Interpretation of errors affecting electromagnetic flowmeter measurement results

1. External electromagnetic interference
The principle of electromagnetic flow sensor tells us that the working magnetic field of electromagnetic flowmeter is a uniformly distributed constant magnetic field. Therefore, when the electromagnetic interference at the measurement site is too large, it will affect the normal working magnetic field, and in severe cases, it will lead to the inability to perform normal measurement.
2. Fluid flow rate fluctuation
The flow axis of the measured fluid must be symmetrically distributed to meet the requirements of the electromagnetic flow sensor. Therefore, the fluctuation of the measured fluid will lead to an asymmetric distribution of the flow axis, which will cause the measurement result to produce errors caused by the asymmetric flow rate.
3. Fluid composition and characteristics
When the liquid contains more than a certain content of solids, slurry noise will be generated, and the output signal will fluctuate to a certain extent. The measured liquid should always fill the pipe, otherwise the liquid will cause a large error in the measurement result even if it does not fill the pipe. In addition, since the electromagnetic flowmeter is an instrument for measuring the flow of conductive liquids, the conductivity of the measured liquid is uniform and isotropic, so the uneven conductivity of the liquid will seriously interfere with the flow indication of the instrument.
4. Installation does not meet the requirements.
The length of the upstream and downstream straight pipe sections of the intelligent electromagnetic flowmeter does not meet the requirements, and the center line of the shell and the center line of the pipeline are not concentric. Installation conditions such as these will also cause errors in the measurement. In addition, do not install the electromagnetic flowmeter in isolation. Use a bracket to support the pipeline to prevent the stress caused by pipeline vibration, impact and expansion from affecting the measurement.