| 摘要 |
PURPOSE:To obtain a system which performs flaw detection automatically as to corrosion nearby the skirt base part of a cylinder by correcting the sensitivity of the level of the echo of a main probe with the received wave of an auxiliary probe which receives an ultrasonic wave oscillated by the main probe. CONSTITUTION:The main probe 6a and auxiliary probe 6b are arranged inside and outside the skirt part 2 of the cylinder 1 nearby the cylinder 1. Then while the cylinder 1 is rotated, flaw detection is performed as to a flaw detection area inside the skirt 2. The length of corrosion in the circumferential direction is calculated by using the rotation of the cylinder 1 detected by a rotary encoder 8. Further, the depth of the corrosion is calculated by using the echo level of the ultrasonic wave from the main probe 6a and the length of the corrosion detected by the rotary encoder 8. The surface roughness and curvature of the bottom surface of the cylinder 1 that the main probe 6a approaches affect how easy the ultrasonic wave enters the plate of the cylinder 1 from the main probe 6a, so the echo of the ultrasonic wave sent out of the main probe 6a is received by the auxiliary probe 6b and the intensity of the received wave is used to make corrections by a sensitivity correction processing block 10. |
