| 摘要 |
PURPOSE:To detect an internal defect at a high accuracy, by transmitting an ultrasonic wave to a thick metal plate through a columnal ultrasonic wave delaying member from a disc-shaped ultrasonic wave transmitting means to receive the reflected wave thereof by a ring-shaped ultrasonic wave receiving means through a cylindrical ultrasonic wave delaying member which is circumscribed and separated acoustically. CONSTITUTION:An ultrasonic wave being transmitted from a transmission vibrator 34 as disc-shaped ultrasonic wave transmission means is made to propagate through a transmission delay wire 38 as a columnal ultrasonic wave delaying member to be transmitted to a thick steel plate 10 to be inspected. The ultrasonic wave transmitted to the steel plate 10 produces a defect echo 20 due to an internal defect 16 of the steel plate 10. The echo 20 and other ultrasonic echoes propagates through a reception delay wire 40 as cylindrical delaying member and is received by a receiving vibrator 36 as ring-sheped ultrasonic wave receiving means. A cylindrical sound splitting member 42 is arranged to be separated acoustically from the delay wire 38 and 40. In this manner, internal defects can be detected at a high accuracy without the use o a short-range sound field on the steel plate 10. |
