Novel displacement eddy current sensor with temperature compensation for electrohydraulic valves

A new displacement eddy current sensor for high-pressure applications is presented, and a simple temperature drift compensation method utilizing a non-inductive compensating coil is also developed. Analysis based on the finite element approach is given, and the predicted results agree well with the experimental results. Extensive experiments have verified that the sensor has good linearity, wide measuring range up to 8 mm, and high temperature stability for the temperature range from 20 to 90 degrees C. Thus, the sensor is suitable for detecting the position of spools of valves or pistons of hydraulic cylinders in high-pressure environments. (C) 2005 Elsevier B.V. All rights reserved.