Excessive Drive Gain; Erratic Drive Gain - Emerson Micro Motion 2700 Configuration And Use Manual

Troubleshooting
Table 6-6 Sensor pickoff values (continued)
(1)
Sensor model
Model F200 sensors
Model H025, H050, and H100 sensors
Model H200 sensors
Model R025, R050, or R100 sensor
Model R200 sensor
Micro Motion T-Series sensors
(1) If your sensor model is not listed, contact Micro Motion Customer Support.
6.12.3

Excessive drive gain

The causes and possible solutions of excessive drive gain are listed in Table 6-7.
Table 6-7 Excessive drive gain causes and solutions
Cause
Excessive slug flow
Plugged flow tube
Cavitation or flashing
Drive board or module failure, cracked
flow tube, or sensor imbalance
Mechanical binding at sensor
Open drive or left pickoff sensor coil
Flow rate out of range
Incorrect sensor characterization
6.12.4

Erratic drive gain

The causes and possible solutions of erratic drive gain are listed in Table 6-8.
Table 6-8 Erratic drive gain causes and solutions
Cause
Wrong K1 characterization constant for sensor
Polarity of pick-off reversed or polarity of
drive reversed
Slug flow
Foreign material caught in flow tubes
Configuration and Use Manual
Pickoff value
2.0 mV peak to peak per Hz based on flow tube frequency
3.4 mV peak to peak per Hz based on flow tube frequency
2.0 mV peak to peak per Hz based on flow tube frequency
3.4 mV peak to peak per Hz based on flow tube frequency
2.0 mV peak to peak per Hz based on flow tube frequency
0.5 mV peak to peak per Hz based on flow tube frequency
Solution
Eliminate slugs.
Change the sensor orientation.
Purge the flow tubes. Sensor may need to be replaced.
Increase inlet or back pressure at the sensor.
If a pump is located upstream from the sensor, increase the
distance between the pump and sensor.
Contact Micro Motion Customer Service.
Ensure sensor is free to vibrate.
Contact Micro Motion Customer Service.
Ensure flow rate is within sensor limits.
Verify characterization. See Section 3.3.
Solution
Re-enter the K1 characterization constant. See
Section 3.3.
Contact Micro Motion Customer Service.
Verify flow tubes are completely filled with process
fluid, and that slug flow limits and duration are properly
configured. See Section 4.12.
Purge flow tubes. Sensor may need to be replaced.
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