| 摘要 |
PURPOSE:To measure the penetration depth of the weld zone of a tube end precisely by detecting an invisible reference surface by an electromagnetic coil sensor, and moving an ultrasonic probe which is incorporated at the same position with it and detecting a penetration tip part. CONSTITUTION:When electromagnetic coil sensor 22 is moved to right or left, a signal varies from a low level to a high level or vice versa. Consequently, the internal end surface 8 of a tube plate 1 is positioned at the position of the sensor 22 where the level is intermediate. Then, when a sensor operation bar 24 is moved to right, the position of the penetration tip part 4 is detected by the function of a probe 9. The size from a pointer 26 to a pointer 27 is equal to the size from the internal end surface 8 to the tip part 4, so this size is subtracted out of the size from the external end surface 7 of the tube plate to the internal end surface 8, i.e. the thickness of the tube plate 1 to measure the penetration depth of the tube end weld zone 3. |
