PURPOSE: To accurately and efficiently inspect piping for defects in a short time by arranging a plurality of coil cases, inside which a plurality of coils, each wound in the shape of a quarter of a circle in such a way as to extend along the outer surface shape of the piping, are enclosed in the form of a semicircle, so that the coil cases sandwich the piping, and using a probe that is placed in such a way as to be free to open and close. ;CONSTITUTION: Each coil 1 is curved into a quarter of a circle and wound in such a way as to extend along the outer surface shape of piping 3. The coil 1 is then enclosed within a coil case 2. The two coil cases enclosing the coils are mounted to sandwich the piping. This probe for flaw detection scans along the longitudinal direction of the piping, and inspects the piping for flaws according to changes in impedance of each coil. By the coils wound along the surface of the sample, an eddy current is produced along the sample surface, and the impedance of the coils is varied as the eddy current is interrupted by flaws. With the use of the probe for flaw detection, the eddy current is produced along the sample surface, and the flaws interrupt the eddy current regardless of their directions, thereby, the accuracy of inspection is increased.;COPYRIGHT: (C)1996,JPO
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