Dear all**, I have a question regarding the accuracy of orifice plate flow meters. Thank you!

Theoretically 1%, and in practice 2% would be the best possible figure. . .

Fluid density has a significant impact, while pressure and temperature also have a certain effect

Accuracy of orifice plate flow meters: Class 0.5, Class 1. Currently, the accuracy classes for flow meters include Class 0.1 (standard flow meters), Class 0.2, Class 0.5, Class 1.0, and lower. Under the appropriate installation conditions, both electromagnetic flowmeters and vortex flowmeters can achieve an accuracy of 0.2 grade or even higher, whereas orifice flowmeters do not have such high precision. In trade settlements, flow meters are generally of class 02 or higher; in some cases, this requirement can be relaxed to class 0.5. The accuracy class of a flow meter indicates the level of precision within a certain flow range, and it must have such a flow range. Today, the new flowmeters produced by various manufacturers can all meet the requirements specified in the selection guides; the only difference lies in their lifespan. The most accurate flowmeters are generally positive displacement flowmeters, such as gear flowmeters, paddle wheel flowmeters, gearbox flowmeters, etc. The measurement accuracy is related to the installation position. Different brands have different requirements. It is generally related to the multiple of the pipe diameter of the straight section at the inlet (high-pressure side) (usually 7---24). Straight pipes also have high precision. The diameter multiplier for the straight pipe section at the outlet (low-pressure side) is generally 2–6

The orifice plate is greatly affected by the straight sections before and after it; in addition, it has high requirements regarding installation. It is also important to ensure that the range ratio is not too large, generally 3:1