Abstract: An exhaust sensor comprises a sensing electrode and a reference electrode each in contact with an electrolyte. At least one of the sensing electrode and the reference electrode are formed by depositing an electrode precursor material on an electrolyte precursor material and sintering the combination at a sufficient temperature for a sufficient time to achieve densification of the electrolyte, wherein the electrode precursor material comprises an alkali salt. Electrode patterns having enhanced perimeter ratios are also disclosed. The resulting exhaust sensor is capable of providing a usable output at a reduced operating temperature.

Abstract: A sensor element includes a substrate (10) having a coating (31) on a portion of the substrate (10). The coating (31) is applied to the substrate (10) by dipping the portion of the substrate (10) into a slurry which includes a pulverized mineral and water, extracting the substrate (10) from the slurry in a direction along an axis, drying the coated substrate (10), and firing the coated substrate (10) so as to promote densification of the mineral and adhesion of the mineral to the substrate (10). The coating (31) after firing has a minimum thickness of about 100 microns at every location around the periphery of a cross section through the substrate (10) taken in a plane normal to the axis. A method for making a coated sensor element is also disclosed.

Abstract: A sensor element includes a substrate having a coating on a portion of the substrate. The coating is applied to the substrate by dipping the portion of the substrate into a slurry which includes a pulverized mineral and water, extracting the substrate from the slurry in a direction along an axis, drying the coated substrate, and firing the coated substrate so as to promote densification of the mineral and adhesion of the mineral to the substrate. The coating after firing has a minimum thickness of about 100 microns at every location around the periphery of a cross section through the substrate taken in a plane normal to the axis. A method for making a coated sensor element is also disclosed.

Abstract: A planar device includes a heating circuit that is disposed between ceramic layers and co-fired with the ceramic. The heating circuit comprises palladium, and the co-firing of the palladium and ceramic is performed in an oxidizing atmosphere. The formation of defects in the planar device that would otherwise be induced as a result of the palladium oxidizing during the co-firing process is prevented by control of the firing profile, by the geometry of the pattern of the heating circuit, and/or by modifying the palladium to reduce its tendency to oxidize.

Abstract: An exhaust sensor comprises a sensing electrode and a reference electrode each in contact with an electrolyte. At least one of the sensing electrode and the reference electrode are formed by depositing an electrode precursor material on an electrolyte precursor material and sintering the combination at a sufficient temperature for a sufficient time to achieve densification of the electrolyte, wherein the electrode precursor material comprises an alkali salt. Electrode patterns having enhanced perimeter ratios are also disclosed. The resulting exhaust sensor is capable of providing a usable output at a reduced operating temperature.

Abstract: An exhaust gas sensing system and a method for determining concentrations of exhaust gas constituents are provided. The exhaust gas sensing system includes a NH3 sensing cell, a NO2 sensing cell, a NOx pumping cell, and a current sensor that detects an electrical current flowing through the NOx pumping cell. A computer determines a NO2 concentration value, a NH3 concentration value, a NO concentration value, and a NOx concentration value based on signals from the NH3 sensing cell, the NO2 sensing cell, and the current sensor.

Abstract: An exhaust gas sensor and a method for determining concentrations of exhaust gas constituents are provided. The exhaust gas sensor includes a NO2 Nernst cell that generates a first voltage indicative of a NO2 concentration in the exhaust gases communicating with the NO2 sensing electrode. The exhaust gas sensor further includes a NOx Nernst cell that generates a second voltage indicative of a NOx concentration in the exhaust gases communicating with the NOx sensing electrode. The exhaust gas sensor further includes a NH3 Nernst cell that generates a third voltage indicative of a NH3 concentration in the exhaust gases communicating with the NH3 sensing electrode.

Abstract: One embodiment of an ammonia gas sensor includes: a reference electrode, an ammonia selective sensing electrode and an electrolyte disposed therebetween. The sensing electrode comprises the reaction product of a main material selected from the group consisting of vanadium, tungsten, molybdenum, vanadium oxides, tungsten oxides, molybdenum oxides, and combinations comprising at least one of the foregoing main materials, and an electrically conducting material selected from the group consisting of electrically conductive metals, electrically conductive metal oxides, and combinations comprising at least one of the foregoing.

Abstract: An exhaust gas sensing system and a method for determining concentrations of exhaust gas constituents are provided. The exhaust gas sensing system includes a NH3 sensing cell, a NO2 sensing cell, a NOx pumping cell, and a current sensor that detects an electrical current flowing through the NOx pumping cell. A computer determines a NO2 concentration value, a NH3 concentration value, a NO concentration value, and a NOx concentration value based on signals from the NH3 sensing cell, the NO2 sensing cell, and the current sensor.

Abstract: An exhaust gas sensor and a method for determining concentrations of exhaust gas constituents are provided. The exhaust gas sensor includes a NO2 Nernst cell that generates a first voltage indicative of a NO2 concentration in the exhaust gases communicating with the NO2 sensing electrode. The exhaust gas sensor further includes a NOx Nernst cell that generates a second voltage indicative of a NOx concentration in the exhaust gases communicating with the NOx sensing electrode. The exhaust gas sensor further includes a NH3 Nernst cell that generates a third voltage indicative of a NH3 concentration in the exhaust gases communicating with the NH3 sensing electrode.

Abstract: Disclosed herein is an ammonia sensor element comprising an ammonia selective sensor electrode, a reference electrode, a solid electrolyte in ionic communication with the ammonia selective sensor electrode and the reference electrode, and a protective layer disposed on the ammonia selective sensor electrode, comprising a porous portion comprising an ammonia-inert material. A method of making an ammonia gas sensor element comprises disposing an ammonia selective sensor electrode on and in ionic communication with a solid electrolyte, disposing a reference electrode on and in ionic communication with the solid electrolyte, and disposing a protective layer comprising a porous portion comprising an ammonia-inert material on the ammonia selective sensor electrode.

Abstract: Disclosed herein is a method of making a gas sensor element, comprising calcining a NOx sensor electrode material at a NOx sensor electrode material calcination temperature of about 1200 to about 1600° C. to form a calcined NOx sensor electrode material, disposing the calcined NOx sensor electrode material on a substrate to form a substrate comprising a NOx sensor electrode, and firing the substrate comprising the NOx sensor electrode at a gas sensor element firing temperature to form a gas sensor element comprising a NOx sensor electrode. Also disclosed is a gas sensor comprising the gas sensor element.

Abstract: Soot sensing systems and soot sensors are provided. In one exemplary embodiment, a soot sensor includes a non-conductive substrate and a first electrode disposed on the non-conductive substrate. The soot sensor further includes a second electrode disposed on the non-conductive substrate and spaced away from the first electrode. The soot sensor further includes a first protective layer disposed over at least a portion of the first electrode. The soot sensor further includes a second protective layer disposed over at least a portion of the second electrode. Further, an electrical parameter between the first and second electrodes is indicative of an amount of soot disposed on the non-conductive substrate between the first and second electrodes.

Abstract: A conductive shield for routing mobile ions to contact pad in accordance with an exemplary embodiment is provided. The conductive shield includes a first conductive path electrically coupled to the contact pad. The conductive shield further includes a second conductive path electrically coupled to first and second locations on the first conductive path such that when a physical break occurs in the first conductive path between the first and second locations, mobile ions in the first conductive path are still routed to the contact pad through the second conductive path.

Abstract: Disclosed herein are NOx sensors and methods of using the same. In one embodiment, a method for sensing NOx comprises: contacting a first NOx electrode with the gas, contacting a second NOx electrode with the gas, determining a NO2 emf between the first NOX electrode and a first reference electrode, determining a NOx emf between the second NOx electrode and a second reference electrode, and determining a NO2 concentration and a NO concentration using the NO2 emf and the NOx emf. The first electrode can be at a first temperature of greater than or equal to about 700° C., and the second electrode can be at a second temperature of about 500° C. to about 650° C.

Abstract: A method for manufacturing a planar sensor, comprises disposing a film of a material on a substrate, wherein the material is selected from the group consisting of platinum, rhodium, palladium and mixtures and alloys comprising at least one of the foregoing materials; annealing the material; measuring a resistance value of the material; laser trimming the annealed material; heat treating the laser trimmed material; and laser trimming the heat treated material to form the sensor.

Abstract: In a planar oxygen sensor having a pump cell, a reference cell, a sensor chamber and a heating device, a ground plane electrode is provided and includes a sensing portion having a first sense lead and a second sense lead and a measuring portion having a first measuring lead and a second measuring lead, wherein the first measuring lead and the second measuring lead have increased surface area relative to said sensing portion such that the resistance between the first measuring lead and the second measuring lead is reduced and wherein the first measuring lead is disposed so as to be communicated with the first sense lead and the second measuring lead is disposed so as to be communicated with the second sense lead.

Abstract: A sensor may comprise a first electrode and a second electrode in mutual ionic communication with an electrolyte, a first socket disposed near a rear portion of a sensor element, a first lead disposed in electrical communication with the first electrode and in physical contact with the first socket and configured for electrical communication with a first terminal element, a second socket disposed near the rear portion of the sensor element, and a second lead disposed in electrical communication with the second electrode and in physical contact with the second socket and configured for electrical communication with a second terminal element. The first socket is disposed through at least one of an edge and an end of the sensor element, and the second socket is disposed through at least one of the edge and the end of the sensor element.

Abstract: One embodiment of an ammonia gas sensor includes: a reference electrode, an ammonia selective sensing electrode and an electrolyte disposed therebetween. The sensing electrode comprises the reaction product of a main material selected from the group consisting of vanadium, tungsten, molybdenum, vanadium oxides, tungsten oxides, molybdenum oxides, and combinations comprising at least one of the foregoing main materials, and an electrically conducting material selected from the group consisting of electrically conductive metals, electrically conductive metal oxides, and combinations comprising at least one of the foregoing.

Abstract: A sensor comprises: a pump cell comprising an inner pump electrode, an outer pump electrode, a pump cell electrolyte layer interposed between the inner pump electrode and the outer pump electrode and a cell isolation layer disposed on the inner pump electrode on a side opposite the pump cell electrolyte, wherein the outer electrode is in fluid communication with a reducing gas. A reference cell is in operable communication with the pump cell, the reference cell comprising an outer reference electrode and an inner reference electrode, and a reference cell electrolyte interposed between the outer reference electrode and the inner reference electrode.