PSN-L Message - Subject: RE: Seismograph for school

wrote: Hi Chris, What sort of "choice of suspension system" would you recommend? Is there a detail I can look at? I have only seen the knife edge style. Thanks, Ted ----- Original Message ----- From: ChrisAtUpw@....... To: psn-l@.............. Sent: Saturday, September 23, 2006 5:09 PM Subject: Re: Seismograph for school In a message dated 23/09/2006, jcpatskan@......... writes: I am thinking of trying to build a seismograph for my son's school. I have quite a bit of experience in shallow exploration geophysic's, mostly electrical and electromagnetic, but none in seismology. I have searched the internet and found quite a few resources. Hi John, You might consider making a medium sized Lehman - about 2 ft long? Say about 1.5 sec period that can be extended to 20 sec? You will need +/-12V stabilised power supplies of you may buy an amplifier and transformer from Larry at http://psn.quake.net Since it will be used with other school systems, I suggest that you use Amaseis and buy a DI-154 12 bit ADC still at just $39! www.dataq.com Amaseis supports this ADC. See http://jclahr.com/science/psn/as1/index.html Use magnetic damping, NOT oil. Use an all metal braced single unit costruction - NO plastic structural components - NO separated sections. Your choice of suspension system is critical. NEITHER a point on a plane NOR knife edge systems are satisfactory - avoid them like the plague. Most other systems are OK to good. You need to be able to get a period of at least 20 seconds. Have a look at http://jclahr.com/science/psn/chapman/lehman/index.html and http://jclahr.com/science/psn/chapman/index.html and http://www.jclahr.com/science/psn/cor_psn.html and http://jclahr.com/science/psn/ ALSO http://www.mgm.monschau.de/seismic/english/artikel/artikel_1_4.php and sequels I have also noticed a seismograph (or strong motion accelerometer) on sale at e-bay, with an opening bid of $75. I suggest that you forget this one! You do not need a strong motion sensor - or the headaches of converting an optical one. This might be called 'buying trouble'! Good Luck! Chris Chapman

Hi, I=20 would like to add a few thoughts. There are some simple plans on the PSN = San=20 Jose website. http://pw2.netco= m.com/~shammon1/equip.htm#Plans

however, I strongly suggest that you look at Larry's WINSDR = software /=20 equipment because in the classroom, the software environment is one of = the most=20 important attributes you need to consider. The stability of=20 the system hardware and software and the quality of the information = provided=20 significantly improves the students interaction and learning outcome = from=20 using the system. For example, if you look at the PSN San Jose main = page http://www.PublicSeismicNet= work.com you=20 will find two links at the bottom left of the page to South Valley = Middle=20 School and Los Altos High School. Both schools are using WINSDR and = Larry's=20 hardware. Initially when we built the system at Los Altos we = provided a PC,=20 sensors and simple amp. At South Valley, Jan Froom went though several = steps=20 getting to the current system configuration you see today. With=20 the evolution of the Internet, there is a real need to incorporate = the=20 seismic data into the classroom websites. This simplifies the teachers=20 interaction with the system and helps to generate significant = student/parent=20 interest in the project. As you can see from the examples, by using the=20 automatic upload feature of Larry's WINSDR, the sensor data is uploaded=20 continuously during the 24 hour period. Another benefit is the amount of = interest the system generates outside of the classroom. Look back at the = Los=20 Alto page and you will see there have been over 24,000 trips to = Greg=20 Stoehr's seismic science page at Los Altos High in the last two years.=20 Considering that he has about 300 students per semester, this provides a = 40-trip=20 / student page access ratio which is a significant amount of return = on=20 investment. Greg keeps the system in his classroom and his students = take=20 part in operating the system during the class year. Greg is extremely = limited on=20 the amount of time he can spend on the system and WINSDR has = significantly=20 improved his productivity. With a minimal investment, you will see a = vast=20 improvement over a simple classroom sensor and amp.

Regards, Steve Hammond PSN San Jose, Aptos=20 California

-----Original Message-----
From: = psn-l-request@................. [mailto:psn-l-request@...............On Behalf Of=20 tchannel
Sent: Tuesday, September 26, 2006 7:38 = AM
To:=20 psn-l@..............
Subject: Re: Seismograph for=20 school

Hi John, Ted here, and I am one = month into=20 a similar project, using my own money, for a non profit=20 organization.

We are having a lot of fun on the = project, but=20 the electronics are challenging, even though I have worked on = circuits, I=20 thought I was up to it electronic task, but now I am not = sure.   I=20 have made some progress however, so I think I am getting = closer.

I am happy to share my successes and = failures if=20 you would like to correspond. Ted

----- Original Message -----
From:=20 John=20 Patskan
To: psn-l@..............

Sent: Monday, September 25, = 2006 11:11=20 PM

Subject: Re: Seismograph for=20 school

Hello everyone,

Thanks for the tips.

I = believe=20 I will try to build the Lehaman style unit.

This is actually = an=20 elementary school. It used to be an Environmental Science = magnet=20 school, and they still have room they call the Eco-Lab. Each = class=20 goes in there once a week and the teachers have them work on some = project.=20 This year the teachers decided on a Geology theme. I = thought a=20 seismograph would be nice to have in the lab. Actually I think = the=20 homemade one would be better because the kids could get a better = idea of how=20 it works. They wouldn't be doing anything in depth but I = thought=20 seeing there own siesmograph records may spark some interest in = science.=20 I Haven't approached the teachers yet as I want to make sure I = can=20 pull it off first.

John P

On 9/23/06, tchannel <tchannel@..............>=20 wrote:=20

Hi Chris, What sort of "choice of suspension system" = would you=20 recommend? Is there a detail I can look at?

I have only seen the knife edge style.

Thanks, Ted

----- Original Message ----- =

From: ChrisAtUpw@.......=20

To: psn-l@..............

Sent: Saturday, = September 23,=20 2006 5:09 PM

Subject: Re: = Seismograph for=20 school

In a message dated 23/09/2006, jcpatskan@............ writes:
I am thinking of trying to build a seismograph for my = son's=20 school. I have quite a bit of experience in shallow = exploration=20 geophysic's, mostly electrical and electromagnetic, but none = in=20 seismology. I have searched the internet and found quite = a few=20 resources.

Hi John,

    You might consider making a medium = sized=20 Lehman - about 2 ft long? Say about 1.5 sec period that can be = extended=20 to 20 sec?

    You will need +/-12V stabilised = power=20 supplies of you may buy an amplifier and transformer from Larry = at http://psn.quake.net

    Since it will be used with other = school=20 systems, I suggest that you use = Amaseis and buy a=20 DI-154 12 bit ADC still at just $39! = www.dataq.com = Amaseis=20 supports this ADC.

    See http://jclahr.com/science/psn/as1/index.html

    Use magnetic damping, NOT oil.

    Use an all metal braced single unit = costruction - NO plastic structural components - NO separated=20 sections.

    Your choice of suspension system is = critical.=20 NEITHER a point on a plane NOR knife edge systems are = satisfactory -=20 avoid them like the plague. Most other systems are OK to good. = You need=20 to be able to get a period of at least 20 seconds.

    Have a look at http://jclahr.com/science/psn/chapman/lehman/index.html=20

    and http://jclahr.com/science/psn/chapman/index.html
    and http://www.jclahr.com/science/psn/cor_psn.html

    and http://jclahr.com/science/psn/

    ALSO http://www.mgm.monschau.de/seismic/english/artikel/artike= l_1_4.php=20 and sequels

    I have also = noticed a=20 seismograph (or strong motion accelerometer) = on sale=20 at e-bay, with an opening bid of $75.

    I suggest that you=20 forget this one! You do not need a strong = motion=20 sensor - or the headaches of converting an optical one. This = might be=20 called 'buying trouble'!

    Good Luck!

    Chris Chapman
=

PSN-L Email List Message