Nippondenso Co., Ltd.

Mitihiro Yamakawa

Hiromi Sano

Masatoshi Suzuki

Toshitaka Saito

Masaya Fujimoto

Masahiro Shibata

An oxygen gas concentration-sensing device comprises a solid electrolyte body which is prepared from an oxygen ion-permeable metal oxide and whose first surface is exposed to the gas to be sensed and the second surface is exposed to a reference gas. First and second electrodes are respectively pressed against the first and second surface of the solid electrolyte body. The first electrode exposed to the gas is covered with a porous gas diffusion-resisting layer. This gas diffusion-resisting layer is chosen to have an average pore-size ranging from 300 .ANG. to 400 .ANG..

Oxygen concentration-sensing device and the method of producing the same

A limiting current type oxygen analyzer designed for detecting oxygen concentration comprising a solid electrolyte element made from an oxygen ion conductive metal oxide and a pair of porous film electrodes provided on the inner and outer sides of said element respectively, at least one side electrodes being coated with a gas-diffusive resistive layer made from a porous insulating metal oxide, wherein the oxygen ions in the gas to which said element is exposed are caused to diffuse in the inside of said electrolyte element by applying a given voltage across said both electrodes and the limiting current corresponding to the concentration of said diffused oxygen ions is measured to determine the oxygen concentration in the gas to be analyzed, further characterized in that said gas-diffusive resistive layer is composed of a three-layer structure consisting of the first, second and third layers counted from the electrode side, said first layer having porosity of 11-15%, the second layer 6-8% and the third layer 15-20%.

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Kariya, Japan

Mitihiro Yamakawa