Density Measurement Problems - Emerson Micro Motion 4200 Configuration And Use Manual

Troubleshooting
April 2019

15.6 Density measurement problems

15.6.1 Erratic density reading
Cause
• Normal process noise
• Two-phase flow
• Line pressure too low
• The flow rate is too high for the installation
• Pipe diameter too small
• Contaminants or suspended solids in the process gas
• Contaminants or suspended solids in the process fluid
• Vibration in the pipeline
• Erosion or corrosion
Recommended actions
1. Check your process conditions against the values reported by the device.
2. Increase the density damping value.
3. Decrease the flow rate.
4. Check for two-phase flow.
5. Ensure that line pressure or sample pressure meets installation requirements.
6. Increase back pressure to minimize bubble formation.
7. Minimize vibration in the pipeline.
8. Increase the pipe diameter.
9. Install a flow control method (bypass, flow chamber, expander, etc.).
10. Perform Smart Meter Verification.
15.6.2 Inaccurate density reading
Cause
• Problem with process fluid
• Incorrect density calibration factors
• Wiring problem
• Incorrect grounding
• Two-phase flow
• Plugged or coated sensor tube
• Incorrect sensor orientation
• RTD failure
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Configuration and Use Manual
MMI-20048166
Micro Motion 4200 Transmitters