Function and applications of gas sensors

Gas sensors directed to high-volume applications are discussed. Mainly semi conductor sensors cover this sector, but the merits of competing devices ar e shown in comparison. Chemical and physical function is elucidated by spec troscopic results and molecular calculations. Important applications, e.g. monitoring of combustibles, especially methane, and the early detection of fires, are presented as illustrations. Progress in microelectronics has enh anced the development of electronic noses. An early example of such noses, the identification of solvents and also the present state of food aroma det ection are described.