Emerson Micro Motion 1000 Series Configuration And Use Manual page 152

Troubleshooting
Table 12-6 Process variables problems and possible remedies
Symptom
Steady non-zero flow rate under
no-flow conditions
Erratic non-zero flow rate under
no-flow conditions
142
Cause
Misaligned piping (especially in new
installations)
Open or leaking valve
Bad sensor zero
Bad flow calibration factor
RF interference
Wiring problem
Incorrectly grounded 9-wire cable (in
9-wire remote installations and remote
core processor with remote transmitter
installations)
Vibration in pipeline at rate close to
sensor tube frequency
Improper sensor grounding (T-Series
sensors only)
Leaking valve or seal
Inappropriate measurement unit
Inappropriate damping value
Slug flow
Plugged flow tube
Moisture in sensor junction box
Mounting stress on sensor
Sensor cross-talk
Incorrect sensor orientation
Possible remedy
Correct the piping.
Check or correct the valve mechanism.
Rezero the meter. See Section 5.5.
Verify characterization. See
Section 6.2.
Check environment for RF interference.
See Section 12.14.4.
Verify all sensor-to-transmitter wiring
and ensure the wires are making good
contact.
Verify 9-wire cable installation. Refer to
Appendix B for diagrams, and see the
installation manual for your transmitter.
Check environment and remove source
of vibration.
Verify that the sensor is grounded to
earth ground.
Check pipeline.
Check configuration. See
Section 12.20.
Check damping configuration.
See Section 12.17.
Check drive gain and tube frequency.
Purge the flow tubes or replace the
sensor.
Open junction box and allow it to dry.
Do not use contact cleaner. When
closing, ensure integrity of gaskets and
O-rings, and grease all O-rings.
Check sensor mounting. Ensure:
• Sensor is not being used to support
pipe.
• Sensor is not being used to correct
pipe misalignment.
• Sensor is not too heavy for pipe.
Check environment for sensor with
similar (±0.5 Hz) tube frequency.
Sensor orientation must be appropriate
to process fluid. See the installation
manual for your sensor.
Micro Motion Series 1000 and Series 2000 Transmitters