem1@.........>
> To: "PSN" <psn-l@..............>
> Sent: Saturday, November 03, 2007 1:16 PM
> Subject: Signal To Noise Ratio
>
>
> When downloading events through IRIS ­ Wilber II, I noticed that they listed
> the signal to noise ratio.  Most of the time the number was ­1; however,
> there were other numbers listed.  I have some questions and hopefully
> someone can answer them.
>
>
> 1.  What is the significance of signal to noise ratio when looking at
> earthquakes?
>
> 2.  How is signal to noise ratio computed?
>
> 3.  What are the ideal numbers to look for and at what point does the data
> become unusable?
>
> Thanks
>
> Bob Hancock
>
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>

__________________________________________________________

Public Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@.............. with
the body of the message (first line only): unsubscribe
See http://www.seismicnet.com/maillist.html for more information.

.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 3                                                           |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Unknown event
From:    <tchannel1@............>
Date:    Tue, 6 Nov 2007 11:19:29 -0700

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Hi Folks,  I got the 5.4 Guerrero, Mexico, here in Boise, at about =
06:42,  It was followed be another one, at about 06:52 UTC.   I can't =
identify this one? =20

Thanks, Ted
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<DIV><FONT face=3DArial size=3D2>Hi Folks,&nbsp; I got the 5.4 Guerrero, =
Mexico,=20
here in Boise, at about 06:42,&nbsp; It was followed be another one, at =
about=20
06:52 UTC.&nbsp;&nbsp; I can't identify this one?&nbsp; </FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Thanks, Ted</FONT></DIV></BODY></HTML>

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Subject: Re: Unknown event
From:    =?ISO-8859-1?Q?J=F3n_Fr=EDmann?= <jonfr@.........>
Date:    Tue, 06 Nov 2007 18:31:27 +0000

Hi

There was a ML4.3 earthquake at 06:41 in SERAM, INDONESIA (sorry for the
caps). Maybe it was that one ?

More details.

http://www.emsc-csem.org/index.php?page=3Dcurrent&sub=3Ddetail&id=3D69262

Regards.
--=20
J=F3n Fr=EDmann
http://www.jonfr.com
http://earthquakes.jonfr.com
http://www.net303.net
http://www.mobile-coverage.com/

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Subject: Guerrero Mexico 5.4M
From:    <tchannel1@............>
Date:    Tue, 6 Nov 2007 13:48:56 -0700

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Hi Folks,  I now think my unidentified event was just the remainder of =
the 5.4,  not a separate event.   Thanks,
Ted
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<DIV><FONT face=3DArial size=3D2>Hi Folks,&nbsp; I now think my =
unidentified event=20
was just the remainder of the 5.4,&nbsp; not a separate =
event.&nbsp;&nbsp;=20
Thanks,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Ted</FONT></DIV></BODY></HTML>

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Subject: idea for an axis From: Randall Peters PETERS_RD@.......... Date: Thu, 08 Nov 2007 11:57:49 -0500 Since the VolksMeter uses tungsten carbide to establish the axis (extracted from ball-point pens), I should have thought of the following a long time ago. A key to reducing rolling friction is to work with hard surfaces. Another key to reducing friction in general (if possible) is to reduce the normal force. Both are achievable by hanging a pendulum from a rare earth magnet, using the ferrous property of the tungsten carbide. In a brief experiment this morning I stuck a 1/2 in cylindrical rare earth magnet to the top of a steel door frame and then hung a ball point pen from the magnet. Discovered that the tungsten carbide tip of the pen could support about 100 grams of weight. Of course this arrangement is unsatisfactory for a seismometer because the physical pendulum that results (swinging pen) moves as a spherical pendulum. To get the required planar motion I took the refills of two pens and glued them together. The pair of pen points can support about 200 grams of an inertial mass while constrained to motion in a plane. The quality factor of this oscillator proved to be really high, with the unit swinging in observable free decay for many hundreds of cycles. It is clear then, that the friction is very small indeed, by (i) taking advantage of the hardness of both the magnet and the small tungsten carbide balls; and (ii) because the field gradient of the magnet provides support for much of the mass of the pendulum, so that the normal force is reduced as compared to most other configurations. For you folks who have played with various axis types, what do you think about this? Randall Subject: Re: idea for an axis From: tchannel1@............ Date: Thu, 8 Nov 2007 10:12:50 -0700 Randall, I think this is brilliant, and well worth dinking with, which I think I will do. Thanks, Ted ----- Original Message ----- From: "Randall Peters" To: Sent: Thursday, November 08, 2007 9:57 AM Subject: idea for an axis > Since the VolksMeter uses tungsten carbide to establish the axis > (extracted from > ball-point pens), I should have thought of the following a long time ago. > A key to reducing rolling friction is to work with hard surfaces. > Another key > to reducing friction in general (if possible) is to reduce the normal > force. Both > are achievable by hanging a pendulum from a rare earth magnet, using the > ferrous > property of the tungsten carbide. > In a brief experiment this morning I stuck a 1/2 in cylindrical rare > earth > magnet to the top of a steel door frame and then hung a ball point pen > from the > magnet. Discovered that the tungsten carbide tip of the pen could support > about > 100 grams of weight. Of course this arrangement is unsatisfactory for a > seismometer because the physical pendulum that results (swinging pen) > moves as a > spherical pendulum. > To get the required planar motion I took the refills of two pens and > glued > them together. The pair of pen points can support about 200 grams of an > inertial > mass while constrained to motion in a plane. > The quality factor of this oscillator proved to be really high, with > the unit > swinging in observable free decay for many hundreds of cycles. It is > clear then, > that the friction is very small indeed, by (i) taking advantage of the > hardness of > both the magnet and the small tungsten carbide balls; and (ii) because the > field > gradient of the magnet provides support for much of the mass of the > pendulum, so > that the normal force is reduced as compared to most other configurations. > For you folks who have played with various axis types, what do you > think > about this? > Randall > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: idea for an axis From: tchannel1@............ Date: Thu, 8 Nov 2007 14:54:20 -0700 Randall, I did this also, and got similar results. With no special effort I just hung a ball point pen, from a nice rare earth magnet, added enough mass to NOT FALL, and pushed the pendulum about 20 degrees. It rocked or circled for 30 mins, and my estimated count of cycles was 2500. I had done other crude pendulums timing, testing hinges and got about 400 cycles, more or less. I have a room full of different sensors, but now I would like to try this concept on a mini-sensor. Someday..... Thanks for the idea. Ted ----- Original Message ----- From: "Randall Peters" To: Sent: Thursday, November 08, 2007 9:57 AM Subject: idea for an axis > Since the VolksMeter uses tungsten carbide to establish the axis > (extracted from > ball-point pens), I should have thought of the following a long time ago. > A key to reducing rolling friction is to work with hard surfaces. > Another key > to reducing friction in general (if possible) is to reduce the normal > force. Both > are achievable by hanging a pendulum from a rare earth magnet, using the > ferrous > property of the tungsten carbide. > In a brief experiment this morning I stuck a 1/2 in cylindrical rare > earth > magnet to the top of a steel door frame and then hung a ball point pen > from the > magnet. Discovered that the tungsten carbide tip of the pen could support > about > 100 grams of weight. Of course this arrangement is unsatisfactory for a > seismometer because the physical pendulum that results (swinging pen) > moves as a > spherical pendulum. > To get the required planar motion I took the refills of two pens and > glued > them together. The pair of pen points can support about 200 grams of an > inertial > mass while constrained to motion in a plane. > The quality factor of this oscillator proved to be really high, with > the unit > swinging in observable free decay for many hundreds of cycles. It is > clear then, > that the friction is very small indeed, by (i) taking advantage of the > hardness of > both the magnet and the small tungsten carbide balls; and (ii) because the > field > gradient of the magnet provides support for much of the mass of the > pendulum, so > that the normal force is reduced as compared to most other configurations. > For you folks who have played with various axis types, what do you > think > about this? > Randall > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: idea for an axis From: ChrisAtUpw@....... Date: Thu, 8 Nov 2007 18:43:00 EST In a message dated 08/11/2007, PETERS_RD@.......... writes: Since the VolksMeter uses tungsten carbide to establish the axis, I should have thought of the following a long time ago. A key to reducing rolling friction is to work with hard surfaces. Another key to reducing friction in general (if possible) is to reduce the normal force. Both are achievable by hanging a pendulum from a rare earth magnet, using the ferrous property of the tungsten carbide. Hi Randall, Stainless Steel ball bearings are available in a wide range of sizes. _www.smallparts.com_ (http://www.smallparts.com) They are martensitic Chrome steel and are strongly magnetic. SS martensitic rod is also readily available. It might be worth considering mounting the balls in mild steel with a magnet bridge and attaching them to a hardened SS rod. The magnetic flux would then pass from the magnet, through the mild steel to the balls, across the suspension contacts to the circular rod and then through it. I am uncertain whether the strong permanent magnetism which will be induced near the contact point will add to the dynamic loss. The relatively low net load should decrease the loss. It should be quite practicable to extend this to crossed cylinder suspensions. I would expect the magnetic attraction to be greater for the same diameter. The dynamic loss does depend on the bearing type. Previous experiments have shown decreasing loss in the series single wires and foils, crossed wires and foils, ball on a plane, crossed cylinders, rolling wires and foils. These rolling systems use a figure of 8 loops around two circular cylinders. They show ~zero rolling force. Ball on a plane and cylindrical systems may be made self centring by curving the plane / providing a circular support. The choice of system may depend on whether the arm needs to be permanently attached to the support structure. Regards, Chris Chapman
In a message dated 08/11/2007, PETERS_RD@.......... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Since=20 the VolksMeter uses tungsten carbide to establish the axis, I should have=20 thought of the following a long time ago.
   A key to reducin= g=20 rolling friction is to work with hard surfaces.  Another key to reduc= ing=20 friction in general (if possible) is to reduce the normal force.  Bot= h=20 are achievable by hanging a pendulum from a rare earth magnet, using the=20 ferrous property of the tungsten carbide.
Hi Randall,
 
    Stainless Steel ball bearings are available in=20= a=20 wide range of sizes. www.smallparts.co= m=20 They are martensitic Chrome steel and are strongly magnetic. SS martensitic=20= rod=20 is also readily available. It might be worth considering mounting the balls=20= in=20 mild steel with a magnet bridge and attaching them to a hardened SS rod. The= =20 magnetic flux would then pass from the magnet, through the mild steel to the= =20 balls, across the suspension contacts to the circular rod and then through=20 it.
    =20
    I am uncertain whether the strong permanent=20 magnetism which will be induced near the contact point will add to the dynam= ic=20 loss. The relatively low net load should decrease the loss.
    It should be quite practicable to extend this t= o=20 crossed cylinder suspensions. I would expect the magnetic attraction to be=20 greater for the same diameter.
 
    The dynamic loss does depend on the bearing typ= e.=20 Previous experiments have shown decreasing loss in the series single wi= res=20 and foils, crossed wires and foils, ball on a plane, crossed cylinders, roll= ing=20 wires and foils. These rolling systems use a figure of 8 loops aro= und=20 two circular cylinders. They show ~zero rolling force. Ball on a plane and=20 cylindrical systems may be made self centring by curving the plane / providi= ng a=20 circular support. The choice of system may depend on whether the arm needs t= o be=20 permanently attached to the support structure.
 
    Regards,
 
    Chris Chapman
 

 
 
Subject: Re: idea for an axis From: "meredith lamb" paleoartifact@......... Date: Thu, 8 Nov 2007 21:37:17 -0700 Dr. Peters and all, Am only adding some further development thoughts here. Some ball point pens could likely be emptied of their contents; a replacement ball bearing could be glued in place, and the empty plastic could contain, say; whatever lead shot the axis ball bearing pivot could handle weight wise. Of course, one could possibly retain the original ball bearing perhaps by cutting off the ink well tube and glueing. Of course the plastic is both the "boom" and the "mass" weight holder in one. One could "entertain" dual pens also for the vertical sensing approach with a suitable spring....the dual ball bearing pivot/axis points should make it quite stable. I suppose its also possible to electrically isolate the contact points of the axis points, and run wires to a bulb somewhere at the base of one of the pens; for light sensing variation output. Of course there is other ways of suing light sensing without using a bulb in one of the pens. Anyway....have tried only one working ball point here. Its a big size, "Gelwriter Rx", I got from a Costco store. It has a screw on head. Even the pocket clip can be easily pulled out of the assembly. The only magnetic item therein was the spring. The clip and the ID ring seem to be stainless. The hand diameter size is noteably larger than the average ball point pens on the U.S. market. Some of the plastic is colored to look like metal. I tried another ball point....but, its ball bearing didn't appear to be even magnetic. Quite some time back, Chris Chapman checked out a variety of ball point pens, and found the ball bearing diameters can vary. Meredith Lamb On Nov 8, 2007 9:57 AM, Randall Peters wrote: > Since the VolksMeter uses tungsten carbide to establish the axis > (extracted from > ball-point pens), I should have thought of the following a long time ago. > A key to reducing rolling friction is to work with hard surfaces. > Another key > to reducing friction in general (if possible) is to reduce the normal > force. Both > are achievable by hanging a pendulum from a rare earth magnet, using the > ferrous > property of the tungsten carbide. > In a brief experiment this morning I stuck a 1/2 in cylindrical rare > earth > magnet to the top of a steel door frame and then hung a ball point pen > from the > magnet. Discovered that the tungsten carbide tip of the pen could support > about > 100 grams of weight. Of course this arrangement is unsatisfactory for a > seismometer because the physical pendulum that results (swinging pen) > moves as a > spherical pendulum. > To get the required planar motion I took the refills of two pens and > glued > them together. The pair of pen points can support about 200 grams of an > inertial > mass while constrained to motion in a plane. > The quality factor of this oscillator proved to be really high, with > the unit > swinging in observable free decay for many hundreds of cycles. It is > clear then, > that the friction is very small indeed, by (i) taking advantage of the > hardness of > both the magnet and the small tungsten carbide balls; and (ii) because the > field > gradient of the magnet provides support for much of the mass of the > pendulum, so > that the normal force is reduced as compared to most other configurations. > For you folks who have played with various axis types, what do you > think > about this? > Randall >
Dr. Peters and all,
 
Am only adding some further development thoughts here.  Some ball point pens
could likely be emptied of their contents; a replacement ball bearing could be
glued in place, and the empty plastic could contain, say; whatever lead shot the
axis ball bearing pivot could handle weight wise.  Of course, one could possibly
retain the original ball bearing perhaps by cutting off the ink well tube and glueing.
Of course the plastic is both the "boom" and the "mass" weight holder in one.
 
One could "entertain" dual pens also for the vertical sensing approach with a
suitable spring....the dual ball bearing pivot/axis points should make it quite stable.
 
I suppose its also possible to electrically isolate the contact points of the
axis points, and run wires to a bulb somewhere at the base of one of the pens;
for light sensing variation output.  Of course there is other ways of suing light
sensing without using a bulb in one of the pens.
 
Anyway....have tried only one working ball point here.  Its a big size, "Gelwriter Rx", I
got from a Costco store.  It has a screw on head.  Even the pocket clip can
be easily pulled out of the assembly.  The only magnetic item therein was the
spring.  The clip and the ID ring seem to be stainless.  The hand diameter
size is noteably larger than the average ball point pens on the U.S. market.
Some of the plastic is colored to look like metal. 
 
I tried another ball point....but, its ball bearing didn't appear to be even magnetic.
 
Quite some time back, Chris Chapman checked out a variety of ball point
pens, and found the ball bearing diameters can vary.   
 
Meredith Lamb 

 
On Nov 8, 2007 9:57 AM, Randall Peters <PETERS_RD@..........> wrote:
Since the VolksMeter uses tungsten carbide to establish the axis (extracted from
ball-point pens), I should have thought of the following a long time ago.
  A key to reducing rolling friction is to work with hard surfaces.  Another key
to reducing friction in general (if possible) is to reduce the normal force.  Both
are achievable by hanging a pendulum from a rare earth magnet, using the ferrous
property of the tungsten carbide.
   In a brief experiment this morning I stuck a 1/2 in cylindrical rare earth
magnet to the top of a steel door frame and then hung a ball point pen from the
magnet.  Discovered that the tungsten carbide tip of the pen could support about
100 grams of weight.  Of course this arrangement is unsatisfactory for a
seismometer because the physical pendulum that results (swinging pen) moves as a
spherical pendulum.
   To get the required planar motion I took the refills of two pens and glued
them together.  The pair of pen points can support about 200 grams of an inertial
mass while constrained to motion in a plane.
   The quality factor of this oscillator proved to be really high, with the unit
swinging in observable free decay for many hundreds of cycles.  It is clear then,
that the friction is very small indeed, by (i) taking advantage of the hardness of
both the magnet and the small tungsten carbide balls; and (ii) because the field
gradient of the magnet provides support for much of the mass of the pendulum, so
that the normal force is reduced as compared to most other configurations.
    For you folks who have played with various axis types, what do you think
about this?
Randall

Subject: Re: idea for an axis From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 05:07:40 -0700 DID you clean the ink off the tip before doing this ? ----- Original Message ----- From: To: Sent: Thursday, November 08, 2007 2:54 PM Subject: Re: idea for an axis > Randall, I did this also, and got similar results. With no special effort > I just hung a ball point pen, from a nice rare earth magnet, added enough > mass to NOT FALL, and pushed the pendulum about 20 degrees. It rocked or > circled for 30 mins, and my estimated count of cycles was 2500. I had done > other crude pendulums timing, testing hinges and got about 400 cycles, more > or less. > > I have a room full of different sensors, but now I would like to try this > concept on a mini-sensor. Someday..... > > Thanks for the idea. > Ted > > > > > ----- Original Message ----- > From: "Randall Peters" > To: > Sent: Thursday, November 08, 2007 9:57 AM > Subject: idea for an axis > > >> Since the VolksMeter uses tungsten carbide to establish the axis >> (extracted from >> ball-point pens), I should have thought of the following a long time ago. >> A key to reducing rolling friction is to work with hard surfaces. >> Another key >> to reducing friction in general (if possible) is to reduce the normal >> force. Both >> are achievable by hanging a pendulum from a rare earth magnet, using the >> ferrous >> property of the tungsten carbide. >> In a brief experiment this morning I stuck a 1/2 in cylindrical rare >> earth >> magnet to the top of a steel door frame and then hung a ball point pen >> from the >> magnet. Discovered that the tungsten carbide tip of the pen could support >> about >> 100 grams of weight. Of course this arrangement is unsatisfactory for a >> seismometer because the physical pendulum that results (swinging pen) >> moves as a >> spherical pendulum. >> To get the required planar motion I took the refills of two pens and >> glued >> them together. The pair of pen points can support about 200 grams of an >> inertial >> mass while constrained to motion in a plane. >> The quality factor of this oscillator proved to be really high, with >> the unit >> swinging in observable free decay for many hundreds of cycles. It is >> clear then, >> that the friction is very small indeed, by (i) taking advantage of the >> hardness of >> both the magnet and the small tungsten carbide balls; and (ii) because the >> field >> gradient of the magnet provides support for much of the mass of the >> pendulum, so >> that the normal force is reduced as compared to most other configurations. >> For you folks who have played with various axis types, what do you >> think >> about this? >> Randall >> > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: idea for an axis From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 05:15:10 -0700 You Will see things like 1mm medium pens and 0.8mm fine I think that may be the diameter of the ball ?? Why Dont People try using these things in a vacuum ? With only Magnetic Damping ?? Put the damper above the sensor so the sensor can get full advantage of the velocity. How in the world can you use such a thing vertically ? ----- Original Message ----- From: "meredith lamb" To: Sent: Thursday, November 08, 2007 9:37 PM Subject: Re: idea for an axis > Dr. Peters and all, > > Am only adding some further development thoughts here. Some ball point pens > could likely be emptied of their contents; a replacement ball bearing could > be > glued in place, and the empty plastic could contain, say; whatever lead shot > the > axis ball bearing pivot could handle weight wise. Of course, one could > possibly > retain the original ball bearing perhaps by cutting off the ink well tube > and glueing. > Of course the plastic is both the "boom" and the "mass" weight holder in > one. > > One could "entertain" dual pens also for the vertical sensing approach with > a > suitable spring....the dual ball bearing pivot/axis points should make it > quite stable. > > I suppose its also possible to electrically isolate the contact points of > the > axis points, and run wires to a bulb somewhere at the base of one of the > pens; > for light sensing variation output. Of course there is other ways of suing > light > sensing without using a bulb in one of the pens. > > Anyway....have tried only one working ball point here. Its a big size, > "Gelwriter Rx", I > got from a Costco store. It has a screw on head. Even the pocket clip can > be easily pulled out of the assembly. The only magnetic item therein was > the > spring. The clip and the ID ring seem to be stainless. The hand diameter > size is noteably larger than the average ball point pens on the U.S. market. > Some of the plastic is colored to look like metal. > > I tried another ball point....but, its ball bearing didn't appear to be even > magnetic. > > Quite some time back, Chris Chapman checked out a variety of ball point > pens, and found the ball bearing diameters can vary. > > Meredith Lamb > > > On Nov 8, 2007 9:57 AM, Randall Peters wrote: > >> Since the VolksMeter uses tungsten carbide to establish the axis >> (extracted from >> ball-point pens), I should have thought of the following a long time ago. >> A key to reducing rolling friction is to work with hard surfaces. >> Another key >> to reducing friction in general (if possible) is to reduce the normal >> force. Both >> are achievable by hanging a pendulum from a rare earth magnet, using the >> ferrous >> property of the tungsten carbide. >> In a brief experiment this morning I stuck a 1/2 in cylindrical rare >> earth >> magnet to the top of a steel door frame and then hung a ball point pen >> from the >> magnet. Discovered that the tungsten carbide tip of the pen could support >> about >> 100 grams of weight. Of course this arrangement is unsatisfactory for a >> seismometer because the physical pendulum that results (swinging pen) >> moves as a >> spherical pendulum. >> To get the required planar motion I took the refills of two pens and >> glued >> them together. The pair of pen points can support about 200 grams of an >> inertial >> mass while constrained to motion in a plane. >> The quality factor of this oscillator proved to be really high, with >> the unit >> swinging in observable free decay for many hundreds of cycles. It is >> clear then, >> that the friction is very small indeed, by (i) taking advantage of the >> hardness of >> both the magnet and the small tungsten carbide balls; and (ii) because the >> field >> gradient of the magnet provides support for much of the mass of the >> pendulum, so >> that the normal force is reduced as compared to most other configurations. >> For you folks who have played with various axis types, what do you >> think >> about this? >> Randall >> > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: idea for an axis From: "Jerry Payton" gpayton880@....... Date: Fri, 9 Nov 2007 06:20:27 -0600 Hi, I have been following this discussion with great interest. I have been wondering how you would control the rotation of the free end of the suspended pendulum? As Ted pointed out in his email, it rotated. How would one maintain the motion in a horizontal plane - - AND - - what kind (size, weight, &etc.) of coil. Of course, Meredith suggested a light bulb. I'm just trying to wrap my brain around this idea as a whole assembly. Best Regards, Jerry Payton
Hi,
 
I have been following this discussion with great interest.  I = have=20 been wondering how you would control the rotation of the free end of the = suspended pendulum?  As Ted pointed out in his email, it = rotated.  How=20 would one maintain the motion in a horizontal plane - - AND - - what = kind (size,=20 weight, &etc.) of coil.  Of course, Meredith suggested a light=20 bulb.
 
I'm just trying to wrap my brain around this idea as a whole=20 assembly.
 
Best Regards,
Jerry Payton
Subject: Re: idea for an axis From: ChrisAtUpw@....... Date: Fri, 9 Nov 2007 07:23:36 EST In a message dated 09/11/2007, gmvoeth@........... writes: DID you clean the ink off the tip before doing this ? Hi Geoff, The BIC pens have tungsten carbide balls. If you cut off the plastic ink holder, you can push out the 1 mm ball with a fine drill / piano wire. You can then clean everything with methylated spirits and reassemble it. The ball can be crimped or glued in position with two part acrylic adhesive. However, you can buy martensitic SS balls from _www.smallparts.com_ (http://www.smallparts.com) They are ferromagnetic. Regards, Chris Chapman
In a message dated 09/11/2007, gmvoeth@........... writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>DID you=20 clean the ink off the tip
before doing this ?
Hi Geoff,
 
    The BIC pens have tungsten carbide balls. If yo= u=20 cut off the plastic ink holder, you can push out the 1 mm ball with a f= ine=20 drill / piano wire. You can then clean everything with methylated spirits an= d=20 reassemble it. The ball can be crimped or glued in position with two part=20 acrylic adhesive. 
 
    However, you can buy martensitic SS balls from=20= www.smallparts.com They are=20 ferromagnetic.
 
    Regards,
 
    Chris Chapman 
Subject: further magnet ideas From: Randall Peters PETERS_RD@.......... Date: Fri, 09 Nov 2007 07:53:07 -0500 Hey, Don't know whether we qualify as 'great minds', but at least we're 'on the same sheet of music'. The first thing I thought about following the 'obvious standard pendulum' was whether the idea could be extended to verticals--just as Meredith suggested. Also, Chris alluded to another element of the idea--rolling cylinders. Before the 'dangling pen' I had noticed that two cylindrical rare earth magnets roll together nicely. If you make one stationary and 'ping' the other it oscillates nicely. What's the primary source of damping? Some is the rolling friction, and some derive from induced eddy current in earch. If we reduce the rolling part, who cares about the eddy current parts? After all, they are part of the desired Q-reduction that has become standard to eliminate transient response of the instrument. Thus an arrangement I think could have promise is the following. A few years ago, now retired Georgia Tech seismologist Tim Long (very highly honored in our state) sent me a picture of a vertical he designed. Unlike with most instruments that use Lucien LaCoste's famous zero-length spring, Tim put the 'approximate' zero-length spring (probably a screen door type) below the boom. This is accomplished by flex-pivot elastic strips at the short end (top) of the U-shaped steel iron strip that serves as the 'backbone' of the instrument. I believe that Tim's flex-pivot strips could be replaced with two rare-earth magnets, one 'stuck' to the top of the frame and the other glued to the non-sensor end of the required non-ferrous boom. The boom magnet would roll on the frame magnet, with the contact force being made small (the two trying to pull apart) by 'proper' placement of each of the magnets. You amateurs are 'like a fresh cool wind' on a 'hot-as-hell Georgia August afternoon' and I love your enthusiam toward what might to the 'pro's' look like hare-brained ideas. I look forward to additional brainstorming on these thoughts. Randall Subject: Re: idea for an axis From: ian ian@........... Date: Fri, 09 Nov 2007 13:14:28 +0000 Hi, just tried this idea with neodymium magnet, 1 pen, 2 straws and a small mass at the end. I get a period of 1.4 seconds and indeed it does go on for a while. Silly question coming up - please be merciful(!) - how can I turn this into a long period teleseismic device (period of 10s of seconds)? Thanks Ian ChrisAtUpw@....... wrote: > In a message dated 09/11/2007, gmvoeth@........... writes: > > DID you clean the ink off the tip > before doing this ? > > Hi Geoff, > > The BIC pens have tungsten carbide balls. If you cut off the > plastic ink holder, you can push out the 1 mm ball with a fine drill / > piano wire. You can then clean everything with methylated spirits and > reassemble it. The ball can be crimped or glued in position with two > part acrylic adhesive. > > However, you can buy martensitic SS balls from www.smallparts.com > They are ferromagnetic. > > Regards, > > Chris Chapman -- Hi,

just tried this idea with neodymium magnet, 1 pen, 2 straws and a small mass at the end.  I get a period of 1.4 seconds and indeed it does go on for a while.

Silly question coming up - please be merciful(!) - how can I turn this into a long period teleseismic device (period of 10s of seconds)?

Thanks

Ian

ChrisAtUpw@....... wrote:
In a message dated 09/11/2007, gmvoeth@........... writes:
DID you clean the ink off the tip
before doing this ?
Hi Geoff,
 
    The BIC pens have tungsten carbide balls. If you cut off the plastic ink holder, you can push out the 1 mm ball with a fine drill / piano wire. You can then clean everything with methylated spirits and reassemble it. The ball can be crimped or glued in position with two part acrylic adhesive. 
 
    However, you can buy martensitic SS balls from www.smallparts.com They are ferromagnetic.
 
    Regards,
 
    Chris Chapman 

--

Subject: ball issues From: Randall Peters PETERS_RD@.......... Date: Fri, 09 Nov 2007 08:23:50 -0500 Geoff, I did not clean the ink from the ball of the pen. Should point out that issues of 'lubrication' are some of the least understood phenomena of the modern science era. As my fluids colleague expert here at Mercer points out (Dr. Loren Sumner, graduate of Georgia Tech), the explanation of bearing friction lubrication starts at the 'opposite end' of Reynolds number thinking as compared to Bernoulli's equation. Some physics types, ignorant of the real world, try to easily explain everything on the basis of the latter. Airplane lift is not to be simply explained on the basis of Bernoulli's equation. Anybody exposed to that foolishness ought to go complain to his teacher! What I can say about rolling friction involving 'clean' as opposed to 'fluid treated' surfaces is that the best we can at present hope for is empirical understanding. Readers may be interested in the paper I wrote that speaks to some of this at arxiv.org/abs/physics/0506143 Don't be turned off by the frontier-physics features of this paper; just look at the photo's to know that it deals with rolling friction. Also note that there are all kinds of differences depending on 'cleanliness'. Truly, as I have stated in the first chapter that I wrote of the book to be published in January by Nova Science Publishers, titled "Science education in the 21st century"--friction, friction everywhere but in our understanding". This chapter is titled "Building on old foundations with new technologies". For those who might be interested, I have posted many papers on my webpage at http://physics.mercer.edu/hpage/peters.html If you look carefully you might 'find a pony in that stall'. My two decades in Texas, surrounded by cowboys whom I now miss here in Georgia, I adopted an expression that is quite applicable to much of the science now practiced: "if you can't impress them with finesse, then baffle them with b.s.". I hope that at least some of my papers at the aforementioned site might by you guys that I appreciate like the range-hands, be viewed as having some degree of finesse. Randall P.S. Jerry, I hope that my other comments, submitted a short while ago, at least speak to your question. Subject: seismometer sensitivity--fundamental physics From: Randall Peters PETERS_RD@.......... Date: Fri, 09 Nov 2007 08:35:16 -0500 Ian, Since you asked about period extension to increase sensitivity, let me explain something very few seem to understand. The sensitivity of a simple pendulum is just like that of every other seismometer; i.e., you can show that it is proportional to the square of the period. This can be proven from the equations of motion of the various mechanical oscillators in general, but for the pendulum, understanding is trivial. As anybody would expect from 'horse-sense', the longer the 'quasi-rigid' pendulum, the greater the sensitivity of the instrument if the sensor is placed at the bottom. Because the period of the pendulum is given by 2 pi times the square root of the ratio of length to earth field (little g), one sees immediately then, from this well known expression, that the sensitivity is proportional to the square of the period. So then--to increase your sensitivity, hang as long a rod as you can find, consistent with your house size, and then place your sensor at the bottom. There are many possible sensor types to go with this incredibly cheap but probably very effective earthquake detector. They could be moire' pattern types with white light (incrediby simple) to function as a tsunami detector. Or they might be greatly, greatly sensitive by means of the Ronchi approach, who made optical testing famous by means of a coarse grating (much better than the classic knife edge test). The Ronchi ruling works with white light! Or the sensor might be capacitive in nature like my SDC array. The list of possibilities goes on and on, thus my interest in the serendipty that is likely to come out of the listserve. Randall Subject: Re: idea for an axis From: "Jerry Payton" gpayton880@....... Date: Fri, 9 Nov 2007 07:39:46 -0600 I just tried using a round "donut" neodymium magnet pressed on the end of a ball point plastic shank, not the ink tube, but the pen itself. Thereby, having the complete pen suspended by two stacked rectangular neodymium magnets and having an attached magnet to the pendulum (pen shaft) on the opposite end. I passed the circular magnet through a coil of bulk wire, and got a meter deflection. It was minute, but possibly usable if amplified. No, Dr. Peters, I do not see an answer to my previous post. Sorry! I've only had one cup of coffee this morning. (Smile) Jerry
I just tried using a round "donut" neodymium magnet = pressed on=20 the end of a ball point plastic shank, not the ink tube, but the pen=20 itself. 
 
Thereby, having the complete pen suspended by two stacked = rectangular=20 neodymium magnets and having an attached magnet to the pendulum (pen = shaft) on=20 the opposite end.  
 
I passed the circular magnet through a coil of  = bulk  wire,=20 and got a meter deflection.  It was minute, but possibly = usable if=20 amplified. 
 
No, Dr. Peters, I do not see an answer to my previous post. =20 Sorry!   I've only had one cup of coffee this morning. = (Smile)
 
Jerry
 
Subject: Re: seismometer sensitivity--fundamental physics From: ian ian@........... Date: Fri, 09 Nov 2007 13:46:20 +0000 Hi, thanks for the reply. I did know that lengthening the pendulum also lengthens the period but to hang one from the top of my house has some practical problems(!). I had hoped there might be some other way of tackling the problem. The Volksmeter II seems to have a pendulum of around 0.5 meters but It's response goes out to 10s of seconds - http://www.rllinstruments.com/VMIIDSPg8.htm . So I guess I'm looking for some cheap/easy way of lengthening the period. I can't afford the $999 to buy it. :-( Thanks Ian Randall Peters wrote: >Ian, > Since you asked about period extension to increase sensitivity, let me explain something very few seem to understand. The sensitivity of a simple pendulum is just like that of every other seismometer; i.e., you can show that it is proportional to the square of the period. This can be proven from >the equations of motion of the various mechanical oscillators in general, but for the pendulum, understanding is trivial. > As anybody would expect from 'horse-sense', the longer the 'quasi-rigid' pendulum, the greater the sensitivity of the instrument if the sensor is placed at the bottom. Because the period of the pendulum is given by 2 pi times the square root of the ratio of length to earth field (little g), one >sees immediately then, from this well known expression, that the sensitivity is proportional to the square of the period. > So then--to increase your sensitivity, hang as long a rod as you can find, consistent with your house size, and then place your sensor at the bottom. There are many possible sensor types to go with this incredibly cheap but probably very effective earthquake detector. They could be moire' pattern >types with white light (incrediby simple) to function as a tsunami detector. Or they might be greatly, greatly sensitive by means of the Ronchi approach, who made optical testing famous by means of a coarse grating (much better than the classic knife edge test). The Ronchi ruling works with white >light! Or the sensor might be capacitive in nature like my SDC array. The list of possibilities goes on and on, thus my interest in the serendipty that is likely to come out of the listserve. > Randall > > > -- Hi,

thanks for the reply.  I did know that lengthening the pendulum also lengthens the period but to hang one from the top of my house has some practical problems(!).

I had hoped there might be some other way of tackling the problem.  The Volksmeter II seems to have a pendulum of around 0.5 meters but It's response goes out to 10s of seconds - http://www.rllinstruments.com/VMIIDSPg8.htm .  So I guess I'm looking for some cheap/easy way of lengthening the period.  I can't afford the $999 to buy it.  :-(

Thanks

Ian

Randall Peters wrote:
Ian,
    Since you asked about period extension to increase sensitivity, let me explain something very few seem to understand.  The sensitivity of a simple pendulum is just like that of every other seismometer; i.e., you can show that it is proportional to the square of the period.  This can be proven from
the equations of motion of the various mechanical oscillators in general, but for the pendulum, understanding is trivial.
    As anybody would expect from 'horse-sense', the longer the 'quasi-rigid' pendulum, the greater the sensitivity of the instrument if the sensor is placed at the bottom.  Because the period of the pendulum is given by 2 pi times the square root of the ratio of length to earth field (little g), one
sees immediately then, from this well known expression, that the sensitivity is proportional to the square of the period.
   So then--to increase your sensitivity, hang as long a rod as you can find, consistent with your house size, and then place your sensor at the bottom.  There are many possible sensor types to go with this incredibly cheap but probably very effective earthquake detector.   They could be moire' pattern
types with white light (incrediby simple) to function as a tsunami detector.  Or they might be greatly, greatly sensitive by means of the Ronchi approach, who made optical testing famous by means of a coarse grating (much better than the classic knife edge test).  The Ronchi ruling works with white
light!  Or the sensor might be capacitive in nature like my SDC array.  The list of possibilities goes on and on, thus my interest in the serendipty that is likely to come out of the listserve.
   Randall

--

Subject: More productive exchange of ideas with graphics? From: John Lahr johnjan@........ Date: Fri, 09 Nov 2007 07:26:02 -0800 The discussion of various hinges and seismometer designs is very interesting, but in many cases I find it difficult to visualize the exact setup that is being described. A photograph or a sketch would be very helpful. One way to do this is to start a blog. It's easy to do at: http://blogger.com. I started a blog, just to see how it worked, and it only took a few minutes to add an entry. My "trial" entry shows the AS-1 sensor: http://seismoedu.blogspot.com/ I'm sure there are other posting options as well. Cheers, John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismometer sensitivity--fundamental physics From: ian ian@........... Date: Fri, 09 Nov 2007 15:34:18 +0000 Hi, I think this morning's fog may be lifting. The idea, presumably, is that it is not used as a pendulum but as a plumb-bob. It points to the centre of the earth and, as the waves pass, the position of the centre of the earth moves relative to the local ground, causing the device to shift about. So absolute position measurement of the end of the device is best. I'll crawl back into my hole now... Ian Randall Peters wrote: >Ian, > Since you asked about period extension to increase sensitivity, let me explain something very few seem to understand. The sensitivity of a simple pendulum is just like that of every other seismometer; i.e., you can show that it is proportional to the square of the period. This can be proven from >the equations of motion of the various mechanical oscillators in general, but for the pendulum, understanding is trivial. > As anybody would expect from 'horse-sense', the longer the 'quasi-rigid' pendulum, the greater the sensitivity of the instrument if the sensor is placed at the bottom. Because the period of the pendulum is given by 2 pi times the square root of the ratio of length to earth field (little g), one >sees immediately then, from this well known expression, that the sensitivity is proportional to the square of the period. > So then--to increase your sensitivity, hang as long a rod as you can find, consistent with your house size, and then place your sensor at the bottom. There are many possible sensor types to go with this incredibly cheap but probably very effective earthquake detector. They could be moire' pattern >types with white light (incrediby simple) to function as a tsunami detector. Or they might be greatly, greatly sensitive by means of the Ronchi approach, who made optical testing famous by means of a coarse grating (much better than the classic knife edge test). The Ronchi ruling works with white >light! Or the sensor might be capacitive in nature like my SDC array. The list of possibilities goes on and on, thus my interest in the serendipty that is likely to come out of the listserve. > Randall > > > -- Hi,

I think this morning's fog may be lifting.  The idea, presumably, is that it is not used as a pendulum but as a plumb-bob.  It points to the centre of the earth and, as the waves pass, the position of the centre of the earth moves relative to the local ground, causing the device to shift about.  So absolute position measurement of the end of the device is best.

I'll crawl back into my hole now...

Ian



Randall Peters wrote:
Ian,
    Since you asked about period extension to increase sensitivity, let me explain something very few seem to understand.  The sensitivity of a simple pendulum is just like that of every other seismometer; i.e., you can show that it is proportional to the square of the period.  This can be proven from
the equations of motion of the various mechanical oscillators in general, but for the pendulum, understanding is trivial.
    As anybody would expect from 'horse-sense', the longer the 'quasi-rigid' pendulum, the greater the sensitivity of the instrument if the sensor is placed at the bottom.  Because the period of the pendulum is given by 2 pi times the square root of the ratio of length to earth field (little g), one
sees immediately then, from this well known expression, that the sensitivity is proportional to the square of the period.
   So then--to increase your sensitivity, hang as long a rod as you can find, consistent with your house size, and then place your sensor at the bottom.  There are many possible sensor types to go with this incredibly cheap but probably very effective earthquake detector.   They could be moire' pattern
types with white light (incrediby simple) to function as a tsunami detector.  Or they might be greatly, greatly sensitive by means of the Ronchi approach, who made optical testing famous by means of a coarse grating (much better than the classic knife edge test).  The Ronchi ruling works with white
light!  Or the sensor might be capacitive in nature like my SDC array.  The list of possibilities goes on and on, thus my interest in the serendipty that is likely to come out of the listserve.
   Randall

--

Subject: Re: More productive exchange of ideas with graphics? From: "Jerry Payton" gpayton880@....... Date: Fri, 9 Nov 2007 09:46:29 -0600 John, I agree that visualization is VERY difficult sometimes, but I hesitate creating a separate blog since it might water down the discussions here. People might move to the blogs instead of here and some might be left out of the comments. I am doing a "desktop experiment" right now with this and it would best be show rather than described. I am suspending a ball point pen, as discussed. On the other end of the pen is a ring magnet which is suspended about 1/2" above the edge of a spool of bulk wire, which is connected directly connected to my electronics. Thus far, it detects my walking up to the desk and other movements. I am allowing some time to see if an EQ event happens (I hope). Of course, it is not damped and movement could be in any direction. I haven't crossed that bridge yet. Jerry ----- Original Message ----- From: John Lahr To: psn-l@.............. Sent: Friday, November 09, 2007 9:26 AM Subject: More productive exchange of ideas with graphics? The discussion of various hinges and seismometer designs is very interesting, but in many cases I find it difficult to visualize the exact setup that is being described. A photograph or a sketch would be very helpful. One way to do this is to start a blog. It's easy to do at: http://blogger.com. I started a blog, just to see how it worked, and it only took a few minutes to add an entry. My "trial" entry shows the AS-1 sensor: http://seismoedu.blogspot.com/ I'm sure there are other posting options as well. Cheers, John __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
John,
 
I agree that visualization is VERY difficult sometimes, but I=20 hesitate creating a separate blog since it might water down = the=20 discussions here.  People might move to the blogs instead of here = and some=20 might be left out of the comments.
 
I am doing a "desktop experiment" right now with this and it would = best be=20 show rather than described.  I am suspending a ball point pen, as=20 discussed.  On the other end of the pen is a ring magnet which is = suspended=20 about 1/2" above the edge of a spool of bulk wire, which is = connected=20 directly connected to my electronics.
 
Thus far, it detects my walking up to the desk and other = movements.  I=20 am allowing some time to see if an EQ event happens (I hope).  Of = course,=20 it is not damped and movement could be in any direction.  I haven't = crossed=20 that bridge yet.
 
Jerry
 
 
----- Original Message -----=20
From: John Lahr =
Sent: Friday, November 09, 2007 9:26 AM
Subject: More productive exchange of ideas with=20 graphics?

The discussion of various hinges and seismometer designs = is very=20
interesting, but in many cases I find it difficult to visualize the=20
exact setup that is being described.  A photograph or a sketch = would=20
be very helpful.

One way to do this is to start a blog.  = It's=20 easy to do
at:  http://blogger.com.  I started a = blog, just=20 to see how it
worked, and it only took a few minutes to add an = entry. =20 My "trial"
entry shows the AS-1 sensor:  http://seismoedu.blogspot.com/

I'm=20 sure there are other posting options as=20 well.

Cheers,
John


_________________________________= _________________________

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: RE: More productive exchange of ideas with graphics? From: "Keith Payea" kpayea@.............. Date: Fri, 9 Nov 2007 08:26:52 -0800 All: One person's problem is another's data. Instead of trying to constrain the movement to one direction, try to figure out a way to measure the displacement direction as well as amplitude. Then one could detect earthquakes from any direction and know something about the direction the waves were travelling. Just throwing another log on this bonfire, I'm afraid... Keith _____ From: psn-l-request@.............. [mailto:psn-l-request@............... On Behalf Of Jerry Payton Sent: Friday, November 09, 2007 7:46 AM To: psn-l@.............. Subject: Re: More productive exchange of ideas with graphics? John, I agree that visualization is VERY difficult sometimes, but I hesitate creating a separate blog since it might water down the discussions here. People might move to the blogs instead of here and some might be left out of the comments. I am doing a "desktop experiment" right now with this and it would best be show rather than described. I am suspending a ball point pen, as discussed. On the other end of the pen is a ring magnet which is suspended about 1/2" above the edge of a spool of bulk wire, which is connected directly connected to my electronics. Thus far, it detects my walking up to the desk and other movements. I am allowing some time to see if an EQ event happens (I hope). Of course, it is not damped and movement could be in any direction. I haven't crossed that bridge yet. Jerry ----- Original Message ----- From: John Lahr To: psn-l@.............. Sent: Friday, November 09, 2007 9:26 AM Subject: More productive exchange of ideas with graphics? The discussion of various hinges and seismometer designs is very interesting, but in many cases I find it difficult to visualize the exact setup that is being described. A photograph or a sketch would be very helpful. One way to do this is to start a blog. It's easy to do at: http://blogger.com. I started a blog, just to see how it worked, and it only took a few minutes to add an entry. My "trial" entry shows the AS-1 sensor: http://seismoedu.blogspot.com/ I'm sure there are other posting options as well. Cheers, John __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
All:
 
One person's problem is another's data.  = Instead of=20 trying to constrain the movement to one direction, try to figure out a = way to=20 measure the displacement direction as well as amplitude.  Then one = could=20 detect earthquakes from any direction and know something about the = direction the=20 waves were travelling.
 
Just throwing another log on this bonfire, I'm=20 afraid...
 
    Keith

From: psn-l-request@................. [mailto:psn-l-request@............... On Behalf Of Jerry=20 Payton
Sent: Friday, November 09, 2007 7:46 AM
To:=20 psn-l@..............
Subject: Re: More productive exchange of = ideas=20 with graphics?

John,
 
I agree that visualization is VERY difficult sometimes, but I=20 hesitate creating a separate blog since it might water down = the=20 discussions here.  People might move to the blogs instead of here = and some=20 might be left out of the comments.
 
I am doing a "desktop experiment" right now with this and it would = best be=20 show rather than described.  I am suspending a ball point pen, as=20 discussed.  On the other end of the pen is a ring magnet which is = suspended=20 about 1/2" above the edge of a spool of bulk wire, which is = connected=20 directly connected to my electronics.
 
Thus far, it detects my walking up to the desk and other = movements.  I=20 am allowing some time to see if an EQ event happens (I hope).  Of = course,=20 it is not damped and movement could be in any direction.  I haven't = crossed=20 that bridge yet.
 
Jerry
 
 
----- Original Message -----=20
From: John Lahr =
Sent: Friday, November 09, 2007 9:26 AM
Subject: More productive exchange of ideas with=20 graphics?

The discussion of various hinges and seismometer designs = is very=20
interesting, but in many cases I find it difficult to visualize the=20
exact setup that is being described.  A photograph or a sketch = would=20
be very helpful.

One way to do this is to start a blog.  = It's=20 easy to do
at:  http://blogger.com.  I started a = blog, just=20 to see how it
worked, and it only took a few minutes to add an = entry. =20 My "trial"
entry shows the AS-1 sensor:  http://seismoedu.blogspot.com/

I'm=20 sure there are other posting options as=20 well.

Cheers,
John


_________________________________= _________________________

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: Re: idea for an axis From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 09:25:24 -0700 Hello PSN; You guys sound more like scientists than laymen ?? Sort of like the American Association for the Advancement of Science that once showed on a cover of their magazine the secrets of how a thermo-nuke is first initiated by converging shock waves of a detonated wafer of high explosive looked at through some kind of XRAY photography. It made me think of how Tim McVey might have improved the performance of his already deadly explosives. I am not sure you want to make motion just be all in one axis of motion I have in the past had very good EQ signatures using a free hanging pendulum with a 5 lb lead mass which had a circular speaker magnet attached. It was damped in synthetic motor oil and free to move over the coil in any horizontal direction. You do not know the direction of motion you only see the various phases as well as first time of arrival. I have never understood the amature infatuation with knowing all the fine details when they are really not necessary to keep a layman happy. Also I have been looking at free periods in relation to gravity and how to oppose or reduce the 32.17fpss to more like 18.9 inpss I am thinking in terms of maybe a five pound mass with a specific gravity of like 1.0516 or so that could be immersed in pure water and use a very delicate spring extended by 12 inches to get a 5 second period or so. There must be some way to emulate specific gravity by the use of bouyancy ( eg using a cylinder or cone or other primative shape to displace water and achieve the right response in free period. I am looking for a cheap way to get maybe 4 second period so I do not need to filter or equalize when I amplify( except anti-alise). It seems there are many different ways to attack this problem and I am certain it has been done so before, so why do we not see any basic research on the part of science to invent the best and cheapest vertical sensor. I really like a free swinging pendulum ( just the horizontal ) and free vertical whatever. with a magnetic damper but not sure the best magnet coil relationship to get the best signal strength. Such a thing in a vacuum and properly shielded should be free of most interference. I guess I am two dimensional in my thinking and not three like the rest of you. The best of all sensors would just be a single unit to measure motion no matter what the dimension it happens in. Now I am ALL DIMENSIONAL and after thinking out loud was wondering to you guys if such an all dimensional ( single unit ) velocity sensor has ever been made ?? Possibly a mass suspended in a magnetic field to be restored to a fixed point in some strange fashion I have never seen ?? Sort of like that (REAL) levitating ball in the movie "Flying Saucers Vs The Earth" This is not a free period kind of issue but more the energy required to recenter the mass once it has been disturbed in whatever direction. Any Thoughts about any of this ? I know where I stand on this world so please do not make fun unless I can laugh too :-) Is there any reason to keep Seismometer Research Secret ?? Almost noone wants these things. Regards geoff ----- Original Message ----- From: "Jerry Payton" To: Sent: Friday, November 09, 2007 5:20 AM Subject: Re: idea for an axis > Hi, > > I have been following this discussion with great interest. I have been > wondering how you would control the rotation of the free end of the > suspended pendulum? As Ted pointed out in his email, it rotated. How would > one maintain the motion in a horizontal plane - - AND - - what kind (size, > weight, &etc.) of coil. Of course, Meredith suggested a light bulb. > > I'm just trying to wrap my brain around this idea as a whole assembly. > > Best Regards, > Jerry Payton > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: More productive exchange of ideas with graphics? From: Dave Youden dyouden@............. Date: Fri, 09 Nov 2007 11:36:12 -0500 John has a good idea. After reading his post I went to blogger and posted some pictures of the two seismos that I am currently operating. Go to http://MarvelousMachines.blogspot.com To view them. I hope that this prompts others to do the same. Dave... John Lahr wrote: > The discussion of various hinges and seismometer designs is very > interesting, but in many cases I find it difficult to visualize the > exact setup that is being described. A photograph or a sketch would > be very helpful. > > One way to do this is to start a blog. It's easy to do at: > http://blogger.com. I started a blog, just to see how it worked, and > it only took a few minutes to add an entry. My "trial" entry shows > the AS-1 sensor: http://seismoedu.blogspot.com/ > > I'm sure there are other posting options as well. > > Cheers, > John > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with the body of > the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > -- David H. Youden Olympic Precision, Inc. WTC LLC 43 Pine Street White River Junction, VT 05001 Office tel: 802-291-7007 Office fax: 802-291-7009 Home office: 802-484-5423 Home fax: 802-484-5429 Cellular: 802-952-8121 __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: idea for an axis From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 09:33:12 -0700 You must find some way to reduce the pull of gravity to meet the formula P=2Pisqrt(Length(inches)/386.04)) That Is the ONLY thing I understand. The 386.04 must be more like 3 inchespss or maybe like the effects of gravity on an incline like one degree from the vertical. There are many ways to do this but none seem to be cheap for a person living on 12K a year. ----- Original Message ----- From: "ian" To: Sent: Friday, November 09, 2007 6:14 AM Subject: Re: idea for an axis > Hi, > > just tried this idea with neodymium magnet, 1 pen, 2 straws and a small > mass at the end. I get a period of 1.4 seconds and indeed it does go on > for a while. > > Silly question coming up - please be merciful(!) - how can I turn this > into a long period teleseismic device (period of 10s of seconds)? > > Thanks > > Ian > > ChrisAtUpw@....... wrote: > >> In a message dated 09/11/2007, gmvoeth@........... writes: >> >> DID you clean the ink off the tip >> before doing this ? >> >> Hi Geoff, >> >> The BIC pens have tungsten carbide balls. If you cut off the >> plastic ink holder, you can push out the 1 mm ball with a fine drill / >> piano wire. You can then clean everything with methylated spirits and >> reassemble it. The ball can be crimped or glued in position with two >> part acrylic adhesive. >> >> However, you can buy martensitic SS balls from www.smallparts.com >> They are ferromagnetic. >> >> Regards, >> >> Chris Chapman > > > -- > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: More productive exchange of ideas with graphics? From: ChrisAtUpw@....... Date: Fri, 9 Nov 2007 11:36:59 EST In a message dated 09/11/2007, kpayea@.............. writes: One person's problem is another's data. Instead of trying to constrain the movement to one direction, try to figure out a way to measure the displacement direction as well as amplitude. Then one could detect earthquakes from any direction and know something about the direction the waves were travelling. Hi Keith, How about putting four magnets on the bottom of the bob and using figure of 8 coils? Alternatively one central magnet and four coils overlapping the edges? Regards, Chris Chapman
In a message dated 09/11/2007, kpayea@.............. writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
One person's problem is another's data.  Ins= tead of=20 trying to constrain the movement to one direction, try to figure out a way= to=20 measure the displacement direction as well as amplitude.  Then one co= uld=20 detect earthquakes from any direction and know something about the directi= on=20 the waves were travelling.
Hi Keith,
 
    How about putting four magnets on the bottom of= the=20 bob and using figure of 8 coils? Alternatively one central magnet and f= our=20 coils overlapping the edges?
 
    Regards,
 
    Chris Chapman
Subject: Re: More productive exchange of ideas with graphics? From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 09:38:56 -0700 You can imagine the wave as a straight line approaching and according to the times received at different stations know direction by the displacement in time between two stations using only first time of arrival. With two stations you get two possibilities with direction and distance but more than likely only one direction will be the Common EQ area. As long as no human is playing games with your station you should be able to have faith in your results. ----- Original Message ----- From: "Keith Payea" To: Sent: Friday, November 09, 2007 9:26 AM Subject: RE: More productive exchange of ideas with graphics? > All: > > One person's problem is another's data. Instead of trying to constrain the > movement to one direction, try to figure out a way to measure the > displacement direction as well as amplitude. Then one could detect > earthquakes from any direction and know something about the direction the > waves were travelling. > > Just throwing another log on this bonfire, I'm afraid... > > Keith > > _____ > > From: psn-l-request@.............. [mailto:psn-l-request@............... On > Behalf Of Jerry Payton > Sent: Friday, November 09, 2007 7:46 AM > To: psn-l@.............. > Subject: Re: More productive exchange of ideas with graphics? > > > John, > > I agree that visualization is VERY difficult sometimes, but I hesitate > creating a separate blog since it might water down the discussions here. > People might move to the blogs instead of here and some might be left out of > the comments. > > I am doing a "desktop experiment" right now with this and it would best be > show rather than described. I am suspending a ball point pen, as discussed. > On the other end of the pen is a ring magnet which is suspended about 1/2" > above the edge of a spool of bulk wire, which is connected directly > connected to my electronics. > > Thus far, it detects my walking up to the desk and other movements. I am > allowing some time to see if an EQ event happens (I hope). Of course, it is > not damped and movement could be in any direction. I haven't crossed that > bridge yet. > > Jerry > > > ----- Original Message ----- > From: John Lahr > To: psn-l@.............. > Sent: Friday, November 09, 2007 9:26 AM > Subject: More productive exchange of ideas with graphics? > > The discussion of various hinges and seismometer designs is very > interesting, but in many cases I find it difficult to visualize the > exact setup that is being described. A photograph or a sketch would > be very helpful. > > One way to do this is to start a blog. It's easy to do > at: http://blogger.com. I started a blog, just to see how it > worked, and it only took a few minutes to add an entry. My "trial" > entry shows the AS-1 sensor: http://seismoedu.blogspot.com/ > > I'm sure there are other posting options as well. > > Cheers, > John > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: More productive exchange of ideas with graphics? From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 09:44:08 -0700 I use my personal website to post images. For small numbers of interested persons this way seems best since most internet users are given a PWP as common practice. So long as the general public does not attack your site this is the most private way of sharing info. I once went on a USENET virus group and attacked virus writers after which I was flooded with all sorts of viruses one that got past a company scanner because it was so new. :-( Never Been infected except maybe with Magic Lantern ??? ----- Original Message ----- From: "John Lahr" To: Sent: Friday, November 09, 2007 8:26 AM Subject: More productive exchange of ideas with graphics? > The discussion of various hinges and seismometer designs is very > interesting, but in many cases I find it difficult to visualize the > exact setup that is being described. A photograph or a sketch would > be very helpful. > > One way to do this is to start a blog. It's easy to do > at: http://blogger.com. I started a blog, just to see how it > worked, and it only took a few minutes to add an entry. My "trial" > entry shows the AS-1 sensor: http://seismoedu.blogspot.com/ > > I'm sure there are other posting options as well. > > Cheers, > John > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: More productive exchange of ideas with graphics? From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 09:46:58 -0700 If you could build a device with like 0.7 Q that is natural Friction or ?? then you need to rob no energy from the detector to create a signal. Better signal to noise ratio I would think. ----- Original Message ----- From: "Jerry Payton" To: Sent: Friday, November 09, 2007 8:46 AM Subject: Re: More productive exchange of ideas with graphics? > John, > > I agree that visualization is VERY difficult sometimes, but I hesitate > creating a separate blog since it might water down the discussions here. > People might move to the blogs instead of here and some might be left out of > the comments. > > I am doing a "desktop experiment" right now with this and it would best be > show rather than described. I am suspending a ball point pen, as discussed. > On the other end of the pen is a ring magnet which is suspended about 1/2" > above the edge of a spool of bulk wire, which is connected directly > connected to my electronics. > > Thus far, it detects my walking up to the desk and other movements. I am > allowing some time to see if an EQ event happens (I hope). Of course, it is > not damped and movement could be in any direction. I haven't crossed that > bridge yet. > > Jerry > > > ----- Original Message ----- > From: John Lahr > To: psn-l@.............. > Sent: Friday, November 09, 2007 9:26 AM > Subject: More productive exchange of ideas with graphics? > > > The discussion of various hinges and seismometer designs is very > interesting, but in many cases I find it difficult to visualize the > exact setup that is being described. A photograph or a sketch would > be very helpful. > > One way to do this is to start a blog. It's easy to do > at: http://blogger.com. I started a blog, just to see how it > worked, and it only took a few minutes to add an entry. My "trial" > entry shows the AS-1 sensor: http://seismoedu.blogspot.com/ > > I'm sure there are other posting options as well. > > Cheers, > John > > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismometer sensitivity--fundamental physics From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 09:49:37 -0700 Then you got to worry about the Earths Rotation affecting the direction of the pendulum. ?? ----- Original Message ----- From: "Randall Peters" To: Sent: Friday, November 09, 2007 6:35 AM Subject: seismometer sensitivity--fundamental physics > Ian, > Since you asked about period extension to increase sensitivity, let me explain something very few seem to understand. The > sensitivity of a simple pendulum is just like that of every other seismometer; i.e., you can show that it is proportional to the > square of the period. This can be proven from > the equations of motion of the various mechanical oscillators in general, but for the pendulum, understanding is trivial. > As anybody would expect from 'horse-sense', the longer the 'quasi-rigid' pendulum, the greater the sensitivity of the > instrument if the sensor is placed at the bottom. Because the period of the pendulum is given by 2 pi times the square root of > the ratio of length to earth field (little g), one > sees immediately then, from this well known expression, that the sensitivity is proportional to the square of the period. > So then--to increase your sensitivity, hang as long a rod as you can find, consistent with your house size, and then place your > sensor at the bottom. There are many possible sensor types to go with this incredibly cheap but probably very effective > earthquake detector. They could be moire' pattern > types with white light (incrediby simple) to function as a tsunami detector. Or they might be greatly, greatly sensitive by means > of the Ronchi approach, who made optical testing famous by means of a coarse grating (much better than the classic knife edge > test). The Ronchi ruling works with white > light! Or the sensor might be capacitive in nature like my SDC array. The list of possibilities goes on and on, thus my interest > in the serendipty that is likely to come out of the listserve. > Randall > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: seismometer sensitivity--fundamental physics From: "Geoff" gmvoeth@........... Date: Fri, 9 Nov 2007 09:50:47 -0700 More than 4 or 5 seconds is a waste of time and money to deal with. ----- Original Message ----- From: "ian" To: Sent: Friday, November 09, 2007 6:46 AM Subject: Re: seismometer sensitivity--fundamental physics > Hi, > > thanks for the reply. I did know that lengthening the pendulum also > lengthens the period but to hang one from the top of my house has some > practical problems(!). > > I had hoped there might be some other way of tackling the problem. The > Volksmeter II seems to have a pendulum of around 0.5 meters but It's > response goes out to 10s of seconds - > http://www.rllinstruments.com/VMIIDSPg8.htm . So I guess I'm looking > for some cheap/easy way of lengthening the period. I can't afford the > $999 to buy it. :-( > > Thanks > > Ian > > Randall Peters wrote: > >>Ian, >> Since you asked about period extension to increase sensitivity, let me explain something very few seem to understand. The >> sensitivity of a simple pendulum is just like that of every other seismometer; i.e., you can show that it is proportional to the >> square of the period. This can be proven from >>the equations of motion of the various mechanical oscillators in general, but for the pendulum, understanding is trivial. >> As anybody would expect from 'horse-sense', the longer the 'quasi-rigid' pendulum, the greater the sensitivity of the >> instrument if the sensor is placed at the bottom. Because the period of the pendulum is given by 2 pi times the square root of >> the ratio of length to earth field (little g), one >>sees immediately then, from this well known expression, that the sensitivity is proportional to the square of the period. >> So then--to increase your sensitivity, hang as long a rod as you can find, consistent with your house size, and then place your >> sensor at the bottom. There are many possible sensor types to go with this incredibly cheap but probably very effective >> earthquake detector. They could be moire' pattern >>types with white light (incrediby simple) to function as a tsunami detector. Or they might be greatly, greatly sensitive by means >>of the Ronchi approach, who made optical testing famous by means of a coarse grating (much better than the classic knife edge >>test). The Ronchi ruling works with white >>light! Or the sensor might be capacitive in nature like my SDC array. The list of possibilities goes on and on, thus my interest >>in the serendipty that is likely to come out of the listserve. >> Randall >> >> >> > > -- > > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: further magnet ideas From: "meredith lamb" paleoartifact@......... Date: Fri, 9 Nov 2007 10:01:33 -0700 Hi Randall and all, As far as utilizing a "crossed rod" pivot/axis (crossed/rolling cylinders) of neo magnets, the standard neo magnet has its poles on the ends of these rods/cylinders...making it somewhat difficult to do much with them. Forcefield magnets (http://forcefieldmagnets.com) does have a 1/4" diameter x 1" length (gold plating...of course..ha) magnet were the magnets poles are through the diameter. It is item #0056, and sells for $3. This would make perhaps right angle positioning one magnet across 2 other magnets of the same polarization alot easier....(who knows they might center pretty good?). Of course the gold plating isn't a hard surface; but it might make for a interesting axis/pivot as the "mass" weights will be fairly limited anyway. Generally....the gold plate "could" peel off after time or from impact abuse more easily than the standard chrome plating. I "think" this could be what Chris Chapman has in mind? These were most useful for diamagnetically levitating select pencil leads afew years back. Unlike some magnets; these have been around for a number of years and I doubt Forcefield will drop selling them anytime soon. I'd think the axis/pivot application could be used for both a hanging horizontal...and perhaps a vertical axis/pivot also. Meredith Lamb On Nov 9, 2007 5:53 AM, Randall Peters wrote: > > Hey, > Don't know whether we qualify as 'great minds', but at least we're 'on > the same sheet of music'. The first thing I thought about following the > 'obvious standard pendulum' was whether the idea could be extended to > verticals--just as Meredith suggested. Also, Chris alluded to another > element of the > idea--rolling cylinders. > Before the 'dangling pen' I had noticed that two cylindrical rare earth > magnets roll together nicely. If you make one stationary and 'ping' the > other it oscillates nicely. What's the primary source of damping? Some is > the rolling friction, and some derive from induced eddy current in earch. > If > we reduce the rolling part, who cares about the eddy current parts? After > all, they are part of the desired Q-reduction that has become standard to > eliminate transient response of the instrument. Thus an arrangement I think > could have promise is the following. > A few years ago, now retired Georgia Tech seismologist Tim Long (very > highly honored in our state) sent me a picture of a vertical he designed. > Unlike with most instruments that use Lucien LaCoste's famous zero-length > spring, Tim put the 'approximate' zero-length spring (probably a screen door > type) below the boom. This is accomplished by flex-pivot elastic strips > at the short end (top) of the U-shaped steel iron strip that serves as the > 'backbone' of the instrument. > I believe that Tim's flex-pivot strips could be replaced with two > rare-earth magnets, one 'stuck' to the top of the frame and the other glued > to the non-sensor end of the required non-ferrous boom. The boom magnet > would roll on the frame magnet, with the contact force being made small (the > two > trying to pull apart) by 'proper' placement of each of the magnets. > You amateurs are 'like a fresh cool wind' on a 'hot-as-hell Georgia > August afternoon' and I love your enthusiam toward what might to the 'pro's' > look like hare-brained ideas. I look forward to additional brainstorming on > these thoughts. > Randall > >
Hi Randall and all,
 
As far as utilizing a "crossed rod" pivot/axis (crossed/rolling cylinders) of neo magnets, the standard
neo magnet has its poles on the ends of these rods/cylinders...making it somewhat difficult to do much
with them.  Forcefield magnets (http://forcefieldmagnets.com) does have a 1/4" diameter x 1"
length (gold plating...of course..ha) magnet were the magnets poles are through the diameter. 
It is item #0056, and sells for $3.  This would make perhaps right angle positioning one magnet
across 2 other magnets of the same polarization alot easier....(who knows they might center pretty
good?).  Of course the gold plating isn't a hard surface; but it might make for a interesting axis/pivot
as the "mass" weights will be fairly limited anyway.   Generally....the gold plate "could" peel off
after time or from impact abuse more easily than the standard chrome plating.
 
I "think" this could be what Chris Chapman has in mind?  These were most useful for diamagnetically
levitating select pencil leads afew years back.  Unlike some magnets; these have been around
for a number of years and I doubt Forcefield will drop selling them anytime soon.   
 
I'd think the axis/pivot application could be used for both a hanging horizontal...and perhaps a vertical
axis/pivot also.
 
Meredith Lamb 

On Nov 9, 2007 5:53 AM, Randall Peters <PETERS_RD@..........> wrote:

Hey,
   Don't know whether we qualify as 'great minds', but at least we're 'on the same sheet of music'.  The first thing I thought about following the 'obvious standard pendulum' was whether the idea could be extended to verticals--just as Meredith suggested.  Also, Chris alluded to another element of the
idea--rolling cylinders.
   Before the 'dangling pen' I had noticed that two cylindrical rare earth magnets roll together nicely.  If you make one stationary and 'ping' the other it oscillates nicely.  What's the primary source of damping?   Some is the rolling friction, and some derive from induced eddy current in earch.  If
we reduce the rolling part, who cares about the eddy current parts?  After all, they are part of the desired Q-reduction that has become standard to eliminate transient response of the instrument.  Thus an arrangement I think could have promise is the following.
   A few years ago, now retired Georgia Tech seismologist Tim Long (very highly honored in our state) sent me a picture of a vertical he designed.  Unlike with most instruments that use Lucien LaCoste's famous zero-length spring, Tim put the 'approximate' zero-length spring (probably a screen door
type) below the boom.  This is accomplished by flex-pivot elastic strips at the short end (top) of the U-shaped steel iron strip that serves as the 'backbone' of the instrument.
   I believe that Tim's flex-pivot strips could be replaced with two rare-earth magnets, one 'stuck' to the top of the frame and the other glued to the non-sensor end of the required non-ferrous boom.  The boom magnet would roll on the frame magnet, with the contact force being made small (the two
trying to pull apart) by 'proper' placement of each of the magnets.
  You amateurs are 'like a fresh cool wind' on a 'hot-as-hell Georgia August afternoon' and I love your enthusiam toward what might to the 'pro's' look like hare-brained ideas.  I look forward to additional brainstorming on these thoughts.
   Randall


Subject: long-period pendulums From: Randall Peters PETERS_RD@.......... Date: Fri, 09 Nov 2007 13:15:30 -0500 I noticed the interest in period lengthening of a compound pendulum, as though any such change toward long period would be an advantage. Unfortunately, this is not the case. I have spent the biggest part of my career studying internal friction using the rod-pendulum-types in which there is a mass located above the axis as well as below. Although the period can be made very long, it does not result in an increased sensitivity in accord with what is experienced with the simple pendulum This style of pendulum is an entirely different system than the folded pendulum, which I have also researched. As a compact unit, the folded pendulum can be made very sensitive. There can be an advantage to the use of the long-period rod pendulum, but not in the traditional seismic sense. I wrote a paper titled "Compound pendulum to monitor hurricanes and tropical storms", online at http://arxiv.org/abs/physics/0610092 and which uses such a pendulum. For those who want to understand the physics behind my preceding comments, this paper provides the details. To appreciate the lack of sensitivity (to anything other than really, really low frequency drive, including tilt), consider the following. Imagine a rod in which the axis approaches the center of mass. The period thus approaches infinity; so you might expect it to have really great sensitivity. The problem with the rod pendulum is it becomes very sensitive to internal structural change while having little sensitivity to high frequency seismic activity. In fact, the sensitivity at frequencies above the very low eigenfrequency is virtually zero. The reason is obvious. If you accelerate an extended object with a force that goes through the center of mass, it does not rotate. Thus it cannot serve as a seismometer. Guess you know already that some mechanical systems can be intuitively hard to understand if not downright baffling! Before I was able to really appreciate what was happening with this pendulum, as relates to seismic sensing, I had to thoroughly describe it with the tools of physics; i.e., mathematics. Only afterwards was I able to conceptually appreciate its properties. There was a comment about the VolksMeter. How can it, through 'period extension' operate well in spite of a pendulum less than a meter in length. The key is in what is done digitally. The raw data output is not good for teleseismic viewing, where sensitivity is a must. But the integral of that data alters the response of the instrument (same as is done in the Shackleford-Gunderson). The Bode plot falls off with frequency, allowing the 20 s period teleseisms to be seen above noise in many cases, for M 6 or more. It is not a case in which the increased SNR derives from the pendulum; rather it derives from the electronics employed. Even force-balance commercial units rely on electronics to give great response even though the eigenfrequency of the non-feedback instrument is too high for good performance. There the tailoring of both lower corner frequency and damping is accomplished by means of the negative feedback employed. Randall Subject: Re: further magnet ideas From: Charles Patton charles.r.patton@........ Date: Fri, 09 Nov 2007 10:32:48 -0800 One thought that occurs to me is to start with a rail of steel angle iron (for a flux return) then add the two "pills" that Meredith mentions below separated by some distance (the length of your pivot) and installed with one N and one S down to the rail. On top of the magnets get some of the flat carbide blades that are replacement parts for some paint scrapers. These are triangular (I seem to remember -- I'm traveling so I can't go look at them at the moment) about 1" on a side and about 0.020" thick. I bought some from ACE hardware, but they're probably also available from Home Depot style stores. The key here is that the angle iron rail gives a flat common reference surface from a geometry viewpoint and has enough bulk for a good flux return. The carbide scraper blades give you the hard, low rolling friction surface -- better than the gold or the composition of the magnet. As a side point, one of the reasons the high strength magnets are plated with nickel or gold is that their alloys are particularly subject to corrosion, hence require plating to protect them. I strongly recommend not removing the "gold" coating as it would make the magnets subject to atmospheric deterioration. Charles Patton meredith lamb wrote: > Hi Randall and all, > > As far as utilizing a "crossed rod" pivot/axis (crossed/rolling > cylinders) of neo magnets, the standard > neo magnet has its poles on the ends of these rods/cylinders...making it > somewhat difficult to do much > with them. Forcefield magnets (http://forcefieldmagnets.com > ) does have a 1/4" diameter x 1" > length (gold plating...of course..ha) magnet were the magnets poles are > through the diameter. > It is item #0056, and sells for $3. This would make perhaps right angle > positioning one magnet > across 2 other magnets of the same polarization alot easier....(who > knows they might center pretty > good?). Of course the gold plating isn't a hard surface; but it might > make for a interesting axis/pivot > as the "mass" weights will be fairly limited anyway. Generally....the > gold plate "could" peel off > after time or from impact abuse more easily than the standard chrome > plating. > > I "think" this could be what Chris Chapman has in mind? These were most > useful for diamagnetically > levitating select pencil leads afew years back. Unlike some magnets; > these have been around > for a number of years and I doubt Forcefield will drop selling them > anytime soon. > > I'd think the axis/pivot application could be used for both a hanging > horizontal...and perhaps a vertical > axis/pivot also. > > Meredith Lamb > > On Nov 9, 2007 5:53 AM, Randall Peters > wrote: > > > Hey, > Don't know whether we qualify as 'great minds', but at least > we're 'on the same sheet of music'. The first thing I thought about > following the 'obvious standard pendulum' was whether the idea could > be extended to verticals--just as Meredith suggested. Also, Chris > alluded to another element of the > idea--rolling cylinders. > Before the 'dangling pen' I had noticed that two cylindrical rare > earth magnets roll together nicely. If you make one stationary and > 'ping' the other it oscillates nicely. What's the primary source of > damping? Some is the rolling friction, and some derive from > induced eddy current in earch. If > we reduce the rolling part, who cares about the eddy current parts? > After all, they are part of the desired Q-reduction that has become > standard to eliminate transient response of the instrument. Thus an > arrangement I think could have promise is the following. > A few years ago, now retired Georgia Tech seismologist Tim Long > (very highly honored in our state) sent me a picture of a vertical > he designed. Unlike with most instruments that use Lucien LaCoste's > famous zero-length spring, Tim put the 'approximate' zero-length > spring (probably a screen door > type) below the boom. This is accomplished by flex-pivot elastic > strips at the short end (top) of the U-shaped steel iron strip that > serves as the 'backbone' of the instrument. > I believe that Tim's flex-pivot strips could be replaced with two > rare-earth magnets, one 'stuck' to the top of the frame and the > other glued to the non-sensor end of the required non-ferrous boom. > The boom magnet would roll on the frame magnet, with the contact > force being made small (the two > trying to pull apart) by 'proper' placement of each of the magnets. > You amateurs are 'like a fresh cool wind' on a 'hot-as-hell > Georgia August afternoon' and I love your enthusiam toward what > might to the 'pro's' look like hare-brained ideas. I look forward > to additional brainstorming on these thoughts. > Randall > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Exchange of ideas with graphics From: "Kay Wyatt" kwyatt@............. Date: Fri, 9 Nov 2007 10:57:42 -0800 To all PSN folks, I joined the PSN group in September and must say that I have learned = much from everybody and I am indeed grateful. I am running my own AS-1. = However, thanks to so many advisors, I am currently constructing both a = vertical and horizontal sensor based on the collective knowledge of many = of you. Picking up knowledge from the PSN-net is like drinking through a fire = hydrant. I have especially had problems visualizing the suggested = designs with a text-only system. After emailing several PSN folks = directly for drawings, I have had many "Aha" moments when receiving = graphics. The PSN mail list doesn't allow graphics to be sent directly. Sending = hyperlinks to drawings and photos on our individual websites works very = well. But many PSN folks do not have personal websites. The PSN system allows for graphics distribution as follows (from the PSN = Welcome email): 6) Send only TEXT messages to the list. Do not include any attachments, HTML tags (this is referring to HTML code not links),=20 or so forth. If you have a picture, or other binary type files=20 to share with the group, you can uploaded when using FTP to ftp://ftp.seismicnet.com/info. See below for more information.=20 Has anybody been able to send graphics to the PSN ftp site? When I ftp = to the site I am asked for account and password. . I agree with Jerry (below) that I would worry about using John Lahr's = blog site INSTEAD of the PSN. But what about using it WITH the PSN = email system. That is, to upload a drawing to the blog and reference it = with a hyperlink to the blog site? I look forward to hearing any further discussion on this important = issue. By the way, are there any other women amateur seismologists on this = list? How many of you guys have shared your hobby with your daughters? = ;-) Kay Wyatt ----- Original Message -----=20 From: Jerry Payton=20 To: psn-l@................. Sent: Friday, November 09, 2007 7:46 AM Subject: Re: More productive exchange of ideas with graphics? John, I agree that visualization is VERY difficult sometimes, but I hesitate = creating a separate blog since it might water down the discussions here. = People might move to the blogs instead of here and some might be left = out of the comments. I am doing a "desktop experiment" right now with this and it would = best be show rather than described. I am suspending a ball point pen, = as discussed. On the other end of the pen is a ring magnet which is = suspended about 1/2" above the edge of a spool of bulk wire, which is = connected directly connected to my electronics. Thus far, it detects my walking up to the desk and other movements. I = am allowing some time to see if an EQ event happens (I hope). Of = course, it is not damped and movement could be in any direction. I = haven't crossed that bridge yet. Jerry ----- Original Message -----=20 From: John Lahr=20 To: psn-l@................. Sent: Friday, November 09, 2007 9:26 AM Subject: More productive exchange of ideas with graphics? The discussion of various hinges and seismometer designs is very=20 interesting, but in many cases I find it difficult to visualize the=20 exact setup that is being described. A photograph or a sketch would=20 be very helpful. One way to do this is to start a blog. It's easy to do=20 at: http://blogger.com. I started a blog, just to see how it=20 worked, and it only took a few minutes to add an entry. My "trial"=20 entry shows the AS-1 sensor: http://seismoedu.blogspot.com/ I'm sure there are other posting options as well. Cheers, John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) To leave this list email PSN-L-REQUEST@.............. with=20 the body of the message (first line only): unsubscribe See http://www.seismicnet.com/maillist.html for more information.
To all PSN folks,
 
I joined the PSN group in September and must say = that I=20 have learned much from everybody and I am indeed grateful.  I am = running my=20 own AS-1.  However, thanks to so many advisors, I am currently = constructing=20 both a vertical and horizontal sensor based on the collective knowledge = of many=20 of you.
 
Picking up knowledge from the PSN-net is like = drinking=20 through a fire hydrant.  I have especially had problems visualizing = the=20 suggested designs with a text-only system.  After emailing several = PSN=20 folks directly for drawings, I have had many "Aha" moments when = receiving=20 graphics.
 
The PSN mail list doesn't allow graphics to be = sent=20 directly.  Sending hyperlinks to drawings and photos on our = individual=20 websites works very well.  But many PSN folks do not have personal=20 websites.
 
The PSN system allows for graphics distribution = as follows=20 (from the PSN Welcome email):
 
6)  Send only TEXT messages to the list.  Do not include=20 any
    attachments, HTML tags (this is referring to = HTML code=20 not links),
    or so forth. If you have a picture, = or other=20 binary type files
    to share with the group, you = can=20 uploaded when using FTP to
    ftp://ftp.seismicnet.com/info.= See=20 below for more information.
Has anybody been able to send graphics to the = PSN ftp=20 site?  When I ftp to the site I am asked for account and = password. =20 ..
 
I agree with Jerry (below) that I would worry = about using=20 John Lahr's blog site INSTEAD of the PSN.  But what about using it = WITH the=20 PSN email system.  That is, to upload a drawing to the blog and = reference=20 it with a hyperlink to the blog site?
 
I look forward to hearing any further discussion = on this=20 important issue.
 
By the way, are there any other women amateur=20 seismologists on this list?  How many of you guys have shared your = hobby=20 with  your daughters?    ;-)
 
Kay Wyatt
 
 
----- Original Message -----
From:=20 Jerry = Payton=20
Sent: Friday, November 09, 2007 = 7:46=20 AM
Subject: Re: More productive = exchange of=20 ideas with graphics?

John,
 
I agree that visualization is VERY difficult sometimes, but = I=20 hesitate creating a separate blog since it might water down = the=20 discussions here.  People might move to the blogs instead of here = and=20 some might be left out of the comments.
 
I am doing a "desktop experiment" right now with this and it = would best=20 be show rather than described.  I am suspending a ball point pen, = as=20 discussed.  On the other end of the pen is a ring magnet which is = suspended about 1/2" above the edge of a spool of bulk wire, = which is=20 connected directly connected to my electronics.
 
Thus far, it detects my walking up to the desk and other = movements. =20 I am allowing some time to see if an EQ event happens (I hope).  = Of=20 course, it is not damped and movement could be in any direction.  = I=20 haven't crossed that bridge yet.
 
Jerry
 
 
----- Original Message -----=20
From: John = Lahr
Sent: Friday, November 09, 2007 9:26 AM
Subject: More productive exchange of ideas with=20 graphics?

The discussion of various hinges and seismometer = designs is=20 very
interesting, but in many cases I find it difficult to = visualize the=20
exact setup that is being described.  A photograph or a = sketch would=20
be very helpful.

One way to do this is to start a = blog.  It's=20 easy to do
at:  http://blogger.com.  I started a = blog, just=20 to see how it
worked, and it only took a few minutes to add an=20 entry.  My "trial"
entry shows the AS-1 sensor:  http://seismoedu.blogspot.com/

I'm=20 sure there are other posting options as=20 = well.

Cheers,
John


_________________________________= _________________________

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email = PSN-L-REQUEST@............... =20 with
the body of the message (first line only): unsubscribe
See = http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: A rough magnetic axis/pivot setup of the crossed rod variety From: "meredith lamb" paleoartifact@......... Date: Fri, 9 Nov 2007 11:58:32 -0700 Hi all, I put up a web page of Dr. Randall Peters magnetic axis/pivot thought and that of Chris Chapmans crossed cylinders/rods pivot suggested idea. The magnet/s involved are those from Forcefield.com, and are of the polarity where the poles are through the rod diameter; and not at the ends of the rod; which is much more common. All in all, it really seems initally VERY interesting, from what little I've seen. The web page will text more observations and possiblities. One main point is that it appears that the mass weight can possibly exceed over 1.5 pounds...and the boom length for the natural period could be easily lengthened. I'd think it would best serve along the "hanging mass" orientation for a horizontal sensing unit; but, it could also be possible to lessen the mass weight to accomodate a vertical sensing unit. http://home.earthlink.net/~meredithlamb/magneticaxispivot/ Meredith Lamb
Hi all,
 
I put up a web page of Dr. Randall Peters magnetic axis/pivot thought and that of Chris
Chapmans crossed cylinders/rods pivot suggested idea. 
 
The magnet/s involved are those from Forcefield.com, and are of the polarity where
the poles are through the rod diameter; and not at the ends of the rod; which is much
more common.
 
All in all, it really seems initally VERY interesting, from what little I've seen.  The web
page will text more observations and possiblities.  One main point is that it appears
that the mass weight can possibly exceed over 1.5 pounds...and the boom length for
the natural period could be easily lengthened.   I'd think it would best serve along the
"hanging mass" orientation for a horizontal sensing unit; but, it could also be possible
to lessen the mass weight to accomodate a vertical sensing unit.
 
 
Meredith Lamb
 
 
Subject: possible vertical using magnets? From: Randall Peters PETERS_RD@.......... Date: Fri, 09 Nov 2007 14:40:43 -0500 Kay, We know how you feel, but here's one more 'drinnk from the firehose'. We're 'on a roll', looks like. Meredith, like yourself, I saw the need to somehow communicate pictures; so I've placed one on my webpage at: http://physics.mercer.edu/hpage/psn/vertical-using-magnets.gif Anybody know instinctively if it's fatally flawed? I know Chris you don't like 'knife edges'. Maybe they're not as bad with load reduction by the pulling shown here. What about your thoughts, Charles, since I like your idea? And Keith, we're not opposed at all to what you've mentioned. I wrote a paper on the pendulum that moves in a way you'd like. Check out the pages that result if you type 'rattle in Seattle' into Google. I wouldn't be surprised if my 1988 paper "Chaotic motion from support constraints of a nondriven rigid spherical pendulum", Phys. Rev. A 38, 5352 prompted the commercial development that resulted in the 'oak and brass' pendulum that writes in sand and which recorded that Seattle earthquake. Randall Subject: Re: possible vertical using magnets? From: "meredith lamb" paleoartifact@......... Date: Fri, 9 Nov 2007 13:13:50 -0700 Randall, Yes, its fatally flawed.....the mass will always go down in that setup....it has no where else to go (sorry). I'd think; putting the spring in back of the pivot, with the spring attachment above the pivot (upright metal fixture holder on the boom itself) would make it more workable (per your drawing). My hard drive and crossed rod pivot vertical experiment is somewhat similar. There the spring is in back of the pivot, but does go down at a slant. I can't go past the vertical point of the pivot, without it going "bonk" down. I can get up to about 1/4" away from the pivot for ~ a 2.5s period that "seems" fairly time stable. Going closer can extend the period (once it hit 11s); but, alas, it was just too unstable over time. Meredith Lamb On Nov 9, 2007 12:40 PM, Randall Peters wrote: > Kay, > We know how you feel, but here's one more 'drinnk from the firehose'. > We're 'on a roll', looks like. > Meredith, like yourself, I saw the need to somehow communicate pictures; > so I've placed one on my webpage at: > http://physics.mercer.edu/hpage/psn/vertical-using-magnets.gif > > Anybody know instinctively if it's fatally flawed? I know Chris you don't > like 'knife edges'. Maybe they're not as bad with load reduction by the > pulling shown here. What about your thoughts, Charles, since I like your > idea? > > And Keith, we're not opposed at all to what you've mentioned. I wrote a > paper on the pendulum that moves in a way you'd like. Check out the pages > that result if you type 'rattle in Seattle' into Google. I wouldn't be > surprised if my > 1988 paper "Chaotic motion from support constraints of a nondriven rigid > spherical pendulum", Phys. Rev. A 38, 5352 > prompted the commercial development that resulted in the 'oak and brass' > pendulum that writes in sand and which recorded that Seattle earthquake. > > Randall > >
Randall,
 
Yes, its fatally flawed.....the mass will always go down in that setup....it has no
where else to go (sorry).  I'd think; putting the spring in back of the pivot, with the
spring attachment above the pivot (upright metal fixture holder on the boom itself)
would make it more workable (per your drawing). 
 
My hard drive and crossed rod pivot vertical experiment is somewhat similar.  There the
spring is in back of the pivot, but does go down at a slant.  I can't go past the
vertical point of the pivot, without it going "bonk" down.  I can get up to about
1/4" away from the pivot for ~ a 2.5s period that "seems" fairly time stable.  Going
closer can extend the period (once it hit 11s); but, alas, it was just too unstable
over time.
 
Meredith Lamb

On Nov 9, 2007 12:40 PM, Randall Peters <PETERS_RD@..........> wrote:
Kay,
   We know how you feel, but here's one more  'drinnk from the firehose'.  We're 'on a roll', looks like.
Meredith, like yourself, I saw the need to somehow communicate pictures; so I've placed one on my webpage at:
http://physics.mercer.edu/hpage/psn/vertical-using-magnets.gif

Anybody know instinctively if it's fatally flawed?  I know Chris you don't like 'knife edges'.  Maybe they're not as bad with load reduction by the pulling shown here.  What about your thoughts, Charles, since I like your idea?

And Keith, we're not opposed at all to what you've mentioned.  I wrote a paper on the pendulum that moves in a way you'd like.  Check out the pages that result if you type 'rattle in Seattle' into Google.  I wouldn't be surprised if my
1988 paper "Chaotic motion from support constraints of a nondriven rigid spherical pendulum", Phys. Rev. A 38, 5352
prompted the commercial development that resulted in the 'oak and brass' pendulum that writes in sand and which recorded that Seattle earthquake.

Randall


Subject: Re: possible vertical using magnets? From: "Les LaZar" llazar@.................. Date: Fri, 9 Nov 2007 13:09:27 -0800 Randall, Your illustration is most informative, but the details of the pivot/axis are unclear. How are the magnets oriented with respect to the blade and what purpose do they serve? Les ----- Original Message ----- From: "Randall Peters" To: Sent: Friday, November 09, 2007 11:40 AM Subject: possible vertical using magnets? > Kay, > We know how you feel, but here's one more 'drinnk from the firehose'. > We're 'on a roll', looks like. > Meredith, like yourself, I saw the need to somehow communicate pictures; > so I've placed one on my webpage at: > http://physics.mercer.edu/hpage/psn/vertical-using-magnets.gif > > Anybody know instinctively if it's fatally flawed? I know Chris you don't > like 'knife edges'. Maybe they're not as bad with load reduction by the > pulling shown here. What about your thoughts, Charles, since I like your > idea? > > And Keith, we're not opposed at all to what you've mentioned. I wrote a > paper on the pendulum that moves in a way you'd like. Check out the pages > that result if you type 'rattle in Seattle' into Google. I wouldn't be > surprised if my > 1988 paper "Chaotic motion from support constraints of a nondriven rigid > spherical pendulum", Phys. Rev. A 38, 5352 > prompted the commercial development that resulted in the 'oak and brass' > pendulum that writes in sand and which recorded that Seattle earthquake. > > Randall > > __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: More productive exchange of ideas with graphics? From: John Lahr johnjan@........ Date: Fri, 09 Nov 2007 13:53:04 -0800 Hi Jerry, I'm not advocating switching from E-mail to a blog, but simply using the blog as a convenient means to post images with captions. Words do not do justice to many of the things people are doing. A blog is just one of many possible ways to share graphics. Cheers, John At 07:46 AM 11/9/2007, you wrote: >I agree that visualization is VERY difficult sometimes, but I >hesitate creating a separate blog since it might water down the >discussions here. People might move to the blogs instead of here >and some might be left out of the comments. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: More productive exchange of ideas with graphics? From: "Jerry Payton" gpayton880@....... Date: Fri, 9 Nov 2007 16:25:15 -0600 I know that you didn't, John. I was just afraid that a separate thread or comments might start on a blog that would not be read by some. I am in TOTAL agreement that we need to exchange drawings and photos when possible. Regards, Jerry Hi Jerry, I'm not advocating switching from E-mail to a blog, but simply using the blog as a convenient means to post images with captions. Words do not do justice to many of the things people are doing. A blog is just one of many possible ways to share graphics. Cheers, John At 07:46 AM 11/9/2007, you wrote: >I agree that visualization is VERY difficult sometimes, but I >hesitate creating a separate blog since it might water down the >discussions here. People might move to the blogs instead of here >and some might be left out of the comments. __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
I know that you didn't, John.  I was just afraid that a = separate=20 thread or comments might start on a blog that would not be read by=20 some.  I am in TOTAL agreement that we need to exchange drawings = and photos=20 when possible.
Regards,
Jerry
 
 
Hi Jerry,

I'm not advocating = switching from=20 E-mail to a blog, but simply using
the blog as a convenient means to = post=20 images with captions.  Words
do not do justice to many of the = things=20 people are doing.  A blog is
just one of  many possible = ways to=20 share graphics.

Cheers,
John

At 07:46 AM 11/9/2007, you = wrote:
>I agree that visualization is VERY difficult sometimes, = but I=20
>hesitate creating a separate blog since it might water down the=20
>discussions here.  People might move to the blogs instead = of here=20
>and some might be left out of the=20 comments.


____________________________________________________= ______

Public=20 Seismic Network Mailing List (PSN-L)

To leave this list email PSN-L-REQUEST@............... with=20
the body of the message (first line only): unsubscribe
See http://www.seismicnet.co= m/maillist.html=20 for more information.
Subject: the design isn't fatally flawed From: Randall Peters PETERS_RD@.......... Date: Fri, 09 Nov 2007 17:51:46 -0500 Meredith, I'm sorry to disagree with your claim that the idea I posted is fatally flawed.. I just assembled a prototype that does work. Pictures have been posted on the same site previously referenced.. The 'edge' is not the hard tungsten carbide that Charles recommended; I used an ordinary razor blade. The Q is not great, but you can see there are steel shavings still on the magnets. Also the lever arm needs to be longer than what I've used (part extending down from the magnets) to get a longer period with a bigger mass. At present, trying to lengthen substantially beyond about 1/2 s pulls the blade off the magnets. The reason the mass doesn't 'go down' to a non-operational state as you expected is because of the magnets' force on the blade; i.e., it is not resting at the center of the magnets. Randall Subject: Re: More productive exchange of ideas with graphics? From: dave dalex@............ Date: Fri, 09 Nov 2007 14:53:52 -0800 what about going to a yahoo account with a place for pictures. dave John Lahr wrote: > Hi Jerry, > > I'm not advocating switching from E-mail to a blog, but simply using the > blog as a convenient means to post images with captions. Words do not > do justice to many of the things people are doing. A blog is just one > of many possible ways to share graphics. > > Cheers, > John > > At 07:46 AM 11/9/2007, you wrote: > >> I agree that visualization is VERY difficult sometimes, but I hesitate >> creating a separate blog since it might water down the discussions >> here. People might move to the blogs instead of here and some might >> be left out of the comments. __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: A rough magnetic axis/pivot setup of the crossed rod variety From: "meredith lamb" paleoartifact@......... Date: Fri, 9 Nov 2007 15:55:19 -0700 Hi all, Interesting day! I added acouple shaft couplers to the end of the steel rod, and the magnetic repelling effect of such; was to force it to laterally center between the magnets. The effect is stronger laterally than with the steel rod going up and down the length of the magnets (per the picture/s)....but now, the overall magnetic fields are indeed tending to keep the axis/pivot into one centralized location. The magnets poles where the steel rod sits on, are of the same polarity in the new picture of such; but it works regardless of the top of the magnets N or S polarity See: http://home.earthlink.net/~meredithlamb/magneticaxispivot/ This is all just a experimental axis/pivot. There could very likely be problems that may end up religating it to the overflowing failure bin. Meredith Lamb
Hi all,
 
Interesting day!  I added acouple shaft couplers to the end of the steel rod, and the
magnetic repelling effect of such; was to force it to laterally center between the magnets.
The effect is stronger laterally than with the steel rod going up and down the length of
the magnets (per the picture/s)....but now, the overall magnetic fields are indeed tending
to keep the axis/pivot into one centralized location.  
 
The magnets poles where the steel rod sits on, are of the same polarity in the new
picture of such; but it works regardless of the top of the magnets N or S polarity   See:
 
 
This is all just a experimental axis/pivot.  There could very likely be problems that may
end up religating it to the overflowing failure bin.
 
Meredith Lamb
 
 
 
Subject: Re: Exchange of ideas with graphics From: Dave Nelson davenn@............... Date: Sat, 10 Nov 2007 09:56:23 +1100 Thanks John, I dont really care if some one uses their www site or a blog ..... after all its primary use will be to dislay the graphics in a very easy to access way As you discovered Kay using the ftp wouldnt be easy for everyone and Larry would need to give password permissions to ppl an added hassle Keep the main discussions on this list but give links to where ever else blog or www site for the graphics :) and all wil be happy I know I also have "fun" trying to understand what ppl are trying to describe and as John has proven its dead easy to create a blog, specially when compared to starting up a www site keep it going John and hope others do the same to share their pix If anyone really wants to share their pix without starting a blog or www site email me the pix and I will create pages on my site for them pand post links on the email list very happy to do that :) Cheers Dave N Sydney At 05:57 AM 10/11/2007, you wrote: >To all PSN folks, >Has anybody been able to send graphics to the PSN ftp site? When I ftp to >the site I am asked for account and password. . >I agree with Jerry (below) that I would worry about using John Lahr's blog >site INSTEAD of the PSN. But what about using it WITH the PSN email >system. That is, to upload a drawing to the blog and reference it with a >hyperlink to the blog site? >I look forward to hearing any further discussion on this important issue. >By the way, are there any other women amateur seismologists on this >list? How many of you guys have shared your hobby with your daughters? ;-) >Kay Wyatt -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: 269.15.26/1119 - Release Date: 08/11/2007 5:55 PM __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: the design isn't fatally flawed From: "meredith lamb" paleoartifact@......... Date: Fri, 9 Nov 2007 16:00:26 -0700 Hi Randall, Yes...I admitted earlier in a email that it could work...I was wrong. Good deal on getting a model working! It will be interesting to keep informed of this one. Meredith Lamb On Nov 9, 2007 3:51 PM, Randall Peters wrote: > Meredith, > I'm sorry to disagree with your claim that the idea I posted is fatally > flawed.. > I just assembled a prototype that does work. Pictures have been posted on > the same site previously referenced.. > The 'edge' is not the hard tungsten carbide that Charles recommended; I > used an ordinary razor blade. > The Q is not great, but you can see there are steel shavings still on the > magnets. Also the lever arm needs to be > longer than what I've used (part extending down from the magnets) to get a > longer period with a bigger mass. At present, trying to lengthen > substantially beyond about 1/2 s pulls the blade off the magnets. > The reason the mass doesn't 'go down' to a non-operational state as you > expected is because of the magnets' force on the blade; i.e., it is not > resting at the center of the magnets. > Randall > >
Hi Randall,
 
Yes...I admitted earlier in a email that it could work...I was wrong.  Good deal on
getting a model working!  It will be interesting to keep informed of this one.
 
Meredith Lamb

On Nov 9, 2007 3:51 PM, Randall Peters <PETERS_RD@..........> wrote:
Meredith,
  I'm sorry to disagree with your claim that the idea I posted is fatally flawed..
I just assembled a prototype that does work.  Pictures have been posted on the same site previously referenced..
The 'edge' is not the hard tungsten carbide that Charles recommended; I used an ordinary razor blade.
The Q is not great, but you can see there are steel shavings still on the magnets.  Also the lever arm needs to be
longer than what I've used (part extending down from the magnets) to get a longer period with a bigger mass.  At present, trying to lengthen substantially beyond  about 1/2 s pulls the blade off the magnets.
  The reason the mass doesn't 'go down' to a non-operational state as you expected is because of the magnets' force on the blade; i.e., it is not resting at the center of the magnets.
 Randall


Subject: Re: the design isn't fatally flawed From: tchannel1@............ Date: Fri, 9 Nov 2007 16:21:25 -0700 Randall, Please,Where are the pictures posted? Thanks,=20 Ted ----- Original Message -----=20 From: meredith lamb=20 To: psn-l@................. Sent: Friday, November 09, 2007 4:00 PM Subject: Re: the design isn't fatally flawed Hi Randall, Yes...I admitted earlier in a email that it could work...I was wrong. = Good deal on getting a model working! It will be interesting to keep informed of = this one. Meredith Lamb On Nov 9, 2007 3:51 PM, Randall Peters wrote: Meredith, I'm sorry to disagree with your claim that the idea I posted is = fatally flawed.. I just assembled a prototype that does work. Pictures have been = posted on the same site previously referenced..=20 The 'edge' is not the hard tungsten carbide that Charles = recommended; I used an ordinary razor blade. The Q is not great, but you can see there are steel shavings still = on the magnets. Also the lever arm needs to be=20 longer than what I've used (part extending down from the magnets) to = get a longer period with a bigger mass. At present, trying to lengthen = substantially beyond about 1/2 s pulls the blade off the magnets. The reason the mass doesn't 'go down' to a non-operational state = as you expected is because of the magnets' force on the blade; i.e., it = is not resting at the center of the magnets. Randall
Randall,   Please,Where are = the pictures=20 posted?  Thanks,
Ted
----- Original Message -----
From:=20 meredith lamb
Sent: Friday, November 09, 2007 = 4:00=20 PM
Subject: Re: the design isn't = fatally=20 flawed

Hi Randall,
 
Yes...I admitted earlier in a email that it could work...I was=20 wrong.  Good deal on
getting a model working!  It will be interesting to=20 keep informed of this one.
 
Meredith Lamb

On Nov 9, 2007 3:51 PM, Randall Peters <PETERS_RD@..........> = wrote:
Meredith,
 =20 I'm sorry to disagree with your claim that the idea I posted is = fatally=20 flawed..
I just assembled a prototype that does work. =  Pictures have=20 been posted on the same site previously referenced..
The 'edge' = is not=20 the hard tungsten carbide that Charles recommended; I used an = ordinary razor=20 blade.
The Q is not great, but you can see there are steel = shavings still=20 on the magnets.  Also the lever arm needs to be
longer than = what=20 I've used (part extending down from the magnets) to get a longer = period with=20 a bigger mass.  At present, trying to lengthen substantially = beyond=20  about 1/2 s pulls the blade off the magnets.
  The = reason the=20 mass doesn't 'go down' to a non-operational state as you expected is = because=20 of the magnets' force on the blade; i.e., it is not resting at the = center of=20 the magnets.
 Randall


Subject: Re: the design isn't fatally flawed From: "meredith lamb" paleoartifact@......... Date: Fri, 9 Nov 2007 19:41:19 -0700 Randalls gif drawing of his vertical is at: http://physics.mercer.edu/hpage/psn/vertical-using-magnets.gif Randalls reference to a pendulum point tracing in sand, or, the "rattle in seattle" phrase is at: http://www.aps.org/publications/apsnews/200105/zero-gravity.cfm Meredith Lamb On Nov 9, 2007 4:21 PM, wrote: > Randall, Please,Where are the pictures posted? Thanks, > Ted > > ----- Original Message ----- > *From:* meredith lamb > *To:* psn-l@.............. > *Sent:* Friday, November 09, 2007 4:00 PM > *Subject:* Re: the design isn't fatally flawed > > Hi Randall, > > Yes...I admitted earlier in a email that it could work...I was wrong. > Good deal on > getting a model working! It will be interesting to keep informed of this > one. > > Meredith Lamb > > On Nov 9, 2007 3:51 PM, Randall Peters wrote: > > > Meredith, > > I'm sorry to disagree with your claim that the idea I posted is > > fatally flawed.. > > I just assembled a prototype that does work. Pictures have been posted > > on the same site previously referenced.. > > The 'edge' is not the hard tungsten carbide that Charles recommended; I > > used an ordinary razor blade. > > The Q is not great, but you can see there are steel shavings still on > > the magnets. Also the lever arm needs to be > > longer than what I've used (part extending down from the magnets) to get > > a longer period with a bigger mass. At present, trying to lengthen > > substantially beyond about 1/2 s pulls the blade off the magnets. > > The reason the mass doesn't 'go down' to a non-operational state as > > you expected is because of the magnets' force on the blade; i.e., it is > > not resting at the center of the magnets. > > Randall > > > > >
Randalls gif drawing of his vertical is at:
 
 
Randalls reference to a pendulum point tracing in sand, or, the
"rattle in seattle" phrase is at:
 
 
Meredith Lamb

On Nov 9, 2007 4:21 PM, <tchannel1@............> wrote:
Randall,   Please,Where are the pictures posted?  Thanks,
Ted
----- Original Message -----
Sent: Friday, November 09, 2007 4:00 PM
Subject: Re: the design isn't fatally flawed

Hi Randall,
 
Yes...I admitted earlier in a email that it could work...I was wrong.  Good deal on
getting a model working!  It will be interesting to keep informed of this one.
 
Meredith Lamb

On Nov 9, 2007 3:51 PM, Randall Peters <PETERS_RD@..........> wrote:
Meredith,
  I'm sorry to disagree with your claim that the idea I posted is fatally flawed..
I just assembled a prototype that does work.  Pictures have been posted on the same site previously referenced..
The 'edge' is not the hard tungsten carbide that Charles recommended; I used an ordinary razor blade.
The Q is not great, but you can see there are steel shavings still on the magnets.  Also the lever arm needs to be
longer than what I've used (part extending down from the magnets) to get a longer period with a bigger mass.  At present, trying to lengthen substantially beyond  about 1/2 s pulls the blade off the magnets.
  The reason the mass doesn't 'go down' to a non-operational state as you expected is because of the magnets' force on the blade; i.e., it is not resting at the center of the magnets.
 Randall



Subject: OmniDirectional Free Hanging Pendulum and Voltage VS Current sensors From: "Geoff" gmvoeth@........... Date: Sat, 10 Nov 2007 06:17:15 -0700 Hello All you PSN Peoples; Please Referr to the following image. It is much like a product called Magnasee that allowes one to actually see the magnetic tracks on a recording tape. It is referred to as a magnetic developer sort of like developing an old photography film. This image is showing a horizontal EQ motion developer using something like a kids toy. Such visualizations will help one understand the reality of what you are dealing with. http://www.aps.org:80/publications/apsnews/200105/zero-gravity.cfm This image from one of your other posts is a visible indicator that a free hanging pendulum with a nondirectional sensor may very well give the best picture of all X or Y sensors. Otherwise you need to sum both X + Y with a summation amp and that will double your effort. Can someone show me the best way to use a single simple pendulum with the magnet as a mass and and one or two coils as the receiver ?? I still like no matter what you say the magnet as the pendulous mass. I also know from past experience if you want to deal with voltages you use vacuum tubes and if you want to deal with current you use semiconductors so why do you need so many coils in a sensor coil ?? Today we use almost always semiconductors and I think a single loop of very heavy wire may be better for semiconductors ( IC OP AMPS ) then having multiple turn coils ??? can anyone please address this idea too ?? I am pretty much a laymen but through the past many years been exposed to many different general ideas of physics. Regards; Geoff __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: HEy all you Eggheads, Please Tell me something I dont Know From: "Geoff" gmvoeth@........... Date: Sat, 10 Nov 2007 07:56:54 -0700 Hi All You PSN Folks; Why Every Time I Send A message to The PSN group do I get this error message ?? Any ONE know please reply to me personally at gmvoeth hotmail.com gmvoeth yahoo.com gmvoeth gmail.com Just add the at sign. any of these will do. I do not even know anyone named dhidayat hotmail.com Regards; geoff ************* BELOW MESSAGE *********** Reporting-MTA: dns;imc2-s4.hotmail.com Received-From-MTA: dns;wim1-s4.hotmail.com Arrival-Date: Sat, 10 Nov 2007 06:09:39 GMT Final-Recipient: rfc822;dhidayat@........... Action: failed Status: 5.5.0 Diagnostic-Code: smtp;550 Requested action not taken: mailbox unavailable __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: pendulum that generated 'rattle in seattle' From: Randall Peters PETERS_RD@.......... Date: Sat, 10 Nov 2007 10:21:21 -0500 Geoff, The pendulum responsible for the now-famous picture you and Meredith mention (and give the American Physical Society-hosted sebsite) is not like the dangling pendulum we've been discussing. As you noted, it is a 'toy'-version of the one that I studied (responsible for the aforementioned article on chaos) and which has for years been used to generate beautiful art-pieces. A picture of that pendulum which I built (while still at Texas Tech University) and which is here in the Mercer physics department is to be found at http://physics.mercer.edu/Science_Art/bowling_ball.htm Also on this website are some of the myriad traces that have been produced with the pendulum. Art-folks love these because of their 'life-like' properties--no two exactly the same (quite unlike computer generated patterns). The bowling ball is supported by a pipe on one end, the other end of which is connected to a universal joint (off a toyota pickup if I remember correctly). Because of this U-joint, the x-y axes are coupled, giving rise to a very large number of different patterns during free decay. The moments of inertia in the two axes are adjustable to provide additional control that assists the near infinity of possible results. In the absence of friction, this instrument would display what's called Hamiltonian chaos. The sensitive dependence on initial conditions (essence of the butterfly effect) means that long term prediction (just like the weather) is unpredictable. There are two capacitive sensors that map the motion of the bowling ball, one in each of the perpendicular axes. The output from the amplified signals is fed to an x-y (analog recorder) that with a ball-point pen generates the images on ordinary paper. I have done a lot of chaos research in the last 15 years. The chaotic pendulum that I designed and which is online here at Mercer (when my colleague Matt Marone gets it back operational after our move to the new building) is at http://physics.mercer.edu/PENDULUM/ This pendulum can be controlled from anywhere in the world over the internet when operational. The parameter that the user can adjust is the frequency of the drive. The pendulum's motion is monitored by one of my SDC sensors functioning as a velocity detector. An aluminum disk rotates with the pendulum between rare-earth magnets positioned on either side, which are on the end of a bending cantilever. The output (velocity) is integrated with a 'leaky' integrator to give the position. Largely because of my pendulum chaos studies I was asked and wrote an article on " math methods used by physicists to study chaos" for the 10th Ed. of the McGraw Hill Encyclopedia of Science and Technology. I'm sure that some readers will note the prominence of other authors in the chaos section of the encylopedia (such as the creator of the butterfly effect, Ed Lorenz) and then will say, "but who's this guy, Peters?". You ask, Geoff, 'why use multiple turn coils for the Faraday-law sensor. The answer is resident within the statement of his law (generated, in the minds of most, by the greatest experimentalist who ever lived). Faraday's law states that the voltage generated within the wire (historically called the electromotive force (emf) even though voltage is not a force) is proportional to the number of turns of the coil times the time rate of change of the magnetic flux passing through the coil. Thus no matter how your amplifier is built (solid state or vacuum tubes) the signal will be greater the larger number of turns you can wind within the constraints of space limitations borne of wire size and increased resistance that results when the wire gets too small trying to put more turns into a given place. Randall Subject: Re: OmniDirectional Free Hanging Pendulum and Voltage VS From: John Lahr johnjan@........ Date: Sat, 10 Nov 2007 08:00:36 -0800 Nice picture of the sand seismoscope. The following explanation is not correct, however: "The "flower" in the center records the surface movements associated with the higher frequency waves that arrived first. The outer larger amplitude oscillations record the lower frequency waves that arrived later. The lines from the largest pattern are interrupted by the rose pattern. The rose is probably due to the earthquake vibrations while the large-scale pattern was human generated some time earlier. Cheers, John __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: magnetic axis/pivot/crossed rod From: Randall Peters PETERS_RD@.......... Date: Sat, 10 Nov 2007 11:14:22 -0500 Meredith, What you've done is VERY interesting. Am I correct in assuming that your latest test (1.5 lbs oscillating 50 minutes) was with the aluminum rod hanging down and swinging from the stationary steel plate, with the 1.5 lb weight at the bottom? If so, how far below the axis was the weight. The moment of inertia is an important issue in the decay time, so I would really like to know this number to try and assess the relative importance of air damping compared to the internal friction associated with your axis. Randall Subject: Re: magnetic axis/pivot/crossed rod From: "meredith lamb" paleoartifact@......... Date: Sat, 10 Nov 2007 11:03:31 -0700 Hi Randall and all, Yes, I put the steel block upside down and clamped it to the edge of a table; with of course the magnets underneath the steel block (and moved the magnets to accomodate a clamp). I put up a third picture and text at the web site in relation to this. See: http://home.earthlink.net/~meredithlamb/magneticaxispivot/ The distance between the center of the pivot and the center of (another steel block) is ~17.625", with a natural period of ~1.34s. The web page distance number is not correct. Of course the surface hardness of the gold plated neo magnets and the surface of the unhardened steel rod are not very good. One could rightly say the whole thing is kind of a curio type experiment, and of little long term operational value...which it is presently. It might be possible to "adapt" some kind of cutoff small section of harder magnetic steel pipe that fits the outer contact portion diameter of the neo magnets to provide a harder contact surface there....while also getting a harder pivot rod. If one compares say a "standard" crossed rod that simply gravitational rests atop the rods, and this magnetic attachment; the standard crossed rods can freely oscillate up to about ~ 4 times longer (per past home brew experiments). However, the magnetic centering aspect of this present unit is of great interest as it can roughly ~"positon zero" itself, whereas the standard non-magnetic crossed rod/cylinder unit can't self adjust, without perhaps resorting to again configuring some kind of magnetic attraction/repulsion system on the "standard" configuration. Obviously I'am interested in the crossed rod pivot approach even though it has its problems of positional zeroing use. I note that per the first web site picture, where the boom goes up, it could also go down through the steel block hole; with the mass hanging underneath. I suppose that route would be even better to manipulate any mechanical or magnetic centering aspects. I've not yet tried any kind of vertical with any kind of spring add on. Can only roughly surmise the mass weight would need to "whatever" the spring and pivot can take of course. If one stands the 1-2-3" block on its 2x1" thick side per the first view (with a base plate slight tilt)....then you can likely get another horizontal sensing route; but likely the mass weight would again be alot less than 2 pounds of course. Yes...there is a variety of possiblities of a number of pivot orientation routes with this....but whether they are proven practical (with improvements) remains to be seen. Meredith Lamb On Nov 10, 2007 9:14 AM, Randall Peters wrote: > Meredith, > What you've done is VERY interesting. Am I correct in assuming that > your latest test (1.5 lbs > oscillating 50 minutes) was with the aluminum rod hanging down and > swinging from the stationary steel plate, > with the 1.5 lb weight at the bottom? If so, how far below the axis was > the weight. The moment of inertia is an > important issue in the decay time, so I would really like to know this > number to try and assess the > relative importance of air damping compared to the internal friction > associated with your axis. > > Randall >
Hi Randall and all,
 
Yes, I put the steel block upside down and clamped it to the edge of a table; with of
course the magnets underneath the steel block (and moved the magnets to accomodate
a clamp).  I put up a third picture and text at the web site in relation to this.  See:
 
The distance between the center of the pivot and the center of (another steel block) is
~17.625", with a natural period of ~1.34s.  The web page distance number is not correct.
 
Of course the surface hardness of the gold plated neo magnets and the surface of the unhardened
steel rod are not very good.  One could rightly say the whole thing is kind of a curio type
experiment, and of little long term operational value...which it is presently.  It might be
possible to "adapt" some kind of cutoff small section of harder magnetic steel pipe that fits the outer
contact portion diameter of the neo magnets to provide a harder contact surface there....while
also getting a harder pivot rod.
 
If one compares say a "standard" crossed rod that simply gravitational rests atop the rods, and this
magnetic attachment; the standard crossed rods can freely oscillate up to about ~ 4 times
longer (per past home brew experiments).   However, the magnetic centering aspect of
this present unit is of great interest as it can roughly ~"positon zero" itself, whereas the
standard non-magnetic crossed rod/cylinder unit can't self adjust, without perhaps resorting to
again configuring some kind of magnetic attraction/repulsion system on the "standard"
configuration.  Obviously I'am interested in the crossed rod pivot approach even though it
has its problems of positional zeroing use. 
 
I note that per the first web site picture, where the boom goes up, it could also go down
through the steel block hole; with the mass hanging underneath.  I suppose that route
would be even better to manipulate any mechanical or magnetic centering aspects. 
 
I've not yet tried any kind of vertical with any kind of spring add on.  Can only roughly
surmise the mass weight would need to "whatever" the spring and pivot can take of
course.
 
If one stands the 1-2-3" block on its 2x1" thick side per the first view (with a base
plate slight tilt)....then you can likely get another horizontal sensing route; but likely
the mass weight would again be alot less than 2 pounds of course.  Yes...there is
a variety of possiblities of a number of pivot orientation routes with this....but whether
they are proven practical (with improvements) remains to be seen.
 
Meredith Lamb   


 
On Nov 10, 2007 9:14 AM, Randall Peters <PETERS_RD@..........> wrote:
Meredith,
   What you've done is VERY interesting.  Am I correct in assuming that your latest test ( 1.5 lbs
oscillating 50 minutes) was with the aluminum rod hanging down and swinging from the stationary steel plate,
with the 1.5 lb weight at the bottom?  If so, how far below the axis was the weight.  The moment of inertia is an
important issue in the decay time, so I would really like to know this number to try and assess the
relative importance of air damping compared to the  internal friction associated with your axis.

 Randall

Subject: map of seismic risk in East Africa? From: "David Saum" DSaum@............ Date: Sat, 10 Nov 2007 16:00:53 -0500 A friend of mine in Tanzania asks > are you aware of anyone on the web who might "publish" or know > of a mechanism that would provide some sort of probability or at least > risk assessment of earthquake frequencey and/or magnitude? For example, we > know that a road built near Ol Donyo Lengai would be subject to higher > risk than a road built in Dar--but is anybody using data to quantify this? Can anyone provide a reference for this? Thanks in advance, Dave __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Re: map of seismic risk in East Africa? From: Angel sismos@.............. Date: Sat, 10 Nov 2007 21:10:55 +0000 Hello David, Much of this work in Central America is sponsored by NORSAR http://www.norsar.no/seismology/ Angel Saturday, November 10, 2007, 9:00:53 PM, you wrote: > A friend of mine in Tanzania asks >> are you aware of anyone on the web who might "publish" or know >> of a mechanism that would provide some sort of probability or at least >> risk assessment of earthquake frequencey and/or magnitude? For example, we >> know that a road built near Ol Donyo Lengai would be subject to higher >> risk than a road built in Dar--but is anybody using data to quantify this? __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: pendulum suspensions From: holmstro@.......... Date: Sat, 10 Nov 2007 13:22:28 -0800 (PST) Hello, This is my first post to the list. I am Bob Holmström, Editor of the Horological Science Newsletter (NAWCC Chapter 161). Pendulum suspensions are of great interest to those interested in precision time keeping. Perhaps there is some use discussing what clockmakers have learned even though a clock pendulum needs to move constantly over a much larger angle than the devices discussed here. But first, since Dr. Peters suggestion to use a magnet suspended carbide ball is what prompted my response, I want to discuss a prior experiment: Marcel Bétrisey, a Swiss artist who has created many clocks and Foucault pendulums from "found materials", has experimented with a Foucault pendulum suspended from a ball attracted to a high strength magnet. He found that the motion was not "homogenious", in that the amplitude of the motion and the rate of change of the direction of motion had significent variations. Anyone who has attemped to build build an accurate Foucault pendulum can attest to the fact that the suspension design is critical and even then error correction devices such as Charon rings or Eddy current damping are required to get anthing close to accurate motion. Unfortunately the error correction devices add there own errors! Kammerling Onnes (1890's) used a crossed knife edge suspension without error correction for a Foucault pendulum and achieved some of the most accurate results ever obtained. Marcel's best results have been with pendulums suspended from guitar wire located by a stack of close fitting watch jewels in a collet. Some of Marcel's work can be seen at www.foucault.ch and www.betrisey.ch For a real treat on the interaction of art, science, and horology see his radiometric pendulums. re clock pendulum suspensions: Most pendulums hang from flexures, including very precise clocks such as those constructed by Shortt and Fedchenko. The connections between the flexure and its support and pendulum are very important - simple clamping can be problematic - Shortt and Fedchenko used spring machined from blocks (i.e. thick ends) with great success. Modern edm techniques make this type of spring relatively easy to construct. Gravity wave detection pendulums use similiar suspensions constructed from low loss materials such as indium. True knife edge suspensions probably do not exist - contact forces and irregular contact geometry produce something less than ideal. Much better results are obtained with edges shaped to a small radius that can be obtained by lapping with an appropriate jig or by more modern edm methods. One test of a pendulum suspension for a clock is to see if it shows true "circular error" (a horological term probably best expressed as period error due to the fact that a pendulum is not truely isochronus - i.e. the period varies with amplitude). It is very difficult to construct a pendulum that agrees well with theoretical predictions. Plotting period versus amplitude squared makes extrapolating the data to zero amplitude much simpler than the traditional form of plot and it shows the errors quite readily. The idea was suggested by Stroud and Matthews, "Period of a rigid pendulum pivoting on flattened knife edges" Physics Education, Volume 22 (1987) pages 170 - 173. I intend to evaluate Chris Chapmen's crossed roller suspension and Meredith Lamb's hard disc id suspension when I return home in a couple of weeks. The best pendulum suspension results that I have obtained so far are with an air bearing suspended pendulum. The pendulum was suspended from both ends of a rod passing through a porus graphite air bearing, first with magnets controling side to side drift and then air bearings on the ends also. Some results and photos of the setup are at http://www.hsn161.com/air.html Perhaps not the most practical - the air bearings are not cheap and a continuly running air compressor is a bit annoying!) Note: John Harrison used a third method to control end to end drift and to reduce friction in his H1 chronometer e.g. he used a small fiber from each end of the rod to a fixed support - in addition the rod was supported on "anti-friction" rollers (imagine segments of two large wheels with the shaft resting at the intersection of their radii at each end of the shaft.) Bob Holmström __________________________________________________________ Public Seismic Network Mailing List (PSN-L) Subject: Paper-Mate -Lubriglide From: tchannel1@............ Date: Sat, 10 Nov 2007 15:06:15 -0700 Hi All, I am now testing the PMG Paper mate Lubriglide, SENSOR, This = took well over a hour and I did not have to go to the hardware store = once. My camera battery is down, but if someone would like some picts just = email me. I know a pict is worth a thousand words, but I will try to = describe it. 1. I use a 1/8" x 36" wood dowel, taped a Paper-Mate pen refill to it, = ball end up. 2. I use a camera tripod, and attached a rare earth magnet to the = handle of the tripod, (the tilting handle which is steel). Using the = crank on the tripod I can raise and lower the dowel. 3. I found a small steel nut which I could thread onto the dowel, a = washer on top of the nut, then a larger hex nut, about 1/4" 20 thread. = on top of the washer. This created a base for two bar magnets,(the washer) and a shoulder for = the ends of the magnets.(the larger nut) So left to right=3D = magnet+nut+magnet The small nut and washer supports the magnets so = they don't fall down the dowel. By threading the small nut and washer up and down the dowel you change = the