| 摘要 |
PURPOSE:To eliminate the need for rotation driving equipment for probes and reduce the cost, and to facilitate the size variation of a tube body and improve the versatility by performing the ultrasonic flaw detection of a flaw in the lateral-axis direction of a body to be inspected over the entire circumference while a probe group is held standstill. CONSTITUTION:An annular probe array 10 formed by arraying probes in a matrix is installed fixed in water 3 and while a group of probes in a matrix of n=8 probes in the axial circumferential direction and m=8 probes in the lateral direction is regarded as one group, ultrasonic wave beam characteristics which converges an ultrasonic wave beam to a point P1 of a tube body 2 are provided under delay control over transmit pulses to this probe group. Then, ultrasonic wave beam characteristics for convergence to a point P2 are generated by delay control over a transmit pulse signal to another probe group of n=8 and m=8 by shifting probes by one in the axial circumferential direction, and ultrasonic flaw detection at the point P2 is performed. Similarly, probes in a matrix of n=8 and m=8 are regarded as one group and a switching scan is made while the probes are shifted by one successively in the axial circumferential direction to make an equivalent ultrasonic wave beam scan over the entire circumference of the tube body 2 as if slanting probes were rotated. |
