Collect Drive Gain Data; Check The Pickoff Voltage - Emerson Micro Motion 2700 Configuration And Use Manual

Table 9-1:
gain
(continued)
Possible cause
Vibrating element
not free to vibrate
Erratic drive gain
Table 9-2:
Possible cause
Foreign material
caught in sensor tubes
9.9.1

Collect drive gain data

Drive gain data can be used to diagnose a variety of process and equipment conditions.
Collect drive gain data from a period of normal operation, and use this data as a baseline
for troubleshooting.
Procedure
1.
2.
9.10

Check the pickoff voltage

If the pickoff voltage readings are unusually low, you may have any of a variety of process
or equipment problems.
To know whether your pickoff voltage is unusually low, you must collect pickoff voltage
data during the problem condition and compare it to pickoff voltage data from a period of
normal operation.
Drive gain and pickoff voltage are inversely proportional. As drive gain increases, pickoff
voltages decrease and vice versa.
Table 9-3:
Possible cause
Process flow rate beyond the limits of the
sensor
Configuration and Use Manual
Possible causes and recommended actions for excessive (saturated) drive
Recommended actions
Ensure that the vibrating element is free to vibrate.
Possible causes and recommended actions for erratic drive gain
Navigate to the drive gain data.
Observe and record drive gain data over an appropriate period of time, under a
variety of process conditions.
Possible causes and recommended actions for low pickoff voltage
Recommended actions
• Purge the sensor tubes.
• Replace the sensor.
Recommended actions
Verify that the process flow rate is not out of range of
the sensor.
Troubleshooting
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