Table of Contents
Diagnostics and troubleshooting
rEF WARn
rEF WArn is an electrode fault message. It means the reference electrode impedance
exceeds the programmed reference warning high (RWH) limit. Ideally, when the
measurement system exceeds the warning limits, you will have adequate time to diagnose
and correct problems before a failure occurs. A high reference impedance implies that the
liquid junction is plugged or the reference electrolyte is depleted. The message also
appears if an inappropriate limit has been entered into the transmitter.
If the measurement system was previously commissioned and operating correctly, rEF
WArn likely means a real problem exists. However, if the system is being started up or if the
advanced diagnostic feature is being used for the first time, rEF WArn could be caused by a
miswired sensor or by programmed limits that are not correct for the sensor.
NOTICE
rEF WArn is a sensor diagnostic message. Sensor diagnostic messages are optional. They can be
turned off.
Troubleshooting rEF WArn problems is exactly the same as troubleshooting rEF FAIL
problems. Refer to
60
b. Inspect and clean the sensor. If the sensor is rebuildable, replace the
reference junction and replenish the electrolyte solution. Refer to the sensor
instruction manual for details. Check the reference impedance again.
-
If cleaning the sensor reduces the impedance...
a. The sensor is in good condition. Calibrate the sensor and return it to
the process.
b. Change the reference failure high (RFH) limit to a value about 50
kilohms greater than the measured reference impedance. If rEF WARN
was also displayed, change the reference warning high (RWH) limit to
about 25 kilohms above the measured reference impedance.
-
If cleaning does not reduce the impedance and the sensor is not
rebuildable...
a. Try the reference junction rejuvenation procedure.
b. The rejuvination procedure may not work. At best, it will get a little
more life out of a sensor with a plugged reference.
c. Whether or not the rejuvenation procedure worked, go to Step c.
c. Recalibrate the sensor using the autocalibration procedure.
-
If the sensor can be calibrated...
a. The sensor is in good condition. Return it to the process.
b. Change the reference failure high (RFH) limit to a value about 50
kilohms greater than the measured reference impedance. If rEF WARN
was also displayed, change the reference warning high (RWH) limit to
about 25 kilohms greater than the measured reference impedance.
-
If the sensor cannot be calibrated, the sensor has failed and must be
replaced.
rEF
FAIL.
Rosemount 5081
- Quick Links:
- 5081 Programming
- Manual Calibration
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Table of Contents
Troubleshooting
