Multi-layered thick-film gas sensor array for selective sensing by catalytic filtering technology

A C3H8 gas sensor array with high sensitivity and good selectivity by the combination of the catalytic filtering and the gas diffusion control has been achieved. The gas sensor array consists of a couple of catalytic filter layers, one with a Pd and the other with a Pt, a SiO2 insulating layer and two sensing layers on an alumina substrate. The sensor array shows high sensitivity to 500 ppm of C3H8 at temperature above 400°C and good selectivity for the interfering gases such as CO and C2H5OH by using a simple signal processing technique.