Abstract: A gas concentration detection device includes: a first sensor having a resistance layer exposed to a gas, and an electrode covered by the resistance layer, the first sensor producing an output according to a gas component ratio on the electrode surface; and a second sensor having a pump cell that pumps oxygen into a gas chamber that contains part of the gas or discharges oxygen out of the gas chamber, and a sensor cell that produces an output according to a gas component ratio in the gas within the gas chamber, the second sensor producing an output based on the pump cell current when the pump cell is operated such that the output of the sensor cell is a predetermined value; and a hydrogen concentration detection unit that detects a hydrogen concentration in the gas based on an output difference between the first sensor output and the second sensor output.

Abstract: A method of operating a system having at least one sensor for detecting an analyte gas in an ambient atmosphere and a sensor responsive to oxygen includes providing a volume in fluid connection with the sensor responsive to oxygen. The volume has an open state in which the volume is in fluid connection with the ambient atmosphere and at least a first restricted state in which entry of molecules from the ambient atmosphere into the volume is restricted as compared to the open state. The method further includes placing the volume in the open state, subsequently placing the volume in the first restricted state, and measuring a dynamic output of the sensor responsive to oxygen while the volume is in the first restricted state. The dynamic output provides an indication of the status of one or more transport paths of the system.

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: Electrocatalysts for carbon dioxide conversion include at least one catalytically active element with a particle size above 0.6 nm. The electrocatalysts can also include a Helper Catalyst. The catalysts can be used to increase the rate, modify the selectivity or lower the overpotential of electrochemical conversion of CO2. Chemical processes and devices using the catalysts also include processes to produce CO, HCO?, H2CO, (HCO2)?, H2CO2, CH3OH, CH4, C2H4, CH3CH2OH, CH3COO?, CH3COOH, C2H6, (COOH)2, or (COO?)2, and a specific device, namely, a CO2 sensor.

Abstract: A sensing device is provided. A suction port of a chamber is sealed by using a gas sealing layer with a gas sealing filter. The gas sealing filter has a plurality of one-way passes. The one-way passes have a width in a range of several nanometers to several hundred nanometers. A gas molecular exhausts to the outside of the chamber through the one-way passes. Owing to preventing the material of gas sealing layer from flowing into the chamber by the gas sealing filter, superior sealing performance is achieved as compared to those adopting solder or sealing material, thereby facilitating control of the condition in the chamber.

Abstract: An integrated sensing device is capable of detecting analytes using electrochemical (EC) and electrical (E) signals. The device introduces synergetic new capabilities and enhances the sensitivity and selectivity for real-time detection of an analyte in complex matrices, including the presence of high concentration of interferences in liquids and in gas phases.

Abstract: An oxygen sensor bung of motor vehicle exhaust pipe comprises at least a base, a catalytic converter and a seal lid. The base has an external connection section at one end that contains a first chamber to hold the catalytic converter and is fastened by the seal lid. The external connection section has a first external thread on the surface to fasten to a holding seat of an exhaust pipe. The base has a second chamber on another end with a third internal screw hole formed inside to hold an oxygen sensor by fastening with a second external thread formed thereon. The catalytic converter includes a barrel type casing containing a beehive structure made of precious metal to increase exhaust gas process area. Therefore impurities in the exhaust gas can be reduced and timely replacement of the catalytic converter can be accomplished, and accurate detection of oxygen content can be achieved.

Abstract: Disclosed is a high sensitive gas sensor using a carbon material containing an ionized metal catalyst and a method of manufacturing the same. The method includes the steps of: (1) preparing a hydroxide solution by dissolving a hydroxide in a distilled water; (2) dissolving a metal catalyst in the hydroxide solution; (3) immersing the carbon material in a solution obtained through step (2) and stirring the carbon material; (4) heat-treating a mixture obtained through step (3); (5) cleaning the heat-treated carbon material obtained through step (4); (6) drying the carbon material cleaned through step (5); and (7) manufacturing the gas sensor by loading the carbon material obtained through step (6) on a substrate. The gas sensor having high sensitivity and responsiveness with respect to a target gas even in a normal temperature is obtained.

Abstract: The present invention includes sensors and systems that include a sensor. A sensor includes a sensor polymer, where the polymer includes a repeating unit having an anilineboronic acid-phosphate complex or an anilineboronic acid complexed with an alcohol or diol. The sensor polymer may be a copolymer, such as a random copolymer, a block copolymer, or an alternate copolymer. The present invention also provides methods for using the sensors described herein, including methods for detecting the presence of an analyte, such as CO2, in a fluid.

Abstract: The present invention is directed to a hierarchical structure characterized by ultrahigh surface area comprising: a solid substrate; an intermediate layer; and at least one plurality of nanoscale attachments that are strongly bonded to the intermediate layer. Also disclosed is a method of fabricating a hierarchical structure comprising: selecting and preparing a parent substrate, wherein the preparing may optionally include cleaning or activation; modifying the substrate surface to form an intermediate layer; attaching at least one plurality of nanoscale attachments, wherein the nanoscale attachments are selected from nanotubes, nanoparticles, or combinations thereof, onto the intermediate layer; optionally attaching a second plurality of nanoscale attachments, wherein the nanoscale attachments are selected from nanotubes, nanoparticles, or combinations thereof, onto the first plurality of nanoscale attachments and intermediate layer.

Abstract: An exhaust sensor comprises a sensing electrode and a reference electrode each in contact with an electrolyte. At least one of the sensing electrode and the reference electrode are formed by depositing an electrode precursor material on an electrolyte precursor material and sintering the combination at a sufficient temperature for a sufficient time to achieve densification of the electrolyte, wherein the electrode precursor material comprises an alkali salt. Electrode patterns having enhanced perimeter ratios are also disclosed. The resulting exhaust sensor is capable of providing a usable output at a reduced operating temperature.

Abstract: A gas sensor includes known types of electrodes such as sensing electrodes, counter electrodes or reference electrodes to sense the presence of a predetermined gas. In addition, at least one diagnostic electrode is carried in the sensor. The diagnostic electrode implements at least one diagnostic function without substantially impairing the gas sensing function. The diagnostic electrode is immersed in sensor electrolyte.

Abstract: An electrochemical gas sensor includes additional gas diffusion electrodes incorporated to carry out one or more diagnostic functions while the sensor is responding to a target gas. Members of a plurality of sensing and diagnostic electrodes can be switched by associated control circuits to intermittently sense a target gas while others intermittently sense a different gas. The diagnostic electrodes are in direct communication with the target gas that is entering the cell.

Abstract: A gas sensor (100) in a sensor housing (1) has a gas-permeable membrane (7) for the inlet of a gas sample to be analyzed to a measuring electrode (6). The gas sensor (100) is provided with a test gas generator (18), which has a generator housing (8). The generator housing (8) is fastened in the area of the gas-permeable membrane (7) and has a central gas outlet opening (21) for the gas sample to pass into the sensor and has outlet openings (19) directed towards the gas-permeable membrane (7) for the test gas.

Abstract: It is an object of the present invention to provide a gas concentration detection apparatus that is capable of forming an accurate activity judgment when a gas concentration detection cell begins to detect gas concentration with high accuracy. When warm-up begins at time t0 in a NOx concentration detection apparatus that achieves NOx concentration detection with a NOx sensor cell after excess oxygen is discharged by an oxygen pump cell, a NOx sensor cell output begins to rise at time t1. Subsequently, at time t2, an oxygen pump cell output begins to rise. An inflection point appearing in the NOx sensor cell output is then located. At time t5 at which the inflection point appears, an activity judgment about the NOx sensor cell is formed.

Abstract: An electrochemical gas sensor includes: a disc-shaped metal bottom member; a cylindrical metal side member that extends along the axial direction of the bottom member to surround the bottom member; a ring-shaped polymer gasket that includes an opening in the center and in which both sides of the opening each have an L-shaped member in cross section, with one section of the L-shaped member being in contact with the inner side of the side member and the other section of the L-shaped member being in contact with the bottom member; a gas sensor body that is located in the opening of the gasket and whose bottom surface is in contact with the bottom member and that includes a pair of electrodes and a solid electrolyte membrane or a separator retaining a liquid electrolyte; and a metal cover that is in contact with the top surface of the gas sensor body.

Abstract: The present invention provides a class of sensors prepared from regions of conducting organic materials and conducting materials that show an increase sensitivity detection limit for amines. The present class of sensors have applications in the detection of spoiled food products and in testing for diseases, such as cholera and lung cancer, which have amines as biomarkers.

Abstract: Fluid analyte sensors include a photoelectrocatalytic element that is configured to be exposed to the fluid, if present, and to respond to photoelectrocatalysis of at least one analyte in the fluid that occurs in response to impingement of optical radiation upon the photoelectrocatalytic element. A semiconductor light emitting source is also provided that is configured to impinge the optical radiation upon the photoelectrocatalytic element. Related solid state devices and sensing methods are also described.

Abstract: An electrochemical sensor includes a polymeric housing and at least a first electrode within the housing. The first electrode includes an electrochemically active surface. The electrochemical sensor further includes a first connector in electrically conductive connection with the first electrode. The first connector includes a first extending member formed from a conductive loaded polymeric material. The first extending member is formed such that an interior thereof comprises conductive elements within a matrix of the polymeric material so that the interior is electrically conductive and an exterior surface thereof comprises the polymeric material and is less conductive than the conductive interior. The conductive interior of the first extending member is in electrically conductive connection with the first electrode. The first connector further includes a first extending conductive element in electrical connection with the conductive interior.

Abstract: The present invention concerns a device for detecting gases or volatile organic compounds (VOC) comprising an electrically conducting or semiconducting zone f unctionalized with an organic film resulting from the polymerization of aromatic diazonium salt derived monomer.

Abstract: A multi-gas microsensor assembly for simultaneously detecting carbon dioxide and oxygen in real time. According to one embodiment, the assembly comprises a non-conductive, solid substrate. A plurality of sensing electrodes, a single reference electrode, and a single counter electrode are positioned on one side of the non-conductive, solid substrate. In addition, all of the electrodes are in intimate contact with the same side of a solid-polymer electrolyte anion-exchange membrane, the solid polymer electrolyte membrane having at least one gas diffusion opening aligned with each sensing electrode. The sensor is operated in a three-electrode potentiostatic mode, in which a constant potential is maintained between the sensing and reference electrodes, and the current is measured between the sensing and counter electrodes. Control of the electrodes is achieved with a small bi-potentiostat.

Abstract: A method for detecting the presence or absence of a gas bubble in an aqueous liquid is provided comprising providing a sensor positioned within a measuring chamber, wherein the sensor is configured to determine the concentration of a gaseous component dissolved in a liquid, the sensor comprising a sensitive region; setting a gas partial pressure at the sensor, wherein the gas partial pressure differs from an expected value of the gas partial pressure of the gaseous component of a liquid to be measured; exposing the sensor to the liquid to be measured; resting the liquid until standstill is attained; recording a signal from the sensor as a function of time until the signal becomes constant; and detecting the presence or absence of a gas bubble from the variation of the signal over time. The gas bubble, if present, is in at least partial contact with the sensitive region of the sensor.

Abstract: A detector includes a smoke detecting section that includes a light-receiving unit at a position at which the light-receiving unit does not directly receive light emitted by a light-emitting unit in a chamber in which a labyrinth for preventing light from directly entering from the outside and an insect net covering the rim of the labyrinth are provided, the light-receiving unit receiving light scattered by smoke flowing into the chamber. An opening hole is formed open in the surface of the cover receiving hot air current, of the detector. In the cover behind the opening hole, an electrochemical gas sensor is placed to bring gas generated by a fire through the opening hole into contact with an electrolyte solution to detect the gas by an electrode.

Abstract: A method is provided for mitigating hydrogen evolution within a flow battery system that includes a plurality of flow battery cells, a power converter and an electrochemical cell. The method includes providing hydrogen generated by the hydrogen evolution within the flow battery system to the electrochemical cell. A first electrical current generated by an electrochemical reaction between the hydrogen and a reactant is sensed, and the sensed current is used to control an exchange of electrical power between the flow battery cells and the power converter.

Abstract: A gas sensor has a cylindrical housing case, a gas sensor element as a sensor component, and a filler portion. The filler portion is formed between the inner surface of the cylindrical housing case and the outer surface of the gas sensor element. The filler portion is filled with filler powder composed of talc as a layered compound. Talc is a principal ingredient of the filler powder. The space formed between the cylindrical housing case and the gas sensor element is sealed with the filler powder in the filler portion. The filler powder in the filler portion has a degree of c-axis orientation within a range of 60% to 85%, The filler powder in the filler portion has a porosity of not more than 10%.

Abstract: A system for operating at least first and second amperometric sensors includes a cartridge and a control device. The cartridge includes a first amperometric sensor and a second amperometric sensor. The first amperometric sensor is in fluid flow communication with a liquid sample inlet and includes a first electrode. The second amperometric sensor is in fluid flow communication with a liquid sample and includes a second electrode. The control device sets the first and second electrodes to about the same potential such that the first and second amperometric sensors can be operated simultaneously.

Abstract: A three-dimensionally ordered macroporous sensor apparatus and method of forming the same. A direct opal film associated with a number of pores can be formed by vertical deposition of one or more nanospheres on a glass substrate. The thickness of the direct opal film can be controlled by concentration of the nanospheres. A mixture of a precursor/monomer of a sensing material and a complexing agent can be filled into the pores associated with the direct opal film, such that the mixture permeates the interstitial spaces between the pores. The nanospheres may then be removed in order to form a three dimensionally-ordered macroporous electrode with an inverse opal structure. Optionally, the sensing material can be coated on an inverse opal backbone structure formed from an external inactive material and utilizing a coating operation.

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 method of operating an electrochemical gas sensor includes: a) exposing, for a first predetermined duration, the electrochemical gas sensor to an atmosphere containing a target gas while the gas reaction capability of the electrode assembly is substantially reduced from a working level, such that target gas is collected within the housing; b) increasing the gas reaction capability of the electrode assembly to a level at which it consumes collected target gas and thereby outputs a signal to the sensing circuit, including an initial transient decay signal; c) monitoring the transient decay signal; and d) analysing the rate of decay of the transient decay signal to determine whether the performance of at least one component of the electrochemical gas sensor is within acceptable limits. An apparatus for operating an electrochemical gas sensor, adapted for connection to an electrochemical gas sensor via a sensing circuit for control thereof, can carry out the disclosed method(s).

Abstract: An electrochemical oxygen sensor includes a micro-porous plastic membrane supported on a sealing disk and located between a gas inflow port and the sensor's electrolyte. The membrane and disk minimize thermal shock effects due to using the sensor at a first location, at a first temperature, and then moving it to a second location at a different temperature.

Abstract: An electrochemical gas sensor has a working electrode having a gas porous membrane and a catalyst layer formed on one side of the membrane; a counter electrode, electrolyte in contact with the catalyst both of the working electrode and of the counter electrode; and a support that is in contact with, and presses against the side of the working electrode remote from the electrolyte and that compresses the electrodes and the electrolyte together. The support includes open areas enabling gas to contact the membrane. The support provides a faster response and provides greater efficiency of catalyst usage.

Abstract: Carbon nanotubes are formed on projections on a substrate. A metal, such as nickel is deposited on the substrate with optional platforms, and heated to form the projections. Carbon nanotubes are formed from the projections by heating in an ethylene, methane or CO atmosphere. A heat sensor is also formed proximate the carbon nanotubes. When exposed to IR radiation, the heat sensor detects changes in temperature representative of the IR radiation. In a gas sensor, a thermally isolated area, such as a pixel is formed on a substrate with an integrated heater. A pair of conductors each have a portion adjacent a portion of the other conductor with projections formed on the adjacent portions of the conductors. Multiple carbon nanotubes are formed between the conductors from one projection to another. IV characteristics of the nanotubes are measured between the conductors in the presence of a gas to be detected.

Abstract: A gas probe, in particular a lambda probe for the analysis of exhaust gases from a mobile internal combustion engine, includes at least one protective device, at least partly surrounding a sensitive sensor element of the gas probe, which comes into contact with a gas. The at least one protective device includes a gas contact face which at least partly has a hygroscopic surface.

Abstract: An electrochemical ethylene sensor and method for ethylene sensing are disclosed. In one aspect, an electrochemical ethylene sensor includes a working electrode and a counter electrode on an electrically insulating substrate. An ionic liquid layer covers the working electrode and counter electrode. In one method, a voltage is applied to the working electrode which is equal to or lower than the voltage required for the onset of oxidation of the material of the working electrode, for example, in the range spanning 700 mV before the onset of oxidation of the material of the working electrode.

Abstract: A gas detector includes at least two electrodes. The electrodes are carried on a common substrate having first and second spaced apart surfaces. The electrodes are formed on respective ones of the surfaces with the substrate sandwiched therebetween.

Abstract: A hydrogen quantity sensor can directly measure hydrogen contained in a hydrogen storage device with simple and easy means. The hydrogen quantity sensor comprises a detecting electrode comprised of a hydrogen storage alloy disposed inside a hydrogen storage vessel, a standard electrode disposed to confront the detecting electrode; and an electrolyte member disposed between the detecting electrode and the standard electrode. The detecting electrode, the standard electrode and the electrolyte member constitute a sensor portion to measure hydrogen concentration within the hydrogen storage alloy as an electromotive force value.

Abstract: An electrochemical sensor is provided especially for gases. The electrochemical sensor has a mediator compound, which is both dissolved in an electrolyte (9) in a saturated form and is present as an excess solid (10) in the electrolyte (9).

Abstract: A control device for a gas sensor is configured to: receive a mode command to specify one of a plurality of sensor energization modes including at least a gas concentration detection mode, a protection mode and a pre-energization mode; switch a sensor element of the gas sensor into the one of the plurality of sensor energization modes according to the mode command; judge satisfaction of a certain condition where the mode command is to specify the gas concentration detection mode and the sensor element is in any of the plurality of sensor energization modes other than the pre-energization mode at the time of receipt of the mode command; and prohibit the sensor element from switching over to the gas concentration detection mode when the certain condition is satisfied.

Abstract: A wellbore tool has an electrochemical sensor for measuring the amount of hydrogen sulphide or thiols in a fluid downhole in a wellbore. The sensor 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 the other side of the membrane being exposed to a chamber containing at least two electrodes and 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. Measurement is made by passing formation fluid along the flow path and repeatedly applying varying potential to one electrode and measuring the peak current flowing between that electrode and a second electrode.

Abstract: A gas sensor is disclosed. The gas sensor includes a gas sensing electrode and a counter electrode disposed within a housing, and respective conductors that connects the gas sensing electrode and the counter electrode to a sensing circuit. The housing includes walls defining a cavity containing electrolyte in fluid communication with the gas sensing electrode and counter electrode and wherein the walls further comprise one or more coatings or second layers superimposed on the walls. The one or more coatings or second layers have a lower water vapor transport rate than that of the walls, such that, in use, water vapor transport between the electrolyte and atmosphere through the walls of the housing is reduced.

Abstract: An electrochemical oxygen sensor is provided. The electrochemical sensor includes a housing having first and second compartments, a sensing electrode disposed within the first compartment of the housing, a consumable anode disposed within the second compartment of the housing, a porous separator between the sensing electrode and consumable electrode that separates the first and second compartments and an electrolyte saturating the porous separator and consumable anode. A first aperture on a first end of the housing extends between an outside surface of the housing and first compartment that allows gas access to the sensing electrode. A venting system on a second, opposing end of the housing includes a second aperture extending between the outside surface of the housing and second compartment and has a predetermined permeability that controls pressure in the second compartment and loss of moisture from the sensor.

Abstract: An apparatus and method for individually detecting NO and NO2 concentrations as NOX components of an object gas. An NO concentration corresponding value is obtained from a first detection element not having a reduction section. An NO concentration corresponding value is obtained from a second detection element having a reduction section, and having an NO2/NO sensitivity ratio greater than that of the first detection element. The difference ?C between the NO concentration corresponding values of the two detection elements is obtained, and divided by the difference ?S between the NO2/NO sensitivity ratios of the two detection elements, whereby an NO2 concentration corresponding value is obtained. A value obtained by multiplying the NO2 concentration corresponding value by the NO2/NO sensitivity ratio of the second detection element is subtracted from the NO concentration corresponding value of the second detection element, whereby an NO concentration corresponding value is obtained.

Abstract: The present invention relates to a gas-monitoring assembly (100) and method for selectively determining the presence of a target gas in a gaseous environment that potentially comprises one or more interfering gases. Such gas-monitoring assembly and method specifically employ one or more gas sensors (S1) one or more getters (G1) arranged and constructed to reduce cross-interference caused by potential presence of the interfering gases in such gaseous environment to be monitored. The gas-monitoring assembly and method of the present invention are capable of monitoring a gaseous environment with respect to potential presence of multiple target gases that may interfere with one another.

Abstract: An electrochemical sensor includes a micro-porous plastic membrane supported on a disk and located between a gas inflow port and an electrolyte having a gelled oxygen diffusion barrier. The oxygen diffusion barrier, formed of gelled agar, minimizes thermal shock effects by impregnating any porous materials in the sensor.

Abstract: The invention provides an electrochemical sensor comprising an electrode assembly which comprises at least two electrodes, one of the electrodes comprising a metal species capable of catalysing the oxidation of hydrogen and/or methane. The sensor may be used in the detection and quantification of hydrogen and/or methane in exhaled breath, for example as a means of diagnosing lactose malabsorption or lactose intolerance.

Abstract: The measuring device 1 includes a measurement vessel 13 contained a liquid 12 filled therein, and a sensor 11 provided in the measuring vessel 13 and for detecting components of a gaseous sample dissolved in the liquid 12. The measuring device 1 also includes a bubble-generating unit 14, which is supplied with a gaseous sample and has an aperture 141 for discharging the gaseous sample in form of bubbles into the liquid. The aperture 141 faces the sensor 11 and the bubble-generating unit 14 is disposed to have a predetermined clearance with the sensor 11. A relation of 1/2Y?X?3/2Y is satisfied, where X represents a distance of a clearance between the bubble-generating unit 14 and the sensor 11 and Y represents a diameter of the aperture 141 of the bubble-generating unit 14.

Abstract: Cartridge unit for an electrochemical sensor includes a cartridge (2) prefilled with electrolyte and having a first end closed by a selectively permeable membrane (7), and a second end (6) having a fastening device (11) arranged for fastening the cartridge to the electrochemical sensor (24). The cartridge unit further has a supporting member (3) to which the cartridge (2) is detachably fastened, and closing devices (4, 20) for closing the second end (6) of the cartridge (2). These closing devices (4, 20) are able to be opened by a user to allow the cartridge (2) to be fastened to the electrochemical sensor (24) and then to be detached from the supporting element (3).

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: A hydrogen gas sensor comprising a detection electrode, a reference electrode, and an electrolyte contacting with these electrodes, in which the reference electrode and the detection electrode are composed of a material having a property that hydrogen molecule doesn't voluntarily dissociate into atomic hydrogen on a surface of the electrode in Standard State such as nickel, titanium, copper, tungsten and the like, in which hydrogen gas is detected by an electromotive force generated between the reference electrode and the detection electrode while at least the detection electrode is maintained at a temperature not less than a temperature that hydrogen molecule begins to dissociate into atomic hydrogen voluntarily on the surface of the detection electrode.

Abstract: Techniques are generally described for a gas sensor testing device. In some examples, the gas sensor testing device comprises a chamber including a wall having an inside surface and an outside surface, the inside surface defining a gas channel, the wall including at least one water molecule. In some examples, the gas sensor testing device includes a first electrode wire coupled to the outside surface of the wall. In some examples, the gas sensor testing device includes a second electrode wire coupled to the inside surface of the wall. In some examples, the wires are operable to generate a current through the wall when a voltage is applied across the wires. In some examples, the current is effective to electrolyze the at least one water molecule to generate a gas.