| 摘要 |
PROBLEM TO BE SOLVED: To provide a flaw detecting probe for eddy current flaw detection to detect a tube-axial or circumferential flaw on a tube simply and accurately without being affected by its own backlash or inclination. SOLUTION: This flaw detecting probe 1 is equipped with a solenoidal exciting coil 3 made by winding polyimide wire on a bobbin 2, and a plurality of annular detection coils 4 disposed along circumferentially all the area of an axially-middle part of the exciting coil 3. If a flaw exists and extends circumferentially of the tube, a local annular eddy current caused by magnetic flux vertical to the surface of the tube on the end part side of the exciting coil 3 changes owing to the circumferential flow. Since secondary magnetic flux caused by the eddy current and perpendicular to the surface of the tube interlinks the detection coils 4, electromotive force is generated due to the existence of the flaw. The electromotive force is detected to detect the circumferential flaw on the tube. COPYRIGHT: (C)2007,JPO&INPIT
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