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

wrote:=20 Hi Chris, What sort of "choice of suspension system" would you = recommend? Is there a detail I can look at?=20 I have only seen the knife edge style.=20 Thanks, Ted ----- Original Message -----=20 From: ChrisAtUpw@.......... To: psn-l@................. Sent: Saturday, September 23, 2006 5:09 PM Subject: Re: Seismograph for school=20 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.=20 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.=20 See http://jclahr.com/science/psn/as1/index.html Use magnetic damping, NOT oil.=20 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.=20 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/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. =20 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 Stephen, Thanks for this = recommended=20 site...I could not enlarge the PSN Preamp and PSN filter Amp by Pete = Rowe, to=20 see the values on the drawings. I searched the net but could not = find any=20 other site for them. Do you know where I might be abe to find = these, large=20 enough to print? Thanks, Ted

----- Original Message -----
From:=20 Stephen=20 Hammond
To: psn-l@..............

Sent: Tuesday, September 26, = 2006 11:38=20 AM

Subject: RE: Seismograph for = school

Hi,=20 I 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=20 most important attributes you need to consider. The stability=20 of the system hardware and software and the quality of the information = provided significantly improves the students interaction and learning = outcome=20 from using the system. For example, if you look at the PSN San = Jose main=20 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=20 PC, sensors and simple amp. At South Valley, Jan Froom went though = several=20 steps 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 = 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=20 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. = Considering that he has about 300 students per semester, this provides = a=20 40-trip / student page access ratio which is a significant amount = of=20 return on investment. Greg keeps the system in his classroom and = his=20 students take part in operating the system during the class year. Greg = is=20 extremely limited on the amount of time he can spend on the system and = WINSDR=20 has significantly improved his productivity. With a minimal = investment, you=20 will see a vast improvement over a simple classroom sensor and amp.=20

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

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

Hi John, Ted here, and I am = one month=20 into 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=20 closer.

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

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

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

Subject: Re: Seismograph = for=20 school

Hello everyone,

Thanks for the = tips.

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

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

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