Gas analysis with SAW sensor systems

At the institute of instrumental analysis, a family of three gas analysis instruments based on mass-sensitive gas sensor devices are developed. The SAW Aroma and Gas Analyzing Systems (SAGAS) are used to detect and analyze a large variety of gases and aromas. The common heart of these systems is a sensor head with eight differently polymer-coated surface acoustic wave (SAW) devices. These “semi-selective” sensors are used to generate typical signal pattern (“finger prints”) of analyte gases and gas mixtures. Using chemometrical data analysis, such as PCA, classification and PLS, as well as artificial neural networks, these signal patterns are used for qualitative analyte recognition and for quantitative gas mixture determination. In the following, some sensor properties are discussed and some applications of the systems are presented.