35
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Sensor Settings and Calibration
AirLink 6940XP Operator’s Manual
Zeroing the Sensor (20.9% for O
2
Sensor)
The first step of calibration is zeroing (20.9% for O
2
sensor). The zeroing (20.9% for O
2
sensor)
process MUST be performed in known clean air, with no contaminants or hazardous gases
present. If air quality cannot be guaranteed, a cylinder of zero air will be required to properly zero
the sensor.
Materials
• 0.5 LPM fixed flow regulator with knob
• calibration cup
• calibration tubing
• zero air cylinder (if not in a fresh air environment)
• 100% N
2
cylinder (if zeroing a CO
2
sensor)
NOTE:
Since there is a background of CO
2
in air, it is necessary to use a CO
2
-free cylinder
when zeroing a CO
2
sensor.
Procedure
1. If necessary, enter the Product Settings and Configuration menu by pressing and holding
MENU
for approximately 6 seconds.
Press and release
ADD
or
SUB
to navigate to the desired sensor settings menu, then press
MENU
to select the menu.
2. Press and release
ADD
until the Zero menu item appears.
3. Press
MENU
to select the menu item.
4. Press
ADD
to begin the zero process.
Non-O
2
Sensor
O
2
Sensor
