Restarts of the air-Q always occur when the sensors produce measured values that cannot (yet) be interpreted by the device.
The air-Q “stresses” the sensors quite strongly due to the second-by-second measurement. It happens that measured values cannot be recorded correctly. Particularly with the electrochemical sensors (which are, for example, somewhat sluggish), “outliers” occur from time to time.
If the air-Q does not get an expected result, a restart is performed automatically. This is not a cause for concern – gradually all sensor error codes are intercepted and corrected with the new firmware.