QRAE II User Guide
Page 49
6.4
Zero (Fresh Air) Calibration
This procedure determines the zero point of the sensor calibration curve. Expose the inlet
to a clean air source with 20.9% oxygen and without any organic, toxic or combustible
gas impurities. This “Zero Air” can be from a cylinder, clean ambient air, or ambient air
purified through a charcoal filter.
6.4.1
Using Fresh Air
Caution!
If your QRAE II is a diffusion model, do not use the Calibration Adapter while
performing zero calibration in fresh air.
Turn on the QRAE II and follow this procedure:
1.
Enter Program Mode.
2.
At Calibrate Monitor, press [Y/+].
You should see:
Fresh Air Calibration?
3.
Press Y+ to start calibration. Calibration is performed automatically.
6.4.2
Using Zero Gas
1.
Attach the Calibration Adapter to the QRAE II (diffusion model only).
2.
Attach the regulator to the Zero Gas cylinder.
3.
If your model is a QRAE II diffusion model, attach a hose to the Calibration
Adapter and to the regulator. If it is a QRAE II Pump model, attach a hose to the
regulator and to the inlet on the front of the QRAE II Pump.
4.
Enter the Password.
5.
At Calibrate Monitor, press [Y/+].
6.
When you see “Fresh Air Calibration?” turn on the regulator to start the Zero Gas flow.
7.
Press [Y/+].
You should see a countdown from 30 seconds:
Calibration
in progress ... 30
