Density Measurement Problems - Emerson Micro Motion 9739 MVD Configuration And Use Manual

Troubleshooting
June 2019

10.3 Density measurement problems

Problem Possible causes
Inaccurate density •
reading
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Unusually high density •
reading
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Unusually low density •
reading
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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
Physical characteristics of sensor have
changed
Plugged or coated sensor tube
Incorrect density calibration factors
Incorrect temperature measurement
RTD problem
In high-frequency meters, this can indicate
erosion or corrosion
In low-frequency meters, this can indicate
tube fouling
Two-phase flow
Ensure that all of the calibration
parameters have been entered correctly.
See the sensor tag or the calibration sheet
for your meter.
In low-frequency meters, this can indicate
erosion or corrosion
Configuration and Use Manual
Recommended actions
• Check your process conditions against the
values reported by the device.
• Ensure that all of the calibration
parameters have been entered correctly.
See the sensor tag or the calibration sheet
for your meter.
• Check the wiring between the sensor and
the transmitter.
• Check the grounding of all components.
• Verify all of the characterization or
calibration parameters. See the sensor tag
or the calibration sheet for your meter.
• Check for two-phase flow.
• If two sensors with similar frequency are
too near each other, separate them.
• Purge the sensor tubes.
• Ensure that all of the calibration
parameters have been entered correctly.
See the sensor tag or the calibration sheet
for your meter.
• Verify all of the characterization or
calibration parameters. See the sensor tag
or the calibration sheet for your meter.
• Purge the sensor tubes.
• Check for coating in the flow tubes.
• Check your process conditions against the
values reported by the device.
• Check for two-phase flow.
• Verify all of the characterization or
calibration parameters. See the sensor tag
or the calibration sheet for your meter.
• Check the wiring between the sensor and
the transmitter.
• Check for tube erosion, especially if the
process fluid is abrasive.
Micro Motion 9739 MVD Transmitters
MMI-20016855