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: 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: 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.