EDDY CURRENT PROVE FOR DETECTING METAL SURFACE FLAW

摘要

PROBLEM TO BE SOLVED: To provide an eddy current probe for detecting a metal surface flaw capable of effectovely detecting the flaw and further detecting directivity of the flaw by reducing an influence of a lifting-off effect and a material discontinuous part. ;SOLUTION: In the eddy current probe 10 for detecting a metal surface flaw having at least one self-induction type differential coil 11 arranged oppositely to a metal surface such as, for example, a rail R, the coils 11 have a nonmagnetic element 12 of a plate-like substantially square shape arranged oppositely on the surface of the rail R, two coils 13, 14 wound on the two sets of opposite sides of the element 12 so as to be intersected with each other and differentially connected, and a sealing resin formed to cover the two coils.;COPYRIGHT: (C)2001,JPO