Abstract: On a cross sectional surface X1 of a pump electrode 3 in a gas sensor element forming a gas sensor, a noble metal area 31 having Pt—Au aggregations, a solid electrolyte area 32 having solid electrolyte aggregations, a mixture area in which Pt—Au alloy and solid electrolyte are distributed, and pores 34. The mixture area 33 is formed within a range of 30 to 90% in an overall area of the cross sectional surface X1, excepting the pores 34. The pores are formed adjacent to the mixture area 33.

Abstract: A gas sensor is equipped with a sensor element which detects a specific gas concentration within a gas that is being measured, a housing having the sensor element disposed in the interior thereof and retained therein, and an element cover disposed at an axial-direction tip end of the housing. The tip of the sensor element is provided with a gas introduction part. The element cover has an inner cover and an outer cover, with a space opened between the inner cover and outer cover. Inner side flow holes provided in the inner cover are disposed closer to an axial-direction base end than is a tapered-diameter step part. The distance between the tip of the sensor element and the inner-side flow holes of the inner cover, with respect to an axial direction, is less than or equal to 1.6 mm.

Abstract: A gas sensor includes a solid electrolyte, a gas chamber, a reference gas chamber, a pump cell, a monitor cell, and a sensor cell. The gas chamber has a spatial width W0 constant in a width direction W orthogonal to the direction of flow of a gas in a position where the pump electrode, the monitor electrode, and the sensor electrode are provided on the solid electrolyte. An amount of shift ?X1 of a central position O2 of a gap S in the width direction W between the monitor electrode and the sensor electrode from a central position O1 in the width direction of the pump electrode has relationship of ?X1?¼ W1 where the pump electrode has a width W1. In addition, positions ?Y1 of a of a side surface of the monitor electrode and of a side surface of the sensor electrode from the central position O1 in the width direction W of the pump electrode have relationship of ?Y1?½ W1.

Abstract: A gas sensor device is equipped with the sensor cell, the pump cell, the inner void space, and the gas inlet. The sensor cell is created by a portion of the solid electrolyte body and a pair of sensor electrodes disposed on the solid electrolyte body. The pump cell is created by a portion of the solid electrolyte body and a pair of pump electrodes disposed on the solid electrolyte body. The inner void space faces the sensor electrode and the pump electrode. If a dimension of said gas inlet in a direction in which the measurement gas flows in the gas inlet is defined as L1, a sectional area of the gas inlet taken perpendicular to the direction of flow of the measurement gas in the gas inlet is defined as S1, a distance between the gas inlet and the sensor cell is defined as L2, and a sectional area of the inner void space taken perpendicular to a direction in which the pump cell and the sensor cell are aligned with each other is defined as S2, a relation of 1000?(L1/S1)×(L2/S2)?5000 is met.

Abstract: A NOx sensor is provided which decreases a change rate of an oxygen ion current in a sensor electrode and shortens an activation time of the sensor electrode. The NOx sensor is equipped with a solid electrolyte body, a pump electrode working to regulate an oxygen concentration in measurement gas G, and a sensor electrode working to measure the concentration of NOx in the measurement gas G. A metallic component of the sensor electrode is a Pt—Rh alloy. The mass ratio of Pt to Rh in the whole of the sensor electrode is Pt:Rh=70:30 to 35:65. The percentage of Rh in the Pt—Rh alloy in a surface layer of the sensor electrode is higher than that in the whole of the sensor electrode by an atomic composition percentage of 4 to 10 atom %.

Abstract: Provided is a gas sensor element that can increase detection accuracy of a specific gas component concentration by means of a sensor cell by reflecting changes in the operating temperature of a gas sensor element. The gas sensor element is provided with a solid electrolyte body having oxygen ion conductivity, a heater stacked to the solid electrolyte body via a reference gas space, a pump cell adjusting oxygen concentration in a measuring gas space, a sensor cell detecting specific gas component concentration in the measuring gas space, and an electronic conduction detector cell detecting current resulting from electronic conduction due to the heater. The electronic conduction detector cell includes an electronic conductor electrode which is provided to a measuring gas side surface of the solid electrolyte body and covered with an insulator.

Abstract: A gas sensor is equipped with a sensor element which detects a specific gas concentration within a gas that is being measured, a housing having the sensor element disposed in the interior thereof and retained therein, and an element cover disposed at an axial-direction tip end of the housing. The tip of the sensor element is provided with a gas introduction part. The element cover has an inner cover and an outer cover, with a space opened between the inner cover and outer cover. Inner side flow holes provided in the inner cover are disposed closer to an axial-direction base end than is a tapered-diameter step part. The distance between the tip of the sensor element and the inner-side flow holes of the inner cover, with respect to an axial direction, is less than or equal to 1.6 mm.

Abstract: A gas sensor is provided which constitutes a pump cell 3 and a sensor cell 5 using a single solid electrolyte body 2, a pump electrode 30, a sensor electrode 50, and a reference electrode 80 and is designed to decrease power consumed by a heater and permit a size thereof to be reduced. A ratio of a minimum distance L2 between the pump electrode 30 and the sensor electrode 50 to a thickness d of the solid electrolyte body 2 is set to be three or more, thereby enabling the gas sensor 1 to make the pump cell 3 and the sensor cell 5 using the single solid electrolyte body 2, the pump electrode 30, the sensor electrode 50, and the reference electrode 80. Only either of the gas chamber or the reference gas chamber is, therefore, located between the solid electrolyte body and the heater, thereby decreasing distances of the pump cell and the sensor cell to the heater. This facilitates the ease with which the heater heats up the pump cell and the sensor cell.

Abstract: On a cross sectional surface X1 of a pump electrode 3 in a gas sensor element forming a gas sensor, a noble metal area 31 having Pt—Au aggregations, a solid electrolyte area 32 having solid electrolyte aggregations, a mixture area in which Pt—Au alloy and solid electrolyte are distributed, and pores 34. The mixture area 33 is formed within a range of 30 to 90% in an overall area of the cross sectional surface X1, excepting the pores 34. The pores are formed adjacent to the mixture area 33.

Abstract: A NOx sensor is provided which decreases a change rate of an oxygen ion current in a sensor electrode and shortens an activation time of the sensor electrode. The NOx sensor is equipped with a solid electrolyte body, a pump electrode working to regulate an oxygen concentration in measurement gas G, and a sensor electrode working to measure the concentration of NOx in the measurement gas G. A metallic component of the sensor electrode is a Pt—Rh alloy. The mass ratio of Pt to Rh in the whole of the sensor electrode is Pt:Rh=70:30 to 35:65. The percentage of Rh in the Pt—Rh alloy in a surface layer of the sensor electrode is higher than that in the whole of the sensor electrode by an atomic composition percentage of 4 to 10 atom %.

Abstract: A gas sensor device is equipped with the sensor cell, the pump cell, the inner void space, and the gas inlet. The sensor cell is created by a portion of the solid electrolyte body and a pair of sensor electrodes disposed on the solid electrolyte body. The pump cell is created by a portion of the solid electrolyte body and a pair of pump electrodes disposed on the solid electrolyte body. The inner void space faces the sensor electrode and the pump electrode. If a dimension of said gas inlet in a direction in which the measurement gas flows in the gas inlet is defined as L1, a sectional area of the gas inlet taken perpendicular to the direction of flow of the measurement gas in the gas inlet is defined as S1, a distance between the gas inlet and the sensor cell is defined as L2, and a sectional area of the inner void space taken perpendicular to a direction in which the pump cell and the sensor cell are aligned with each other is defined as S2, a relation of 1000?(L1/S1)×(L2/S2)?5000 is met.

Abstract: Provided is a gas sensor element that can increase detection accuracy of a specific gas component concentration by means of a sensor cell by reflecting changes in the operating temperature of a gas sensor element. The gas sensor element is provided with a solid electrolyte body having oxygen ion conductivity, a heater stacked to the solid electrolyte body via a reference gas space, a pump cell adjusting oxygen concentration in a measuring gas space, a sensor cell detecting specific gas component concentration in the measuring gas space, and an electronic conduction detector cell detecting current resulting from electronic conduction due to the heater. The electronic conduction detector cell includes an electronic conductor electrode which is provided to a measuring gas side surface of the solid electrolyte body and covered with an insulator.

Abstract: A gas sensor includes a solid electrolyte, a gas chamber, a reference gas chamber, a pump cell, a monitor cell, and a sensor cell. The gas chamber has a spatial width W0 constant in a width direction W orthogonal to the direction of flow of a gas in a position where the pump electrode, the monitor electrode, and the sensor electrode are provided on the solid electrolyte. An amount of shift ?X1 of a central position O2 of a gap S in the width direction W between the monitor electrode and the sensor electrode from a central position O1 in the width direction of the pump electrode has relationship of ?X1?¼ W1 where the pump electrode has a width W1. In addition, positions ?Y1 of a of a side surface of the monitor electrode and of a side surface of the sensor electrode from the central position O1 in the width direction W of the pump electrode have relationship of ?Y1?½ W1.

Abstract: A gas sensor is provided which constitutes a pump cell 3 and a sensor cell 5 using a single solid electrolyte body 2, a pump electrode 30, a sensor electrode 50, and a reference electrode 80 and is designed to decrease power consumed by a heater and permit a size thereof to be reduced. A ratio of a minimum distance L2 between the pump electrode 30 and the sensor electrode 50 to a thickness d of the solid electrolyte body 2 is set to be three or more, thereby enabling the gas sensor 1 to make the pump cell 3 and the sensor cell 5 using the single solid electrolyte body 2, the pump electrode 30, the sensor electrode 50, and the reference electrode 80. Only either of the gas chamber or the reference gas chamber is, therefore, located between the solid electrolyte body and the heater, thereby decreasing distances of the pump cell and the sensor cell to the heater. This facilitates the ease with which the heater heats up the pump cell and the sensor cell.