Effect of a bridge balance network on a semiconductor pressure transducer

Abstract

Pressure transducers and accelerometers that make use of semiconductors strain gages or have strain gages diffused on a silicon diaphragm cannot be used with a bridge balance network if one wants to achieve thermal zero compensation. Thermal zero compensation is compensating for the change in output due to temperature only, and is typically +-1.5 percent of the full scale output for a temperature change of 100/sup 0/F. The reason for not using a balance network is the way in which the transducer is thermally compensated. There are two ways to obtain thermal zero compensation with a semiconductor transducer: either match each individual gage to each other, or trim one-half of the bridge to match the other half of the bridge. It is the latter that is easiest to do and the method the manufacturers use. The method is described.