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1. Press enter to enter the pressure compensation mode.
The default value of 1013 hpa flashes on the display.
2. Press to increase the air pressure value and to
decrease it.
3. When finished press enter again to return to P4.0. Hold
power for 2 seconds to return to normal mode.
CO2 Calibration
The meter is calibrated at 400ppm CO2 concentration at the
factory. We suggest recalibrating at least once a year for
the best accuracy. This should be done in fresh air (=equals
400ppm). Calibrating the meter in higher CO2 concentrations
will lead to inaccurate readings. Calibration procedure:
1. With the meter off press and release power, and
simultaneously to enter the CO2 calibration mode. “CAL
will appear in the lower display and the meter begins
counting down for 30 seconds and then begins calibration
to 400ppm.
