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.

Averaging pitot tube flow meters which adopted the advanced technologies a flow sensor based on the design of combining the working principle of the different pressure type, and the plug in installation method. BF10 average pipe flow sensor, different pressure transmitter and integrating instrument and other sencondary instruments constitute a high level system of different pressure flow measurement.