Abstract
An integrated multi-piezoresistive gauge (IMPG) sensor was designed for differential pressure transmitters. The sensor measures three quantities: the differential and static pressures, and the ambient temperature. Three pizoresistive gauges were positioned on a {110} plane crystallographic silicon diaphragm. The voltage outputs of the gauges were calculated with respect to the distance between a modulus of the silicon diaphragm and its mounting glass die. Numerical analysis revealed that crosstalk between the gauges were occurred when a differential pressure was applied to the sensor. This resulted in elastic deformation of the diaphragm on the periphery. The proper dimensional design and the optimal gauge positioning maximized the output and minimized the crosstalk. The three voltage outputs were combined by a microcomputer to yield a compensated sensor output. An experimental IMPG sensor was fabricated and the compensation scheme was proved to be useful. The accuracy was within ±0.1% of the full scale in the pressure range of ±80kPa. The drift was less than 0.25% for the temperature change of 50°C and was less than 0.2% for the static pressure change of 10MPa.
