Abstract: Poisoning-preventive and poisoning-resistant materials are described, including: a poisoning-preventive layer-possessing support including a support and, formed thereon, a poisoning-preventive layer having a compound containing at least one element selected from the Group IIa element of the periodic table.

Abstract: A poisoning-resistant catalyst for a catalytic converter, includes a support, a noble metal catalytic component deposited on the support, and a poisoning-preventive layer formed on the side of the catalytic component exposed to an exhaust gas, said poisoning-preventive layer having a compound containing at least one element selected from the Group IIa elements of the periodic table.

Abstract: Poisoning-preventive and poisoning-resistant materials including: a poisoning-preventive layer-possessing support comprising a support and, formed thereon, a poisoning-preventive layer having a compound containing at least one element selected from the Group IIa element of the periodic table; a poisoning-resistant catalyst for catalytic converter, which comprises a support, a noble metal catalytic component deposited on the support, and a poisoning-preventive layer formed on the side of the catalytic component exposed to an exhaust gas, the poisoning-preventive layer having a compound containing at least one element selected from the Group IIa elements of the periodic table; an exhaust gas converter device comprising a poisoning-preventive material provided on the exhaust gas inlet side, the poisoning-preventive material being either a ceramic material or the poisoning-preventive layer-possessing support as described above, the ceramic material comprising a compound containing at least one element selected fr

Abstract: An air/fuel ratio sensor is described, comprising an oxygen concentration electrochemical cell and an oxygen pump disposed in a face-to-face relationship with a gap being formed therebetween, the side of said electrochemical cell opposite the side facing said oxygen pump being in contact with the atmosphere, said gap forming a gas diffusion compartment that communicates with a gas to be analyzed by a gas diffusion limiting means, wherein the gap existing between said oxygen concentration electrochemical cell and said oxygen pump has a width of no more than 0.2 mm and no less than 0.01 mm.

Abstract: An air/fuel ratio sensor is described, comprising an oxygen concentration electrochemical cell and an oxygen pump disposed in a face-to-face relationship with a gap being formed therebetween, the side of said electrochemical cell opposite the side facing said oxygen pump being in contact with the atmosphere, said gap forming a gas diffusion compartment that communicates with a gas to be analyzed by a gas diffusion limiting means, wherein the gap existing between said oxygen concentration electrochemical cell and said oxygen pump has a width of no more than 0.22 mm and no less than 0.01 mm.

Abstract: A method for producing an oxygen detection element having uniform pores and an excellent durability against toxic matter contained in the measurement gas. The method includes a first step of applying a paste to be sintered to form a catalytic electrode layer onto at least a part of an oxygen-ion conductive solid-state electrolytic body, and sintering the paste to thereby form said catalytic electrode layer at a predetermined position on said surface of said solid-state electrolytic body after sintering, and a second step of forming an electrode protection layer for coating and protecting at least a part of the catalytic electrode layer either after or simultaneous with the first step. In a first embodiment, the paste contains mainly a noble metal powder acting as a catalyst and an organic metal compound, in a second embodiment mainly co-precipitated powder consisting of a noble metal and a metal hydroxide, and in a third embodiment mainly noble metal powder and a powder of a metal other than a noble metal.

Abstract: An oxygen sensor comprising a hollow cylindrical member closed at one end but open at the other to admit a reference gas. There is at least one radial through-hole in the hollow cylindrical member. An oxygen-ion conductive solid electrolyte later has at least one pair of electrodes on its opposite sides. The electrolyte layer is wrapped around the hollow cylindrical member with the electrode on its inner side facing the through hole. In other embodiments, an oxygen sensor is provided which is very insensitive to the direction of flow of the gas to be analyzed. The electrodes of the sensor are spaced at substantially equal intervals on the circumference of a cylindrical solid electrolyte layer in registry with through-holes formed in a hollow tubular member surrounded by the electrolyte layer. A heating unit may be formed on either the inner or outer surface of the solid electrolyte layer.

Abstract: An apparatus for evaluating an oxygen sensor includes a device for mixing a fuel and an oxygen-containing gas in an appropriate ratio to prepare a fuel mixture. A burner is connected to the mixing device for burning the fuel mixture to produce a gaseous combustion product. A tubular member extends from the burner for supplying the combustion product. A nozzle is connected to the tubular member for introducing a fuel and an oxygen-containing gas into the tubular member so that the combustion product is of a desired excess air ratio (air-fuel ratio) and a mounting device for the sensor to be evaluated is disposed on the tubular member, downstream of the nozzle.