RKI Instruments 35-3000RKA-LEL - Manual (Page 13)

Sample Draw Combustible Gas Detector • 13
Slow or no response/difficult or unable to calibrate
Symptoms
• The detector responds slowly or does not respond during the monthly response test.
• Unable to accurately set the zero or response reading during the calibration
procedure.
• The detector requires frequent calibration.
NOTE: Under “normal” circumstances, the detector requires calibration once a quarter.
Some applications may require a more frequent calibration schedule.
Probable causes
• The calibration cylinder is low, out-dated, or defective.
• 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 demand flow regulator is not operating properly (if one is used for calibration
instead of a gas bag).
Recommended action
1. Verify that the calibration cylinder contains an adequate supply of a fresh test sample.
2. If necessary, set the correct flow rate with the bypass valve or flow adjust
potentiometer.
3. If you cannot set the correct flow rate, check the sample line for obstructions or kinks.
4. If a demand flow regulator is used for calibration, try a different demand flow
regulator or a gas bag setup and see if the calibration/response difficulties continue.
5. If the calibration/response difficulties continue, replace the sensor as described later
in this section.
6. If the calibration/response difficulties continue, contact RKI Instruments, Inc., for
further instruction.