The development of measurements can be traced back to ancient water conservancy projects and urban water supply systems. Guromache has used orifice plates to measure the drinking water quantity of residents. The flow of the Nile was measured by the Weir method in ancient Egypt in 1000. China's famous Dujiangyan Water Conservancy project application water level of the water to observe the size and so on.
Metrology is the eye of industrial production. Flowmeter is one of the components of metrology science and technology, it is closely related to national economy, national defense construction and scientific research. Do this work, to ensure product quality, improve production efficiency, promote the development of science and technology has an important role, especially in the energy crisis, industrial production automation of the increasingly high degree of the current era, flowmeter in the national economy in the position and role of more obvious. Flowmeter is divided into differential pressure flowmeter, rotor flowmeter, throttle type flowmeter, fine seam flowmeter, volumetric flowmeter, electromagnetic flowmeter, ultrasonic flowmeter and Weir. Classified by media: liquid flowmeter and gas flowmeter.