PSN-L Email List Message

Subject: RE: two home-made vertical seismometers
From: "Steve Hammond" shammon1@.............
Date: Wed, 22 Feb 2006 09:02:10 -0800


If you want to build a simple seismograph, here is a URL of a very simple
vertical seismograph that was designed by a fellow in Pasadena in the early
1990's.
http://pw2.netcom.com/~shammon1/compressed/VERTICAL.GIF
It uses a screen door spring and cost under $20. It is made from common
parts in a local hardware store and produces good results. It does lack the
electronics however, so if you check the same site,
 http://pw2.netcom.com/~shammon1/equip.htm#Electronics
you will find a pre-amp using OP-07's that can be used with this. The coil
can be built from #44 wire on a plastic frame. You can get the frame from
Radio Shack if you just purchase a spool of their red/black/green #22
construction wire. Hand wind about 4,000 turns of the #44 wire onto a frame.
Warp the coil in black electrical tape to protect it. The magnet is a cow
magnet sold in an animal feed stores but other magnets will also work. I
used these plans to build a system for a 5th grade classroom and the
students were able to locate local events with it.

Regards, Steve Hammond PSN San Jose, Aptos California
  -----Original Message-----
  From: psn-l-request@.............. [mailto:psn-l-request@.................
Behalf Of Gerencher, Joseph J
  Sent: Tuesday, February 21, 2006 12:09 PM
  To: PSN-L@..............
  Subject: two home-made vertical seismometers


  I have photographs of two vertical seismometers that were made by Jim
Lehman and given to me.  Both have been in continuous operation for several
years and both have a natural period of about one second.  The smaller unit
is in my classroom and the larger one is in the basement beneath the
classroom.  I modified the damping of the smaller unit using copper plumbing
fittings, which makes it both easier to construct and easier to operate than
the larger one.  The web address for going directly to the photographs is
too long to post on an e-mail, so if you want to see images of both these
seismometers go to my opening web page at

  http://home.moravian.edu/users/phys/mejjg01/

  then click "homemade seismographs," click "Illustrated history of the
seismometer system, 1991 to 1998" and click the links on that page.
Additional detailed photographs of the construction design of the smaller
home-made seismometer can be found at the following web site:
http://www.netquake.org/seismometers/vertical.htm  Unfortunately, I have not
yet gotten around to annotating these photographs, but intend to do so in
the next several days.



  Joe Gerencher











If you=20 want to build a simple seismograph, here is a URL of a very simple = vertical=20 seismograph that was designed by a fellow in Pasadena in the early=20 1990's.
http://p= w2.netcom.com/~shammon1/compressed/VERTICAL.GIF
It=20 uses a screen door spring and cost under $20. It is made from = common parts=20 in a local hardware store and produces good results. It does lack the=20 electronics however, so if you check the same site,
 http://pw2= ..netcom.com/~shammon1/equip.htm#Electronics 
=
you=20 will find a pre-amp using OP-07's that can be used with this. The coil = can be=20 built from #44 wire on a plastic frame. You can get the frame from Radio = Shack=20 if you just purchase a spool of their red/black/green #22 construction = wire.=20 Hand wind about 4,000 turns of the #44 wire onto a frame. Warp the = coil in=20 black electrical tape to protect it. The magnet is a cow magnet = sold in an=20 animal feed stores but other magnets will also work. I used these = plans to=20 build a system for a 5th grade classroom and the students were = able to=20 locate local events with it.
 
Regards, Steve Hammond PSN San Jose, Aptos = California
-----Original Message-----
From: = psn-l-request@................. [mailto:psn-l-request@...............On Behalf Of Gerencher, = Joseph=20 J
Sent: Tuesday, February 21, 2006 12:09 PM
To:=20 PSN-L@..............
Subject: two home-made vertical=20 seismometers

I have photographs of = two vertical=20 seismometers that were made by Jim Lehman and given to me.  Both = have=20 been in continuous operation for several years and both have a natural = period=20 of about one second.  The smaller unit is in my classroom and the = larger=20 one is in the basement beneath the classroom.  I modified the = damping of=20 the smaller unit using copper plumbing fittings, which makes it both = easier to=20 construct and easier to operate than the larger one.  The web = address for=20 going directly to the photographs is too long to post on an e-mail, so = if you=20 want to see images of both these seismometers go to my opening web = page at=20

http://home.moravia= n.edu/users/phys/mejjg01/

then click = “homemade=20 seismographs,” click “Illustrated history of the = seismometer system, 1991 to=20 1998” and click the links on that page.  Additional = detailed photographs=20 of the construction design of the smaller home-made seismometer can be = found=20 at the following web site:  http://www.net= quake.org/seismometers/vertical.htm =20 Unfortunately, I have not yet gotten around to annotating these = photographs,=20 but intend to do so in the next several days.

 

Joe Gerencher

 

 


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