Piezoresistive Media Isolated

If pressure sensors are required for “harsh environments” in pressure ranges below 10bar, especially below 1bar, so-called oil-filled sensor modules have proven their worth.

Standard piezoresistive MEMS pressure sensor elements used here, are protected from the measurement medium by an additional thin stainless steel diaphragm. An oil serves as the pressure transfer medium from the steel membrane to the silicon chip.

This type of sensors (at Prignitz Mikrosystemtehnik under the brand name PMI) are used very successfully in many fields of application such as oil production, dirty water, chemicals, sea water.

Depending on the application, different designs are available e.g. “inside” protected diaphragm, dead volume free “flash” diaphragm, clamping connection. Depending on the type of construction and calibration electronics, accuracies and long-term stabilities of less than 0.2% down to 0.04% are possible.