| 摘要 |
PROBLEM TO BE SOLVED: To provide an eddy current flaw detector which accurately detects the flaw of the surface layer part of a steel material having no magnetism such as a non-magnetic material, or a hot material. SOLUTION: The eddy current flaw detector A is equipped with an exciting part 10, a detection part 20, a first signal processing part 30, a second signal processing part 40, and a differential amplifier 50. The first signal processing part 30 detects the signal related to a first exciting coil 11 in the detection signal detected by the detection part 20 to subject the same to signal processing. The second signal processing part 40 detecs the signal related to a second exciting coil 12 in the detection signal detected by the detection part 20 to subject the same to signal processing so that the intensity of the detected play noise signal j22 coincides with the intensity of a play noise signal j12 processed by the first signal processing part 30. The differential amplifier 50 is constituted so as to subject the flaw detecting pre-signal j1 from the first signal processing part 30, and the flaw detecting pre-signal j2 from the second signal processing part 40, both to subtraction processing. COPYRIGHT: (C)2004,JPO&NCIPI
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