| 摘要 |
<p>PURPOSE: To provide such an overcurrent probe that responds to internal defects, but is not affected much by noise, for inspecting ferromagnetic tubes. CONSTITUTION: A probe 30 carries a pair of closely arranged rings and each ring is provided with a plurality of pancake coils. The first ring 32 contains eight pancake coils 34 having a first diameter and the second ring 36 contains four pancake coils 38 having a second diameter. A torochoidal coil 40 is provided as a common reference coil and becomes an absolute electrode for the actuation of the pancake coils. Therefore, tubes can be inspected easily and accurately for internal defects.</p> |
