LASER ULTRASONIC FLAW DETECTION METHOD AND LASER ULTRASONIC FLAW DETECTOR

摘要

PROBLEM TO BE SOLVED: To propose a technique for performing very accurate laser ultrasonic flaw detection even for surfaces under inspection each having a complicated three-dimensional shape.;SOLUTION: According to this laser ultrasonic flaw detection method, laser beams 22 and 23 are projected from a transmission probe 12 to the surfaces 5a and 5b under inspection to excite ultrasonic waves while projecting laser beams 22 and 23 from a receiving probe 13 to the surfaces to receive the ultrasonic waves, and defects existing on the surfaces are detected from data on the received ultrasonic waves. While measuring distances L2 and L3 from the transmitting and receiving probes 12 and 13 to the surfaces 5a and 5b by distance measurement means 12b and 13b, the output setting of the laser beam 22 projected from the transmission probe 12 is adjusted, based on the distances L2 and L3. Focal distances of variable condenser lenses 12a and 13a of the transmitting and receiving probes 12 and 13 are adjusted to sequentially correct the projection conditions of the laser beams.;COPYRIGHT: (C)2006,JPO&NCIPI