| 摘要 |
<p>A leakage flux flaw detector for detecting a flaw (K) of a material (P) in a predetermined direction by magnetizing the material (P) and detecting a flux leaking from the flaw (K). The detector includes a pair of magnets (1a, 2a) for magnetizing the material in a direction different from the flaw detection direction; a pair of magnets (1a, 2b) for magnetizing the material in a direction different from the direction of magnetization and from the flaw detection direction, the magnets (1a, 2b) being spaced apart by a predetermined distance in the flaw detection direction from the magnetization regions of both magnets; and leakage flux sensors (3a, 3b) disposed between the two pairs of magnets. In the leakage flux sensors which detect a flux leaking from a flaw of the magnetized material by two magneto-sensitive portions so disposed as to oppose the material and spaced apart by a predetermined distance from each other in the flaw detection direction, the distance between the centers of the magneto-sensitive portions is d « 4 mm, their length orthogonal to the flaw detection direction is L » 0.5 mm, and d/L » 1. The present invention provides also a leakage flux sensor wherein two circular magneto-sensitive portions of different sizes are disposed concentrically.</p> |
