| 摘要 |
<p>It is possible to accurately and stably inspect a scratch in the vicinity of a surface of a cell external case formed by a cylindrical copper plate by using a simple device. The cell external case (1) is rotated around the center axis of the cylindrical shape by a rotation device (2) and a magnetic flux is applied to the rotating cell external case from both ends of a frame (4). When a scratch is present on the cell external case (1), leak magnetic flux is generated which is detected by a magnetic sensor (6) arranged in the vicinity of the cell external case (1) and displayed on a display device (12) via a signal processing device (11). Since the cylindrical cell external case (1) rotates around its center axis, the distance between its surface and the magnetic sensor (6) is not changed and a scratch can be detected stably.</p> |
