| 摘要 |
PURPOSE:To enable highly reliable flaw detection by a method wherein automatic flaw detection is performed with surface waves detected by making ultrasonic waves slantly enter an outer peripheral surface of a specimen. CONSTITUTION:A generating and receiving circuit 18 outputs low frequency driving signals according to an instruction from an arithmetic control circuit 20, emits ultrasonic waves having the same frequency as driving signals from a slanted angle probe 12, and transmits surface waves along a facial layer of a specimen 10. The probe 12 detects an echo of the surface wave or the surface wave that has come around the outer periphery of the specimen 10 and supplies a detection signal indicating the echo or the surface wave that has come around to the circuit 18. The circuit 18 removes noise from the detection signal as well as amplifies the detection signal and supplies it to the circuit 20 via an A/D-converter 22. The circuit 20 processes an input signal and verifies that the surface wave is actually transmitted to a flaw-detection region as the specimen moves lengthwise while it automatically identifies existence of a defect on the surface or under the surface, and the results are output to a display/recorder 24 and a marker 26. |
