| 摘要 |
PURPOSE: To obtain an exact and repeatable result by providing two transducer means arranged in a duct with an interval and a measuring pipe for increasing the velocity of fluid and a beam forming device parallel to an acoustic signal. CONSTITUTION: Inside a duct 11, a pair of transducers 36 and 37 are arranged and these transducers 36 and 37 are connected via wires and an electric connector 48 to an electronic circuit board. Power source for the electronic circuit functioning together with the both transducers 36 and 37 is formed with a battery 35. A transmitter/receiver block transmits burst of the signal using the transducer 36. If the functioning of the transducer is revered, the transmission and reception of the transducer are reversed. The measured difference of the transmission time is of a limited bore size of the pipe 40 based on the gas velocity and so the relative velocity increases and the transmission time difference is made clear. |
