Array of thick film sensors for atmospheric pollutant monitoring

Chemical routes such as set-gel techniques and thermal decomposition of het eronuclear complexes have been used to prepare nanosized powders of n-type (SnO2, TiO2 and In2O3) and p-type (LaFeO3) semiconducting oxides. Thick fil m gas sensors have been fabricated using these powders, printed on laser pr e-cut 96% alumina substrates, each 2 X 2 mm element being provided with a h eater, Au interdigitated contacts and a Pt-100 resistor for controlling the operating temperature. The films have been fired at different temperatures suitable to keep the grain size at the nanometer level. Electrical respons es to some major polluting gases (CO, NO, NO2 and O-3) obtained in the fiel d have been compared with international standard analytical techniques. (C) 2000 Elsevier Science S.A. All rights reserved.