Abstract: 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.

Abstract: 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.