PSN-L Email List Message
Subject: Re: Magnetic Phono Cartridge as a Seismic Velocity sensor ?
From: ChrisAtUpw@.......
Date: Thu, 13 May 2010 08:19:04 EDT
In a message dated 12/05/2010, gmvoeth@........... writes:
i just cant help but think there is a very simple way to do this that does
not require a mass and spring. Such as a strain guage and a mass, resting
upon it.
Hi Geoff,
Strain gauges have too low an output.
You set some mass on something like a bathroom scale and amplify the
output from the scale.
These are likely to have too much in-built friction.
Touch a Phono Needle to the bottom of a mass on a spring. Why not get a
meaningful signal.
It should work just like any velocity sensor. Sum the outputs of a stereo
cartridge.
I told you three good reasons why a phono cartridge would make a lousy
seismic sensor. If you don't believe me, OK. Waste your own time, effort and
money, but don't waste that of other experimenters.
You can make a seismic sensor with a large PZT sounder disk and a mass.
Regards,
Chris Chapman
In a message dated 12/05/2010, gmvoeth@........... writes:
i just=20
cant help but think there is a very simple way to do this that does not=
=20
require a mass and spring. Such as a strain guage and a mass, resting up=
on=20
it.
Hi Geoff,
Strain gauges have too low an output.
You set=20
some mass on something like a bathroom scale and amplify the output from=
the=20
scale.
These are likely to have too much in-built=20
friction.
Touch a=20
Phono Needle to the bottom of a mass on a spring. Why not get a meaningf=
ul=20
signal.
It should work just like any velocity sensor. Sum the outputs=
of a=20
stereo cartridge.
I told you three good reasons why a phono car=
tridge=20
would make a lousy seismic sensor. If you don't believe me, OK. Waste your=
own=20
time, effort and money, but don't waste that of other experimenters.
You can make a seismic sensor with a large PZ=
T=20
sounder disk and a mass.
Regards,
Chris Chapman
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