PIEZOELECTRIC CRYSTAL SENSOR ARRAY USED AS AN ORGANIC VAPOR SENSING SYSTEM

To stimulate the biochemical sensor system, an organic vapor sensing d evice based on a sensor array for recognizing solvents with different organic functional groups has been constructed. The array consists of 12 piezoelectric quartz crystals, each coated with an adsorptive mater ial with unselective, but different response characteristics. The step wise regression analysis shows that a subset of seven sensors is suffi cient for the classification purpose. The principal component analysis is applied to the original and autoscaled data. The results show that autoscaling of the original data substantially improves the classific ation of alcoholic, carbonyl, etherous, and esterous groups. The array have been applied to classification of spirit and beverage samples. ( C) 1995 Academic Press, Inc.