The most likely cause of a high reading, is the presence of sulfur dioxide(SO₂).
The air-Q’s existing Sulfur dioxide (SO2) measures according to an electrochemical measuring principle. Various effects, e.g. climatic shocks, can cause a shift of the zero line. This can be remedied by calibration.
See also: How do I perform a manual calibration?
Another cause for very high or deviating measured values can also be the cross-sensitivities that the sulfur dioxide sensor has. For example, it reacts positively to hydrogen sulfide, nitric oxide; negatively to alcohol and ozone(O₃).
Thus, all framework conditions must be checked and the measured values must also be compared with the measured value of the nitrogen dioxide(NO₂) sensor and ozone(O₃) sensor in the air-Q to rule out possible cross-sensitivities as a cause.
