Temperature Drift Reduction Method of an Eddy Current Displacement Sensor

Abstract

In this paper, a theoretical analysis of temperature drift of an eddy current displacement sensor in the case of being applied to copper, and methods for reducing it are described. The change in impedance of the sensor, when the temperature varies, chiefly depends on the change in resistivity of both the wounded wire and the target metal. There recognized little effect of thermal expansion in the prototyped sensor. We analyzed the combinations of one or two sensors, and envelope detection or phase detection. And it was confirmed that the minimum temperature drift could be achieved in the case of two sensors and phase detection.