Function and applications of gas sensors

Gas sensors directed to high-volume applications are discussed. Mainly semiconductor sensors cover this sector, but the merits of competing devices are shown in comparison. Chemical and physical function is elucidated by spectroscopic 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 enhanced the development of electronic noses. An early example of such noses, the identification of solvents and also the present state of food aroma detection are described.