| 摘要 |
PROBLEM TO BE SOLVED: To provide an eddy current flaw detector capable of sizing of a flaw in pulse excitation eddy current flaw detection and capable of ensuring the inspection accuracy even on an inspection object which requires flaw detection at a deep position.SOLUTION: An eddy current flaw detector 10 includes: exciting means 14 that supplies a pulse-like current to each of excitation coils 11, two or more of which are disposable in an identical plane for forming an eddy current in an inspection object 1; detection means 17 that receives voltage signals detected by detection elements 15 which detect changes in eddy current distribution within the inspection object; holding means 13 that holds the excitation coils and the detection elements so as to perform three-dimensional scanning; calculation and extraction means 18 that calculates flaw position and flaw depth within the inspection object on the basis of the waveforms of the voltage signals detected by the detection means and time-changes of a frequency spectrum; and control means 19 that controls the holding means, when no time-change is generated on the frequency spectrum, to stop and to supply a pulse-like current having a time difference to each of the excitation coils. |
