| 摘要 |
PURPOSE:To evaluate a defect of a tube speedily by inspecting the tube with an eddy current flaw detection probe and calculating the relation between a phase angle and a thickness reduction rate, and comparing it with inspection data on a tube which is worked into a standard defective previosuly. CONSTITUTION:The defect of the tube 20 is inspected with, for example, an air gun type pusher puller 10. The eddy current flaw detection probe 18 incorporating an exciting coil 24 and a detection coil 26 is inserted into and drawn out of the tube 20 with a trigger. Signals of the phase angle and thickness reduction rate corresponding to the defect are inputted from the probe 18 to a separating circuit 28 and a microcomputer 34. Then, the relation between the phase angle and thickness reduction rate as to the tube in which the standard defect is worked previously is inputted to the microcomputer 34. Then, the phase angle and thickness reduction rate as to the objective tube 20 are measured and their signals are inputted to the microcomputer 34 and compared with the signals of the standard defect to detect the defect of the tube 20. Therefore, even when inspection conditions change, the relation between the phase angle and thickness reduction rate on the conditions is calculated and the inspection result is evaluated speedily. |
