Sensitive Technique for Detecting Outer Defect on Tube with Remote Field Eddy Current Testing
小林 徳康 Noriyasu KOBAYASHI 長井 敏 Satoshi NAGAI 落合 誠 Makoto OCHIAI 神保 昇 Noboru JIMBO 小舞 正文 Masafumi KOMAI
Exciter CoilFlux GuideHigh SensitivityOuter DefectRemote Field Eddy Current Testing
In the remote field eddy current testing, we proposed the method of enhancing the magnetic flux density in the vicinity of an exciter coil by controlling the ma gnetic flux direction for increasing the sensitivity of detecting outer defects on a tube and used the flux guide made of a magnetic material for the method. T he optimum structural shape of the flux guide was designed by the magnetic field analysis. On the experiment with the application of the flux guide, the magneti c flux density increased by 59 % and the artificial defect detection signal became clear. We confirmed the proposed method was effective in a high sensitivity.