| 摘要 |
<p>The apparatus (1) comprises an induced current sensor (3) formed from at least two cores (5, 6) of ferromagnetic material, on each of which at least one conducting winding (7, 8) is provided. Said cores (5, 6) have adjacent terminal portions (9, 10) which are conveniently separated by an air gap (a) of the order of a few tens of mu m and which, when in use, are made to traverse the surface of the workpiece (2) in which any microdefects are to be detected.</p> |
