Sensorsystem zur Detektion von Gasen und Dämpfen in Luft

The Invention relates to method as well as a sensor device with a sensor element for detection of gases and vapors in air. The sensor element is preferably a heated metal oxide sensor with heating structure and gas sensitive layer, wherein the temperature of the gas sensitive layer can be maintained constant by way of a heating structure and an automatic control device. The sensor element is disposed in a heat in a preferably heat insulating casing for protecting against air flows, wherein the gas can penetrate into the casing through a gas permeable diffusion layer. The resistance of the heating structure, which is a measure for the temperature of the gas sensitive layer, is employed as a temperature reference for the automatic control according to the present Invention method. The temperature of the sensor element is purposefully influenced by adding further interference values to the automatic control value "sensor temperature'. The evaluation is performed by comparison the in each case actual sensor signal with a reference value, wherein the reference value is formed out of the weighted average signal of the sensor values and wherein the reference value adapts to the specific situation in each case.