Nippon Soken, Inc.

Tomio Kawakami

Minoru Ohta

Yutaka Hattori

Michitoshi Onoda

Michitosi Onoda

Eturo Yasuda

Yoichi Kotanshi

A gas composition sensor includes a gas sensor element having an electric resistance value which varies in accordance with the composition of exhaust gases to be sensed, and a pair of electrodes attached to the gas sensor element for detecting the electric resistance value, whereby the resistance value of the gas sensor element is detected to sense the composition of the exhaust gases. A layer of material substantially impervious to the gases is formed on the gas sensor element to extend between the electrodes and surround the electrodes and the layer is also formed on other portions of the electrodes exposed to the exhaust gases.

Gas composition sensor

A gas detecting sensor for precisely detecting the partial pressure of oxygen gas in the exhaust gases without being affected by the change of the temperature of the environment thereof, is disclosed. The sensor is provided with a ceramic base member, a film-shaped gas sensing element having a characteristic in response to the partial pressure of oxygen gas which is held by the base member so as to be exposed to the exhaust gases, a film shaped temperature sensing element having temperature coefficient of resistance substantially equal to that of the gas sensing element, which is held by the base member so as to be isolated from the exhaust gases, and an electric current wherein the gas and the temperature sensing elements are connected to each other in series to form an electric junction therebetween, from which output voltage is taken. In the preferred embodiment, the temperature sensing element is embedded within the base member and a heating member is further provided for maintaining both elements within a temperature range in which temperature coefficient of resistance of both elements are substantially equal to each other.

Gas detecting sensor

A compact and high sensitive gas detecting sensor for detecting the partial pressure of oxygen gas in the exhaust gases of an internal combustion engine is disclosed. The sensor is provided with a sensing element made of the ceramic material having an electrical characteristic which varies in response to variations in the partial pressure of oxygen gas, such as CoO, a base member made of ceramic material having a characteristic of generating heat when an electric current is supplied thereto, such as silicon carbide. The sensing element is integrally fixed to the base member through an insulating layer made of ceramic material. To the base member, electrodes are connected for supplying an electric current thereto so that the base member is maintained at a predetermined temperature regardless of the temperature change of the exhaust gases.

A compact and durable gas detecting sensor for detecting the partial pressure of oxygen gas in the exhaust gases of an internal combustion engine is disclosed. The sensor is provided with a sensing element made of ceramic material having an electrical characteristic which varies in response to variations in the partial pressure of oxygen gas, such as CoO, a base member made of electrically insulating ceramic material, such as alumina, and electrodes held by the base member. The sensing element is integrally fixed to the base member through an intermediate layer made of ceramic material which is non-reactive with the sensing element.

A high sensitive and high responsive gas detecting sensor for detecting the partial pressure of oxygen gas in the exhaust gases is disclosed. The sensor is provided with a sensing element having an electrical characteristic in response to the partial pressure of oxygen gas, a ceramic base member which supports the sensing element so that the sensing element is exposed to the exhaust gases, and electric current conducting means for supplying an electric current to the sensing element. The sensing element is formed of alloy ceramic material composed of 20 to 60 mol percent of cobalt monoxide, 20 to 60 mol percent of magnesium monoxide and 10 to 50 mol percent of nickel monoxide. In the preferred embodiment, the base member is formed into a plate shape and the sensing element is formed on the base member like a film.

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Nishio, Japan

Tomio Kawakami