| 摘要 |
PURPOSE:To precisely estimate the actual sound velocity from the ultrasonic wave propagation time in the inspection object and measure the thickness with a high degree of accuracy by using the estimated sound velocity, in a sound velocity measuring method and thickness measuring method of ultrasonic detector such that the inspection object is non-destructively inspected while rolling a tire probe with built-in transmitting ultrasonic probe and receiving ultrasonic probe on the inspection object such as an asphalt paved road. CONSTITUTION:The propagation time, the time for a ultrasonic wave emitted from a transmitting ultrasonic probe 11 to propagete as a surface wave along the vicinity of an inspection object surface until arriving at a receiving ultrasonic probe 12, is measured, and then the sound velocity of the surface wave is computed from the distance between the transmitting ultrasonic probe 11 and the receiving ultrasonic probe 12 and the underwater propagation time in a tire probe 2. The sound velocity of the longitudinal wave propagating inside the inspection object is estimated by multiplying the sound velocity of the surface wave by a predetermined coefficient, and further the thickness is measured based on the estimated sound velocity of the longitudinal wave. |
