The external clamp ultrasonic flowmeter product adopts the principle of ultrasonic time difference to measure flow, and can achieve flow measurement in DN15~DN100 pipelines. No need to break the tube, easy measurement. The flow rate can be measured without the need to attach the sensor to the pipeline. Installation is very convenient and fast. The ultrasonic heat metering function can also be selected based on the flow measurement to provide reference for the heating efficiency of the heating industry. When an ultrasonic beam propagates in a liquid, the flow of the liquid will cause a slight change in propagation time, which is proportional to the flow velocity of the liquid. At zero flow rate, the time required for the two sensors to emit and receive sound waves is the same. When the medium flows, the propagation time of the sound waves in the countercurrent direction is greater than that in the downstream direction. It adopts advanced multi pulse technology, digital signal processing technology, and error correction technology, making the flow meter more adaptable to the industrial environment, making measurement more convenient, economical, and accurate. The product has reached the advanced level at home and abroad. It has the characteristics of good stability, small zero drift, high measurement accuracy, wide range ratio, and strong anti-interference. It can measure the flow rate of medium with large pipe diameters and can also be used for measuring medium that is difficult to contact and observe. Especially, it can solve the flow measurement problem of media that cannot be measured with other instruments. Widely used in scenarios and fields such as heating, municipal water supply, and mobile multi-point measurement.