Troubleshooting
Table 10-3
Flow problems and recommended actions
continued
Problem
Possible causes
Recommended actions
Erratic non-zero flow
rate when flow is
steady
•
Slug flow
•
Damping value too low
•
Plugged flow tube
•
Excessive or erratic drive gain
•
Output wiring problem
•
Problem with receiving device
•
Wiring problem
•
Verify that the sensor orientation is
appropriate for your application (refer to
the sensor installation manual).
•
Check the drive gain and the pickoff
voltage. See Section 10.25 and Section
10.26 .
•
For installation with 9-wire cabling,
verify that the 9-wire cable is correctly
grounded.
•
Check the wiring between the sensor and
transmitter. See Section 10.10.
•
For sensors with a junction box, check
for moisture in the junction box.
•
Purge the flow tubes.
•
Check for open or leaking valves or
seals.
•
Check for sources of vibration.
•
Verify damping configuration.
•
Verify that the measurement units are
configured correctly for your application.
•
Check for slug flow. See Section 10.24.
•
Check for radio frequency interference.
See Section 10.12.
•
Contact Micro Motion.
Inaccurate flow rate
or batch total
•
Bad flow calibration factor
•
Inappropriate measurement unit
•
Bad sensor zero
•
Bad density calibration factors
•
Bad flowmeter grounding
•
Slug flow
•
Problem with receiving device
•
Wiring problem
•
Verify characterization parameters.
•
Verify that the measurement units are
configured correctly for your application.
•
Zero the meter.
•
Check grounding. See Section 10.11.
•
Check for slug flow. See Section 10.24.
•
Verify that the receiving device, and the
wiring between the transmitter and the
receiving device
•
Check the wiring between the sensor and
transmitter. See Section 10.10.
186
Micro Motion 9739 MVD Transmitters
