| 摘要 |
1,225,424. Ultrasonic inspection devices. NIPPON KOKAN K.K. 28 March, 1968 [28 March, 1967], No. 15052/68. Heading H4D. In an ultrasonic flaw inspection system a block having an artificial flaw therein and coupled to the workpiece being inspected is used to reflect ultrasonic energy back to a transmitting/receiving probe. In an embodiment for detecting a weld flaw 14 in workpiece 9 an acrylite block 6 is coupled to the workpiece. An ultrasonic pulse is launched by directional probe 10 and returns to the probe as a flaw echo and after perpendicular reflection from an upper face of block 6. A chart record or cathoderay tube A-scan presentation of the probe signals is obtained, and the apparatus sensitivity is optimized by adjusting it so that the echo from block 6 is represented at half the amplitude of the transmitted pulse. The block reflection surface may be plane or curved and the artificial flaw, e.g. a hole or groove, is for checking the flaw detection resolution of the system (by moving probe 10 along the workpiece surface and looking for a double peak in the block echo on the A-scan presentation). |
