It might happen that the CO2 sensor displays incorrect values, e.g. after transportation. There are two ways to get it calibrated.
Wait for the Automatic Baseline Calibration (ABC)
The CO2 sensors takes the lowest value every week and assumes it is ambient level. This means that latest after seven days, the monitor should display correct values. You do not need to do anything here.
Forced Baseline Calibration
If you want to immediately calibrate the sensor, please follow this:
Put the monitor outside or open all windows for at least 20 minutes. Ensure you have ambient CO2 levels at the monitor
Go to the Edit Sensor page on the dashboard (only for Admins).
Check “Request CO2 calibration”
Wait for 10 minutes. The monitor should then display around 400ppm.