Identification of organic solvents by a virtual multisensor system with hierarchical classification

To improve the selectivity of semiconductor gas sensors temperature modulation is often used We present a study showing the potential of this technique with information gained comparable to multisensor systems. A dynamic operating mode coupled with a low complexity evaluation strategy allows identification of six organic solvent vapors over a wide concentration range (2 - 200 ppm) with a single sensor, for example for leak detection systems. The system features low false alarm rates, in addition interference by other gases such as CO or NO/sub 2/ can be suppressed For even higher identification power switching on-line between different temperature cycles was studied, which provides better information for critical decisions.