Sensors to observe the environment

Considering the state-of-the-art methods to measure gaseous and particulate air pollution constituents, the author shows that chemical sensors play a relatively insignificant role in environmental science and technology. The dominant problem consists in satisfying the requirements with respect to sensitivity, accuracy, and response time. A brief survey of chemical sensors used to detect trace gases in air is given. The application of chemical sensors for the measurement of the deposition velocity of single pollutant components seems to be of great importance, because toxic effects occur in the deposited state only. The performance of devices containing multiple sensor arrays shows that the degree of detection selectivity can be improved by using pattern-recognition techniques