Abstract: A gas sensor includes an element body, an inner main pump electrode, an inner auxiliary pump electrode, an inner preliminary pump electrode, a measurement electrode, a reference electrode, a measurement voltage detection device, a specific gas concentration detection device. The inner preliminary pump electrode, the inner main pump electrode, the inner auxiliary pump electrode and the measurement electrode include each contain a noble metal having catalytic activity. At least one of the inner preliminary pump electrode and the inner main pump electrode contains no noble metal having a catalytic activity suppression ability, the catalytic activity suppression ability being an ability to suppress the catalytic activity of the noble metal having the catalytic activity from being exhibited to the specific gas. The inner auxiliary pump electrode contains a noble metal having the catalytic activity suppression ability.

Abstract: A gas sensor includes an element body, an adjustment pump cell, a preliminary pump cell, a measurement electrode, a reference electrode, a specific gas concentration detection device. The element body provides a measurement-object gas flow section to allow a measurement-object gas to be introduced into and flow through the measurement-object gas flow section. The adjustment pump cell adjusts an oxygen concentration of an oxygen concentration adjustment chamber in the measurement-object gas flow section. The preliminary pump cell pumps oxygen into a preliminary chamber to prevent the measurement-object gas in a low-oxygen atmosphere from reaching the oxygen concentration adjustment chamber, the preliminary chamber being provided upstream of the oxygen concentration adjustment chamber in the measurement-object gas flow section.

Abstract: A gas sensor includes a structural body made up from a solid electrolyte that exhibits oxygen ion conductivity, a gas introduction port formed in the structural body, a preliminary chamber communicating with the gas introduction port and equipped with a preliminary pump electrode, a main chamber communicating with the preliminary chamber and equipped with a main pump electrode, and a measurement chamber communicating with the main chamber and equipped with a measurement electrode. In the gas sensor, at least a surface of the preliminary pump electrode is made of a material which exhibits a low activity with respect to a reaction between ammonia and oxygen.

Abstract: A gas sensor, and a method for measuring the concentrations of a plurality of target components in a gas to be measured are disclosed. The gas sensor is provided with: a specific component measurement means which measures the concentration of a specific component in a measurement chamber; a preliminary oxygen concentration control means which controls the oxygen concentration in a preliminary adjustment chamber; a drive control means which controls the driving and stopping of the preliminary oxygen concentration control means; and a target component acquisition means which, on the basis of the difference between sensor outputs from the specific component measurement means when the preliminary oxygen concentration control means is being driven and when the preliminary oxygen concentration control means is stopped, and one of the respective sensor outputs, acquires the concentrations of a first target component and a second target component.

Abstract: A gas sensor includes a laminated body constituted by at least two ceramic layers laminated thereon, and having at least one gas introduction port, and at least one internal vacancy, and an outer side electrode formed on the laminated body, and provided in order to discharge oxygen from the internal vacancy, wherein a slit portion connected to an external space, and which is formed in the laminated body in covering relation to the outer side electrode, is interposed between the ceramic layers and the outer side electrode.

Abstract: A gas sensor is capable of measuring the concentrations of each of a plurality of target components in a gas being measured. The gas sensor has a sensor element, and one or more processors configured to control an oxygen concentration and to acquire a target component concentration. The oxygen concentration is controlled in a first chamber and a second chamber of a first sensor cell, and the oxygen concentration is also controlled in a second chamber of a second sensor cell. The concentration of a second target component is acquired on the basis of a difference ?Ip between a first pump current value and a second pump current value, and the concentration of a first target component is acquired by subtracting the concentration of the second target component from the second pump current value (total concentration).

Abstract: A gas sensor, and a method for measuring the concentrations of a plurality of target components in a gas to be measured are disclosed. The gas sensor is provided with: an oxygen concentration control means for controlling the oxygen concentration in an oxygen concentration adjustment chamber; a temperature control means for controlling the temperature of a sensor element; a condition setting means which sets the oxygen concentration of the oxygen concentration adjustment chamber and/or the temperature of the sensor element to conditions corresponding to the types of target components in the introduced gas to be measured; and a concentration calculation means which calculates the concentrations of the different target components on the basis of the respective sensor outputs obtained under the plurality of conditions corresponding to the types of target components.

Abstract: A first gas sensor includes a main pump cell that pumps oxygen inside a main oxygen concentration adjustment chamber, by applying a main pump voltage between a main interior side electrode and an exterior side electrode, and causing a main pump current to flow, a preliminary pump cell that pumps the oxygen inside a preliminary adjustment chamber by applying a preliminary pump voltage between an interior side preliminary electrode and the exterior side electrode, and causing a preliminary pump current to flow, and a constant control unit that controls the preliminary pump voltage of the preliminary pump cell in a manner so that the main pump current of the main pump cell becomes constant.

Abstract: An exhaust gas purification system and an exhaust gas purification method are disclosed. The exhaust gas purification system is provided with: an injector for injecting urea water, said injector being installed between a combustion device and a selective catalytic reduction (SCR) catalyst; a first gas sensor which is installed downstream of the SCR catalyst, and which detects the NO concentration and the NH3 concentration in exhaust gas outputted from the SCR catalyst; and an opening amount control means for controlling the opening amount of the injector for injecting urea water.

Abstract: A gas sensor is capable of measuring the concentrations of each of a plurality of target components in a gas being measured. The gas sensor has a sensor element, and one or more processors configured to control an oxygen concentration and to acquire a target component concentration. The oxygen concentration is controlled in a first chamber and a second chamber of a first sensor cell, and the oxygen concentration is also controlled in a second chamber of a second sensor cell. The concentration of a second target component is acquired on the basis of a difference AIp between a first pump current value and a second pump current value, and the concentration of a first target component is acquired by subtracting the concentration of the second target component from the second pump current value (total concentration).

Abstract: A gas sensor includes an element body, an inner main pump electrode, an inner auxiliary pump electrode, an inner preliminary pump electrode, a measurement electrode, a reference electrode, a measurement voltage detection device, a specific gas concentration detection device. The inner preliminary pump electrode, the inner main pump electrode, the inner auxiliary pump electrode and the measurement electrode include each contain a noble metal having catalytic activity. At least one of the inner preliminary pump electrode and the inner main pump electrode contains no noble metal having a catalytic activity suppression ability, the catalytic activity suppression ability being an ability to suppress the catalytic activity of the noble metal having the catalytic activity from being exhibited to the specific gas. The inner auxiliary pump electrode contains a noble metal having the catalytic activity suppression ability.

Abstract: A gas sensor includes an element body, an adjustment pump cell, a preliminary pump cell, a measurement electrode, a reference electrode, a specific gas concentration detection device. The element body provides a measurement-object gas flow section to allow a measurement-object gas to be introduced into and flow through the measurement-object gas flow section. The adjustment pump cell adjusts an oxygen concentration of an oxygen concentration adjustment chamber in the measurement-object gas flow section. The preliminary pump cell pumps oxygen into a preliminary chamber to prevent the measurement-object gas in a low-oxygen atmosphere from reaching the oxygen concentration adjustment chamber, the preliminary chamber being provided upstream of the oxygen concentration adjustment chamber in the measurement-object gas flow section.

Abstract: A first gas sensor includes a main pump cell that pumps oxygen inside a main oxygen concentration adjustment chamber, by applying a main pump voltage between a main interior side electrode and an exterior side electrode, and causing a main pump current to flow, a preliminary pump cell that pumps the oxygen inside a preliminary adjustment chamber by applying a preliminary pump voltage between an interior side preliminary electrode and the exterior side electrode, and causing a preliminary pump current to flow, and a constant control unit that controls the preliminary pump voltage of the preliminary pump cell in a manner so that the main pump current of the main pump cell becomes constant.

Abstract: A gas sensor includes a structural body made up from a solid electrolyte that exhibits oxygen ion conductivity, a gas introduction port formed in the structural body, a preliminary chamber communicating with the gas introduction port and equipped with a preliminary pump electrode, a main chamber communicating with the preliminary chamber and equipped with a main pump electrode, and a measurement chamber communicating with the main chamber and equipped with a measurement electrode. In the gas sensor, at least a surface of the preliminary pump electrode is made of a material which exhibits a low activity with respect to a reaction between ammonia and oxygen.

Abstract: A gas sensor, and a method for measuring the concentrations of a plurality of target components in a gas to be measured are disclosed. The gas sensor is provided with: an oxygen concentration control means for controlling the oxygen concentration in an oxygen concentration adjustment chamber; a temperature control means for controlling the temperature of a sensor element; a condition setting means which sets the oxygen concentration of the oxygen concentration adjustment chamber and/or the temperature of the sensor element to conditions corresponding to the types of target components in the introduced gas to be measured; and a concentration calculation means which calculates the concentrations of the different target components on the basis of the respective sensor outputs obtained under the plurality of conditions corresponding to the types of target components.

Abstract: An exhaust gas purification system and an exhaust gas purification method are disclosed. The exhaust gas purification system is provided with: an injector for injecting urea water, said injector being installed between a combustion device and a selective catalytic reduction (SCR) catalyst; a first gas sensor which is installed downstream of the SCR catalyst, and which detects the NO concentration and the NH3 concentration in exhaust gas outputted from the SCR catalyst; and an opening amount control means for controlling the opening amount of the injector for injecting urea water.

Abstract: A gas sensor, and a method for measuring the concentrations of a plurality of target components in a gas to be measured are disclosed. The gas sensor is provided with: a specific component measurement means which measures the concentration of a specific component in a measurement chamber; a preliminary oxygen concentration control means which controls the oxygen concentration in a preliminary adjustment chamber; a drive control means which controls the driving and stopping of the preliminary oxygen concentration control means; and a target component acquisition means which, on the basis of the difference between sensor outputs from the specific component measurement means when the preliminary oxygen concentration control means is being driven and when the preliminary oxygen concentration control means is stopped, and one of the respective sensor outputs, acquires the concentrations of a first target component and a second target component.

Abstract: A gas sensor element, wherein an amount of flexure in a first section extending in a longitudinal direction of the sensor element from the position 8/27 of a size of the element apart from one end of the element to the other end, is set to be greater than or equal to 1/1360 and less than or equal to 1/670 with respect to the size in the longitudinal direction of the element. The amount of flexure is a sum of a distance from a regression line to an upper side maximum displacement point and a distance from the regression line to a lower side maximum displacement point when calculating the regression line representing the relation of the position X in the longitudinal direction of the element and the displacement Y in a thickness direction from a plurality of data sets showing the relation of position X and displacement Y.

Abstract: A gas sensor contains a sensor element for detecting the concentration of a particular gas component in a measurement gas and a housing for supporting the sensor element inside, and the sensor element has a rectangular solid structure of a solid electrolyte body containing a ceramic material. In the gas sensor, four edges of the solid electrolyte body are beveled over the entire length thereof to form eleventh to fourteenth chamfered portions corresponding to the four edges.

Abstract: A gas sensor and nitrogen oxide sensor, which, when fitted to the exhaust system of an internal combustion engine, can suppress the influence of harmful substances contained in a measurement gas and can prevent the reduction in sensitivity over time. A harmful substance-trapping layer is formed at a gas inlet for introducing a to-be-measured gas from an external space into an internal space, and in a buffering space formed between diffusion resistance portions. In a trap-formed portion of a gas passage in which the harmful substance-trapping layer is formed, the measurement gas can pass in an amount of 80% or more of when the harmful substance-trapping layer is not formed in the trap-formed portion. A diffusion resistance is attained in the diffusion resistance portions; a harmful substance is trapped in the harmful substance-trapping layer; and the measurement gas is allowed to flow into a detection electrode side.