| 摘要 |
PROBLEM TO BE SOLVED: To make simultaneously measurable the circumferential length and the length of a pipe by setting an ultrasonic probe for transmitting ultrasonic waves and receiving reflecting waves, and a distance-measuring means to which receive signals from an ultrasonic probe pair receiving passing waves are inputted and which measures the distance between the probe and a reflecting part and the distance between the pair of probes. SOLUTION: The pipe length is measured by a reflection method by the use of a probe 4 for transmission and reception, and the pipe circumferential length is measured by a transmission method with the use of a probe 6 for transmission and a probe 7 for reception. The apparatus has a switching device 8 for switching the measurement to the pipe length and pipe circumferential length, to which a distance- measuring means of an ultrasonic range finder 9 for measuring the distance between the probe 4 and a pipe end and the distance between probes 6 and 7 from receive signals from the probes 4 and 7, a display device 10 and a BCD 11 are connected. Manual work using distance measurement by surface waves and a tape measure can measure with a difference within 0.1 mm. Ultrasonic waves take a measurement time of several tens msec if a sound velocity is known, facilitating repeated measurement to a repeatability of approximately 0.5 mm of measured values unlike manual work.
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