Air quality prediction by using semiconducting gas sensor with newly fabricated SmFeO3 film

The conductance changes of SmFeO3-based p-type gas sensor and n-type SnO2 gas sensor (TGS2600), with volatile organic compounds (VOCs) and NO2 in air were examined. Prediction of the contaminated levels with VOCs became difficult when NO2 levels were changed and also vice versa. The use of one sensor was poor to detect a level of contaminated air's quality. By using at least two SmFeO3 sensor operating at a different temperature, prediction of each contaminated level with VOCs and NO2 became possible. Furthermore, by the combination with both sensor sub-ppm levels contamination with VOCs and NO2 was interpretable due to a higher sensitivity of TGS2600 for NO2 and of SmFeO3 for VOCs. (C) 2003 Elsevier B.V. All rights reserved.