Bellows
Measuring pressure with bellows device
The bellows is a device which operates
on a very similar principle to the diaphragm. The sensitivity of a
bellows is greater than for a diaphragm, which is its principal
attribute. Pressure changes within the bellows produce translational
motion of the end of the bellows which can be measured by capacitive,
inductive (LVDT) or potentiometric transducers according to the range
of movement produced.
A typical measuring range for a
bellows-type instrument is 0-1 bar (gauge pressure). The bellows is
now rarely used because of its high manufacturing cost and proneness
to failure. Its traditional advantage of being able to measure low
pressures with a high sensitivity can now be satisfied more cheaply by
diaphragm-type devices, using recent developments in electronics.

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Pressure Measurements
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