PSN-L Email List Message
Subject: Re: Piezoelectric seismic sensor
From: ChrisAtUpw@.......
Date: Thu, 27 Jun 2002 16:10:44 EDT
In a message dated 27/06/02, sbartz@....... writes:
> Has anyone ever heard of using a piezoelectric transducer in a force balance
> accelerometer? I am in the process of building one, and it seems quite
> sensitive
> over a broad range of frequencies.
> Steve Bartz
Hi Steve,
Piezo transducers are not well adapted to a force balance setup. They
are basically AC capacitative devices and have a high coefficient of voltage
versus temperature. They have a very high leakage resistance when dry, but
this can be a limitation in humid conditions.
They do make quite reasonable substitutes as uncalibrated geophones
and you can get periods of up to about 10 seconds out of them with a TL071
opamp or similar. I can pick up a car on the main highway 1000 yds away.
Since they respond up to well over 1 KHz, you do need to filter seriously for
seismic applications.
One company does produce piezo sensors for seismic use.
Regards,
Chris Chapman
In a message dated 27/06/02, sbartz@....... writes:
Has an
yone ever heard of using a piezoelectric transducer in a force balance
accelerometer? I am in the process of building one, and it seems quite sensitive
over a broad range of frequencies.
Steve Bartz
Hi Steve,
Piezo transducers are not well adapted to a force balance setup. They are basically AC
capacitative devices and have a high coefficient of voltage versus temperature. They have a very high leakage resistance when
dry, but this can be a limitation in humid conditions.
They do make quite reasonable substitutes as uncalibrated geophones and you can get pe
riods of up to about 10 seconds out of them with a TL071 opamp or similar. I can pick up a car on the main highway 1000 yds awa
y. Since they respond up to well over 1 KHz, you do need to filter seriously for seismic applications.
One company does produce piezo sensors for seismic use.
Regards,
Chris Chapman
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