| 摘要 |
PROBLEM TO BE SOLVED: To enable a nitrogen oxide sensor to detect the NO2 concentration of a gas to be inspected even when NO2 and NO coexist in the gas by providing first and second electrodes on the surface of a solid electrolyte having ionic conductivity and constituting the first electrode of an oxide having a spinel structure or a material containing the oxide. SOLUTION: A solid electrolyte 1 can be made of any kind of ionic conductor, but zirconia entirely or partially stabilized with yttria, calcia, ceria, magnesia, etc., is preferable in respect of the thermal stability and heat resistance. Electrodes 2 and 3 are provided on one surface of the platy solid electrolyte 1. The electrode 2 is formed of an oxide film formed by a sputtering method by using an oxide having the spinel structure prepared in advance through a solid phase reaction as a target and heat-treating the film. The electrode 3 is constituted of platinum, etc., which does not respond to NOx . The electrodes 2 and 3 are so-called gas electrodes and formed as porous electrodes. Lead wires 4 and 5 composed of platinum are connected to a measurement circuit. |
