A gas sensor, which includes a solid electrolyte layer including positive charge carriers to which detection-target gas coordinates, an electrode arranged on part of a plane of the solid electrolyte layer, and a unit configured to accelerate movements of the positive charge carriers.

A gas sensor which detects a concentration of a specific gas contained in a gas to be measured is provided with a gas sensor element. The gas sensor element has an ion conductive solid electrolyte body, a measuring gas electrode which is mounted on a surface of the solid electrolyte body, a reference gas electrode mounted on a surface of the solid electrolyte body, and a catalyst layer mounted on an outer-side relative to the measuring gas electrode-side. The catalyst layer contains a metal catalyst loaded onto a carrier. The metal catalyst is a Pt single substance, and has a specific surface area defined by the equation below of equal to or more than 0.01 to equal to or less than 23: Specific surface area=total surface area of metal catalyst which exists on an electrode unit surface area/actual surface area of electrode per electrode unit surface area.

Some embodiments presented here relate to chemical sensors with enhanced sensitivity and selectivity. In an embodiment, the sensor is a composite thin film that comprises (e.g., is made of) chemically-modified carbon black and a chemically-sensitive polymer base. By grafting gold nanoparticles on carbon black, the number of binding sites on the sensor thin film is increased, thereby increasing the sensitivity. Furthermore, ligand attached gold nanoparticles are grafted on carbon black to increase the binding sites on the sensor thin film in some embodiments, which results in increased sensitivity as well as improved selectivity in some cases.

An amperometric electrochemical sensor for measuring the concentrations of one or more target gas species in a gas sample or gas stream, the sensor having at least one electrochemical cell with first and second surface electrodes, an electrolyte layer and a passive signal amplifying layer (“SAL”) comprising electrically conductive material like platinum, wherein at least a portion of the electrolyte layer is located between the surface electrodes and the SAL such that the SAL is in direct, conductive contact with the electrolyte layer but is not in direct contact with the surface electrodes. Sensor systems and detection methods are also provided.

A sensor element for detecting a specific gas concentration in a measurement-object gas includes: an element body including an oxygen-ion-conductive solid electrolyte layer, and having inside a measurement-object gas flow portion that introduces and flows a measurement-object gas and a reference gas chamber used to store a reference gas that is a reference for detecting a specific gas concentration; a reference electrode disposed in the reference gas chamber; and an electrically conductive portion which includes a reference electrode terminal and a reference electrode lead portion that provides electrical continuity between the reference electrode terminal and the reference electrode. The reference gas chamber is provided inside the sensor element in an isolated form, and at least part of the electrically conductive portion is densely formed so as to block movement of oxygen between the reference gas chamber and the outside of the sensor element via the electrically conductive portion.

A controller of a gas sensor determines whether a determination target value to be an indicator of operation of pumping in oxygen in at least one electrochemical pump cell exceeds a threshold during a predetermined determination time, controls the gas sensor in a basic mode in which the at least one electrochemical pump cell is operated to maintain the oxygen concentration in at least one internal space constant unless the determination target value exceeds the threshold, and controls the gas sensor in a protected execution mode in which the at least one electrochemical pump cell is protected against operation of excessively pumping in oxygen when the determination target value exceeds the threshold.

A gas sensor element in which oxidation of electrodes and a heater occurring with continued use is suppressed is provided. The gas sensor element includes a plurality of solid electrolyte layers stacked one over another, and includes an electrochemical cell including a pair of electrodes and a portion of the plurality of solid electrolyte layers existing between the pair of electrodes; a heater part capable of heating the gas sensor element; and a gettering layer located between the plurality of solid electrolyte layers and between the plurality of solid electrolyte layers and each of the pair of electrodes, and gettering impurities in a metal component of the electrodes and the heater part during driving of the gas sensor element.

A sensor element includes an element body, a detection unit, a connector electrode, a porous layer that covers at least the front end-side part of a side surface on which the connector electrode is disposed and that has a porosity of 10% or more, and a dense layer. The dense layer is disposed on the side surface so as to divide the porous layer in the longitudinal direction of the element body or to be located closer to the rear end than the porous layer. The dense layer is located closer to the front end of the sensor element than the connector electrode. The dense layer covers the side surface and has a porosity of less than 10%. The dense layer includes an overlap portion that is a front end portion of the dense layer and covers the outer surface of a part of the porous layer.

In an embodiment, a hydrogen monitoring system comprises a plurality of sensing elements that individually comprise a working electrode, a counter electrode, an insulating layer located in between the working electrode and the counter electrode, a catalyst located on an end of both the working electrode and the counter electrode, an electrolyte located on the end of the sensing elements on both the working electrode and the counter electrode, between the working electrode and the counter electrode, and in contact with the catalyst, and an electrical circuit located on an opposite end of the sensing element that connects the working electrode and the counter electrode.

A gas sensor including a detection element section (71) including a solid electrolyte body and a pair of electrodes disposed on the solid electrolyte body, and a heater (73) for heating the detection element section (71). Inherent characteristic information is recorded in a record section (170) provided on the gas sensor or a record section provided separately from the gas sensor. The inherent characteristic information is information specific to the detection element section (71) and which allows setting of a relation between a change in the temperature of the detection element section (71) and a change in the internal resistance between the pair of electrodes.