PROGRAMMING THE AREARAE
4-8
4.4.1 Fresh Air Calibration
This procedure determines the zero point of the sensor
calibration curve. To perform fresh air calibration, the
calibration adapter and a bottle of fresh air (optional) are
required. The bottle of fresh air contains 20.9% oxygen
concentration and contains no organic, toxic or combustible
gases or other impurities. If a fresh air bottle is not available,
any clean ambient air without detectable contaminants may
also be used. A charcoal filter should be used if purity of the
ambient air is unknown.
1. “Calibrate Monitor?” is the first menu item. Press [Y/+] to
perform calibration. The first submenu is: “Fresh Air
Calibration?”
2. If a bottle of fresh air is being used, attach the calibration
adapter to the gas inlet port. Connect the other end of the
tube to the bottle of fresh air. If a bottle of fresh air is not
available, leave the monitor in an area free of any
detectable vapors.
3. Press [Y/+] to start fresh air calibration. The display shows
“zero...in progress” followed by the name of each sensor,
and then the message “zeroed.” The display should show
a reading of “20.9” for the oxygen sensor and “0.0” or a
very small number for all other sensors.
4. After a five-second pause, the display shows “Zero Cal
Done!” and moves to the next submenu, “Multiple Sensor
Calibration?”