Emerson Model 1700 User Manual
Possible causes and recommended actions for excessive (saturated)
drive gain
drive gain
(continued)
Table 10-8:
Possible cause
Recommended actions
Bent flow tube
). If either of them
are close to zero (but neither is zero), the flow tubes may be bent.
The sensor will need to be replaced.
The sensor will need to be replaced.
Cracked flow tube
Replace the sensor.
Sensor imbalance
Contact Micro Motion.
Mechanical binding at sensor
Ensure sensor is free to vibrate.
Open drive or left pickoff sen-
sor coil
sor coil
Contact Micro Motion.
Flow rate out of range
Ensure that flow rate is within sensor limits.
Incorrect sensor characteriza-
tion
tion
Verify the characterization parameters.
Erratic drive gain
Possible causes and recommended actions for erratic drive gain
Table 10-9:
Possible cause
Recommended actions
Wrong K1 characterization constant for sensor
Verify the K1 characterization parameter.
Polarity of pick-off reversed or polarity of drive reversed Contact Micro Motion.
Slug flow
Foreign material caught in flow tubes
•
Purge the flow tubes.
•
Replace the sensor.
10.26.1
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.
Collect drive gain data from a period of normal operation, and use this data as a baseline
for troubleshooting.
Procedure
1.
Navigate to the drive gain data.
2.
Observe and record drive gain data over an appropriate period of time, under a
variety of process conditions.
variety of process conditions.
10.27
Check the pickoff voltage
If the pickoff voltage readings are unusually low, you may have any of a variety of process
or equipment problems.
or equipment problems.
Troubleshooting
208
Micro Motion
®
Model 1700 Transmitters with Analog Outputs