While making amendment mannered null many magnet of individual difference of the magnetometric sensor in inspecting

摘要

PROBLEM TO BE SOLVED: To provide a method by which the characteristics of many magnetic sensors arranged correspondingly to the inner periphery of a pipe to be inspected can be approximately found by using thin parts, namely, identical peripheral grooves from which the same leakage magnetic flux density is obtained and, at the same time, to eliminate the individual difference of the output of each magnetic sensor at the time of inspecting the pipe. ;SOLUTION: In a method in which a pipe to be inspected is inspected by collecting data outputted from each magnetic sensor at prescribed intervals by moving a leakage flux pig on which many magnets and magnetic sensors are arranged correspondingly to the inner periphery of the pipe in the axial direction of the pipe and a plurality of identical peripheral grooves 2a, 2b, and 2c are formed on the surface of the pipe 1 through which the leakage flux pig can pass so that the outputs of the magnetic sensors may become different and the correspondence relation between the magnetic flux density at each sensor and the output of the sensor is found by passing the pig through the pipe 1 and measuring the output of each sensor against each groove, the output of each sensor is corrected based on the above-mentioned correspondence relation.;COPYRIGHT: (C)1998,JPO