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 plural-cell gas sensor including at least an oxygen pump cell (40) comprising a solid electrolyte ceramic layer; an internal space (210) formed between the cells; and a heater substrate (190) arranged on the side of the oxygen pump cell; the heater substrate heating the oxygen pump cell that pumps oxygen out of the internal space.

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 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).

Abstract: A plural-cell gas sensor including at least an oxygen pump cell (40) comprising a solid electrolyte ceramic layer; an internal space (210) formed between the cells; and a heater substrate (190) arranged on the side of the oxygen pump cell; the heater substrate heating the oxygen pump cell that pumps oxygen out of the internal space.