| 摘要 |
PURPOSE:To detect a defect part in detail without taking a long time for flaw detection by performing flaw detection normally at large subscanning pitch and decreasing the subscanning pitch for a part where a defect is detected. CONSTITUTION:An ultrasonic probe 16 is scanning automatically on the surface of an object body 12 in two dimensions. In this flaw detecting means, when a defect 14 is detected for the 1st time while the probe 16 is scanned along a scanning course 15, the probe 16 is returned to the subscanning position which is one-pitch before and scanning is made again while the subscanning pitch is decreased from the position. When the defect 14 is not detected any more, scanning is made at the original subscanning pitch. Consequently, the scanning is made as shown by a scanning course 18, the time required for the flaw detection is shortened, and the flaw detection is performed in detail for the defect part. |
