| 摘要 |
PURPOSE:To measure the distance between a transducer and a moving body with high power by transmitting an impulsive acoustic wave from the transducer, transmitting an acoustic wave again when a reflected acoustic wave from the moving body is detected by the transducer, and measuring intervals of reception time of the acoustic wave. CONSTITUTION:To allow the moving body 2 such as pig which runs in a pipeline 1 to detects its position by itself, a pulse string generator 3 which constitutes the transmission part of a position detector and a transducer 4 connected to it are provided at adequate positions in the pipeline 1, and the moving body 2 is provided with a distance measuring device 5 which constitutes the reception part of the position detector and a transducer 6 connected to it. The pulse string generator 3 sends a pulse string from the transmitter to the transducer 4 through an electronic switch for a short time to transmit an impulsive acoustic or ultrasonic wave, which is reflected by the moving body 2 and received by the transducer 4 to be sent to a logical arithmetic circuit through a receiver and a filter. |
