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 concentrations in the range of the first alarm thresholds for urban environments. Their mutual interference has been studied at three operating temperature ranges. The results showed that different sensitivities and selectivities 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 gases, and even measure the concentration of both gases with a sufficient accuracy.