Perovskite-type electrode materials of the compositions La_0.6Ca_0.4B′_1-xB″_xO_3±δ (B = Mn, Cr; B″ = Ni, Co, Fe; x = 0, ..., 0.6) were investigated with regard to their NO sensitivity and the cross-sensitivity to NO₂ and propylene in a potentiometric solid electrolyte measuring setup. The highest NO sensitivity was found for nickel and iron manganites with x = 0.2 and 0.3. Dependencies on the NO gas concentration were found using impedance spectroscopy. For some materials, the catalytic conversion of NO, NO₂, methane and propene was determined by thermal investigation in the temperature range of 25-800 °C.