For troubleshooting, check the process variables under both normal flow and tubes-full no-flow conditions.
Except for flow rate, you should see little or no change between flow and no-flow conditions. If you see a
significant difference, record the values and contact customer service for assistance.
Unusual values for process variables may indicate a variety of different problems. The following table lists
several possible problems and suggested remedies.
Table 15-3: Process variables problems and remedies
Symptom
Cause
Suggested remedy
Steady non-zero flow rate
under no-flow conditions
Misaligned piping
(especially in new installations)
Correct the piping.
Open or leaking valve
Check or correct the valve mechanism.
Bad sensor zero
.
Erratic non-zero flow rate
under no-flow conditions
Leaking valve or seal
Check pipeline
Slug flow
See
Check for two-phase flow (slug flow)
Plugged flow tube
Check drive gain and tube frequency.
Purge the flow tubes.
Incorrect sensor orientation
Sensor orientation must be appropriate to the
process fluid. See the installation manual for
your sensor.
Wiring problem
Check the sensor circuitry. See
Vibration in pipeline at rate close to
sensor tube frequency
Check the environment and remove the
source of the vibration.
Damping value too low
Check the configuration.
See the appropriate section:
•
•
•
Mounting stress on sensor
Check the sensor mounting to ensure:
•
Sensor is not being used to support the
pipe
•
Sensor is not being used to correct pipe
misalignment
•
Sensor is not too heavy for pipe
Sensor cross-talk
Check the environment for sensor with a
similiar (±0.5 Hz) tube frequency.
Erratic non-zero flow rate
when flow is steady
Slug flow
See
Check for two-phase flow (slug flow)
Damping value too low
Plugged flow tube
Check drive gain and tube frequency.
Purge the flow tubes
Configuration and Use Manual
Troubleshooting
MMI-20048166
April 2019
Configuration and Use Manual
199
Содержание Micro Motion 4200
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