CHEMOSENSORS FOR HIGH-TEMPERATURE APPLICATIONS

In the field of high temperature sensory analysis (T-max = 1000 degrees C), gas sensors are being developed on the basis of semiconducting metal oxides. The gases to be detected occur with the selected metal oxides alternately as either a volume or a surface effect. If the volume effect is more dominant, the metal oxide can be used as an oxygen sensor. If surface effects with more reactive gases (e.g. carbon monoxide, hydrocarbons or hydrogen) predominate, the metal oxide can be used primarily as a gas sensor for these gases. To reduce the reaction time and increase sensitivity as well as promoting compatibility with microsystem technology, it is useful to prepare the metal oxides in the from of thin layers (typical layer thickness is 1 mu m to 5 mu m).