I looked at the block diagram for the MET sensor.   I am a little =
confused (my block diagrams often need telepathy to understand also). =20

There are two cathodes they re between the Anodes.  In the block diagram =
they are connected to an inverted triangle which has two outputs to a =
"feedback amplifier".  The only way I could figure to make it work was =
to connect the catodes to ground through a shunt resister and convert =
current to voltage by measuring teh voltage drop across the shunt?  Then =
take those volatages and sum them on an op amp to get the erro voltage.  =
=20

Am I off base.

The sensor looks like fun.  I wonder if they are usable on tiltmeters as =
two 500 gallon taks seperated by a few hunder yards with a MET half way =
could sense tilt.  There is an issue of rate of course.

Speaking of tilt has anyone heard from Sean-Thomas ?

Tom Schmitt

tschmitt@..............
  ----- Original Message -----=20
  From: Jim ODonnell=20
  To: psn-l@.................
  Sent: Thursday, August 30, 2001 12:53 AM
  Subject: PMD or MET seismometer & PEPP, USESN, PSN, NESN


  Hi All- A little more info on the PMD/MET seismometer.  I first heard =
of it 2-3 years ago, as it was one of the PEPP (Princeton Earth Physics =
Program) http://lasker.princeton.edu/education.html seismometers along =
with the Guralp.  I believe ~9 of the ~90 PEPP seismometers are the PMD =
type.  I always called it the chemical seis for lack of a better name.  =
The early PMD2's that PEPP has had, have not performed well.  However, =
Tom Owens's South Carolina group, SCEPP, has had a good experience with =
the newer three component PMD machines.  They have purchased around 40 =
3-component PMDs.  At this time you cannot run SCREAM (Guralp's =
software) with these machines, though. I am not sure about WinQuake- As =
good as Scream is, many PEPP people prefer WinQuake!!!!!


  PMD or MET:
  You can see more about it at: =
http://www.eentec.com/PMD/pmdproductpage.htm
   and MET Theory at: http://www.eentec.com/PMD/ELECTROCHEMICA-1.doc

  US Educational Seismic Network (USESN):
  BTW, I attended the IRIS annual meeting in June and volunteered to =
serve on the US Educational Seismic Network (USESN) Committee.  It =
consists of 9 states, which have their own high school seismic networks, =
PEPP related, and the PSN.  I believe Gary Simila, seismologist from Cal =
State Northridge, suggested  PSN be part of the USESN.  Since I was =
familiar with the PSN, I seconded the motion and described many of the =
PSN activities.  The main focus of the USESN is to effectively promote =
programs for educational seismographs in schools.  No buddy does it =
better than you guys!

  Nevada Educational Seismic Network (NESN):
  I am working on putting together a 20 site network for Nevada high =
schools which I hope to have up and running by the beginning of 2002.  =
Funding comes from the Nevada Earthquake Safety Council and the Nevada =
Public Agency Insurance Pool. The planning has been going on for over a =
year, and much of the design and components has come from the PSN and =
Larry Cochrane.  These sites will be much cheaper per site (~$500) than =
the PEPP (~$2500) sites.....Jim =20

  Jim O'Donnell
  UNLV Adjunct Research Associate
  Geoscience Dept. & Engineering Geophysics Lab.







I looked at the block diagram for the =
MET=20
sensor.   I am a little confused (my block diagrams often need =

telepathy to understand also).  
 
There are two cathodes they re between =
the=20
Anodes.  In the block diagram they are connected to an inverted =
triangle=20
which has two outputs to a "feedback amplifier".  The only way I =
could=20
figure to make it work was to connect the catodes to ground through a =
shunt=20
resister and convert current to voltage by measuring teh voltage drop =
across the=20
shunt?  Then take those volatages and sum them on an op amp to get =
the erro=20
voltage.   
 
Am I off base.
 
The sensor looks like fun.  I =
wonder if they=20
are usable on tiltmeters as two 500 gallon taks seperated by a few =
hunder yards=20
with a MET half way could sense tilt.  There is an issue of rate of =

course.
 
Speaking of tilt has anyone heard from =
Sean-Thomas=20
?
 
Tom Schmitt
 
tschmitt@..............


  
----- Original Message ----- 
  From:=20
  Jim =
ODonnell 
  
To: psn-l@.............. 
  
Sent: Thursday, August 30, 2001 =
12:53=20
  AM
  
Subject: PMD or MET seismometer =
&=20
  PEPP, USESN, PSN, NESN
  


  
Hi All- A little more info on the PMD/MET seismometer.  I =
first=20
  heard of it 2-3 years ago, as it was one of the PEPP (Princeton Earth =
Physics=20
  Program) http://lasker.princet=
on.edu/education.html=20
  seismometers along with the Guralp.  I believe ~9 of the =
~90 PEPP=20
  seismometers are the PMD type.  I always called it the chemical =
seis for=20
  lack of a better name.  The early PMD2's that PEPP has had, have =
not=20
  performed well.  However, Tom Owens's South Carolina group, =
SCEPP, has=20
  had a good experience with the newer three component PMD =
machines.  They=20
  have purchased around 40 3-component PMDs.  At this time you =
cannot run=20
  SCREAM (Guralp's software) with these machines, though. I am not sure =
about=20
  WinQuake- As good as Scream is, many PEPP people prefer =
WinQuake!!!!!
  
 
  
 
  
PMD or MET:
  
You can see more about it at: http://www.eentec.c=
om/PMD/pmdproductpage.htm
  
 and MET Theory at: http://www.eentec=
..com/PMD/ELECTROCHEMICA-1.doc
  
 
  
US Educational Seismic Network (USESN):
  
BTW, I attended the IRIS annual meeting in June and volunteered =
to serve=20
  on the US Educational Seismic Network (USESN) Committee.  It =
consists of=20
  9 states, which have their own high school seismic networks, PEPP =
related,=20
  and the PSN.  I believe Gary Simila, seismologist from Cal =
State=20
  Northridge, suggested  PSN be part of the USESN.  Since I =
was=20
  familiar with the PSN, I seconded the motion and described many of the =
PSN=20
  activities.  The main focus of the USESN is to effectively =
promote=20
  programs for educational seismographs in schools.  =
No buddy=20
  does it better than you guys!
  
 
  
Nevada Educational Seismic Network (NESN):
  
I am working on putting together a 20 site network for Nevada =
high=20
  schools which I hope to have up and running by the beginning of =
2002. =20
  Funding comes from the Nevada Earthquake Safety Council and the Nevada =
Public=20
  Agency Insurance Pool. The planning has been going on for over a year, =
and=20
  much of the design and components has come from the PSN and Larry =

  Cochrane.  These sites will be much cheaper per site (~$500) than =
the=20
  PEPP (~$2500) sites.....Jim  
  
 
  
Jim O'Donnell
  
UNLV Adjunct Research Associate
  
Geoscience Dept. & Engineering Geophysics=20
Lab.