Table of Contents
- How to check the flowtube of an electromagnetic flowmeter?
- Electromagnetic Flowmeter Troubleshooting Guide
- Symptom 1: Significant flow variations
- Symptom 2: Flow rate indication is unstable
- Symptom 3: Empty Pipe alarm
- Symptom 4 No Power/No Display
- Symptom 5: Coil alarm
- Symptom 6: Inaccurate Flow Rate Indication
- Symptom 7: No Flow Output Signal
- Symptom 8: Unstable Zero Value in the Absence of Flow
- Symptom 9 : Flow Rate is Too low or high value
Electromagnetic flowmeter troubleshooting includes verifying power and wiring, assessing fluid conductivity, inspecting electrode condition, calibrating for precision, and addressing interference or grounding issues to ensure accurate measurements.
How to check the flowtube of an electromagnetic flowmeter?
To check the flowtube of an electromagnetic flowmeter, follow these steps:
Check Coil Resistance
- Disconnect the flowtube from the flowmeter electronics to ensure safety.
- Using a multimeter, set it to the resistance (ohms) measurement mode.
- Measure the resistance across the coil terminals, typically labeled as Coil+ and Coil-. The resistance should typically be within the manufacturer’s specified range, which can vary depending on the flowmeter model but is usually between 100 and 1,000 ohms.
Check Electrode Resistance
- Make sure the flowtube is filled with water or a conductive fluid.
- Disconnect the flowtube from the flowmeter electronics.
- Using a multimeter set to the resistance (ohms) measurement mode, measure the resistance between the two electrode connections.
- The resistance reading should typically fall within the range of 3 to 50 kilohms (3,000 to 50,000 ohms). If it’s outside this range, it may indicate electrode contamination or coverage, which can affect the accuracy of the flowmeter.
- Examine the connection between the terminal block and the internal electrode for continuity. Resistance must be less than one ohm. This is due to the electrodes being directly attached to terminal block connections.
Check Signal Wiring Connection
- Ensure the flowmeter electronics are powered off.
- Inspect the signal wiring connections, including the wiring to the SIG1, SIG2, and SIG GND terminals.
- Make sure all connections are secure and free from damage.
- If there are any loose or damaged connections, correct them as needed.
Test for Alarms
- Connect the terminal SIG1, SIG2, and SIG GND as instructed by the manufacturer.
- Power on the flowmeter electronics.
- If there was an alarm display related to fluid bubbles, it should disappear when the signal terminals are connected. This confirms that the converter is functioning normally.
Electromagnetic Flowmeter Troubleshooting Guide
The table below serves as a starting point for diagnosing typical issues with electromagnetic flowmeters, including possible causes and solutions. Additional diagnostics and processes may be required depending on the specific model and circumstances.
Symptom 1: Significant flow variations
| Possible cause | Solutions |
|---|---|
| There are too many air bubbles or particles in the medium at the moment | Alteration made to install in a vertical orientation |
| medium’s conductivity is unequal or near the middle value | Change the installation location or choose a different model |
| A failure in the split line. | Look over the split cable before selecting a cable with strong shielding |
| Sensor insulation deteriorates | Return to the factory for repair |
| The electrode is either rusted or covered in dirt. | Electrodes need to be inspected and cleaned. |
| Incorrect damping value set | Adjust the damping time |
| Rapid changes in fluid velocity | Consider using a flow straightener to stabilize flow |
| Pipe vibrations or turbulence | Reinforce pipe installation to reduce vibrations |
| Electromagnetic interference | Shield cables and avoid nearby electrical equipment |
| Faulty grounding | Verify and improve grounding as required |
Symptom 2: Flow rate indication is unstable
| Possible cause | Solutions |
|---|---|
| Problem with the grounding | Check that the meter is correctly grounded to a reliable earth ground. |
| Air or gas entrapped in the fluid | Ensure proper degassing or venting of the fluid |
| obstruction of a pipeline. | Ensure that the pipes are clear by inspecting and cleaning them regularly. |
| Location of the converter away from areas with electrical interference. | Ensure that the converter is not placed in a location that is too close to potential sources of electrical interference. |
| Slurry conductivity variations in medium | Use robust electrode materials, clean or replace.Reconfigure flow meter settings for slurry characteristics |
| Abrasive or adhesive nature of slurry | choose appropriate electrode materials and clean regularly |
| Inadequate electrode material selection | Consult with manufacturer to select suitable electrodes |
Symptom 3: Empty Pipe alarm
| Possible cause | Solutions |
|---|---|
| No fluid flow in the pipe | Verify that there should be flow in the pipe. |
| Flow velocity below the flowmeter’s minimum detection | Check the flowmeter’s minimum velocity specification. |
| Air or gas pockets in the fluid | Ensure proper degassing or venting of the fluid. |
| Electrode issues (fouling or damage) | Inspect and clean or replace electrodes as necessary. |
| Faulty sensor or signal processing unit | Replace the faulty components |
| The conductivity of the fluid is minimal. | Replace it with a different type of flowmeter. |
Symptom 4 No Power/No Display
| Possible cause | Solutions |
|---|---|
| Faulty power supply | Ensure that the power supply and connections are correct. |
| Either the fuse has blown or the circuit breaker has tripped. | Either replace the fuse or the breaker and turn it back on. |
| Problems with the wiring | Perform any necessary inspections and rewirings. |
| Defective electronics within the flowmeter | Replace the defective electronics |
| LCD displays have far inadequate contrast. | Raise the level of contrast. |
Symptom 5: Coil alarm
| Possible cause | Solutions |
|---|---|
| Coil circuit malfunction | Check the integrity of the coil and its connections. |
| Open circuit in the coil | Replace the flowtube or flowmeter |
| Electrical wiring issues | Inspect and rewire the coil electrical connections as needed. |
| Faulty power supply | Ensure a stable and adequate power supply. |
| Electromagnetic interference | Shield cables and avoid nearby electrical equipment. |
| Faulty grounding | Verify and improve grounding as required. |
| Sensor or coil damage due to abrasive materials | Protect the sensor or coil from abrasive materials. |
Symptom 6: Inaccurate Flow Rate Indication
| Possible cause | Solutions |
|---|---|
| Electrode fouling or scaling | Clean or replace electrodes as necessary. |
| Incorrect electrode material selection | Ensure electrode material is suitable for the fluid. |
| Calibration drift | Re-calibrate the flowmeter for accurate readings.Regularly re-calibrate the flowmeter for accuracy. |
| Pipe vibrations or turbulence | Stabilize the installation to minimize vibrations |
| Electromagnetic interference | Shield cables and avoid nearby electrical equipment. |
| Changes in fluid properties (e.g., temperature) | Compensate for changes if necessary. |
| Electrode wear | Monitor electrode condition and replace when necessary. |
| Aging or degradation of flowmeter components | Perform regular maintenance and replace worn parts. |
By clicking on the link that is provided below will take you to the procedure for calibrating the electromagnetic flow meter.
Calibration procedure for Electromagnetic flowmeter
Symptom 7: No Flow Output Signal
| Possible cause | Solutions |
|---|---|
| Power supply failure | Verify the power source and connections. |
| Wiring issues | Inspect and rewire the electrical connections as needed. |
| faulty signal processing | Replace the defective signal processing unit |
| Incorrect parameter settings | Reconfigure flow meter settings accurately. |
| Communication problems (if applicable) | Check communication cables and settings. |
| Check to see if the arrow on the sensor corresponds with the direction that the fluid is flowing | If there is inconsistency, the direction in which the sensor was installed should be switched |
Symptom 8: Unstable Zero Value in the Absence of Flow
| Possible cause | Solutions |
|---|---|
| Incorrect zero calibration point | Recalibrate the flowmeter and set the zero point correctly. |
| Sensor or wiring damage | Inspect and repair/replace damaged components |
| Electrical noise or interference | Shield cables and minimize electromagnetic sources |
| Grounding issues | Verify and improve grounding as required. |
| Electrode fouling or scaling | Clean the electrodes as necessary. |
| Electromagnetic interference | Shield cables and avoid nearby electrical equipment. |
Symptom 9 : Flow Rate is Too low or high value
| Possible cause | Solutions |
|---|---|
| Incorrect scaling factor | Adjust the scaling factor to match the expected flow range. |
| Calibration issues | Recalibrate the flowmeter for accurate readings. |
| Incorrect parameter settings | Reconfigure flow meter settings accurately. |
| Sensor or signal processing problems | Verify the function of flow tube or signal processing units |
| Communication problems (if applicable) | Check communication cables and settings. |
| Faulty display unit | Inspect and replace the display unit if necessary. |
| Conductivity of medium in flowtube is too low or too high | Replace it with a different type of flowmeter which is suitable for the process. |
