Maintenance • 21
3. Verify a display reading of 0% LEL for the combustible gas channel and 0 ppm for the
carbon monoxide channel at the controller. Investigate significant changes in the display
reading.
Quarterly Calibration
Calibrate the sample-draw detector as described in “Calibration, LEL Sensor” on page 28 and
“Calibration, CO Sensor” on page 30.
Troubleshooting
The troubleshooting guide describes symptoms, probable causes, and recommended action for
problems you may encounter with the sample-draw detector.
NOTE:
This troubleshooting guide describes sample-draw detector problems only. See the
controller Operator’s Manual if the controller exhibits any problems.
Fail Condition
Symptoms
•
The sample-draw detector’s Fail LED is on.
•
The monitoring device is operating properly but indicates a reading well below zero.
Probable causes
•
The sample-draw detector’s flow rate is too low because of an obstructed sample line,
failed pump, etc.
•
The sample-draw detector is malfunctioning.
•
The sensor wiring is disconnected or misconnected.
Recommended action
1. At the sample-draw detector, set the correct flow rate with the sensor flow control valve.
2. If you cannot set the correct flow rate, check the sample lines for obstructions or kinks.
3. Verify that the sensor wiring is correct and secure. “Wiring the Sample-Draw Detector to a
Controller” on page 17 describes sensor wiring connections.
4. Calibrate the sample-draw detector as described in “Calibration, LEL Sensor” on page 28
and “Calibration, CO Sensor” on page 30.
5. If the fail condition continues, replace the sensor(s) as described in “Replacing
Components of the Sample-Draw Detector” on page 22.
6. If the fail condition continues, contact RKI Instruments, Inc. for further instruction.
Slow or No Response/Difficult or Unable to Calibrate
Symptoms
•
Unable to accurately set the zero or response reading during the calibration procedure.
•
The sensor requires frequent calibration.