Emerson Micro Motion 4200 Configuration And Use Manual

Table 15-3: Process variables problems and remedies (continued)
Symptom Cause Suggested remedy
Temperature reading
significantly different
from process temperature
RTD failure Check for alarm conditions and follow
troubleshooting procedure for indicated
alarm.
Temperature reading
slightly different
from process temperature
Sensor leaking heat Insulate the sensor.
Unusually high density
reading
Plugged flow tube Check drive gain and tube frequency.
Purge the flow tubes.
Incorrect K2 value Verify characterization. See Characterize the
meter (if required).
Unusually low density
reading
Slug flow Use standard procedures to check the quality
of the process fluid.
Incorrect K2 value Verify characterization. See Characterize the
meter (if required).
Unusually high tube frequency Sensor erosion Contact Micro Motion.
Unusually low pickoff voltages Plugged fow tube, corrosion, or
erosion
Purge the flow tubes.
Unusually low pickoff voltages Several possible causes See Check the pickoff voltage.
Unusually high drive gain Several possible causes See Check the drive gain.
15.31 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 15-4: Possible causes and recommended actions for low pickoff voltage
Possible cause Recommended actions
Process flow rate beyond the limits of the sensor Verify that the process flow rate is not out of range of the
sensor.
Sensor tubes are not vibrating • Check for plugging or deposition.
• Ensure that the vibrating element is free to vibrate (no
mechanical binding).
Moisture in the sensor electronics Eliminate the moisture in the sensor electronics.
The sensor is damaged, or sensor magnets may have
become demagnetized
Replace the sensor.
Configuration and Use Manual Troubleshooting
MMI-20048166 April 2019
Configuration and Use Manual 201

Emerson Micro Motion 4200 Specifications

General

Brand	Emerson
Model	Micro Motion 4200
Category	Transmitter
Language	English