Abstract: A gas sensor includes a sensor element and a pump cell controller. During a normal operation time of the sensor element, the pump cell controller executes a normal time measurement pump control process of pumping out the oxygen in a measurement chamber by controlling a measurement pump cell so that voltage for measurement reaches a normal time target value. At the start-up time of the sensor element, the pump cell controller executes a start-up time measurement pump control process of pumping out the oxygen in the measurement chamber by controlling the measurement pump cell so that the voltage for measurement reaches a start-up time target value higher than the normal time target value. When determining that the oxygen concentration in the measurement chamber is stabilized, the pump cell controller makes switching from the start-up time measurement pump control process to the normal time measurement pump control process.

Abstract: A gas sensor includes a sensor element and a controller. The sensor element includes an element body provided with a measurement-object gas flow section therein, a measurement electrode disposed in the measurement-object gas flow section, an outer pump electrode provided in the element body so that the outer pump electrode comes into contact with a measurement-object gas, a reference electrode, a reference-gas introduction section that causes a reference gas to flow to the reference electrode, and a reference-gas adjustment pump cell constituted by including the outer pump electrode and the reference electrode. The controller performs a moisture-absorption-state diagnosis process of diagnosing a moisture absorption state around the reference electrode based on a pump current flowing through the reference-gas adjustment pump cell when the reference-gas adjustment pump cell is controlled to pump out oxygen from a periphery of the reference electrode to a periphery of the outer pump electrode.

Abstract: A sensor element configured to detect a concentration of a specific gas in a measurement-object gas, the sensor element includes an element body having a front end, a rear end and a peripheral face; an inner electrode disposed inside the element body; and a conducting section including an inner conducting section and an outer conducting section, the outer conducting section including a connector electrode disposed at a part of the peripheral face that is near the rear end, the outer conducting section further including a segment disposed on the peripheral face and/or a segment disposed on the peripheral face and exposed to an outside of the sensor element, the outer conducting section being electrically continuous with the inner conducting section. Letting a porosity be Rp [%] and a thickness be Dc [mm], a covering portion of the outer conducting section that covers the inner conducting section satisfies Rp/Dc?145%/mm.

Abstract: A sensor element includes: an element body; a conducting section including an inner conducting section and an outer conducting section, the outer conducting section, being electrically continuous with the inner conducting section, wherein the outer conducting section includes a connecting segment connected to a routing part of the inner conducting section, wherein the connecting segment of the outer conducting section has gas permeability, and/or at least a portion of the routing part of the inner conducting section is exposed to an outside of the sensor element, and wherein an outer periphery of the routing part of the inner conducting section has a perimeter that is a sum of a first perimeter of a portion covered by the connecting segment having the gas permeability and a second perimeter of a portion exposed to the outside of the sensor element, the sum being shorter than 1.30 mm.

Abstract: A sensor element configured to detect a concentration of a specific gas in a measurement-object gas, the sensor element includes an element body having a front end, a rear end and a peripheral face; an inner electrode disposed inside the element body; and a conducting section including an inner conducting section and an outer conducting section, the outer conducting section disposed at the peripheral face and including a connector electrode disposed at a part of the peripheral face that is near the rear end, the outer conducting section being electrically continuous with the inner conducting section. A connection portion in the outer conducting section to the inner conducting section is gas permeable, and a contact area between the connection portion and the solid electrolyte body is 1.10 mm2 or smaller.

Abstract: A sensor element includes an element body, a reference electrode, a measurement-object gas side electrode, a first conducting section that has a reference electrode terminal and a reference electrode lead, and a lead insulation layer. The reference electrode lead is configured to flow a reference gas, which serves as a reference for detecting the specific gas concentration in the measurement-object gas, to the reference electrode. A region of 50% or more, from an end on the reference electrode side, of the total area of the lead insulation layer in a planar view is configured as a dense region with a porosity of 5% or less.

Abstract: A sensor element includes an element body provided with a measurement-object gas flow section therein, a measurement electrode, a reference electrode, a reference-gas introduction section, and a heater that heats the element body. The reference-gas introduction section has a reference-gas introduction space that is open outward of the element body and that introduces a reference gas into the element body, and also has a porous reference-gas introduction layer that causes the reference gas to flow from the reference-gas introduction space to the reference electrode. The reference-gas introduction layer has a first porous region and a second porous region in a path segment serving as a reference-gas path between the reference-gas introduction space and the reference electrode. The second porous region has a low porosity region with a lower porosity than the first porous region and is disposed closer to the reference electrode relative to the first porous region.

Abstract: A gas sensor includes a sensor element and a control device, and detects a specific gas concentration that is a concentration of a specific gas in a measurement-object gas. The sensor element includes an element body including an oxygen-ion-conductive solid electrolyte layer and provided with a measurement-object gas flow portion therein, the measurement-object gas flow portion introducing the measurement-object gas and causing the measurement-object gas to flow therethrough; a measurement electrode disposed in a measurement chamber of the measurement-object gas flow portion; and a reference electrode disposed inside the element body to come into contact with a reference gas that serves as a reference for detection of the specific gas concentration. The control device measures a voltage across the ground and the reference electrode, and identifies a deviation of the reference potential that is the electrical potential of the reference electrode based on the measured voltage.

Abstract: A sensor element includes: a plurality of internal spaces which sequentially communicate from a gas inlet, and in which respective inner electrodes are arranged; an outer electrode; a porous body region covering the outer electrode; and a plurality of electrochemical pump cells capable of pumping in or out oxygen between the internal spaces and an outside, and a ratio A/B is 0.07 or more, where A is a magnitude of a limiting current when a main pump cell including a main pump electrode in a first internal space located closest to the inlet and the outer pump electrode pumps in oxygen to the first internal space in a case where a pump in current evaluation gas is introduced, B is a magnitude of a limiting current when oxygen is pumped out from the first internal space in a case where a pump-out current evaluation gas is introduced.

Abstract: A gas sensor includes a sensor element and a controller. The sensor element includes an element body provided with a measurement-object gas flow section therein, a measurement electrode disposed in the measurement-object gas flow section, an outer pump electrode provided in the element body so that the outer pump electrode comes into contact with a measurement-object gas, a reference electrode, a reference-gas introduction section that causes a reference gas to flow to the reference electrode, and a reference-gas adjustment pump cell constituted by including the outer pump electrode and the reference electrode. The controller performs a moisture-absorption-state diagnosis process of diagnosing a moisture absorption state around the reference electrode based on a pump current flowing through the reference-gas adjustment pump cell when the reference-gas adjustment pump cell is controlled to pump out oxygen from a periphery of the reference electrode to a periphery of the outer pump electrode.

Abstract: A gas sensor that detects a specific gas concentration in a measurement-object gas, the gas sensor includes: a sensor element having an element body provided with a measurement-object gas flow section therein, the measurement-object gas flow section introducing the measurement-object gas, a measurement electrode disposed in the measurement-object gas flow section, a measurement-object-gas side electrode provided on the element body, a reference electrode, a reference-gas introduction section that causes a reference gas to flow to the reference electrode, and a reference-gas adjustment pump cell constituted by including the measurement-object-gas side electrode and the reference electrode; and a controller that performs a moisture-concentration decrease process of controlling the reference-gas adjustment pump cell so that oxygen is pumped out from a periphery of the reference electrode to a periphery of the measurement-object-gas side electrode to decrease a moisture concentration around the reference electrod

Abstract: A gas sensor includes a sensor element and a pump cell controller. During a normal operation time of the sensor element, the pump cell controller executes a normal time measurement pump control process of pumping out the oxygen in a measurement chamber by controlling a measurement pump cell so that voltage for measurement reaches a normal time target value. At the start-up time of the sensor element, the pump cell controller executes a start-up time measurement pump control process of pumping out the oxygen in the measurement chamber by controlling the measurement pump cell so that the voltage for measurement reaches a start-up time target value higher than the normal time target value. When determining that the oxygen concentration in the measurement chamber is stabilized, the pump cell controller makes switching from the start-up time measurement pump control process to the normal time measurement pump control process.

Abstract: A gas sensor includes a sensor element and a pump cell controller. The pump cell controller performs a normal time control process after a heater control process is started, the normal time control process including a main pump control process, an auxiliary pump control process of controlling an auxiliary pump cell so that a voltage for auxiliary pump reaches a target value, and a normal time measurement pump control process of pumping out oxygen in a measurement chamber by controlling the measurement pump cell so that a measurement voltage reaches a normal time target value. In an early stage of the normal time control process, the pump cell controller performs a correction process of correcting the target value of the voltage for auxiliary pump to a value higher than a target value in a period after the early stage.

Abstract: A gas sensor includes a sensor element including an element body, a measurement pump cell being configured to pump out oxygen from surroundings of an inner measurement electrode to surroundings of an outer measurement electrode, and a measurement voltage detection sensor cell that detects a measurement voltage between a reference electrode and the inner measurement electrode, and a pump cell controller that executes a normal time measurement pump control process of pumping out oxygen in the measurement chamber during a normal operation time of the sensor element so that the measurement voltage reaches a normal time target value, and executes a start-up time measurement pump control process of pumping out oxygen in the measurement chamber at a start-up time of the sensor element earlier than the normal operation time so that the measurement voltage reaches a start-up time target value higher than the normal time target value.