RKI Instruments 61-0191RK - Manual (Page 12)

8 • 61-1004RK/61-0191RK Carbon Dioxide Detector
Maintenance
This section describes maintenance procedures. It includes preventive maintenance,
troubleshooting, and component replacement procedures.
Preventive Maintenance
This section describes a preventive maintenance schedule to ensure the optimum
performance of the CO
2
detector. It includes daily, monthly, and biannual procedures.
Daily
Verify a display reading at the controller of the background concentration of CO
2
. Typical
background concentrations of CO
2
vary from about 300 to 600 ppm (0.03 to 0.06 %volume)
depending on location. The 0-5,000 ppm and 0-5 %volume detectors will display a reading
in a fresh air environment because they have low ranges. The 0-50 %volume and 0-100%
volume detectors will not display a reading in fresh air because their ranges are too large.
Investigate significant changes in the display reading.
Monthly
This procedure describes a test to verify that the CO
2
detector responds properly to the
target gas.
WARNING: The controller is not an active gas monitoring device during the response
test procedure.
NOTE: Performing a response test on the CO
2
detector may cause alarms. Be sure to put
the controller into its calibration program or disable external alarms before
performing this test.
The procedure below describes applying CO
2
to the detector using a calibration kit that
includes a calibration cup, a CO
2
calibration gas cylinder, sample tubing, and a 0.5 LPM
(liters per minute) fixed flow regulator with an on/off knob.
1. Place the controller into its calibration program or disable external alarms.
2. Verify that the controller display reading for the channel you are testing is consistent
with typical background levels of CO
2
.
If the reading is not consistent with typical background levels of CO
2
, set the zero
reading then continue this procedure. See “Setting the Zero Reading” on page 11 to set
the zero reading.
3. Screw the calibration cup onto the detector.
4. Use the sample tubing to connect the regulator to the calibration cup.
5. Screw the regulator into the calibration cylinder.
6. Turn the on/off knob on the regulator counterclockwise to open the regulator.
7. Apply gas to the detector for one minute.
8. Verify that the reading is within ± 20% of the gas concentration.