For protective purposes, the piezoresistive sensor is flushed with a hydraulic fluid. The medium is separated by means of a stainless steel diaphragm. Flexure of the diaphragm as the result of the external pressure causes a change in the hydraulic pressure of the fluid around the piezoresistive sensor. The sensor emits a pressureproportional signal which is converted to a 4 - 20 mA output signal.
The measuring method is very wellsuited for the detection of low pressures and high overload factors can be achieved with it.
Principle of piezoresistive sensor