Emerson MMI-20019043 Satellite Radio User Manual


 
12.5 Temperature measurement problems
Temperature measurement problems and recommended actionsTable 12-5:
Problem Possible causes Recommended actions
Temperature reading
significantly different
from process temper-
ature
RTD failure
Wiring problem
Check junction box for moisture or verdi-
gris.
Perform RTD resistance checks and check
for shorts to case (see Section 12.28.1).
Confirm the temperature calibration factor
matches the value on the sensor tag.
Refer to status alarms (especially RTD fail-
ure alarms).
Disable external temperature compensa-
tion.
Verify temperature calibration.
Check the wiring between the sensor and
transmitter. See Section 12.10.
Temperature reading
slightly different from
process temperature
Sensor temperature not yet equalized
Sensor leaking heat
The RTD has a specification of ±1 °C. If the
error is within this range there is no prob-
lem. If the temperature measurement is
outside the specification for the sensor,
contact Micro Motion.
The temperature of the fluid may be
changing rapidly. Allow sufficient time for
the sensor to equalize with the process flu-
id.
Insulate the sensor if necessary.
Perform RTD resistance checks and check
for shorts to case (see Section 12.28.1).
The RTD may not be making good contact
with the sensor. The sensor may need to
be replaced.
Troubleshooting
Configuration and Use Manual 223