Common errors in the application of flow meters include poor operation, flow disturbances, and poor installation; There will be air pockets and bubbles in the liquid; Gas contains condensate; Wear and deposition, etc. These errors often result in inaccurate or malfunctioning flow meters.
　

Poor installation due to improper operation and layout, common ones include:
　　
1) The sharp angle of the standard orifice plate is not installed on the upstream side.
　　
2) The inner diameter dg of the sealing gasket between the instrument and the pipeline is smaller than the inner diameter dp of the pipeline and the inner diameter dm of the instrument, resulting in beam flow. Dg should be slightly larger than dm, such as dg
　　
3) The sealing gasket is eccentric (not aligned with the center). The installation of the sealing gasket is eccentric, covering part of the flow area and causing severe distortion and asymmetry of the velocity distribution. Due to asymmetric flow occurring at the inlet of the flow sensor, where the length of the upstream straight pipe section is zero, it can cause measurement errors in instruments such as differential pressure, turbine, vortex street, ultrasonic, target, and electromagnetic. For example, if the gasket of the DN50mm electromagnetic flowmeter is eccentric by 10mm, the measurement error can be as high as 4% to 10%.
　　
4) The flow meter is in the wrong flow direction.
　　
5) Install instruments sensitive to vibration interference on pipelines with vibration.
　　
6) Lack of necessary protective accessories.

Although the inner diameter of the sealing gasket is too small or the installation is eccentric, it has little or no effect on the flow value of volumetric, float, Coriolis mass and other instruments, but it will increase additional pressure loss.