摘要 |
Electro-chemical sensor to determine oxygen concentration in hot internal combustion exhaust gases in the form of a closed, tubular element having a solid ion conductive electrolyte; an electron-conductive coating on the inner surface thereof; a porous or fissured electron conductive layer on the outer surface of said solid electrolyte or on a part of said surface, part of the pores or fissures being macroporous, said layer being of a material which catalyzes the formation from said hot exhaust gases of those compounds that are thermodynamically stable at the exhaust temperature; and a porous protective electrically insulating coating on said porous electron-conductive layer. Preferably, a top coating of a heat-resistant metal is applied, which top coating has additionally properties to act as a getter with respect to poisons affecting the catalyzing material.
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