Chemical Gas Sensors for Car Exhaust and Cabin Air Monitoring

Abstract

A combination of charcoal and particle filters has pre viously been shown to reduce effectively the smell of diesel exhaust. In this paper it is shown that the smell of diesel exhaust can successfully be predicted by the con centration of total volatile organic compounds and the concentration of certain carbonyl compounds. Projection to latent structures was utilised for model building. An electronic nose consisting of MOSFET and MOS sensors could less successfully predict the smell, but identified the same filter combination as being most efficient. The car cabin air during urban driving was also monitored, both by the means of MOSFET sensors and by chemilu minescence. The pollution level inside the car is shown to be elevated by about 30% compared to outside the car. A combination filter together with an air inlet sensor switch is shown to reduce the NOx levels inside the car by 30% compared to outside, with the ability to signifi cantly decrease the peak levels. Copyright © 2002 S. Karger AG, Basel