| 摘要 |
PROBLEM TO BE SOLVED: To provide a flaw inspection device by an AC electromagnetic field measuring method capable of reducing the effect of noise or a false signal even when there is a structural change part such as a welding excess metal part or a T-shaped joint part in the vicinity of an inspection place and capable of easily and certainly calculating the position, size and depth of a flaw or the like. SOLUTION: The flaw inspection device is equipped with an AC magnetic field producing coil 12, a Bx measuring coil 13, a Bz measuring coil 14, a flaw detection probe 10 having a pair of magnetic shields 17, an Ac electromagnetic field measuring instrument 20 for applying an AC magnetic field to the flaw detection probe to output magnetic flux densities Bx and Bz and a data analyzer 30 for analyzing the data of the magnetic flux densities Bx and Bz to detect the position of the flaw or the like present on the surface of an inspection target. A pair of the magnetic shields 17 are constituted so as to hold a Bx measuring coil and a Bz measuring coil so as to leave an interval to shield only a magnetic field in a y-axis direction. Each of the magnetic shields comprises a magnetic body thin film having thickness capable of removing the false signal and capable of detecting a magnetic flux density Bx in an x-axis direction and a magnetic flux density Bz in a z-axis direction. COPYRIGHT: (C)2008,JPO&INPIT
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