| 摘要 |
PROBLEM TO BE SOLVED: To obtain a solid electrolyte carbon dioxide sensor element, in which an electromotive force is not changed even when the sensor element is left for many hours in a non-heating state inside an atmosphere at a high moisture concentration, and in which the time until the stabilization of the electromotive force from the start of an operation is shortened, by a method wherein a working electrode layer on the surface of a solid electrolyte layer is constituted so as to contain a metal oxide, and a reference electrode layer is constituted so as to contain a composite oxide. SOLUTION: A working electrode layer 1 is formed on one face of a solid electrolyte layer 2, a reference electrode layer 3 is formed on the opposite face, and a ceramic plate 4 is bonded to the reference electrode layer 3 by an adhesive 5. A heater 6 is formed on the surface of the ceramic plate 4, and electricity is supplied from a power supply 7. A lead wire from the working electrode layer 1 and a lead wire from the reference electrode layer 3 are connected to a voltmeter 8, and an electromotive force is measured. The solid electrolyte layer 2 is formed in such a way that an electrolyte powder is uniaxially molded so as to be sintered for ten minutes in an air atmosphere at 1200 deg.C and that a discoidal pellet is formed. The working electrode layer 1 is formed in such a way that rare-metal oxides are kneaded in a specific ratio so as to be changed into a paste, and that the paste is screen- printed on the solid electrolyte layer 2 so as to be dried and fired. In addition, the reference electrode layer 3 is formed in such a way that composite oxides which contain lithium as an oxide are kneaded in a specific ratio so as to be changed into a paste, and that the paste is screen-printed on the solid electrolyte layer 2 so as to be dried and fired. |
