Abstract: The gas sensor includes a gas sensor element, a casing, and an insulating inner member contained inside the casing. The gas sensor element includes a detection element and a heater. The detection element includes one or more cells each having a solid electrolyte body and a pair of electrodes. Each of the opposite side surfaces of the detection element includes a region including a smallest current cell and extending forward of the smallest current cell in the direction of an axial line. The region and the forward-facing surface of the detection element are covered with a glass coating having a glass transition point of higher than 700° C. but not higher than 800° C. and a porosity of 3.0% or less. The detection element is controlled to have a temperature equal to or lower than the glass transition point of the glass coating.

Abstract: The gas sensor includes a gas sensor element, a casing, and an insulating inner member contained inside the casing. The gas sensor element includes a detection element and a heater. The detection element includes one or more cells each having a solid electrolyte body and a pair of electrodes. Each of the opposite side surfaces of the detection element includes a region including a smallest current cell and extending forward of the smallest current cell in the direction of an axial line. The region and the forward-facing surface of the detection element are covered with a glass coating having a glass transition point of higher than 700° C. but not higher than 800° C. and a porosity of 3.0% or less. The detection element is controlled to have a temperature equal to or lower than the glass transition point of the glass coating.

Abstract: A gas sensor unit includes a gas sensor and a control unit. The gas sensor unit includes: a first oxygen pump cell having a pair of electrodes and controlling the oxygen concentration; a second oxygen pump cell controlling the oxygen concentration; and a sensor cell that detects the concentration of a specific gas component in a measurement target gas. The control unit is electrically connected to the gas sensor and sets a voltage between the pair of electrodes of the first oxygen pump cell to a predetermined set value, and performs energization control to control the introduction or discharge of oxygen while changing a voltage applied between a pair of electrodes of the second oxygen pump cell so that an oxygen pump current of the first oxygen pump cell is maintained within a predetermined range of IL?I?IH.

Abstract: In a gas sensor element of a gas sensor, reference oxygen chamber (113) assumes the shape of a rectangular parallelepiped. A reference electrode (111) is disposed on a surface of a third solid electrolyte body (73) which is exposed to the reference oxygen chamber (113). A second outer electrode (117) is disposed opposite the reference electrode, on a surface of a second solid electrolyte body (77) which is exposed to the reference oxygen chamber. Further, a porous, insulative protection layer (165) is formed so as to cover the entire surface of the second outer electrode. A gap (167) is present between the reference electrode and the insulative protection layer. The thickness of the gap is greater than that of the insulative protection layer.

Abstract: A gas sensor includes a gas sensor element. The gas sensor element includes a first detection chamber; a first oxygen pumping cell including a first solid electrolyte body and a pair of first electrodes; a second detection chamber; a second oxygen pumping cell including a second solid electrolyte body and a pair of second electrodes; and an oxygen-concentration sensing cell including a third solid electrolyte body and a pair of third electrodes. A sensing electrode of the third electrodes is disposed downstream beyond a first inner electrode of the first electrodes relative to a gas flow direction. A cross-sectional area of a space of the first detection chamber which faces the first inner electrode falls within a range from 0.03 mm2 to 0.22 mm2.

Abstract: A gas sensor including a gas sensor element having a first measurement chamber (16); a first pumping cell (11); a second measurement chamber (18) into which a gas to be measured having a controlled oxygen partial pressure is introduced; and a second pumping cell (13) having a second inner pump electrode (13b) and a second counterpart electrode (13c) pump electrode configured to detect a specific gas component. The second inner pump electrode is made of a material that contains, as a principal ingredient, two kinds of Pt particles having different particle sizes and whose particle size ratio measured by a sedimentation particle-size distribution ranges from 1.75 to 14.2. A mixing ratio between large Pt particles and small Pt particles has a mass ratio of 10/90 to 50/50. A 10 kHz-1 Hz resistance value across the second pumping cell at 600° C. is 150? or less.

Abstract: In a gas sensor element of a gas sensor, reference oxygen chamber (113) assumes the shape of a rectangular parallelepiped. A reference electrode (111) is disposed on a surface of a third solid electrolyte body (73) which is exposed to the reference oxygen chamber (113). A second outer electrode (117) is disposed opposite the reference electrode, on a surface of a second solid electrolyte body (77) which is exposed to the reference oxygen chamber. Further, a porous, insulative protection layer (165) is formed so as to cover the entire surface of the second outer electrode. A gap (167) is present between the reference electrode and the insulative protection layer. The thickness of the gap is greater than that of the insulative protection layer.

Abstract: A gas sensor controller 190 stops an operation of pumping in or out oxygen that is being performed by a first pump cell 111 in a state that the oxygen concentration (oxygen partial pressure) of a gas to be measured is equal to a status judgment reference value (20%). The gas sensor controller 190 calculates an oxygen pressure in a second measurement chamber 161 on the basis of a second pump current Ip2. If the oxygen pressure in the second measurement chamber 161 is equal to a deterioration judgment reference value, the gas sensor controller 190 judges that the second pump cell 113 is in a normal state. If the oxygen pressure in the second measurement chamber 161 is different from the deterioration judgment reference value, the gas sensor controller 190 judges that the second pump cell 113 is in a deteriorated state.

Abstract: A gas sensor (200) has a gas sensor element (10) including a first measurement chamber (16); a first pumping cell (11) having a first interior pump electrode (11c) and its counterpart electrode (11b); a second measurement chamber (18); a second pumping cell (13) that has a second interior pump electrode (13b); and a beater (50). The heater (50) has a lead section (50a); a first resistance portion (50bx) having a higher resistance than the lead portion (50a); and a main heating portion (50k) having a second resistance portion (50by) having a higher resistance than the first resistance portion (50bx) disposed at a leading end side in a longitudinal direction relative to a leading end of the first resistance portion (50bx). The second interior pump electrode (13b) is located within the first resistance portion (50bx) in the longitudinal direction.

Abstract: A sensor element having a plate-like shape and extending in a longitudinal direction and having a chamfered portion at an edge between a main surface and a rear-end surface or between a main surface and a side surface of the sensor element. The sensor element includes a solid electrolyte layer, an insulating layer disposed on the solid electrolyte layer and constituting at least part of the main surface, and an electrode pad disposed away from the chamfered portion for connection to an outside circuit. Furthermore, the solid electrolyte layer and the insulating layer are exposed at the chamfered portion. Also disclosed are a gas sensor including the sensor element and a method of manufacturing the sensor element.

Abstract: A sensor element including: a first solid electrolyte layer as defined herein; and a second solid electrolyte layer as defined herein, wherein the first solid electrolyte layer includes a first inner insulating layer, a first outer insulating layer, a first inner conductive layer and a first outer conductive layer as defined herein, the second solid electrolyte layer includes a second inner insulating layer, a second outer insulating layer, a second inner conductive layer and a second outer conductive layer as defined herein, and the first outer conductive layer and the second outer conductive layer are in contact with one another.

Abstract: In a sensor diagnosis process, a controller for controlling an NOx gas sensor performs processing of changing the oxygen partial pressure in a second measurement chamber by changing the oxygen partial pressure in a first measurement chamber (S190), processing of detecting a current flowing through a second pump cell before the change of the oxygen partial pressure (S180), and processing of detecting a current flowing through the second pump cell after the change of the oxygen partial pressure (S230). Furthermore, the controller performs processing of judging whether or not the ratio between the current values detected by the respective current detecting unit falls within an allowable range, judging that the second pump cell 113 is in a normal state if the ratio between the current values falls within the allowable range, and judging that the second pump cell 113 is in a deteriorated state if the ratio between the current values is out of the allowable range (S240 and S250).

Abstract: A gas sensor including a gas sensor element configured by laminating three or more ceramic layers and having an electrode pad disposed on an outer surface thereof and penetrating holes extending in a laminating direction through two or more of the ceramic layers disposed between an inner conductor and the electrode pad. The gas sensor element has a conductive path formed therein which passes through the penetrating holes formed in different respective ones of the ceramic layers and electrically connects the inner conductor and the electrode pad. Further, the conductive pad is a type 1 conductive path which passes through a plurality of the penetrating holes disposed so as not to overlie one another as viewed from the laminating direction.

Abstract: A gas sensor includes a gas sensor element. The gas sensor element includes a first detection chamber; a first oxygen pumping cell including a first solid electrolyte body and a pair of first electrodes; a second detection chamber; a second oxygen pumping cell including a second solid electrolyte body and a pair of second electrodes; and an oxygen-concentration sensing cell including a third solid electrolyte body and a pair of third electrodes. A sensing electrode of the third electrodes is disposed downstream beyond a first inner electrode of the first electrodes relative to a gas flow direction. A cross-sectional area of a space of the first detection chamber which faces the first inner electrode falls within a range from 0.03 mm2 to 0.22 mm2.

Abstract: A gas sensor including a gas sensor element having a first measurement chamber (16); a first pumping cell (11); a second measurement chamber (18) into which a gas to be measured having a controlled oxygen partial pressure is introduced; and a second pumping cell (13) having a second inner pump electrode (13b) and a second counterpart electrode (13c) pump electrode configured to detect a specific gas component. The second inner pump electrode is made of a material that contains, as a principal ingredient, two kinds of Pt particles having different particle sizes and whose particle size ratio measured by a sedimentation particle-size distribution ranges from 1.75 to 14.2. A mixing ratio between large Pt particles and small Pt particles has a mass ratio of 10/90 to 50/50. A 10 kHz-1 Hz resistance value across the second pumping cell at 600° C. is 150? or less.

Abstract: A gas sensor (200) has a gas sensor element (10) including a first measurement chamber (16); a first pumping cell (11) having a first interior pump electrode (11c) and its counterpart electrode (11b); a second measurement chamber (18); a second pumping cell (13) that has a second interior pump electrode (13b); and a beater (50). The heater (50) has a lead section (50a); a first resistance portion (50bx) having a higher resistance than the lead portion (50a); and a main heating portion (50k) having a second resistance portion (50by) having a higher resistance than the first resistance portion (50bx) disposed at a leading end side in a longitudinal direction relative to a leading end of the first resistance portion (50bx). The second interior pump electrode (13b) is located within the first resistance portion (50bx) in the longitudinal direction.

Abstract: A sensor element including: a first solid electrolyte layer as defined herein; and a second solid electrolyte layer as defined herein, wherein the first solid electrolyte layer includes a first inner insulating layer, a first outer insulating layer, a first inner conductive layer and a first outer conductive layer as defined herein, the second solid electrolyte layer includes a second inner insulating layer, a second outer insulating layer, a second inner conductive layer and a second outer conductive layer as defined herein, and the first outer conductive layer and the second outer conductive layer are in contact with one another.

Abstract: A sensor element having a plate-like shape and extending in a longitudinal direction and having a chamfered portion at an edge between a main surface and a rear-end surface or between a main surface and a side surface of the sensor element. The sensor element includes a solid electrolyte layer, an insulating layer disposed on the solid electrolyte layer and constituting at least part of the main surface, and an electrode pad disposed away from the chamfered portion for connection to an outside circuit. Furthermore, the solid electrolyte layer and the insulating layer are exposed at the chamfered portion. Also disclosed are a gas sensor including the sensor element and a method of manufacturing the sensor element.

Abstract: A gas sensor controller 190 stops an operation of pumping in or out oxygen that is being performed by a first pump cell 111 in a state that the oxygen concentration (oxygen partial pressure) of a gas to be measured is equal to a status judgment reference value (20%). The gas sensor controller 190 calculates an oxygen pressure in a second measurement chamber 161 on the basis of a second pump current Ip2. If the oxygen pressure in the second measurement chamber 161 is equal to a deterioration judgment reference value, the gas sensor controller 190 judges that the second pump cell 113 is in a normal state. If the oxygen pressure in the second measurement chamber 161 is different from the deterioration judgment reference value, the gas sensor controller 190 judges that the second pump cell 113 is in a deteriorated state.

Abstract: In a sensor diagnosis process, a controller for controlling an NOx gas sensor performs processing of changing the oxygen partial pressure in a second measurement chamber by changing the oxygen partial pressure in a first measurement chamber (S190), processing of detecting a current flowing through a second pump cell before the change of the oxygen partial pressure (S180), and processing of detecting a current flowing through the second pump cell after the change of the oxygen partial pressure (S230). Furthermore, the controller performs processing of judging whether or not the ratio between the current values detected by the respective current detecting unit falls within an allowable range, judging that the second pump cell 113 is in a normal state if the ratio between the current values falls within the allowable range, and judging that the second pump cell 113 is in a deteriorated state if the ratio between the current values is out of the allowable range (S240 and S250).