| 摘要 |
PROBLEM TO BE SOLVED: To detect a defect in the entire width-directional range and the entire length of a lead sheath pipe by arranging angle beam testing ultrasonic proves, a normal beam testing ultrasonic prove, etc., on an outer circumference of the lead sheath pipe. SOLUTION: Angle beam testing ultrasonic proves 2A are arranged inclinedly to the left/right by approximately 30 deg., in relation to the central line and the vertical direction of the lead sheath pipe 1, a normal beam testing ultrasonic prove 2B is arranged on the vertical line, and surface angle beam testing ultrasonic proves 2C are arranged incluinedly to the left/right by approximately 40 deg. in relation to the central line and the vertical direction. An ultrasonic wave is emitted in a defect detection water 3 which rotates, while rotating the proves 2A, 2B, 2C about the lead sheath pipe 1 and the reflection wave is received thereby, so that foreign matter, voids, etc., in the lead sheath pipe 1 are detected. The surface angle beam testing ultrasonic proves 2C are inclinedly (approximately 40 deg.), so arranged that refraction of the ultrasonic wave reaches around the criticalvicinity. The ultrasonic wave is propagated in the surface layer, so that a defect in the adjacent to the surface can be detected. |
