Study of the interferences of NO2 and CO in solid state commercial sensors

Commercial solid state gas sensors have been used to measure NO2 and CO con centrations in the range of the first alarm thresholds for urban environmen ts. Their mutual interference has been studied at three operating temperatu re ranges. The results showed that different sensitivities and selectivitie s can be obtained with the same type of sensors. This fact is used to make a multisensorial system based on commercial solid state gas sensors. Using artificial neural networks analysis, we detect the presence of NO2 and CO g ases, and even measure the concentration of both gases with a sufficient ac curacy. (C) 1999 Elsevier Science S.A. All rights reserved.