Simultaneous quantification of carbon monoxide and methane in humid air using a sensor array and an artificial neural network

The simultaneous quantification of carbon monoxide and methane in humid air is presented. The response of a three-sensor array, including an undoped and a platinum doped tin dioxide sensor showing non-ideal selectivity and a humidity sensor is fed into an optimised feed forward back propagation artificial neural network in order to obtain the carbon monoxide and methane concentration as network output. The gaseous environments under study were ternary mixtures in the concentration ranges of 0-0.5% methane, 0-1000 ppm carbon monoxide and 0-60% relative humidity at 20 degrees C. The network structure, network output with respect to a priori known test concentrations and the influence of the size of the training data set is discussed. (C) 1997 Elsevier Science S.A.