In the flowmeasurement process, measuring method is also varied because of the complex ofthe tested medium, thus it can also be made up of many different measuringprinciples based on the flow measurement device.

According to themeasuring method and structure, the types can be divided into: differentialpressure type, float type, volumetric, turbine, electromagnetic type, vortextype, ultrasonic type, thermal type; According to installation, they can bedivided into: insert, closed pipeline, open channel type. The most widely used,the biggest use level is the flow measurement device of differential pressuretype, accounting for above 50% of the total.