An angular position A-C electromotive-force transducer and its application to null-type recorders

THE measurement of process variables by means of a-c excited primary elements has been somewhat neglected. The general use of potentiometric systems has resulted largely from their excellent performance characteristics and their adaptability to a wide range of primary elements. It is generally true, however, that for a given measurement application an a-c system is simpler and hence less expensive. No provision need be made for d-c to a-c conversion, cold junction compensation, or for battery standardization.