Electromagnetic measurement of the rail displacement by two triangular coils

This paper describes the structure and output characteristics of a rail displacement sensor using two triangular coils. We demonstrate that the measurement principle of the rail displacement sensor is equivalent to measuring the impedance of the coil. We demonstrate a theoretical calculation under the some assumptions. The maximum error is. 0.7 mm between the measured and calculated values. We confirm the validity of the measurement method of rail displacement because of these results.