EDDY CURRENT FLAW DETECTION SYSTEM AND EDDY CURRENT FLAW DETECTION METHOD

To provide an eddy current flaw detection system and an eddy current flaw detection method capable of detecting a front surface flaw and a rear surface flaw of an inspection object by discrimination.SOLUTION: An eddy current flaw detection system includes: an eddy current probe 11 having an excitation coil 22, a first detection coil 23A, and a second detection coil 23B; a flaw detection device 13; and a computer 14, and then detects a front surface flaw 4 and a rear surface flaw 5 of a circular tube 2. The computer 14 determines whether detection signals correspond to a front surface flaw signal according to whether a phase angle θ1 of the detection signal of the first detection coil 23A and a phase angle θ2 of the detection signal of the second detection coil 23B are within a reference range ABCD or reference range GHIJ of a discrimination map, determines whether the detection signals correspond to a rear surface flaw signal according to whether the phase angles are within a reference range ABCEF or reference range GHIKL of the discrimination map, and then outputs the determination result.SELECTED DRAWING: Figure 3 【課題】検査対象物の表面きずと裏面きずを識別して検出することができる渦電流探傷システム及び渦電流探傷方法を提供する。【解決手段】渦電流探傷システムは、励磁コイル２２、第１検出コイル２３Ａ、及び第２検出コイル２３Ｂを有する渦電流プローブ１１と、探傷装置１３と、コンピュータ１４とを備え、円管２の表面きず４及び裏面きず５を検出する。コンピュータ１４は、第１検出コイル２３Ａの検出信号の位相角θ１及び第２検出コイル２３Ｂの検出信号の位相角θ２が、識別マップの基準範囲ＡＢＣＤ又は基準範囲ＧＨＩＪ内にあるか否かにより、検出信号が表面きず信号に相当するか否かを判定すると共に、識別マップの基準範囲ＡＢＣＥＦ又は基準範囲ＧＨＩＫＬ内にあるか否かにより、検出信号が裏面きず信号に相当するか否かを判定し、その判定結果を出力する。【選択図】図３