| 摘要 |
PURPOSE:To measure the sound velocity of a columnar or cylindrical material and to measure hydrogen corrosion and stress which affect the sound velocity by making probe holding devices abut on two points on the outer periphery of the columnar or cylindrical material. CONSTITUTION:The probe holding devices 2 and 3 are made to abut on the two points of the outer periphery of the columnar or cylindrical material, an ultrasonic wave is sent and received from one side to the other side in a chord direction, and the sound velocity of the longitudinal wave or lateral wave is found from a relational equation V=d/t, where (d) is the distance between the two probes 2a and 3a, and (t) is the propagation time of the ultrasonic wave. For example, the propagation time (t) is found by reading the time t1 from the sent pulse P1 of the ultrasonic wave to the received pulse P2 by a counter C, A/D converter, etc., and subtracting the internal propagation times t2 and t3 of probes 2a and 3a which are measured in advance. Further, even if the probes 2a and 3a change owing to the state of a curved surface, incidence points 2c and 3c are held in the same state as to a steel beam 4 with a scale at all times and the sound velocity can be measured by finding the distance (d) between the probes 2a and 3a. |
