Before commissioning an electromagnetic flow meter, it's essential to conduct a thorough inspection to ensure its accuracy and longevity. This blog post outlines the critical pre-commissioning checks and the importance of moisture protection at cable junctions to prevent measurement discrepancies.

Pre-Commissioning Checks for Electromagnetic Flow Meters

1. Inspection of Measurement Pipeline: Ensure that the pipeline is free from debris and that the flow meter is clean.

2. Moisture Protection: Verify that the electrodes are adequately protected against moisture and water damage.

3. Reliable Grounding: Confirm that the electrical connections are properly grounded to prevent interference.

4. Insulation and Ground Resistance Testing: Perform tests to ensure that the insulation resistance and ground resistance meet the required standards.

The Impact of Poor Moisture Protection on Measurement Accuracy

    Despite initial flawless operation, an electromagnetic flow meter may exhibit anomalies after a year of service. If the issues aren't due to partially filled pipes or gas in the medium, consider the possibility of cable faults. Specifically, inadequate moisture protection at the junctions of the sensor and converter cables can lead to unstable measurements:

1. Fluctuating Measurement Results: This can occur if there's unstable contact resistance at the signal cable connections or the excitation circuit cable connections.

2. Underestimation of Measurements: This is primarily due to signal attenuation caused by a decrease in insulation resistance of the signal wires to ground, a decrease in insulation resistance of the excitation coil to ground, and a reduction in excitation current.

    Proper pre-commissioning checks and effective moisture protection measures are vital for maintaining the accuracy and reliability of electromagnetic flow meters. By addressing these potential issues, you can prevent measurement errors and ensure consistent performance of your flow measurement equipment.