Detection of HC in exhaust gases by an array of MISiC sensors

Future legislations for car emissions make direct measurements in exhaust gases of hydrocarbon (HC) as well as CO and NOx interesting. Robust sensors that can stand the high temperature and rough environment in the exhaust gases are needed. Silicon carbide has the advantage of being a chemically very inert material, which, due to its high band gap, is a semiconductor even at temperatures around 800 degreesC. Catalytic metal insulator silicon carbide Schottky diode sensors respond to gases like H-2, HC, NOx in exhaust gases. The choice of catalytic metal, structure of the metal. and the operation temperature determines the response pattern to different gases. Here we will demonstrate that an array of different MISiC sensors to some extent predicts the HC concentration in gasoline exhaust gases. Chemometric methods are used for the evaluation of the signals. (C) 2001 Elsevier Science B.V. All rights reserved.