Gas analysis with SAW sensor systems

At the institute of instrumental analysis, a family of three gas analysis i nstruments based on mass-sensitive gas sensor devices are developed. The SA W 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 s ensor head with eight differently polymer-coated surface acoustic wave (SAW ) devices. These "semi-selective" sensors are used to generate typical sign al pattern ("finger prints") of analyte gases and gas mixtures. Using chemo metrical data analysis, such as PCA, classification and PLS, as well as art ificial neural networks, these signal patterns are used for qualitative ana lyte recognition and for quantitative gas mixture determination. In the fol lowing, some sensor properties are discussed and some applications of the s ystems are presented. (C) 2000 Elsevier Science S.A. All rights reserved.