I. overview

Pressure is one of the important parameters in industrial production, in order to ensure the production and operation of parties, to monitor and control the pressure, but it should be noted that the pressure, pressure is actually physical concept, namely the role in the vertical force per unit area.

In pressure measurement, the absolute pressure, surface pressure, negative pressure or vacuum. The so-called absolute pressure refers to the role of the measured medium in the container unit area of all the pressure, with the symbol pj. An absolute pressure gauge is used to measure absolute pressure. The average pressure