Ein physikalisches System für chemische Sensoren

: Drost, S.; Endres, H.-E.; Sandmaier, H.

Abstract
When applied correctly, system technology can also improve the properties of chemical sensors remarkably. simple physical considerations result in decisive consequences for the development of chemical sensors. For instance: The results from sensor analytics on sensitive films for dielectric gas sensors clearly demonstrate that not only one physical film parameter is altered due to the adsorption of gases. In the case of heteropolysiloxanes, at least three physical parameters are influenced by the adsorption of sulphur dioxide: - mass - permittivity at low frequencies (capacitive) - permittivity at high frequencies (optical). A simultaneous investigation of various physical film parameters and the integration into a microsystem can improve a wide range of characteristics, e.g. sensitivity, selectivity, etc. . This physical microsystem is demonstrated on the example of a sensor system based on dielectric and mass-sensitive gas sensors for sulphur dioxide. The investigations show that the sensitivity and the recognition of an overload (too high gas concentration) of these sensors can be improved by this system.