PSN-L Email List Message

Subject: Re: instrument design
From: meredith lamb paleoartifact@.........
Date: Wed, 21 Oct 2009 20:56:29 -0600


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).
>
> ** 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.
>
> Randall Peters
>

Meredith Lamb

>
>


On Tue, Oct 20, 2009 at 8:12 AM, Randall Peters = <PETERS_RD@mer= cer.edu> wrote:
=A0
(Clip)
=A0
Randall,
=A0
** In regard to the Kinemetrics SH-1; I'am h= aving difficulty visualizing the spring directlyabove the
horizontal pendulum mass.=A0 Might you and anyon= e have a PDF file with a picture/s they could share?

=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 A commercial horizo= ntal seismometer that successfully uses the same physical principle is the = Kinemetrics SH-1.=A0 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.=A0 The instrument emplo= ys two magnet/coil subsystems: (i) one for Faraday law detection with which= every amateur seismologist is familiar, and the (ii) other one for calibra= tion (by introducing a current to the coil) and for damping when operationa= l (by placing a resistor across the coil).

** Feel free to offe= r your thoughts on the sensors.

I hae not here me= ntioned sensor type.=A0 For those with interest I can offer thoughts based = on my long-time experience with both velocity and position types.=A0

Randall Peters=A0=A0=

=A0
Meredith Lamb
=A0

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