摘要:
A measuring electrode and a reference plate are formed on the front and rear surfaces, respectively, of the electrolytic plate. The vent plate is provided with a vent channel. The heater base comprises a heating element. The electrolytic plate is made of a green sheet of zirconium oxide consisting of 5 to 7 molar % Y.sub.2 O.sub.3 and 0 to 5 parts by weight of aluminum oxide. The average particle diameter of the zirconium oxide powder is less than 2.0 .mu.m. The green sheet of zirconium oxide has a thickness of 50 to 300 .mu.m. The heater base is made of a green sheet of aluminum oxide consisting of aluminum oxide powder having an average particle diameter of less than 1.0 .mu.m and 0 to 10 parts by weight of zirconium oxide or yttria-stabilized zirconium oxide. The green sheet of aluminum oxide is at least 4 times the thickness of the green sheet of zirconium oxide. To complete the oxygen sensor, these four components are sintered together at 1300.degree. to 1600.degree. C. to be integrated.
摘要:
A measuring electrode and a reference plate are formed on the front and rear surfaces, respectively, of the electrolytic plate. The vent plate is provided with a vent channel. The heater base comprises a heating element. The electrolytic plate is made of a green sheet of zirconium oxide consisting of 5 to 7 molar % Y.sub.2 O.sub.3 and 0 to 5 parts by weight of aluminum oxide. The average particle diameter of the zirconium oxide powder is less than 2.0 .mu.m. The green sheet of zirconium oxide has a thickness of 50 to 300 .mu.m. The heater base is made of a green sheet of aluminum oxide consisting of aluminum oxide powder having an average particle diameter of less than 1.0 .mu.m and 0 to 10 parts by weight of zirconium oxide or yttria-stabilized zirconium oxide. The green sheet of aluminum oxide is at least 4 times the thickness of the green sheet of zirconium oxide. To complete the oxygen sensor, these four components are sintered together at 1300.degree. to 1600.degree. C. to be integrated.
摘要:
This invention aims at providing an oxygen concentration sensor having electrodes which are excellent in heat resistance and durability and maintain quick response. An electrode 26 on an exhaust side is formed on one of the side surfaces of a solid electrolyte 25, and an electrode 24 on an atmosphere side is formed on the other side surface. The electrode 26 on the exhaust side has a composite structure comprising a skeletal electrode 26a and a reaction electrode 26a. The skeletal electrode 26a has a film thickness of 5 to 20 .mu.m and a porosity of less than 10%, and is a heat-resistant thick film for primarily forming a skeletal region. In contrast, the reaction electrode 26b has a film thickness of 0.5 to 2 .mu.m and a porosity of 10 to 50%, and is a high response thin film for primarily forming a reaction region.
摘要:
An oxygen concentration detector provides high durability by increasing the thermal stability of coating layers applied to an electrode face thereof. A catalyst layer is formed on an outer surface of an electrode at the analysis gas side of a partition wall made of an ion oxygen conductive ceramic for generating electromotive force according to the difference between the concentration of oxygen in the analysis gas and the concentration of oxygen in the reference gas. The catalyst layer is composed of heat resistant ceramic particles and a particulate metallic catalyst made of platinum, rhodium or the like, supported by the surface of the heat resistant ceramic particles. The catalyst layer is formed so that the catalyst is supported by the heat resistant support particles. The support particles are heat treated to grow to a particle size so that particle growth can be restrained when the support particles are exposed to the exhaust gas from an internal combustion engine. The outside of the electrode of the partition wall is covered with support particles having such heat treated large cohered catalyst particles, and good responsivity of the sensor is thereby maintained.
摘要:
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..
摘要:
According to the present invention, an oxygen sensor element includes a solid electrolyte having a side surface at one side thereof, the side surface being contactable with a gas to be measured, a skeletal electrode provided on the side surface and having a plurality of pore portions, each of the pore portions passing through the skeletal electrode up to the solid electrolyte, and a reactive electrode made of a porous film and provided in each of the pore portions, a thickness of the porous film being smaller than that of said skeletal electrode. An area percentage (SH/SZ) which is a ratio of a total area (SH) of the reactive electrode to a total area (SZ) of the skeletal electrode and the reactive electrode is in a range from 10 to 50%, an average area (SA) of the pore portions is 100 .mu.m.sup.2 or less, a film thickness of the skeletal electrode is in a range from 1.5 to 4 .mu.m, and the film thickness of the reactive electrode is in a range from 0.6 to 1.5 .mu.m. The oxygen sensor element is superior in the heat resistance characteristics and the response characteristics.
摘要:
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%.
摘要:
An air-fuel ratio sensing element comprises a pump cell having at least one pair of pump electrodes thereon, a sensor cell having at least one pair of sensor electrodes thereon, and a gas chamber having two surfaces defined by the pump cell and the sensor cell. Two to five gas holes, each having approximately the same diameter and communicating with the gas chamber, are provided for introducing sensed gas into the gas chamber. The gas holes form their projection images on the surface of the sensor cell which has a sensor electrode thereon and faces the gas chamber. The sensor electrode is shaped such that it is dividable into a plurality of similar subsections defined by virtual lines connecting the geometric centroid of the sensor electrode and the center of the projection image of each gas hole.
摘要:
A multilayered air-fuel ratio sensor consists of a plurality of substrate layers. At least one heterogeneous boundary layer is interposed between the plurality of substrate layers. The heterogeneous boundary layer has a thickness in a range of 10 to 100 μm. The heterogeneous boundary layer absorbs thermal shocks or any other stresses acting on the substrate layers and stops the growth of cracks.
摘要:
A main body of a NOx sensor has a sensor cell and defines a reference gas chamber and a sample gas chamber therein. The sample gas chamber has a wall formed by a solid electrolytic substrate having an oxygen ion conductivity. The sensor cell is disposed between the reference gas chamber and the sample gas chamber for detecting a concentration of a NOx gas. A pump cell body of the NOx sensor has a surface facing to the sample gas chamber and has a pump cell for introducing and exhausting an oxygen gas to and from the sample gas chamber. In manufacturing this NOx sensor, the main body and the pump cell body are fabricated individually as separate items. The main body and the pump cell body are sintered independently. Then, the main body and the pump cell body are assembled into to the NOx sensor.