Experimental Study of Temperature on Eddy Current Sensor for Clearance Measurement

Abstract

AbstractHigh-precision eddy current sensors are mainly used for measuring the tip clearance of rotating parts of aero-engines in which the ambient temperature is up to 2000 K. The coil impedance value of the eddy current sensor not only reflects the distance from the probe to the conductor, it is also affected by the ambient temperature. Thus, it is necessary to investigate the influence of temperature on the eddy current sensor probe. The experimental research show: when the temperature is lower than 673 K, the temperature has a significant effect on the eddy current sensor gap measurement curve. Otherwise, it’s not. Secondly, it is found that when the ambient temperature is between 573 K and 1273 K, the equivalent resistance of the eddy current sensor increases linearly with temperature, with an average change of 60%, but the average change of its equivalent inductance with temperature is only 5%. In addition, the experimental results also prove that the leaf tip gap eddy current sensor can be used not only to measure the gap, but also to measure the ambient temperature. The eddy current sensor can be used as a multifunction sensor in the engineering application with the corresponding data processing method.KeywordsEddy currentTip clearanceTemperatureEquivalent resistanceMultifunction sensor