Patent ID: 11674927

Abstract:
The eddy current flaw detection apparatus includes: a pair of detecting coils 10a, 10b arranged in coaxial and spaced relation with a specimen 3; and a bridge circuit two sides of which are constituted by the detecting coils so that magnetic fields generated by these detecting coils 10a, 10b are in opposite phases to each other. A pair of exciting coils 11a, 11b are arranged coaxially with the detecting coils 10a, 10b in a manner to sandwich the pair of detecting coils 10a, 10b therebetween. A distance D between the detecting coil and the exciting coil adjacent thereto is set to a distance where a vibrational noise signal excited in the exciting coil and detected by its adjacent detecting coil is in opposite phase to that of a vibrational noise signal excited in the detecting coil and detected by the detecting coil.