Emerson Micro Motion 5700 Configuration And Use Manual page 227

Table 15-4: Flow measurement problems and recommended actions
Problem Possible causes
Erratic non-zero flow •
rate when flow is •
steady •
•
•
•
Inaccurate flow rate •
•
•
•
•
•
•
•
•
Configuration and Use Manual
Two-phase flow
Damping value too low
Plugged or coated sensor tube
Output wiring problem
Problem with receiving device
Wiring problem
Wiring problem
Inappropriate measurement unit
Incorrect flow calibration factor
Incorrect meter factor
Incorrect density calibration factors
Incorrect grounding
Two-phase flow
Problem with receiving device
Incorrect sensor zero
(continued)
Recommended actions
• Verify that the sensor orientation is appro-
priate for your application. See the installa-
tion manual for your sensor.
• Check the drive gain and the pickoff volt-
age.
• If the wiring between the sensor and the
transmitter includes a 9-wire segment,
verify that the 9-wire cable shields are cor-
rectly grounded.
• Check for air entrainment, tube fouling,
flashing, or tube damage.
• Check the wiring between the sensor and
the transmitter.
• For sensors with a junction box, check for
moisture in the junction box.
• Purge the sensor tubes.
• Check for open or leaking valves or seals.
• Check for sources of vibration.
• Verify damping configuration.
• Verify that the measurement units are con-
figured correctly for your application.
• Check for two-phase flow.
• Check for radio frequency interference.
• Contact customer service.
• Check the wiring between the sensor and
the transmitter.
• Verify that the measurement units are con-
figured correctly for your application.
• Verify all of the characterization or calibra-
tion parameters. See the sensor tag or the
calibration sheet for your meter.
• Zero the meter.
• Check the grounding of all components.
• Check for two-phase flow.
• Verify the receiving device, and the wiring
between the transmitter and the receiving
device.
• Check the sensor coils for electrical shorts.
If you find problems, replace the sensor.
• Replace the core processor or transmitter.
Troubleshooting
219