Influence of MOS Gas-Sensor Production Tolerances on Pattern Recognition Techniques in Electronic Noses

Temperature cycling at metal-oxide-semiconductor (MOS) sensor elements in combination with pattern recognition algorithms is applied for detecting various gas mixtures. Through this process, the influence concerning the capability of gas identification has been investigated in the case of transferring the recorded reference library from a distinct sensor element to several further sensors. This comparative study has been followed based on responses of four sensors exposed to the same gas composition. The results are analyzed and compared for two sensor types with differing variations of sensing-layer resistance. It is shown that gas identification, particularly the determination of gas concentration, is improved by the implementation of sensors with smaller resistance variations if the reference library from one sensor is also used for other sensor elements.