The web site showing the various pendulum configurations is very =
interesting.  Has anyone experimented with or know of a seismometer =
based on the Scott-Russel Linkage pendulum reflected in the web site =
Chris referenced?
James Allen
  ----- Original Message -----=20
  From: ChrisAtUpw@..........
  To: psn-l@.................
  Sent: Saturday, September 20, 2008 11:16 AM
  Subject: Re: Crossed wire mass pendulum signal extension/s


  In a message dated 2008/09/20, tchannel1@............ writes:


    Hi Folks,  This is one approach I have not tried.  =
http://www.phy.mtu.edu/~suits/PH3110/pendulums.html
    Has anyone built one, as a mock up to see the results?
    If someone would suggest some dimensions, I would like to try it, to =
see how it would work and the period possible.


  Hi Ted,

         I suggest that you forget these systems in general. The X =
suspension shown is quite bulky and the high swire stresses are likely =
to give problems.

         We were considering the LIGO variant where the mass is mounted =
on a stalk on top of the lower plate. By varying the mass height above =
the lower plate, you can vary the period. The whole setup can be quite =
compact. You can also use rolling wire or foil suspensions for easy =
construction and very low intrinsic noise.

         Regards,








The web site showing the various =
pendulum=20
configurations is very interesting.  Has anyone experimented with =
or know=20
of a seismometer based on the Scott-Russel Linkage pendulum reflected in =
the web=20
site Chris referenced?
James Allen

  
----- Original Message ----- 
  From:=20
  ChrisAtUpw@....... 
  
To: psn-l@.............. 
  
Sent: Saturday, September 20, =
2008 11:16=20
  AM
  
Subject: Re: Crossed wire mass =
pendulum=20
  signal extension/s
  

In a message dated 2008/09/20, tchannel1@............=20
writes:


  Hi Folks,  This is one approach I have not =
tried. =20
    http://www.p=
hy.mtu.edu/~suits/PH3110/pendulums.html
Has anyone built one, as a mock up to see the=20
    results?
If someone would suggest some dimensions, I would =
like to try=20
    it, to see how it would work and the period =
possible.

Hi=20
  Ted,

       I suggest that you =
forget=20
  these systems in general. The X suspension shown is quite bulky and =
the high=20
  swire stresses are likely to give=20
  problems.

       We were =
considering the=20
  LIGO variant where the mass is mounted on a stalk on top of the lower =
plate.=20
  By varying the mass height above the lower plate, you can vary the =
period. The=20
  whole setup can be quite compact. You can also use rolling wire or =
foil=20
  suspensions for easy construction and very low intrinsic=20
  noise.

      =20
  Regards,

       Chris =
Chapman=20