Method for controlling the combustion in a combustion device

Method for monitoring combustion in a gas burner, especially a natural gas burner, whereby the gas to air ratio is measured and evaluated in an evaluation unit. If a change in the gas constitution occurs a correction signal for the calorific value is produced based on a correlation with the measured gas-air or lambda ratio. A probe is used to measure either the oxygen or carbon dioxide content in the exhaust gas. An independent claim is made for a method for monitoring combustion of natural gas in a burner that is equipped with an emissions reduction plant, whereby the gas-air ratio is measured and compared with a set value. If the measured value exceeds the set value by more that a threshold a warning is issued and or the burner is shut down to prevent harmful emissions.