Abstract: A catalyst supported oxygen sensor element detecting the oxygen concentration in exhaust gas from vehicle engines is composed of a tubular container of a solid ion-conductive electrolyte with the one end portion thereof closed, an inner electrode being positioned on the inner circumference of the container, an outer electrode being positioned on the outer circumference, a protective layer of a refractory material being provided on the outer circumference of the outer electrode, a catalyst layer being provided on the outer circumference of the protective layer, and optionally provided on the outer circumference of the catalyst layer, and a method of manufacturing the same.

Abstract: An oxygen sensor with an oxygen sensor element having an outer protective layer of alumina, acting as getters with respect to catalyst poisons, particularly phosphorus, in exhaust gases, formed on the outer surface of a catalyst layer of platinum or a mixture of platinum and rhodium which is coated on an electrode protective layer provided on the outer electrode of an oxygen sensor element. Such an outer protective layer is additionally provided on the inner wall of the inner louver of the oxygen sensor having a double louver structure. A method of manufacturing an oxygen sensor with an oxygen sensor element comprising the steps of coating such an outer alumina protective layer onto the outer surface of said catalyst layer formed on an electrode protective layer provided onto the outer electrode of an oxygen sensor element and additionally coating such an alumina protective layer onto the inner wall of the inner louver of an oxygen sensor having a double louver structure.

Abstract: An oxygen sensor element is manufactured by successively forming on the outside of the output lead wire, a solid pole, a first metal electrode layer, a solid electrolyte layer, and a second metal electrode layer from inside to outside.