| 摘要 |
PROBLEM TO BE SOLVED: To certainly and clearly detect even a fine defect occurring in the inner peripheral surface of a narrow pipe. SOLUTION: Ultrasonic wave UT is output from a focusing type vibrator 31 disposed in an ultrasonic probe 30 toward the inner peripheral surface 1in of the narrow pipe 1. The incidence angleθof the ultrasonic wave UT to the pipe 1 exceeds 45°and is 55°or smaller or 60°or smaller, and the focusing position F of the ultrasonic wave UT is on the inner peripheral surface side than the half position with respect to the thickness direction of the pipe 1. The ultrasonic wave UT is thus made to enter the pipe 1, so that defective surface echo Ep and defective tip echo Et occur certainly, thereby the defect K can be accurately detected and sized. COPYRIGHT: (C)2011,JPO&INPIT |
