| 摘要 |
PURPOSE:To enable highly accurate measurement without moving probes by bringing the two transmitting and receiving probes into contact separately with a curved surface, and receiving ultrasonic waves transmitted toward a receiving probe and a surface layer part by a receiving part. CONSTITUTION:A transmitting probe 1 and a receiving probe 2 are brought into close contact with each other at a prescribed distance on the outside surface of a material 11 to be measured, and ultrasonic waves are transmitted over a wide range toward the probe 2 from the probe 1 and toward the surface between both probes. The ultrasonic waves in these two passages are received respectively by the probe 2, and propagation time of a direct wave and a reflected wave can be obtained by a pulse wave displayed on a CRT, and from this, a distance between both probes by a steal beam 9 and a displacement quantity of a depth of a reflected wave obtained by a depth gauge 10, direct wave sound speed Vi and reflected wave sound speed Vo can be obtained. A stress condition or hydrogen corrosion on the inside and outside surfaces of the material 11 to be measured can be evaluated efficiently with high accuracy by using the sound speeds Vo and Vi. When this operation is repeated by changing an arrangement position of the probes 1 and 2, highly accurate measurement becomes possible. |
