Abstract: One embodiment of an ammonia gas sensor includes: a reference electrode, an ammonia selective sensing electrode and an electrolyte disposed therebetween. The sensing electrode comprises the reaction product of a main material selected from the group consisting of vanadium, tungsten, molybdenum, vanadium oxides, tungsten oxides, molybdenum oxides, and combinations comprising at least one of the foregoing main materials, and an electrically conducting material selected from the group consisting of electrically conductive metals, electrically conductive metal oxides, and combinations comprising at least one of the foregoing.

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 contamination-resistant sensor element and methods for making the same are provided. A sensor element may include a contamination-resistant coating on at least a portion thereof. The coating may comprise gamma-delta alumina and lithium oxide and may have a thickness of about 100 to about 600 microns and a porosity of about 20 to about 70 percent. The method may include using gamma-delta alumina and lithium oxide to form a mixture, applying the mixture to at least a portion of a sensor element, and temperature treated the mixture to form a contamination-resistant coating on the surface of the measuring cell.

Abstract: The invention provides an electrochemical oxygen sensor including a cathode, an anode, and an electrolyte solution, wherein the electrolyte solution contains a chelating agent. Since the electrolyte solution in the electrochemical oxygen sensor of the invention contains the chelating agent, the speed of response can be increased. In the invention, the provision of an anode of tin is preferred from the viewpoints of low cost, a low environmental load, and a low susceptibility to liquid leakage. In the invention, the concentration of the chelating agent in the electrolyte solution is preferably not less than 0.005 mol/liter because response speed characteristics are less likely to lower.

Abstract: A method for detecting the presence or absence of a gas bubble in an aqueous liquid is provided comprising providing an amperometric sensor positioned within a measuring chamber, wherein the amperometric sensor is configured to determine the concentration of a gaseous component dissolved in a liquid, the amperometric sensor comprising a sensitive region; positioning the liquid in the measuring chamber; taking at least one first measurement value of the gaseous component from a first portion of the liquid after a predetermined response time, the first portion located in the sensitive region of the sensor; moving the liquid along in the measuring chamber, such that a second portion of the liquid, which had previously been located outside the sensitive region of the amperometric sensor, is positioned in the sensitive region; taking at least one second measurement value of the gaseous component from the second portion of the liquid; and detecting the presence or absence of a gas bubble by comparing the first and

Abstract: A gas concentration detecting system has a first cell generating electric current at first oxygen sensitivity, a second cell generating current at second oxygen sensitivity and a reference cell generating current at reference oxygen sensitivity. The cells have the same structure except that the second cell has a catalyst layer for removing hydrogen as from measured gas containing oxygen gas. The system determines first corrected current from current of the first cell exposed to measured gas, current of the first cell exposed to inspection gas containing oxygen gas at reference concentration and reference cell current of the reference cell exposed to inspection gas, determines second corrected current from current of the second cell exposed to measured gas, current of the second cell exposed to inspection gas and the reference cell current, and detects concentration of hydrogen gas in measured gas from the corrected currents.

Abstract: A gas sensor including a pump electrode and a method for manufacturing a conductive paste for forming the pump electrode. When the pump electrode constituting an electrochemical pump cell for adjusting an oxygen partial pressure inside a gas sensor to measure a concentration of a gas component in a measurement gas by a current-limiting method is formed of a cermet of a noble metal and an oxide having oxygen ion conductivity, the noble metal contains a first noble metal having a catalytic activity, and a second noble metal having a catalytic activity suppressing ability to suppress the catalytic activity of the first noble metal with respect to an oxide gas except for oxygen, and an abundance ratio of the second noble metal with respect to the first noble metal in a particle surface of the first noble metal existing in the pump electrode is to be 0.01 to 0.3.

Abstract: A liquid electrolyte composition obtainable by combining a first component comprising bistrifluoromethanesulfonimide and/or an analogue thereof with a second component comprising a dialkyl sulfone, diaryl sulfone, alkyl aryl sulfone, alkyl acyl sulfone, boric acid, alkyl boronic acid, aryl boronic acid, dialkyl phosphite, trialkyl phosphite, dialkyl phosphate, trialkyl phosphate, alkylene carbonate, alkanoic lactone, preferably alkanoic ?-lactone an analogue of any of these, or mixtures thereof, wherein any of the alkyl, aryl of alkenyl groups may be substituted or unsubstituted. The liquid electrolyte is used in an electrochemical gas sensor.

Abstract: A ceramic gas sensor for measuring a gas component in a gas mixture, which includes a sensor element, which has at least one first electrode exposed to the gas mixture to be determined, and at least one further electrode. Only one shared electrical contacting is provided for the first electrode and for the additional electrode, an electrical resistor, which is situated inside the gas sensor, being preconnected to the first electrode and/or the additional electrode.

Abstract: A monitor is disclosed for monitoring an atmosphere for the presence of a target gas. The monitor includes an electrical gas sensor having a working (sensing) electrode and a counter electrode, an operational amplifier connected between the sensor electrodes, a detector, and a circuit. The sensor provides a current between the electrodes that is indicative of the amount of a target gas in the atmosphere. The operational amplifier generates an output signal according to the current flowing between the terminals where the output signal is indicative of the amount of target gas in the atmosphere. The detector detects when the current flowing between the sensor electrodes exceeds a predetermined threshold. The circuit restricts the potential difference between the sensor electrodes when the current between the terminals exceeds the predetermined threshold by supplying additional current or removing current from the working sensor electrode.

Abstract: A gas-sensor element having a layer-type arrangement or configuration, in particular for determining gas components and/or concentrations of gas components of a measuring gas, having a sensor cell, including a first electrode, which is to be exposed to the measuring gas, a second electrode, which is to be exposed to a reference gas, and a solid-state electrolyte situated between the two electrodes, including a reference-air channel situated between the electrode that is exposed to the reference gas and the solid-state electrolyte, and including a heating element. In the superposition of two gas-sensor element layers, a path formed by an electrode facing the heating element is developed at a lateral offset with respect to a path formed by the heating element.

Abstract: The presently-disclosed subject matter provides sensors and methods for detecting hydrogen by determining the conductivity of a chemiresistant film upon exposure to hydrogen, including for example chemiresistant films comprised of alkylamine-, alkylthiolate-, and/or surfactant-coated metal alloy nanoparticles.

Abstract: Disclosed is a gas permeable electrode comprising an electrocatalyst which is permeable to a reactant or reaction product, the electrocatalyst comprising particulate boron-doped diamond. There is also disclosed a method of making an electrocatalyst which is permeable to a reactant or reaction product, the method comprising the step of forming an electrocatalyst comprising particulate boron-doped diamond.

Abstract: In a method for operating a semiconductor gas sensor, the gas sensor including at least one gas-sensitive electrode, the method may provide for impression of a voltage sequence on the gas-sensitive electrode. The operation may take place in a measuring cycle which is subdivided into at least one initialization phase and at least one subsequent measuring phase, a first voltage sequence being impressed on the gas-sensitive electrode during the initialization phase, a second voltage sequence being impressed on the gas-sensitive electrode during the measuring phase, and the first voltage sequence differing from the second voltage sequence. A semiconductor gas sensor may be provided for implementing the method according to the invention, and a method may relate to the use of such a sensor.

Abstract: The present invention relates to planar electrochemical sensors with membrane coatings used to perform chemical analyses. The object of this invention is to provide unit-use disposable sensors of very simple and inexpensive construction, preferably with only a single membrane coating on an electrode. The invented devices are potentiometric salt-bridge reference electrodes and dissolved gas sensors constructed with a heterogeneous membrane coating of a conductor. The heterogeneous membrane, which is an intimate admixture of a hydrophobic and a hydrophilic compartment, concurrently supports constrained transport of non-volatile species through its hydrophilic compartment and rapid gas and water vapor transport through its hydrophobic compartment.

Abstract: A device, which detects information about a hydrogen concentration level, includes an air-fuel ratio sensor, an air-fuel ratio controller, and a detecting portion. The detecting portion calculates either a ratio of response periods or a difference between the response periods to detect the hydrogen concentration level. One of the response periods is a period from the time the air-fuel ratio controller switches the target air-fuel ratio from rich to lean to the time the air-fuel ratio sensor detects this. The other of the response periods is a period from the time the air-fuel ratio controller switches the target air-fuel ratio from lean to rich to the time the air-fuel ratio sensor detects this. This allows the decisions of a variation between cylinders and an exhaust purifying catalyst degradation.

Abstract: The present invention provides a low-cost hydrogen gas sensor, which exhibits high sensory selectivity for protons and operates at room temperature, and can also provide a highly sensitive sensor capable of fulfilling the important functions of detecting hydrogen gas and preventing leakage accidents in production plants that use hydrogen gas as a carrier, in hydrogen gas storage facilities, and in so-called fuel cells that use hydrogen gas as an energy source. In addition, the sensor is also effective as an acid sensor for hydrofluoric acid and the like. The present invention relates to an acid and hydrogen gas sensor, wherein protons are brought into contact with an organic compound containing an introduced pyridine ring (such as pyridine-DPP), and the change in electrical resistivity, photoconductivity, or optical absorption band for the organic compound that accompanies proton addition is detected.

Abstract: A gas-component measurement device includes a housing having an suction port that introduces a measurement-targeted gas, and an exhaust port that discharges the measurement-targeted gas, and a water-absorbing member that is disposed in the housing and impregnated with a solvent that dissolves a gas component, and an electrochemical sensor that detects the gas component trapped by the solvent in the water-absorbing member. The exhaust port and suction port are disposed to oppose each other while sandwiching therebetween the electrochemical sensor.

Abstract: An electrochemical sensor with at least one ionic liquid (4) as the electrolyte, contains at least one electrode (1), whose active surface is substantially larger than the geometric area covered by said electrode (1). The electrolyte and at least one of the electrodes (1, 2, 3) are in direct contact with the ambient atmosphere.

Abstract: An electrochemical sensor for measuring the amount of hydrogen sulphide or thiols in a fluid in a wellbore comprises a temperature- and pressure-resistant housing containing a flow path for the fluids. The fluids flow over one side of a gas permeable membrane made of zeolite or a suitable ceramic material, the other side of the membrane being exposed to a chamber containing a reaction solution which together with the hydrogen sulphide or thiols create a redox reaction resulting in an electrical current dependent upon the amount of hydrogen sulphide or thiols in the fluid.

Abstract: A lead portion (25) of a heater coil (22) is constituted of a single coil wound into a coil and a bead portion (24) is constituted of a double coil formed by further winding the single coil into a coil. By constituting a detecting element (2) by burying the bead portion (24) in a heat conductive layer (21) and adhering a catalyst layer (23) on the surface of the heat conductive layer (21), improvement of the gas sensitivity and the response speed of a catalytic combustion gas sensor is facilitated. Zero point variation is reduced by improving impact resistance. When both ends of the heater coil are fixed to electrode pins, both ends of the heater coil are welded to the electrode pins using a resistance welding method, etc., with a platinum wire, etc., wound on a primary core wire, and thereafter, the primary core wire is melted and eliminated while leaving the platinum wire, etc., by a wet etching process.

Abstract: An ultra-sensitive gas sensor using semiconductor oxide nanofibers and a method of fabricating the same are provided. The gas sensor includes an insulating substrate, a metal electrode formed on the insulating substrate, and a semiconductor metal oxide nanofibers layer formed on the metal electrode and having nanoparticles of high sensitivity coated thereon. The method of fabricating a semiconductor oxide nanofibers gas sensor includes fabricating an oxide using a solution for electrospinning, electrospinning the solution, performing an annealing process to form an oxide semiconductor nanofiber, and partially coating a nano-sized metal oxide or metal catalyst particle having high sensitivity to a specific gas on a surface of the nanofiber having a large specific surface area. As a result, a semiconductor oxide nanofibers gas sensor having ultra sensitivity, high selectivity, fast response and long-term stability can be fabricated.

Abstract: Between a gas sensing layer (4) and a base member (15) composed of a silicon substrate (2) and an insulating coat layer (3), there is formed an adhesion layer 7, to improve the adhesion therebetween, and to prevent separation. The gas sensing layer (4) and sensing electrodes (6) are electrically connected by abutment of a confronting surface (61) of sensing electrodes (6) confronting the gas sensing layer (4) and sides surfaces of the sensing electrodes on both sides, on the gas sensing layer (4), and accordingly the gas sensor properly senses an electric characteristic of the gas sensing layer (4) varied in accordance with a concentration variation of a specified gas. Furthermore, the sensing electrodes (6) are in contact with the gas sensing layer (4), but the sensing electrodes are not in contact with the adhesion layer (7).

Abstract: An electrochemical sensor and method of detecting gaseous analytes are provided, which involve the use of a working electrode comprising edge plane pyrolytic graphite.

Abstract: A galvanic sensor for analyzing gases present in blood includes a duct suitable for being crossed by a flow of gas and provided with an inlet opening and an outlet opening, a reference galvanic element including a container containing an electrolytic solution in which a reference electrode is inserted, and a measuring galvanic element. The container is fixed to the duct and the measuring galvanic element includes a measuring electrode arranged transversally to the axis of the duct and a filiform element having a high capillarity so as to act as a wick. The filiform element is anchored to the container and has a first end contacting the measuring electrode and a second end contacting the electrolytic solution. The measuring element of the galvanic sensor is extremely miniaturized and allows to detect in real time and continuously gases in traces, on the order of parts per million or even lower.

Abstract: A lead free, galvanic sensor. The sensor having a housing, a cathode, an anode, a diffusion barrier, contact wires and an electrolyte, the anode being made of a tin containing alloy. The sensor electrolyte is an aqueous solution of phosphoric acid or an aqueous solution of a cesium salt.

Abstract: A gas sensor is provided that has the diffusion of the measuring gas toward the working electrode adapted in such a way as to obtain a good signal-to-basic current ratio. Provisions are made for the measuring gas to be transported via a capillary arrangement (11), wherein the capillary arrangement (11) is designed as an arrangement extending in parallel to the working electrode (4).

Abstract: A urea concentration identification device comprising a concentration identification sensor unit (2) and a support unit (4) attached at the bottom end thereof with this sensor unit and provided at the top end thereof with a mounting unit (4a) to a urea solution tank opening. The concentration identification sensor unit (2) has an indirectly-heated concentration detector and liquid temperature detector provided with metal fins (21c),(22c), respectively, for heat-exchanging with urea solution. The concentration identification sensor unit (2) is provided with a cover member (2d) that forms an opposite-ends-opened urea solution induction passage so as to surround the metal fins (21c), (22c).

Abstract: An electrochemical gas sensor is provided with a carbon-based measuring electrode (3) that it can be used for a large number of electrochemical detection reactions and can be manufactured at a low cost. The measuring electrode (3) contains carbon nanotubes.

Abstract: A gas sensing device (nanosensor) includes a substrate with at least a pair of conductive electrodes spaced apart by a gap, and an electrochemically functionalized semiconductive nanomaterial bridging the gap between the electrodes to form a nanostructure network. The nanomaterial may be single-walled carbon nanotubes (SWNTs) functionalized by the deposition of nanoparticles selected from the group consisting of an elemental metal (e.g., gold or palladium), a doped polymer (e.g., camphor-sulfonic acid doped polyaniline), and a metal oxide (e.g. tin oxide). Depending on the nanoparticles employed in the functionalization, the nanosensor may be used to detect a selected gas, such as hydrogen, mercury vapor, hydrogen sulfide, nitrogen dioxide, methane, water vapor, and/or ammonia, in a gaseous environment.

Abstract: A flue gas analyser for measuring the concentration of oxygen in flue gas, comprising an electrochemical oxygen sensor and water vapour removing means for reducing the relative humidity of received gas and/or nitrogen-containing-gas removing means for removing from received gas one or more gaseous species comprising nitrogen and oxygen which are either nitrogen dioxide, or formed from nitrogen dioxide in the presence of sufficient water vapour, which would otherwise lead to damage of the electrochemical oxygen sensor,

Abstract: An electrochemical sensor for corrosive gases that contains at least two electrodes is described. The presence of a target corrosive gas results in the formation of metal ions that can be reduced at an electrode producing an electrical current that depends on the instantaneous corrosive gas concentration and deposition of the metal on the electrode. Extension of this deposit to a second electrode through further deposition will result in a short circuit, the longer the time to the short circuit, the lower the cumulative corrosive gas concentration.

Abstract: Novel membranes comprising various polymers containing heterocyclic nitrogen groups are described. These membranes are usefully employed in electrochemical sensors, such as amperometric biosensors. More particularly, these membranes effectively regulate a flux of analyte to a measurement electrode in an electrochemical sensor, thereby improving the functioning of the electrochemical sensor over a significant range of analyte concentrations. Electrochemical sensors equipped wish such membranes are also described.

Abstract: An apparatus to detect particulate matter. The apparatus includes a sensor electrode, a shroud, and a heater. The electrode measures a chemical composition within an exhaust stream. The shroud surrounds at least a portion of the sensor electrode, exclusive of a distal end of the sensor electrode exposed to the exhaust stream. The shroud defines an air gap between the sensor electrode and the shroud and an opening toward the distal end of the sensor electrode. The heater is mounted relative to the sensor electrode. The heater burns off particulate matter in the air gap between the sensor electrode and the shroud.

Abstract: A single-cell sensor element is configured for ammonia gas sensing. The sensor includes an electrolyte layer, an NH3 sensing electrode and a NOx sensing electrode. The NH3 sensing electrode is sensitive to NH3 but is also vulnerable to cross-interference from NO2. To directly correct for this cross-interference, a second (NOx) electrode is provided and is used in a differential connection arrangement with the NH3 sensing electrode. The NOx sensing electrode has a first electrochemical sensitivity to NO2 that is greater than second and third electrochemical sensitivities to NH3 and NO, respectively. The NOx sensing electrode may have low or no sensitivity to NH3 or NO. The sensor element also includes first and second electrical leads respectively connected to the NH3 and NOx sensing electrodes.

Abstract: A gas measurement system includes a sensor element and an associated electronic control unit (ECU) or the like connected thereto for receiving sensor element emf outputs. The ECU is configured to provide output signals or parameters indicative of ammonia and heavy HC gas concentrations. The sensor element has an NH3 sensor electrode output and a NOx sensor electrode output. The information conveyed by the NOx sensor electrode output may be selectively used by the ECU, in accord with so-called emf selection rules, to correct for a cross-interference effect that NO2 has on the NH3 electrode. Heavy HC gas concentrations may cause electrochemical activity on the NH3 electrode, and can be misinterpreted. A further emf selection rule is configured to detect the presence of heavy HC gas and is used by the ECU to suppress an output signal or parameter indicative of an ammonia gas concentration.

Abstract: Disclosed herein is a hydrogen gas sensor which requires no purging, has excellent hydrogen gas selectivity, and can be produced at relatively low cost. The hydrogen gas sensor includes a detection unit having a base body composed of a solid polymer electrolyte or a carbon-containing solid polymer electrolyte obtained by dispersing a carbon material in a solid polymer electrolyte and a catalyst layer provided on one of the surfaces of the base body to perform catalytic function on contact with hydrogen gas.

Abstract: An oxygen concentration detecting element including a base member made of an electrically insulating material, a heater disposed on an outer surface of the base member, the heater being adapted to generate heat upon being energized, and an oxygen detecting unit disposed in an offset position on the outer surface of the base member in which the oxygen detecting unit is prevented from overlapping with the heater, the oxygen detecting unit including a solid electrolyte layer and a pair of electrodes between which the solid electrolyte layer is disposed.

Abstract: A dual gas sensor is described, having first and second working electrodes separated by a gas impermeable portion. The electrodes are preferably located on a gas permeable polymer support, with the gas impermeable portion being formed by compression of the permeable support. The sensor may also include one or more filters for location adjacent the electrodes to filter certain gases from the air. The preferred sensor is able to detect carbon monoxide and hydrogen sulfide. The sensor housing is formed with four connection pins, allowing a standard sensor housing to be used for dual sensors as well as single sensors having a dummy pin.

Abstract: A mediator-based electrochemical gas sensor reacts selectively with hydrogen sulfide. The gas sensor has an electrolyte solution (9), which contains a mediator compound in the form of metallates of transition metals.

Abstract: The invention provides an air-fuel ratio control system in which high precision can be applied to the air-fuel ratio feedback control of an engine by using a gas sensor mainly configured by an oxygen sensor that prevents the deterioration of the holding power of sealing material which enables high density filling with a small compressive load or the deterioration of the sealing material. The gas sensor such as the oxygen sensor is based upon a gas content detecting sensor that includes a gas content detecting element and a holder holding the gas content detecting element and that seals a measuring part of the gas content detecting element in the holder by a sealing part in which the sealing material is compressively filled, and has a characteristic that the sealing material is molded by mixed powder including plural species of forms of particles.

Abstract: A protective coating sustains the long term performance of a solid-state hydrogen sensor that includes a catalyst layer for promoting the electrochemical dissociation of hydrogen. The catalyst is susceptible to deterioration in the presence of at least one contaminant, including carbon monoxide, hydrogen sulfide, chlorine, water and oxygen. The coating comprises at least one layer of silicon dioxide having a thickness that permits hydrogen to diffuse to the catalyst layer and that inhibits contaminant(s) from diffusing to the catalyst layer. The preferred coating further comprises at least one layer of a hydrophobic composition, preferably polytetrafluoroethylene, for inhibiting diffusion of water through the protective coating to the catalyst layer. The preferred protective coating further comprising at least one layer of alumina for inhibiting diffusion of oxygen through the protective coating to said catalyst layer.

Abstract: A sensor for detecting a gas is provided. The gas sensor may have a sensing section, a heating section, and a resistance temperature detector. The resistance temperature detector may be co-fired to be integral with at least one of the sensing section and the heating section.

Abstract: An electrochemical sensor with at least one measuring electrode (3), at least one auxiliary electrode (7) and at least one reference electrode (5), wherein a protective electrode (6), which ensures at the reference electrode (5) the at least partial shielding of the reference electrode (5) against substances that would lead to a change in the reference potential when reaching the reference electrode (5), is arranged in the vicinity of the reference electrode (5). A highly stable reference potential can be obtained with the present invention.

Abstract: A laminated gas sensor element extending in a longitudinal direction and having a detection part including a plate-shaped element body which has a heater layer having an embedded resistance heating body and a detection layer laminated to the heater layer and having a vertical surface along a lamination direction and a horizontal surface perpendicular to the lamination direction; and a porous protective layer coating the vertical surface and the horizontal surface of the element body constituting the detection part, wherein a thickness of the protective layer formed on the vertical surface is thicker than a thickness of the protective layer formed on the horizontal surface.

Abstract: An apparatus for sensing an analyte gas is provided. The apparatus may include a signal amplifier that may include a thin film transistor that may include a semiconducting film that may include a metal oxide capable of chemical interaction with the analyte gas, such as carbon monoxide. The apparatus may be tuned for detecting the analyte gas by varying the gate voltage of the transistor.

Abstract: An electrode comprising a conducting substrate for detecting species such as nitric oxide (NO), carbon monoxide (CO), oxygen (O2) and hydrogen (H2) and a polymer matrix formed from a first layer only or first and second layers with the second layer applied to the first. The matrix forms a permselective barrier. Each layer has a first pre-coat or first and second pre-coats. Each pre-coat may be formed by: depositing a liquid form of at least one halogenated polymer such as fluorinated or chlorinated polymers onto a substrate and allowing the material to dry. A liquid form of at least one halogenated polymer adheres the first and second layers to the substrate. The electrode allows for detection of the target species and allows real time in vivo measurements to be taken. Blood flow can also be monitored. An electrode bundle with electrodes for different target species is also provided.

Abstract: A gas sensing mechanism and a gas sensor based on a semiconducting carbon nanotube diode structure are disclosed. The gas sensor operates by detecting the change in conductivity characteristic of the current vs. voltage behavior of an I—N, or I—P junction, in the carbon nanotube. In the presence of electrophilic gas species at the I—N junction, or nucleophilic gas species at the I—P junction, a P—N, or N—P, junction is created by doping of the carbon nanotube by the respective gas species. The resulting change from the undoped, instrinsic i-type to p-type, or n-type, creates a diode structure whose conductivity characteristics can be measured with high accuracy and selectivity.

Abstract: A gas sensor for detecting a predetermined gas component in a measurement gas includes a sensor element in which an opening of a first gas inlet and an opening of a second gas inlet for introducing the measurement gas from an outside are provided at one end. The openings are elongated and substantially rectangular. A sum of sizes in a lateral direction of the openings is greater than or equal to 8 ?m and less than or equal to 60 ?m, and a sum of areas of the openings is greater than or equal to 0.02 mm2 and less than or equal to 0.1 mm2. The sizes in the lateral direction and the areas of the openings are set to be within a preferable range so that the water droplets attached on the forward end surface can be prevented from entering into the sensor element through the openings.

Abstract: A gas sensor element, wherein an amount of flexure in a first section extending in a longitudinal direction of the sensor element from the position 8/27 of a size of the element apart from one end of the element to the other end, is set to be greater than or equal to 1/1360 and less than or equal to 1/670 with respect to the size in the longitudinal direction of the element. The amount of flexure is a sum of a distance from a regression line to an upper side maximum displacement point and a distance from the regression line to a lower side maximum displacement point when calculating the regression line representing the relation of the position X in the longitudinal direction of the element and the displacement Y in a thickness direction from a plurality of data sets showing the relation of position X and displacement Y.