| 摘要 |
PURPOSE:To measure exactly a reference propagation time by a general measurer, too, by adopting an ultrasonic propagation time as the reference propagation time, when the ultrasonic propagation time of a part which is supposed to be sound part is in a forecasting width stored in a memory. CONSTITUTION:A well-known measuring means A consisting of an ultrasonic transmitting probe 2a, a receiving probe 2b, a propagation time counting counter 7, etc. is arranged on the outside circumferential part of a measured section 1 of an object to be measured (a wooden pole). A measured value of a propagation time is read by a microcomputer 8. The microcomputer 8 decides whether a propagation time T satisfies the (3) expresssion or not, basing on the (3) expression stored in an ROM 8b and an outside circumferential length L stored in an RAM 8a. If this result is ''YES'', T is made a reference time t0 and stored in the RAM 8a. Subsequently, a propagation time t1 of a part to be inspected is measured, t1 is compared with t0, and a defect in the pole is detected by a delay time method. |
