Array eddy current probe capable of actively removing electromagnetic coupling between adjacent coils

Abstract

The invention provides an array eddy current probe capable of actively removing electromagnetic coupling between adjacent coils, and mainly overcomes two defects that an existing array eddy current probe adopts a shielding cover to passively shield electromagnetic coupling: 1, a channel for detecting joule heat of coils in a cover and external convective heat transfer is blocked, coil temperaturerise is easily caused, and temperature drift errors are caused; and 2, the probe size is increased, and the probe spatial resolution is reduced. According to the technical scheme, two auxiliary coilscoaxial with detection coils are arranged outside the detection coils of the probe, and a magnetic field generated by the auxiliary coils weakens an external magnetic field generated by the detectioncoils, so that magnetic field interference of adjacent detection coils is reduced. The auxiliary coils are each provided with a metal slip sheet, the length and the number of turns of the auxiliary coils connected to a loading circuit can be changed by moving a slip sheet, the weakening degree of the external magnetic field is further adjusted, and different requirements of different application scenes for the electromagnetic decoupling degree of the adjacent coils are met. Compared with an existing array eddy current probe, the probe provided by the invention is smaller in size and smaller intemperature drift error.

Description

Technical field [0001] The invention belongs to the technical field of non-destructive testing, and further belongs to the technical field of eddy current testing, and specifically relates to an array eddy current probe for non-destructive testing, in particular to an array eddy current probe without shielding that reduces electromagnetic coupling between adjacent detection coils Probe. Background technique [0002] Eddy current testing is a non-destructive testing technology that is widely used in the industrial field. Its working principle is based on the principle of electromagnetic induction: when a detection coil carrying an alternating current is close to a metal conductor, an alternating magnetic field will be generated in the metal conductor, called a primary magnetic field At the same time, the alternating magnetic field induces an eddy current on the surface of the metal conductor; the eddy current in the metal conductor will also generate a magnetic field, which is cal...

AI Technical Summary

Problems solved by technology

However, the closed shield structure will hinder the heat exchange of the energized coil in the shield, which will easily cause the coil to overheat and affect the accuracy and service life of the coil; secondly, the introduction of the shield will increase the volume of the probe, resulting in low spatial resolution of the probe

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