1.Water calibration is commonly used for orifice flow meters in China. The core reason is that water, as a liquid medium, has stable physical properties, is easy to control, safe to operate, and can more accurately meet the actual measurement needs of most industrial scenarios.

2.Under standardized operation and ideal conditions, the main calibration of orifice flow meters is the outflow coefficient, which is calibrated with water(Cvalue)It is stable, and this coefficient is mainly determined by the geometric structure of the orifice plate(Such as aperture, opening shape, edge sharpness)And the flow state(Reynolds number)The direct correlation with the medium is relatively small.

3.Verification Regulations for Differential Pressure Flowmeters（JJG640-2016）Inside3.1.18Item, determination of outflow coefficient-The parameter that represents the relationship between the actual flow rate through a differential pressure component and the theoretical flow rate determined for incompressible fluids. The incompressible fluid refers to a liquid.