SO3 GAS SENSOR AND PRODUCTION METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide an SO3 gas sensor capable of continuously measuring the concn. of SO3 even in exhaust gas high in the concn. of SO3 for a long time. SOLUTION: In an SO3 gas sensor equipped with the reference electrode 12 formed on one surface of a substrate 10 comprising a solid electrolyte such as yttria stabilized zirconia or the like, the auxiliary electrode 14 comprising sulfate as a crystalline inorg. salt formed on the other surface of the substrate 10 and the detection electrode 16 formed on the auxiliary electrode 14 from a metal wire material comprising a metal chemically stable against SO3 gas, the detection electrode 14 is coated with a porous metal layer 28 comprising a reactive metal reacting with SO3 gas to form sulfate.