Influence of SO[sub 2] Gas on Output of Resistive Oxygen Sensors Using CeO[sub 2] and Ce[sub 0.8]Zr[sub 0.2]O[sub 2]

The influence of on the output of resistive oxygen sensors using and thick films was investigated. At 873 and 1073 K, the resistance of the sensors using film was strongly influenced by 1, 500 ppm , and caused a decrease of resistance. On the contrary, the resistance of the sensors using was hardly influenced. The resistivity of the reaction product, which was , was 100 times greater than that of at 873 K. Thermodynamic calculation revealed that was more stable than at 1073 K in 500 ppm . These results showed that the resistance decrease of the sensor using film, caused by the introduction of , was unrelated to the formation of the reaction product. It was believed that the resistance decrease of the sensor using film was due to the adsorption of electrically conductive substances on the surface. It was considered that the reason the influence of on thick film was less than that on thick film was that the resistivity of was times that of .