Abstract: A gas sensor including a gas detection element and a gas selective permeation element covering at least part of the gas detection element. The gas sensor is arranged so that gases containing a gas to be detected is brought in contact with the gas detection element via the gas selective permeation element.

Abstract: First and second solid electrolyte bodies are opposed to one another to form a reference gas chamber therebetween. A measurement cell for detecting an air fuel ratio in measurement gas is provided on the first solid electrolyte body with a measurement electrode exposed to the measurement gas and a reference electrode exposed to the reference gas chamber. An oxygen pump cell is provided on the second solid electrolyte body with a first pump electrode exposed to the measurement gas and a second pump electrode exposed to the reference gas chamber. When a voltage is applied to the first and second oxygen pump cell, the oxygen gas is introduced from the measurement gas into the reference gas chamber.

Abstract: An exhaust gas oxygen sensor (10) mounted in the exhaust stream of an engine includes a zirconia plate (14) mounted to two electrodes (16,18), covered with porous layers (20,22). The two porous layers (20,22) are designed to sense the two conditions of air/fuel mixture, lean and rich, by creating a delay in the sensing of the rate of transmission of oxygen through one of these layers (20,22), without the need for a voltage source pumping oxygen through the sensor. A heating element (60) can be used with the sensor to reduce the light-off time of the sensor. Also, a latch 52 can be used to modify the signal from the sensor to provide for a more conventional EGO signal.

Abstract: A metallic layer is provided on the surface of a ceramic body. A junction layer is provided on the metallic layer. The junction layer contains 40.about.98 wt % Cu and 2.about.20 wt % Ni. A conductive member is bonded to the metallic layer via the junction layer.

Abstract: A method of operating an oxygen sensor in the exhaust stream of an engine. The oxygen sensor includes a zirconia plate (14) mounted to two electrodes (16,18), covered with porous layers (20,22). The two porous layers (20,22) are designed to sense the two conditions of air/fuel mixture, lean and rich, by creating a delay in the sensing of the rate of transmission of oxygen through one of these layers (20,22). The method includes flowing exhaust gas over the sensor, maintaining essentially no flow of current through the leads when the exhaust gas maintains a state of rich or lean air/fuel ratio, and sensing induced emf spikes between the leads as the exhaust gas stream transitions between rich and lean air/fuel ratios.

Abstract: An air-to-fuel (A/F) ratio sensor includes an insulation layer, two solid electrolyte layers made of a porous composite ceramic formed at both sides of the insulation layer, each solid electrolyte layer having an internal electrode layer on its boundary surface with the insulation layer and an external electrode layer on its other surface, and a diffusion barrier layer made of a porous composite ceramic, covering one of the external electrode layers. The A/F ratio sensor provides a linear A/F ratio signal by controlling only a pumping current for a reference partial pressure of oxygen. Thus, the A/F ratio sensor operates by a simpler driving principle, thereby simplifying the driving circuit thereof.

Abstract: The present invention provides a gas sensor element having physical, electrical and chemical properties capable of detecting methane and carbon monoxide selectively with 1 intergrated filtering, catalyzing sensor by improving gas selectivity of the semiconductor gas sensor. The present invention relates to a gas sensor element, which has a carbon monoxide sensor layer with an ability to function as a catalyst film that blocks carbon monoxide, which impedes detection of methane, and has a layer-built structure where the surface of a methane sensor is covered with the carbon monoxide gas sensor which can be obtained by a gas-phase method.

Abstract: A sensor for determining the concentration of oxidizable constituents in a gas mixture includes a substrate which is planar and electrically insulating; a reference electrode which is positioned on a surface of the substrate and which catalyzes equilibrium adjustment of the gas mixture; a solid electrolyte which is ion-conducting and which is provided on at least the reference electrode; and at least one measuring electrode which is positioned on the ion-conducting solid electrolyte, which is one of not capable of catalyzing equilibrium adjustment of the gas mixture or is capable of catalyzing equilibrium adjustment of the gas mixture only to a small degree, which includes at least 50% of at least one of rutile and zirconium dioxide, and which is doped with acceptors and donors in which the acceptor contains at least one transition element, rare earth element, and mixtures thereof, and in which the donor is at least one of tantalum and niobium.

Abstract: There are proposed an air/fuel ratio sensor which can detect a wide range of an air/fuel ratio and provides a simple structure, a superior mechanical strength or durability and a reduced manufacture cost, and a method of detecting the air/fuel ratio using the air/fuel ratio sensor. An air/fuel ratio sensor 1 is formed of a detecting portion 2 and a heater portion 3 laminated via a porous body 16. In the detecting portion 2, on an inner face of a plate-like solid electrolytic body 5, a reference electrode 7 is provided for controlling an oxygen gas diffusion rate, and on an outer face of the solid electrolytic body 5, a measurement electrode 6 is provided. A surface of the measurement electrode 6, on which the diffusion rate is not controlled, is covered with a protective layer 14 having an ventilation property to a degree to which the diffusion rate is not substantially controlled. A lead portion 7b of the reference electrode 7 is a porous layer which substantially controls the diffusion rate.

Abstract: An oxygen sensor element includes a solid electrolyte having cavities on a surface thereof and an electrode formed on the surface of the solid electrolyte. In a method of producing the oxygen sensor element, a solution containing a noble metal compound for nucleus formation is first applied to an electrode forming portion of the solid electrolyte to form a coating film. Then, the coating film is heat-treated to form a nucleus forming portion where noble metal nuclei are deposited. Subsequently, metal plating is applied to the nucleus forming portion to form a plating film deeply entering the cavities. Thereafter, the plating film is burned to form the electrode deeply entering the cavities.

Abstract: An air-fuel ratio sensing element comprises a cup-shaped solid electrolyte with one end opened and the other end closed, an external electrode provided on an outer wall surface of the solid electrolyte so as to be exposed to measured gas, and an internal electrode provided on an inner wall surface of the solid electrolyte in a confronting relationship to the external electrode. A first insulating layer, made of a gas-permeable and nonconductive porous material, is provided on the external electrode at least in a region used for detecting of an air-fuel ratio. A second insulating layer is provided outside the first insulating layer and, a heater layer as provided between the first insulating layer and the second insulating layer.

Abstract: A gas sensor has a sensor cell unit which includes a detection member made up of an oxygen concentration cell, oxygen pump cell and a spacer interposed between the oxygen concentration cell and the oxygen pump cell to define therebetween a measurement gas chamber. The spacer has a pair of communicating holes for providing communication between the measurement gas chamber and the outside. Diffusion control layers made of porous material are formed within the communicating holes of the spacer so as to control flow of the detection gas into the measurement gas chamber, etc. The diffusion control layer is made of alumina and has on the outer surface thereof (i.e.

Abstract: A method of fabricating a sintered ceramic composite body having at last one hollow portion therein is disclosed. According to this method, at least one green ceramic body in the form of a sheet or plate and an adhesive sheet made of a ceramic powder and a binder resin are provided. The adhesive sheet is capable of adhering to the green ceramic body after drying and is shaped to provide a hollow portion in association with green ceramic body. The adhesion body and the green ceramic body are brought into intimate contact with each other so that a hollow portion is established therebetween. The resulting composite body is pressed and sintered to obtain a sintered ceramic composite body having the hollow portion therein. The binder preferably includes acrylic resin(s) and/or vinyl resin(s) having a molecular weight of 300,000 to 800,000 and a glass transition temperature of -30.degree. C. or below.

Abstract: A gas composition sensor for detecting oxygen, and hydrocarbon group fuel or combustible composition produced after combustion having a zirconia solid electrolyte body, a concentration cell composed of a platinoid metal catalytic detecting electrode and a reference electrode opposite to each other and a sensing element composed of a gas diffusion limiting member coating the detecting electrode, which further comprises a pair of the sensing elements and heaters for setting both of the sensing elements to operating temperatures different from each other, whereby a specified gas component is selectively detected by operating both of the sensing elements so as to have sensitivity coefficients to the specified gas component different from each other.

Abstract: A device for sensing ammonia (NH.sub.3) and nitrogen oxide (NO.sub.x) gases comprising: a sensor for detecting said ammonia and said nitrogen oxide gases, said sensor including a substrate and a layer consisting of cuprate material for detection of said ammonia and said nitrogen oxide gases, wherein said layer of cuprate material is selected from the group consisting of Y:Ba:Cu:O (YBCO) and Bi:Sr:Ca:Cu:O (BSCCO); a sensor holder for supporting said sensor; a perforated cap positioned over said sensor, said perforated cap having openings for passage of said ammonia and said nitrogen oxide gases to said sensor; a detection circuit communicating with said sensor for measuring output from said sensor; and a display or recording device connected to said detection circuit for displaying or recording a concentration of said ammonia and said nitrogen oxide gases based on the output from said sensor.

Abstract: A nitrogen oxide detecting sensor, according to the present invention, incorporates a gas detecting portion including, as a main component thereof, an oxide compound having electric conductivity or semiconductivity, the oxide compound having a crystal structure of 2212 phase and expressed generally as: Bi.sub.2 Sr.sub.2 (Ca.sub.1-x Y.sub.x)Cu.sub.2 O.sub.8.+-..delta. where 0.6.ltoreq.x<1; 0.ltoreq..delta..ltoreq.1. Electrodes are electrically connected to the gas detecting portion. When the gas detecting portion is analyzed by X-ray diffraction using cuK.alpha. rays to obtain diffraction peak values thereof in the range of a diffraction angle between 5.degree. and 65.degree., the diffraction peak values having a sum .SIGMA. I?2212! expressed by one of the following:(a) .SIGMA. I?2212!/.SIGMA. I?T!>88.1%(b) {.SIGMA. I?2212!+.SIGMA. I?2201!}/.SIGMA. I?T!>94.8%(c) {.SIGMA. I?2212!+.SIGMA. I?Y.sub.2 O.sub.3 !} .SIGMA. I?T!>88.1%(d) {.SIGMA. I?2212!+.SIGMA. I?(Bi, Ca) O!}/.SIGMA. I?T! >88.8%where .

Abstract: Oxygen sensor element (ZrO.sub.2 solid electrolyte etc) for detecting oxygen concentration in an exhaust gas has a protective layer which is made of a heat-resistant metal oxide and which carries a component of a IIa subgroup element (Ca, Mg etc) on the side exposed to the exhaust gas of the sensor element, at least a part of the protective layer being present as a nonstoichiometric compound (Ti oxide etc) with respect to the heat-resistant metal oxide. Si-poisoning is prevented. Heater for heating the sensor element is provided for preventing Si-poisoning at low temperatures.

Abstract: A self-contained, integrated-structure, miniature, electrochemical-type oxygen sensor is described which uses an oxygen ion conducting solid electrolyte. An encapsulated metal-metal oxide reference electrode on one surface of the solid electrolyte provides a reference oxygen pressure. A sensing electrode is placed on the other surface. The voltage developed between the reference electrode and the sensing electrode is indicative of the oxygen content of the fluid the sensing electrode is contacting.

Abstract: An insulation layer system, in particular for gas sensors, is proposed, having at least one electrically conductive solid-electrolyte layer (10), an electrically conductive layer (20) and at least one electrically insulating layer (13) between the solid-electrolyte layer (10) and the electrically conductive layer (20). The material of the insulating layer (13) contains, prior to sintering, pentavalent metal oxides of niobium or tantalum as an additive, it being possible for the additive to diffuse into the adjoining solid-electrolyte layer (10) during sintering.

Abstract: An oxygen concentration detecting device comprises a solid electrolyte body, inner and outer electrodes formed on the opposite sides of the solid electrolyte body, and a protective layer formed on the outer electrode and comprised of coarse particles and fine particles mutually bonded through an inorganic binder while substantially keeping the original forms of the both types of particles. A ratio of an average particle size, RB, of the coarse particles to an average particle size, RA, of the fine particles of 30:1 or above, and a content, WA, of the fine particles in the protective layer based on the total content, W, of the content, WA, of the fine particles and the content, WB, of the coarse particles on the weight basis is in the range of 15 to 80 %. A method for fabricating the detecting device having such a protective layer as set out above is also described.

Abstract: An exhaust gas sensor has first and second sensor elements. Exhaust gas surroundings of the first sensor element are catalytically activated, so that an oxygen partial pressure which is in equilibrium will always be measured by the first sensor element, regardless of the conversion capability of a catalytic converter. The exhaust gas surroundings of the second sensor element are separate from the exhaust gas surroundings of the first sensor element, so that the exhaust gas surroundings of the second sensor element are not catalytically active. As a function of the conversion capability of the catalytic converter, the second sensor element measures either an equilibrium oxygen partial pressure or a free oxygen partial pressure, which are of different magnitudes. A malfunction of the catalytic converter is detected by comparing measurement signals of the first and second sensor elements.

Abstract: Disclosed is a method and a sensing device capable of measuring a predetermined measurement gas component continuously and accurately with good response over a long period of time without being affected by a high oxygen concentration in a measurement gas. The measurement gas is introduced into a first processing zone. A first electrochemical pumping cell is used to lower a partial pressure of oxygen in an atmosphere thereof to a degree sufficient to control a partial pressure of oxygen in a subsequent second processing zone. The gas is introduced into the second processing zone. Oxygen in an atmosphere is pumped out by using a second electrochemical pumping cell so that the partial pressure of oxygen in the atmosphere is controlled to have a low value of partial pressure of oxygen which does not substantially affect measurement of an amount of the measurement gas component. The gas is introduced into a third processing zone.

Abstract: A planar air-to-fuel (A/F) ratio sensor and a driving circuit therefor are provided.

Abstract: An oxygen sensor element for detecting an oxygen concentration, the oxygen sensor includes a solid electrolyte; a porous film covering the solid electrolyte at the gas-measuring side; and a reaction electrode provided on the porous film; wherein the porous film includes ceramic particles and metallic particles, and the metallic particles are bonded with the reaction electrode by a metallic bond. In this way, the porous film includes the ceramic particles and the metallic particles to form an irregular surface, and the reaction electrode is adhered to the irregular surface of the porous film in such a manner that the electrode bites into the surface of the porous film. The metallic particles in the irregular surface of the porous film are tightly bonded to the reaction electrode by the metallic bond.

Abstract: A wide-range air fuel ratio oxygen sensor including a pump cell, a sensor cell, and a porous diffusion layer interposed between the pump cell and the sensor cell and a method for fabricating the oxygen sensor. The oxygen sensor generates output pumping current with a very small dispersion range of about .+-.2% by virtue of the activation effect of the catalyst such as Pt mixed into Al.sub.2 O.sub.3 of the porous diffusion layer.

Abstract: A measuring sensor for determining oxygen content in a gas mixture including exhaust gases of internal combustion engines, includes a base substrate which is comprised of a base material and which is electrically insulating; and an electrochemical measuring probe and an electrochemical reference probe arranged separate from each other on the base substrate. The measuring probe includes at least one internal electrode; at least one solid electrolyte island; and at least one external electrode. The measuring probe additionally includes a diffusion barrier. Further base material layers composed of the base material are provided so as to embed at least the diffusion barrier, the at least one internal electrodes for the measuring probe and the internal electrode for the reference probe. A diffusion hole is defined between the measuring probe and the reference probe which extends from the base substrate through the diffusion barrier and respective base material layers, and out to the gas mixture to be measured.

Abstract: a limiting current type oxygen concentration sensor element includes a measured gas side electrode formed at one side of a solid electrolyte, and a diffusion resistance portion formed on the measured gas side electrode to provide diffusion resistance to passing measured gas therein. The diffusion resistance portion includes a concave portion formed at a position at least corresponding to a position of the measured gas side electrode. In the concave portion, a porous trap layer is disposed to trap contamination in measured gas. The side wall of the concave portion contacts with the trap layer. The area of a contact surface becomes larger than that without the concave portion, which can effectively prevent the trap layer from being peeled off and dropping down. The trap layer can be easily made thicker. By changing the depth of the concave portion appropriately, diffusion resistance of the diffusion resistance portion can be easily adjusted.

Abstract: An air-fuel ratio detecting element is composed of an oxygen pump portion and an oxygen sensor portion which are provided on a single solid electrolyte sheet, a heating element, and a spacer. The oxygen pump portion is composed of a pair first of electrodes provided on opposite sides of the solid electrolyte sheet, and a communication hole which is formed through the solid electrolyte sheet and the electrodes. Electrodes are disposed on the solid electrolyte sheet on the same side as the second electrode, whereby the oxygen sensor portion is formed. The spacer has an opening and a slit-like opening. The heating element 4, the spacer, and the solid electrolyte sheet are stacked from bottom to top, and then the stacked assembly is baked. In this case, they are stacked such that the opening faces the first electrodes and the second electrode.

Abstract: The electrochemical sensor for determination of an oxygen content of exhaust gases, includes a probe element including a tube made from a raw material mixture consisting essentially of an ionically conductive solid electrolyte; an outer electrode located on the outer surface of the tube; a substantially pore-free conductor strip layer located on the outer surface, connected to the outer electrode, and extending toward the open end, the conductor strip layer having a portion in close proximity to the tube open end; and a substantially pore-free cover layer hermetically covering at least the portion of the pore-free conductor strip layer in close proximity to the open end of the tube, the cover layer being made from a cover layer material including the ionically conductive solid electrolyte. The cover layer material advantageously a sintering activity which is at least equal to that of the raw material mixture from which the tube is made.

Abstract: A limit current sensor for determining lambda values of a gas mixture includes a solid electrolyte layer comprised of a material which conducts oxygen ions; an anode provided on a surface of the solid electrolyte layer and having a surface opposite the solid electrolyte layer which is exposed to a gas which is one of the gas mixture being measured or a reference gas; a first pumping cell comprising the anode and a first cathode provided on a surface of the solid electrolyte layer opposite the anode; a second pumping cell comprising the anode and a second cathode provided on the surface of the solid electrolyte layer on which the first cathode is provided and spaced apart from the first cathode; a diffusion layer which is provided across the first cathode and the second cathode in contact therewith and along surfaces thereof opposite the solid electrolyte layer, and which is in communication with the gas mixture to be measured so that diffusion of the gas mixture to be measured through the diffusion layer occu

Abstract: An electrochemical sensor for determining the oxygen concentration in gas mixtures is proposed. The sensor has a solid electrolyte (10) with oxygen ionic conductivity, which has a measuring electrode (11) that does not catalyze establishment of equilibrium of the gas mixture and is exposed to the gas mixture. The measuring electrode (11) contains platinum and bismuth. The effect of these materials is that the free oxygen contained in the gas mixture is preferentially adsorbed, without reacting with the other gas components such as CO and HC.

Abstract: A thin-film gas sensor and manufacturing method of the same is disclosed which includes a silicon substrate; an insulating layer formed on the surface of the silicon substrate; a heater formed in zigzag on the surface of said insulating layer; a temperature sensor formed in zigzag on the surface of the insulating layer in parallel with the heater; an interlayer insulating layer for electrically insulating the heater and temperature sensor formed on the insulating layer; a plurality of electrodes formed on the interlayer insulating layer placed between the heater and temperature sensor; a plurality of pairs of gas sensing layers disposed in an array on the electrodes and for reacting on detected gas; and a plurality of gas shielding layers formed on one gas sensing layer out of the pair of gas sensing layers and for shielding the detected gas so that the gas sensing layers do not react on the detected gas.

Abstract: An oxygen concentration detector includes a one-end closed cylindrical oxygen sensing element having an inside electrode, outside electrode provided on the inner side and outer side respectively, an electrode protecting layer made up of ceramics porous member provided further outside the outside electrode, and a trap layer 1 of ceramics porous member having a surface roughness of 20 to 100 .mu.m measured according to a 10 point mean roughness measurement and provided outside the electrode protecting layer is employed. By dipping the to-be-detected gas side surface of an oxygen sensing element into a slurry with coarse heat-resisting metal oxide particles, 2 to 50 .mu.m in average grain size, dispersed, depositing the slurry on the surface of a protective layer of an oxygen sensor element, thereafter drying and baking the deposit, a porous poisonous substance trap layer, 10 to 500 .mu.m thick, is formed.

Abstract: A method and apparatus are disclosed for measuring atmospheric pressure in conjunction with an air-fuel ratio sensor of the type comprising a concentration cell with atmospheric air and exhaust electrodes on opposite sides of a solid-state electrolyte having oxygen ion conductivity. During an atmospheric pressure measuring cycle, oxygen ions are pumped from the atmospheric air electrode to the exhaust electrode, in a quantity which is either predetermined at a fixed value, or is sufficient to bring the cell to an equilibrium state. Atmospheric pressure is then calculated from measured emf of the cell, using an experimentally derived functional relationship. In a second embodiment, ions are pumped until a predetermined change of the concentration cell emf is achieved, and atmospheric pressure is determined based on the amount of time required to achieve such change. The atmospheric pressure measuring mode is operated on a time shared basis with the air-fuel ration detection mode.

Abstract: A device for temperature measurement at an oxygen probe, in particular a lambda probe, having a solid electrolyte arranged between two electrodes. At least one of the electrodes is provided with two spaced terminals for measuring an electrical resistance of the electrodes.

Abstract: A sensor system accurately measures nitrogen oxide (NO.sub.x) in a gas mixture via the use of at least one electrochemical sensing cell and differential pulse voltammetry (DPV). The sensor system has a sensor with an electrochemical sensing cell for producing an electrical signal (current, voltage, etc.) indicative of an amount of the nitrogen oxide within the gas mixture. The sensing cell has an electrolyte interposed between an anode electrocatalyst and a cathode electrocatalyst. Significantly, a DPV mechanism is connected to the sensing cell for enhancing the sensitivity and selectivity of the electrolyte associated with the sensing cell.

Abstract: An oxygen sensor element comprises a reference-gas-side electrode on one surface of a solid electrolyte having oxygen-ion conductivity, a detection-gas-side electrode on another surface, and a porous coated layer formed of a heat-resistant metal oxide formed on the surface of the detection-gas-side electrode, wherein at least a part of said coated layer is formed of a nonstoichiometric compound of transition metal (Ti, Co, Ni) oxide, and a portion formed of said nonstoichiometric compound carries a catalyst for equilibrating gas components of a detection gas. The catalyst (Pt, Rh) is 0.2-5 mole % relative to the portion formed of said nonstoichiometric compound. The coated layer may be thickened at the distal end portion.

Abstract: A planar polarographic sensor for determining the lambda value of gas mixtures, for use with exhaust gases in internal combustion engines, includes a planar ceramic carrier sheet having an outer pumping electrode and an inner pumping electrode respectively arranged on opposite planar sides thereof, and a diffusion barrier. The outer and inner pumping electrodes, and the diffusion barrier are arranged on the planar ceramic carrier sheet so that the measuring gas is fed via the diffusion barrier to the inner pumping electrode. The sensor has front and side edge faces. The diffusion barrier is configured as a diffusion layer at least partially covering the inner pumping electrode and exposed at least at one edge face of the sensor to the measuring gas. A diffusion-free planar region of the sensor is provided with an equalizing layer having the same thickness as the diffusion layer, and the equalizing layer is disposed in the same plane with and adjacent to the diffusion layer.

Abstract: An oxygen sensor has alumina porous layer on a surface of a solid electrolyte to cover electrodes and the alumina porous layer is simultaneously baked with the solid electrolyte. The alumina porous layer has baking contraction percentage which is the same range of the solid electrolyte. Alumina powder which is a starting material of the alumina porous layer includes 0.3 to 0.5 .mu.m of a 50% grain size, 0.4 to 1.1 .mu.m of a 70% grain size, and 0.8 to 4.0 .mu.m of a 90% grain size in a grain size distribution of weight integration frequency and further a specific surface area according to a BET method is approximately 8.5 to 11.0 m.sup.2 /g. It is preferable that the baking contraction percentages of the solid electrolyte and alumina porous layer are approximately 16 to 22%.

Abstract: An oxygen concentration detecting device has a solid electrolyte made of a partially stabilized zirconia on one face of which is formed a measuring electrode exposed to a gas to be measured and on the other face of which a standard electrode exposed to a standard gas. An oxygen concentration detecting device provided with a protecting layer covers the measuring electrode formed on the oxygen concentration detecting device on the face exposed to the gas to be measured, the protecting layer being made of a partially stabilized sintered material of a partially stabilized zirconia material having a specific surface area of not less than 3 m.sup.2 /g and not more than 6.4 m.sup.2 /g to which a divalent or trivalent metal oxide, such as yttria, is added.

Abstract: A layer system for electrochemical probes has a ceramic substrate, electrodes applied on the ceramic substrate, a sensor layer arranged over the electrodes, and a structure for improving adherence of the sensor layer to the substrate and including at least one adherence improving layer portion which is located under and extends upwardly into the sensor layer and also is sintered with the substrate.

Abstract: A sensor arrangement for determining at least one of gas components and gas concentrations of gas mixtures including CO, NO.sub.x and HC in exhaust gases of internal combustion engines, includes a measuring element which has a sensitive region; and a pump cell that includes a solid electrolyte and inner and outer pump electrodes which are opposingly disposed at least on the solid electrolyte and which effect an oxygen transfer to the measuring element, wherein the pump cell and the measuring element are spatially separated from one another, are located in different temperature zones during operation of the sensor arrangement, and are connected to one another by a diffusion segment through which oxygen can diffuse from the pump cell to the measuring element.

Abstract: The invention includes the use of a pre-equilibration zone on an exhaust gas sensor to provide catalytic site to catalyze non-reacted components of the exhaust gas prior to the gas sample reaching the sensor's outer electrode. The pre-equilibration zone preferably includes a precious metal on the surface of a porous carrier. The invention also includes a method of making an exhaust sensor including a pre-equilibration zone, and a method of sampling an exhaust gas by passing the same through a pre-equilibration zone.

Abstract: An electrochemical measuring probe for determining the oxygen content of gases, in particular of exhaust gases of internal combustion engines, whose measuring probe body consists essentially of a solid electrolyte, for example stabilised ZrO.sub.2 and whose electrode exposed to the gas to be measured is a cermet electrode which is coated with a finely porous ion-conducting covering layer composed of an ion-conducting supporting matrix material having no sintering activity of the type standard for cermet electrodes the covering layer is covered by a porous protective layer. The ion-conducting porous covering layer appreciably increases the activity of the cermet electrode.

Abstract: 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.

Abstract: A method and a sensor to measure the sulfur activity in sulfur-containing environments are disclosed. The active component is a non-stoichiometric metal sulfide foil or film. In the case of a thin sulfide film, a ceramic substrate is employed for improved mechanical rigidity. The electrical conductivity of the sulfide is related to the sulfur activity of the process stream to which it is exposed.

Abstract: A sensor for determining at least one of gas constituents and gas concentrations in a gas mixture, such as CO, NO.sub.x and HC, in exhaust gas from an internal combustion engine, includes a semiconductor gas sensor having a gas sensitive region in communication with the gas mixture; a pumping cell including a solid electrolyte carrier and pumping electrodes disposed on the solid electrolyte carrier, the pumping cell being positioned in communication with the semiconductor gas sensor for effecting oxygen transfer to the semiconductor gas sensor on the side thereof opposite the gas mixture by pumping oxygen thereto to provide an O.sub.

Abstract: A porous alumina coating layer covering an oxide semiconductor type or solid electrolyte type oxygen concentration sensor carrys a catalyst (Pt/Rh) for accelerating equilibration reaction of an unburnt gas in exhaust gas from an automobile engine. The deterioration of the catalyst activity can be prevented by incorporating a thermal stability improving agent into the alumina coating layer.

Abstract: Oxygen-sensor element comprises reference-gas-side and detection-gas-side electrodes on both surfaces of a solid-electrolyte body, and a porous protective layer on the surface of the detection-gas-side electrode, wherein at least a part (including at least a surface layer) of said porous protective layer is formed by a granular texture of a grain size of 0.1 to 0.5 .mu.m formed mainly of a nonstoichiometric compound of a transition metal oxide (TiO.sub.x), and a catalyst for having gas components of the gas to be measured react is carried in at least a part (including at least a surface layer) of the porous protective layer. Oxidation reaction of gas components is improved to prevent deterioration of the responsive property.

Abstract: An electrochemical measuring sensor is proposed for determining the oxygen content in exhaust gases which has a base body made of an ion-conducting solid electrolyte in the form of a tube closed at one end, an inner electrode, an outer electrode disposed on the external surface of the probe block and having a conductor track on the connection side which has a covering layer, a ceramic protective layer and a metallic sealing ring for sealing the reference space from the exhaust gas space and for making an electrical contact to the housing in which the measuring sensor is to be inserted. The electrochemical covering layer covering the conductor track is brought down on the reference side of the probe block to below the metallic sealing ring and the track is formed with uncovered lateral extensions making electrical contact with the ring. This makes it possible to significantly prolong the service life of the measuring sensor.