At the beginning of flue gas measurement, the combustion temperature is measured. This can be done either with a combustion air sensor or via the gas extraction probe. In air-flue gas systems in the annular gap of the supply air, in atmospheric furnaces in the room air. For the calculation of the coefficient of performance and flue gas loss, the combustion air temperature is absolutely necessary.
Subsequent to this determination, the gas extraction probe is fed into the flue gas tube. The next step is the search for the core flow, in which the hottest gases with the lowest oxygen content in the flue gas are found. Once the core flow has been found, the actual measurement and flue gas analysis of the heating system commences.