The most widely used transducers are external clamp type and insertion type. Mono-channel ultrasonic flowmeter is simple in structure and easy to use, but it has poor adaptability to the change of flow pattern distribution. The rapid development of microelectronics and computer technology has greatly promoted the renewal of instruments. New flowmeters have sprung up like bamboo shoots after a spring rain.
So far, it is said that hundreds of flowmeters have been put into the market, and many difficult problems in field use are expected to be solved. In our country, the work of modern flow measurement technology is relatively late. It is set at the upstream end of measuring flow channel 6 and relative to hole 11 and 12 to reduce the flow of measured fluid into hole 11 and 12. The measurement control unit 19 is used to measure the transmission time of ultrasound between ultrasonic transducer 8 and 9. The calculation unit 20 is used to calculate flow according to the signal of the measurement control unit 19.