RKI Instruments Eagle Series - Manual (Page 72)

65 • Appendix D: Carbon Dioxide Sensors Eagle Instruction Manual
This scrubber is for use when setting the carbon dioxide sensor’s zero
reading only. Two black vinyl caps cover either end of the carbon
dioxide scrubber. To prolong the life of the scrubber, be sure the caps
are installed while the scrubber is not in use or while it is being stored.
Replace the scrubber when it turns from white to a violet color.
CAUTION: Do not connect the probe to the scrubber during normal
operation or when setting the span reading during calibration.
Normal Operation of Carbon Dioxide Sensors
Carbon dioxide is a background gas in fresh air. Table 11 indicates
typical gas readings for each of the Eagle’s carbon dioxide sensors.
Demand Zero for Carbon Dioxide Sensors
When setting the zero reading, the carbon dioxide scrubber mounted
to the front of the Eagle allows you to eliminate carbon dioxide
normally found in fresh air.
NOTE: When performing a demand zero with a 0 - 20% or 0 - 60%
CO
2
unit, the use of a scrubber is not required.
1. Remove the black caps from the ends of the carbon dioxide
scrubber. Be sure to grab the scrubber by the Eagle fitting so that
the fitting and tubing do not come off.
2. Connect the carbon dioxide scrubber directly to the Eagle’s inlet
fitting.
3. Wait one minute for the fresh air sample to flow through the
Table 11: Carbon Dioxide Fresh Air Readings
Range
Approximate
Fresh Air Reading
0 - 5000 ppm 400 ppm
0 - 10,000 ppm 400 ppm
0 - 5.00% 0.04%
0 - 20.0 & 0 - 60.0% 0.0%
End Caps