• Yashtec Instrumentation & Engg Source

Piezoresistive Pressure Sensors

KELLER AG für Druckmesstechnik, a Swiss company, offers Piezoresistive Pressure Sensors for absolute-, gauge- and differential pressure, Series 2, 3 and 4. These are suited for direct-mounting on printed circuit boards. The pressure sensor is a piezoresistive measuring cell consisting of a glass back plate and the silicon chip with the diffused resistor bridge. The cell is mounted on a glass feed through and packaged in a housing for easy pressure connection. The high, stable and reliable output signal of the sensor can easily be conditioned with standard amplifiers.All sensors are tested for temperature, stability and linearity and are delivered with an individual calibration sheet. Series 2: the medium is acting directly on the silicon chip and comes into contact with the strain gauges of the Wheatstone bridge; application in dry air only. Series 3: the sensor is mounted in an aluminium housing; housing and sensor are protected by a thin (7 ?m) parylene layer; this layer grants full protection in applications where condensation may occur; continuous water exposure is not recommended; and the average time of water resistance of the parylene layer is 6 months. Series 4: the medium acts on the rear side of the silicon chip; the pressure medium may be wet.