Eddy current testing method of the inner surface finned tube, probe for eddy flow and differential coil for eddy current

摘要

PROBLEM TO BE SOLVED: To provide a method for detecting an eddy current flaw of a tube with an inner fin, capable of surely detecting microdefects generated in the trough part of an inner tube surface, even when the inner surface shape of the tube with an inner fin is not uniform in the tube circumferential direction.;SOLUTION: The method for detecting an eddy current flaw has a size arranged in the trough part of the tube P, arranges a differential coil, comprising a pair of coils 21, 22 separated in an axis center direction X in the trough part of the tube P, along an extending direction of the trough part of the tube P, and detects the flaw existing in the trough part of the tube P by being relatively moved in the extending direction of the trough part of the tube P.;COPYRIGHT: (C)2008,JPO&INPIT