SILICON SENSORS LEAD PRESSURE TRANSMITTER TECHNOLOGY.

Microelectronics and micromachining combine to reduce the cost and size, and improve the accuracy, of pressure sensors. The sensor-on-a-chip concept began with the introduction of the piezoresistive sensor, which is a strain gage and Wheatstone bridge circuit diffused onto a silicon crystal. Today, these sensors, as well as capacitive types, are available in a single microminiature chip. The chip contains the sensing element and all the electronics needed for temperature compensation, linearization, and A/D conversion. Still newer technology, called micromachining, is completely changing the nature of the silicon chips and making rapid headway in sensor manufacturing. This article reviews the latest in pressure sensing technology, and tells what technology advances can be expected in the future.