Shape Sizes of a Detecting Coil for Rail Joint Gap Measurements

摘要

This paper deals with the characteristics of a voltage-detecting-type rail joint gap sensor using an air-coil. The sensor, designed for ordinary railways, is able to detect the flux change due to the eddy current between the sensor and the rail. The key points of this paper are as follows: (1) the principle of the measurement on the rail joint gap sensor, which is composed of two detecting coils under one exciting coil, (2) the dependence of the output voltage on the area of the detecting coils on the rail and the rail joint gap, (3) the distinction between normal and singular rail joint gaps.