Piezometers

Piezometers measure PRESSURE and are available in several pressure ratings from 345 to 6895 kPa.

Operating principle & output signal

The Piezometer consists of internal strain gages which convert mechanical motion into an electronic signal. Resistance is proportional to the strain experienced by the sensor. If a wire is held under tension, it gets slightly longer and its cross-sectional area is reduced. This changes its resistance (R) in proportion to the strain sensitivity (S) of the wire's resistance.

When a strain is introduced, the strain sensitivity, which is also called the gage factor (GF), is given by:

As fluid pressure is applied to the exposed side of the flexible diaphragm, the diaphragm deflects, causing a change in the resistance of the strain gauge. The resultant resistance output can be measured in 4-20mA or 0-10mV and converted into Engineering Units using a strain gages readout.