Electromagnetic flowmeter transient flow instability causes

Project Overview

　　Electromagnetic flow meters are one of the commonly used tools in the flow monitoring process. However, sometimes we may notice that the electromagnetic flowmeter instantaneous flow rate is not stable, the flow rate value will jump frequently, which is undoubtedly a challenge for our flow monitoring work. So, what exactly is the reason for the instability of the electromagnetic flowmeter instantaneous flow? Qingdao and Sheng measurement and control simply take you to understand.

　　First, the electromagnetic flowmeter instantaneous flow instability causes

　　(A) installation location and pipeline conditions:

　　Flowmeter installed in the vibration or strong electromagnetic interference.

　　Before and after the flow meter does not have a sufficient length of straight pipe section, or installed at the elbow, easily caused by medium flow fluctuations.

　　Pipeline outlet position below the flowmeter, resulting in no back pressure throughout the pipeline is not full of pipe.

　　(ii) the conditions of the measured medium:

　　The measured medium does not conduct electricity or conductivity is too low.

　　The medium contains more ferromagnetic substances or a large number of bubbles.

　　Medium flow for pulsation, rather than a constant flow rate.

　　(C) flowmeter electrode status:

　　The electrode is covered or contaminated, resulting in poor contact with the liquid.

　　Electrode plane adhering to the spoils or poor contact with the terminals.

　　(iv) Flow meter parameter settings:

　　Flow rate units, filter settings and other parameters are set incorrectly.

　　(E) flowmeter working condition:

　　Flowmeter long-term work at higher temperatures or higher pressures (or negative pressure), resulting in the measurement of the lining of the pipe and the pipe wall detached or cracked.

　　The front end of the flowmeter valve is not fully open, half-open valve is easy to cause fluctuations in media flow.

　　(F) flow meter damage:

　　Flowmeter sensor part of the water or sensor and converter connection wiring broken pressure line.

　　Flowmeter sensor or excitation coil insulation damage.

　　Second, the solution

　　(A) adjust the installation location and piping conditions:

　　Ensure that the flowmeter is installed in a place without electromagnetic interference, less vibration.

　　Before and after the flowmeter should have a sufficient length of straight pipe section, avoid installation at the elbow.

　　Ensure that the pipeline outlet position is higher than the flowmeter, to ensure that the full pipe condition.

　　(B) check the measured medium conditions:

　　Confirm that the measured medium conductive and conductivity in line with the requirements.

　　Avoid the medium contains excessive ferromagnetic material or air bubbles.

　　As far as possible, the media flow to maintain a constant flow rate.

　　(iii) Clean or replace the electrode:

　　Clean the electrode regularly to ensure that the electrode is in good contact with the liquid.

　　If the electrode is seriously polluted or damaged, it should be replaced in time.

　　(D) Optimize the working condition of the flowmeter:

　　Avoid the flowmeter working under extreme temperature or pressure for a long time.

　　Ensure that the front end of the flowmeter valve is fully open to avoid fluctuations in media flow.

　　(E) repair or replacement of the flowmeter:

　　Flowmeter sensor part of the water or broken wiring, should be promptly repaired.

　　Sensor or excitation coil insulation damage, should replace the flow meter.

　　More flow measurement problems can be consulted Qingdao and Sheng measurement and control.