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CO
2
CALIBRATION
Manually calibrate the meter in an environment where the
expected ambient air CO
2
concentration is approximately
400ppm.
This is typically fresh outdoor air that is well ventilated,
preferably sunny and away from crowds of people. Avoid
calibrating the meter in crowds of people, near ventilation
ducts, fireplaces, or areas of industrial or combustion
engine exhaust.
Procedure
1. Take the meter to an appropriate calibration area.
2. Turn the meter on and simultaneously hold down
CAL
and
MODE
to enter CO
2
calibration mode.
3. 400ppm and “CAL” will blink on the LCD while cal-
ibration is being performed.
4. In approximately 10 minutes, blinking stops, calibration
is completed and the meter returns to Normal mode.
5. To abort calibration, turn the meter off at any time during
this process.
Note…
Before performing calibration, ensure batteries are in good
condition to prevent interruption or calibration failure.