Do you mean vibrating wire type pressure sensors? If so, here's a clip out of the wiki entry:
"Uses the changes in resonant frequency
in a sensing mechanism to measure stress, or changes in gas density,
caused by applied pressure. This technology may be used in conjunction
with a force collector. Alternatively, resonant technology may be employed by expose the
resonating element itself to the media, whereby the resonant frequency
is dependent upon the density of the media. Sensors have been made out
of vibrating wire, vibrating cylinders, quartz, and silicon MEMS.
Generally, this technology is considered to provide very stable
readings over time."
Straight from the entry: http://en.wikipedia.org/wiki/Pressure_sensor
Hope that helps.
__________________
The first law of thermodynamics is you do NOT talk about thermodynamics.
Pressure Measurement
Re: Pressure Measurement
