| 摘要 |
PURPOSE:To execute calibration and scanning for the flaw detection of an electro-unite tube welding part under the most appropriate status by making a flaw detector head having a probe scan a calibrating test tube having an artificial defect in the tube axis direction like a square. CONSTITUTION:The calibrating test tube 20 is set up on rotary rollers 31a, 31b and guide wheels 33a, 33b are arranged under the rollers 31a, 31b. An artificial defect 21 is formed on the test tube 20. A probe holder 8 storing a probe using ultrasonic waves is set up on the test tube 20. The test tube 20 is rotated in the tube-peripheral direction and the artificial defect 21 is matched with the end of a scanning range. Then, the test tube 20 is reciprocated in the axial direction with a stroke S and rotated with a fine index pitch P to scan 38 the test tube 20 like a square. In this case, the stroke S is set up longer than the length l of the holder 8. Since the tube axis direction stroke is long, bending due to the friction of the tube axis direction is reduced and calibration and scanning can be executed in the same condition to detect a flaw. |
