To Meredith and all, there is a Kinemetrics SH1 currently listed on Ebay =
with the case removed so that you can see the mechanism.
Jim Allen
  ----- Original Message -----=20
  From: meredith lamb=20
  To: psn-l@.................
  Sent: Wednesday, October 21, 2009 7:56 PM
  Subject: Re: instrument design





  On Tue, Oct 20, 2009 at 8:12 AM, Randall Peters  =
wrote:

  (Clip)

  Randall,

  ** In regard to the Kinemetrics SH-1; I'am having difficulty =
visualizing the spring directlyabove the
  horizontal pendulum mass.  Might you and anyone have a PDF file with a =
picture/s they could share?

                 A commercial horizontal seismometer that successfully =
uses the same physical principle is the Kinemetrics SH-1.  The torque =
acting in opposition to gravity is provided by means of a vertical =
elastic metal strip (spring) that holds the seismic mass in an =
equilibrium position directly above it.  The instrument employs two =
magnet/coil subsystems: (i) one for Faraday law detection with which =
every amateur seismologist is familiar, and the (ii) other one for =
calibration (by introducing a current to the coil) and for damping when =
operational (by placing a resistor across the coil).=20

    ** Feel free to offer your thoughts on the sensors.

    I hae not here mentioned sensor type.  For those with interest I can =
offer thoughts based on my long-time experience with both velocity and =
position types. =20

    Randall Peters =20


  Meredith Lamb







To Meredith and all, there is a =
Kinemetrics SH1=20
currently listed on Ebay with the case removed so that you can see the=20
mechanism.
Jim Allen

  
----- Original Message ----- 
  From:=20
  meredith lamb 
  
To: psn-l@.............. 
  
Sent: Wednesday, October 21, =
2009 7:56=20
  PM
  
Subject: Re: instrument =
design
  




  
On Tue, Oct 20, 2009 at 8:12 AM, Randall =
Peters <PETERS_RD@..........> =

  wrote:
  
 
  
(Clip)
  
 
  
Randall,
  
 
  
** In regard to the Kinemetrics SH-1; I'am =
having=20
  difficulty visualizing the spring directlyabove the
  
horizontal pendulum mass.  Might you and =
anyone=20
  have a PDF file with a picture/s they could share?

  
    

    

    
             =

    A commercial horizontal seismometer that successfully uses the same =
physical=20
    principle is the Kinemetrics SH-1.  The torque acting in =
opposition to=20
    gravity is provided by means of a vertical elastic metal strip =
(spring) that=20
    holds the seismic mass in an equilibrium position directly above =
it. =20
    The instrument employs two magnet/coil subsystems: (i) one for =
Faraday law=20
    detection with which every amateur seismologist is familiar, and the =
(ii)=20
    other one for calibration (by introducing a current to the coil) and =
for=20
    damping when operational (by placing a resistor across the coil).=20

    
** Feel free to =
offer your=20
    thoughts on the sensors.
  
    

    

    
I hae not =
here mentioned sensor type.  For those =
with interest=20
    I can offer thoughts based on my long-time experience with both =
velocity and=20
    position types.  

    
Randall=20
    Peters  
  
 
  
Meredith Lamb