摘要 |
A calibration pipe having a predetermined length is connected to an end of a pipe to be measured. A sound emitter and a sound receiver are connected to a base end of the calibration pipe. The sound emitter emits a sound into the calibration pipe and the pipe to be measured, and the sound receiver receives a sound reflected from a discontinuous portion of the pipe. A calculator is provided for calculating a period of time from emitting of the sound to receiving of the reflected sound. The length of the pipe is calculated based on speed of the sound in the calibration pipe.
|