The most probable cause for a high reading is the presence of Nitrogen dioxide (NO₂) in the air.
The nitrogen dioxide sensor (NO₂) in the air-Q measures according to an electrochemical measuring principle. Various effects, e.g. climatic shocks, can cause a shift in the zero line. This can be remedied by calibration.
See here: How do I perform a manual calibration?Another reason for very high or deviating measured values at certain points can be the cross-sensitivity of the nitrogen dioxide sensor. For example, it reacts slightly positively to Ozone (O₃) and Chlorine (Cl).
All general conditions must therefore be checked and the measured values must also be brought into connection with the measured value of the ozone (O₃) sensor in the air-Q in order to exclude possible cross-sensitivities as a cause.
