Gas sensor array systems, also known as electronic noses, are used since many years in the food industry. The principle of operation is simple: a gas mixture is measured with a combination of gas sensors and by comparing actual measured data with stored data, using pattern recognition techniques, a classification of the mixtures is possible. The interesting point about gas sensor arrays is that a classification of complex mixtures is possible on site. The analysis is fast and does not require an analysis in the lab. By improvement of the sensors itself and also due to better sampling techniques it is also possible to use the systems online (or at-line) in industrial			applications. It is also possible to use the systems online (or at-line) in industrial applications. Preconcentrator A trap can be used for lowering detection limits and for increasing the selectivity. Industrial plants can be monitored with the system. The continuous sampling and thermal desorption step are preformed automatically. In applications where a manual sampling is preferred, the system can also be used just as a thermal desorption device. Applications with a sensor array as a detector, but also with a gas chromatograph and/or mass spectrometer are possible.
Applications
PEN & EDU, i-PEN
	Food Rancidity of food using the PEN Identification of spices and control of dosage using i-PEN Off flavor in food using PEN Freshness of meat using PEN Different aroma of fruits using PEN Differences in yogurt using PEN Differentiation of juices and soft drinks using PEN Differentiation of alcoholic beverages using PEN & EDU Condition of grain using PEN Supervision of roast process and differentiation of coffee using i-PEN Control of tobacco and the artificial aroma using PEN   Materials Stopper for beverages, detection of solvents and off odor using PEN Control of paper based packaging material using PEN & EDU Smell and/or solvents in polymers using PEN Degradation of flavors in perfumes using PEN & EDU Environment & Safety Supervision of biological filters and smells in waste water plants using i-PEN Correlation to smell by olfactometry in composting plants using PEN & EDU Determination of solvents at workplace atmospheres using PEN Detection of artificial odorants (also non sulfur) in natural gas using PEN & EDU Medicine Identification of bacteria on agar plates using PEN Degradation of flavor in medicine using PEN Supervision of fermentation processes using i-PEN Off odors in medicine using PEN & EDU
Keg & Process Control
	Contamination in recycled bins using Keg-Control Leakage of natural gas (monitoring of methane, benzene, H2S) using Process Control Nose