RKI Instruments EAGLE 2 Manual - Manual (Page 236)

226 • Start Up and Normal Operation EAGLE 2 Operator’s Manual
Start Up and Normal Operation
For instructions to startup and use an EAGLE 2 that includes an infrared CO
2
sensor, reference “Start Up” on page 22, “Measuring Mode, Normal
Operation” on page 29, and “Measuring Mode, Alarms” on page 35. Follow
these instructions keeping the following special considerations in mind:
• A background level of CO
2
exists in fresh air. The low range sensors will
display a reading in fresh air. Table 23 below indicates typical gas
readings in fresh air.
• When you perform a demand zero during start up, operation, or
calibration of a 0-10,000 ppm or 0-5 %vol CO
2
instrument, you must use
the CO
2
scrubber provided with the instrument to remove background
CO
2
from the air being sampled. See “Performing a Demand Zero for
Carbon Dioxide Sensors” below.
• Since there is a background of CO
2
in air, do not use the AUTO FRESH
AIR ADJ feature that can be turned on and off in Setup Mode. The factory
setting for the feature is off.
Performing a Demand Zero for Carbon Dioxide Sensors
When setting the zero reading, the carbon dioxide scrubber mounted to the
side of the EAGLE 2 allows you to eliminate carbon dioxide normally found
in fresh air. To perform a demand zero, do the following:
1. Remove the black caps from the ends of the carbon dioxide scrubber. Be
sure to grab the scrubber by the EAGLE 2 fitting so that the fitting and
tubing do not come off.
2. Connect the carbon dioxide scrubber directly to the EAGLE 2’s inlet
fitting.
3. Wait one minute for the fresh air sample to flow through the carbon
dioxide scrubber, then press AIR ▲ YES to set the zero reading.
4. Remove the scrubber from the inlet fitting.
Table 23: Carbon Dioxide Fresh Air Readings
Sensor
Range
Approximate Fresh Air
Reading
0-5 %vol 0.04 %vol
0-10,000 ppm 400 ppm
0-60 %vol 0.0 %vol