| 摘要 |
PROBLEM TO BE SOLVED: To provide a pulse excitation type eddy current flaw detection method and device capable of evaluating the inclination of attenuation on the basis of magnetic flux by an eddy current. SOLUTION: The flaw detection device includes: a probe 24 consisting of an exciting coil and a detection element; an exciting means for making a pulsed exciting current flow through the exciting coil; and a computation means for making magnetic fluxes by the exciting current penetrate a body to be tested and computing temporal attenuation characteristics of magnetic flux by an eddy current which has occurred in the body to be tested due to the cutoff of the exciting current and detected by the detection element 34. The exciting coil is constituted of a plurality of exciting coils 32 an 33. In the plurality of exciting coils 32 and 33, a magnetic flux is made to penetrate the body to be tested as mutually interfering with each other in such a way as to reduce the amount of magnetic fluxes interlinking with each exciting coil and attenuate magnetic fluxes by the exciting current at the detection element in a short time when the exciting current is cut off. COPYRIGHT: (C)2010,JPO&INPIT
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