Abstract: A solid electrolyte three-electrode electrochemical test device comprises a housing, a working electrode, a counter electrode, a reference electrode, a first conductive structure, a second conductive structure, a third conductive structure, and a solid electrolyte layer. The housing comprises a groove and a first through hole located at a bottom of the groove. The reference electrode is insulated from the counter electrode. The first conductive structure and the working electrode are stacked with each other, and the working electrode and at least a part of the first conductive structure are located in the first through hole. The solid electrolyte layer, the counter electrode, the reference electrode, the second conductive structure and the third conductive structure are located in the groove, and the first conductive structure, the working electrode, the solid electrolyte layer, the counter electrode, and the second conductive structure are sequentially stacked and located coaxially with each other.

Abstract: A continuous glucose monitoring system may utilize electrode current (Isig) signals, Electrochemical Impedance Spectroscopy (EIS), and Vcntr values to optimize sensor glucose (SG) calculation in such a way as to enable reduction of the need for blood glucose (BG) calibration requests from users.

Abstract: A lactate-responsive enzyme may form the basis for lactate detection and quantification using an electrochemical analyte sensor. Various features may be incorporated within an analyte sensor containing a lactate-responsive enzyme, particularly lactate oxidase, to improve sensitivity and response stability of the analyte sensor. Such analyte sensors may comprise: a working electrode having an active area disposed thereon, and a mass transport limiting membrane overcoating at least the active area upon the working electrode. The active area comprises at least a polymer, an albumin, and a lactate-responsive enzyme that is covalently bonded to the polymer. The mass transport limiting membrane may comprise at least a crosslinked polyvinylpyridine homopolymer or copolymer. The analyte sensors may determine a lactate concentration in a biological fluid, particularly in vivo, which may be correlated to various physiological conditions.

Abstract: An interface for coupling a dissolved oxygen sensor to a single-use bioreactor container is provided. A dissolved oxygen (DO) window membrane is operably coupled to the single-use container and configured to position a DO sensor at least partially within the single-use container. In some embodiments, a DO window body mounts the DO window membrane at a distal end thereof. The DO window body can include a slide lock for facilitating positioning of a DO sensor within the DO window body. Additionally, the DO window body may include at least one heat exchange fin.

Abstract: A sensor can include a nanostructure in a housing configured to contact a sample.

Abstract: Provided is a preparation method for an immunoelectrode. The immunoelectrode comprises a substrate, a gold layer, a conductive polymer layer and an antibody layer. The substrate, the gold layer, the conductive polymer layer and the antibody layer are sequentially attached from bottom to top. The preparation method for the immunoelectrode specifically comprises the following steps: (1) preparing the conductive polymer layer: preparing a polypyrrole layer on a gold-plated substrate to obtain a polypyrrole/gold-plated substrate; (2) preparing the immunoelectrode: preparing the antibody layer on the polypyrrole layer to obtain an antibody/polypyrrole/gold-plated substrate; and (3) forming an immunoelectrode system: fixing a bare gold-plated substrate to the outer side of the antibody/polypyrrole/gold-plated substrate to obtain the immunoelectrode system. A polypyrrole material is used for fixing an antibody of a biological recognition element and immobilizing the antibody on the immunoelectrode.

Abstract: Provided is an electrolyte analyzing device in which contamination caused by contacting different reagents with a suction nozzle is prevented when reagent replacement is performed by a user. The electrolyte analyzing device includes a reagent container setting unit 502 that sets a dilute solution bottle 101-1 which houses a dilute solution, an internal standard solution bottle 101-2 which houses an internal standard solution, and a reference electrode solution bottle 101-3 which houses a reference electrode solution. The reagent container setting unit includes a partition wall between the dilute solution bottle 101-1 and the internal standard solution bottle 101-2, and the reference electrode solution bottle 101-3 when the dilute solution bottle 101-1, the internal standard solution bottle 101-2, and the reference electrode solution bottle 101-3 are set.

Abstract: A symmetrical supercapacitor cell is disclosed comprising at least two electrode split sections, at least two electrodes, a plurality of ring isolators, and a spring pin arrangement. The at least two electrodes are placed in between the at least two electrode split sections, wherein a plurality of ring isolators is connected with a plurality of bolts to fasten the at least two electrode split sections. Also disclosed is an integrated thermal management system with a supercapacitor cell including a base support holder, a heating coil casing, a heating coil, and a cavity. The heating coil is installed inside the heating coil casing that is underneath a supercapacitor cell body. Further, a cavity is formed around the supercapacitor cell and contains an oil that is heated via the installed heating coil to achieve a desired temperature.

Abstract: Disclosed herein are puncturing devices and puncturing systems including the puncturing devices. Such puncturing devices and systems include those that sense a difference between venous blood and arterial blood as a function of blood oxygen, impedance, or pressure. As a result, the puncturing devices and systems are able to differentiate between a venipuncture and an arterial puncture. Methods of the puncturing devices and systems for differentiating between a venipuncture and an arterial puncture for are also disclosed.

Abstract: A chlorine dioxide gas generating device is provided. The device includes a housing, an anode and a cathode, a first reagent and a second reagent, and a hydrophobic membrane. The housing has a cavity. The anode and the cathode are each coupled to and located within the cavity. The first reagent and the second reagent are each located within the cavity. The first reagent and the second reagent are configured to generate chlorine dioxide gas via electrolysis responsive to an electric current being passed into the anode and the cathode. The hydrophobic membrane is coupled to the housing, and is configured to allow the chlorine dioxide gas to exit the housing while preventing fluids from flowing therethrough.

Abstract: Infusion systems including infusion devices and consumables and related operating methods are provided. An exemplary consumable component includes a housing, a reservoir contained within the housing, a pumping mechanism for dispensing a fluid from the reservoir, and a readable element associated with the housing. The readable element maintains calibration data characterizing a relationship between delivery of the fluid and actuation of the pumping mechanism.

Abstract: An electrochemical oxygen sensor includes a sensing surface having a working electrode and a reference electrode, a hydrophilic layer formed from an oxygen diffusion-limiting layer emulsion overlaying the working electrode and a hydrophobic membrane formed from a hydrophobic solution disposed over the hydrophilic layer. The hydrophilic layer contains an epoxy network and a hydrophilic polymer. The hydrophobic layer contains an acetate copolymer and a cross-linking agent that reacts with the liquid epoxy resin in the hydrophilic layer forming the epoxy network where the hydrophobic member is water vapor and oxygen permeable.

Abstract: A system for separating and analyzing a discrete sample of multiphase fluid includes a separation vessel having a first inner chamber containing a discrete sample of multiphase fluid, and an analytical cell in fluid communication with the separation vessel. The analytical cell has a second inner chamber containing a diluted aqueous liquid phase sample for analysis. The system further includes probes disposed in the second inner chamber, each probe having a sensing area at a distal end, and being oriented in the second inner chamber such that the sensing area is immersed in the diluted aqueous liquid phase sample contained in the second inner chamber. The plurality of probes include a first probe whose sensing area surface is coated with a first ion-exchange membrane; and a second probe whose sensing area surface is coated with a second ion-exchange membrane, the second ion-exchange membrane being different from the first ion-exchange membrane.

Abstract: Methods and apparatus including determining a rate of occurrence of a glycemic excursion event, determining a frequency of an alarm activation associated with the glycemic excursion event, determining an analyte level associated with the alarm activation, and setting an alarm parameter based on one or more of the determined rate of occurrence of the glycemic excursion event, the frequency of the alarm activation associated with the glycemic excursion event or the determined analyte level are provided.

Abstract: A microbial sensor, system, and method that can be used to determine a chemical environment and/or substrate concentrations in anaerobic or aerobic environments, such as soils, sediments and ground waters, are disclosed. An exemplary system uses one or more (e.g., inert) measurement electrodes and a reference electrode. The reference electrode can include an electrode exposed to atmospheric oxygen (e.g., a cathode) or an electrode exposed to stable anaerobic or aerobic conditions. The exemplary microbial sensor system measures open-circuit voltage to characterize the chemical (oxidizing or reducing) environment and/or recovery voltage to measure substrate concentrations in the subsurface.

Abstract: In one aspect, an apparatus for monitoring a physiological condition of a patient is disclosed. The apparatus includes a body having an attachment portion configured to be inserted into the skin of a patient to affix the body to the patient. The apparatus includes a sensor coupled to the body that is configured to generate sensor data corresponding to a physiological condition of the patient when the body is secured to the skin of the patient. The apparatus further includes a reference sensor that is remote from the sensor coupled to the body and is configured to engage an outer surface of skin to generate reference data against which the sensor data is compared.

Abstract: A control handle for a steerable catheter body for navigation of the catheter body through a biological lumen and manipulation at a treatment site. The control handle includes a housing assembly that houses a piston assembly and a resistance adjusting assembly. The resistance adjusting assembly can be adjusted to provide the desired frictional characteristics of the user for control of the resistance between the piston assembly and the housing assembly. In one embodiment, the piston assembly is configured to provide a frictional resistance that varies dynamically to substantially match the restorative force across the range of catheter tip deflection. Other embodiments include a vibrating member that provides tactile feedback to the operator to indicate conditions at the distal end of the catheter, such as contact force.

Abstract: In some examples, a medical device includes an elongated body defining an inner lumen. The medical device further includes an anchoring member and a first sensor at a proximal portion of the elongated body, and a second sensor at a distal portion of the elongated body or distal to a distal end of the elongated body. The second sensor is configured to sense a substance of interest and the elongated body comprises a material that is a substantially non-permeable to the substance of interest.

Abstract: A ventilation system includes an electrochemical filter for depleting alkyl phenols, especially 2,6-diisopropyl phenol, in breathing gas. A method uses the filter for removing alkyl phenols, especially 2,6-diisopropyl phenol, from breathing gas.

Abstract: The invention relates to a method for controlling a concentration of dissolved oxygen in a volume (V) of water (W), wherein a device (1) for dissolving oxygen in water (W) is submerged in said volume (V) of water, wherein oxygen is injected by the device (1) with an adjustable flow rate into a main water stream (W?) sucked into a housing (100) of the device (1), and wherein the oxygen enriched main water stream (W?) is discharged by the device (1) out of the housing (100) of the device (1) into said volume (V) of water (W), and wherein a current concentration of oxygen dissolved in the sucked main water stream (W?) is measured with an oxygen probe (6) that is integrated into the housing (100) of the device (1), wherein said current concentration of dissolved oxygen is transmitted in a wireless fashion to a hand-held device (9) of an operator, and wherein the flow rate of the injected oxygen is controlled such that the measured current concentration of dissolved oxygen approaches a pre-defined reference value.

Abstract: Various embodiments include a sensor for use in an exhaust gas stream of an internal combustion engine comprising: a first electrode; a second electrode electrically insulated from the first electrode by an insulation; and a connection arrangement secured to the first electrode and the insulation by a solder connection. The connection arrangement is configured to position the first electrode relative to the second electrode. The solder connection is arranged at least partly outside an electric field generated during measurement operation of the sensor by applying a first electrical potential to the first electrode and applying a second, different, electrical potential to the second electrode.

Abstract: An electrochemical oxygen sensor includes a sensing surface having a working electrode and a reference electrode, a hydrophilic layer formed from an oxygen diffusion-limiting layer emulsion overlaying the working electrode and a hydrophobic membrane formed from a hydrophobic solution disposed over the hydrophilic layer. The hydrophilic layer contains an epoxy network and a hydrophilic polymer. The hydrophobic layer contains an acetate copolymer and a cross-linking agent that reacts with the liquid epoxy resin in the hydrophilic layer forming the epoxy network where the hydrophobic member is water vapor and oxygen permeable.

Abstract: The present disclosure relates to methods of creating a biosensor. A palladium film is deposited onto a surface of a substrate. The palladium film is then treated with an air plasma to stabilize the palladium and reduce or eliminate its catalytic activity. The biosensor is created from the treated palladium film and the substrate.

Abstract: The invention relates to a comparison unit (130) configured for determining if a first pH measuring device of a first tank (104; 106) is affected by a pH-measuring problem, the comparison unit being configured for: —receiving a first CO2 concentration and a first pH value, the first CO2 concentration being a CO2 concentration of a first gas volume above a medium in a first tank, the first CO2 concentration and the first pH value being measured at a first time when the medium in the first tank is in pH-CO2 equilibrium state with the first gas volume and before said equilibrium state is modified by the metabolism of a cell culture in the first tank, the first pH value being a measured value provided by a first pH measuring device operatively coupled to the first tank (102); —receiving a second CO2 concentration and a second pH value, the second CO2 concentration being a CO2 concentration of a second gas volume above a medium in a second tank, the second CO2 concentration and the second pH value being measured a

Abstract: A process for determining a content of hydrogen in a fluid medium includes contacting the fluid medium with a sensor. The sensor has a housing enclosing a chamber containing an ionic liquid electrolyte, a window which is permeable to hydrogen and positioned in an opening in the housing, and electrodes in contact with the ionic liquid electrolyte in the chamber. Hydrogen is allowed to pass through the window from the fluid medium into the electrolyte and the sensor is heated. Temperature and pressure of the fluid medium is determined and electrical potential is applied to the electrodes. The method also includes measuring current flow. The sensor can be used to observe hydrogen concentration by voltammetry. The method and sensor may be used for measuring downhole hydrogen content, monitoring fiber-optic cables for damage by hydrogen, corrosion monitoring, and in small-scale process plants where hydrogen is part of a gas stream.

Abstract: Molybdenum oxide is doped with vanadium, nobidium, tantalum or titanium to form a stable M5O14 theta phase crystal structure as a vapor sensitive material for detecting vapors of volatile organic compounds. That material is used between electrodes connected to a measuring device to measure a change in an electrical quality in the presence of a vapor of a volatile organic compound. Concentration of the vapor is measured to low part per million ranges.

Abstract: An electrochemical sensor (1, 101) has a sensor element (15, 115) with a measuring surface (8, 108) that faces a measuring medium (5) during use. The sensor element has a planar measuring element (2, 102). A sensor shaft (4, 104) has an aperture (13, 113) with a bezel (11, 111) at an end which, during use, faces the measuring medium. The sensor element is installed in the area of the aperture. The electrochemical sensor also has an annular sealing element (9, 109), which is arranged between the sensor element and the bezel. An insulator element (10, 110) is firmly and inseparably connected to the measuring element, exposing or recessing the measuring surface. Thus, the sealing element, which protects the electrochemical sensor against the ingress of measuring medium, is arranged sealingly between the insulator element and the bezel.

Abstract: Embodiments relate generally to a filter (110), for example, for attachment onto a gas detector device or a gas sensor, and attempt to improve the efficiency and service life of the filter (110). Embodiments typically comprise a dustproof membrane (114) and a waterproof membrane (113). Some embodiments may also comprise a splash-proof cap (130) and/or features to reduce negative pressure on the filter (110).

Abstract: Apparatus and associated methods relate to a compact gas sensor (CGS) including a housing with a central stepped cavity with one or more first lead contact(s) forming a portion of a base plane in a bottom of the cavity and one or more second lead contact(s) forming a portion of a stepped plane higher than the base plane, the cavity sized to receive a chemically based stack of material made up of a bottom diffusion electrode layer, a middle electrolyte gel layer, and a top diffusion electrode layer. The bottom diffusion electrode layer is in electrical contact with the first lead contact(s). The top diffusion electrode layer electrically couples to the second lead contact(s) via an overlaying micro electromechanical system (MEMS) element layer with conductive coating. In an illustrative example, the CGS may provide gas sensing in small spaces.

Abstract: Provided herein are devices (e.g., electrochemical sensors useful for detecting volatile organic compounds associated with certain diseases or conditions and/or diagnosing certain diseases or conditions). The devices comprise one or more layers of metal on a layer of silicon, and a layer of molecularly imprinted polymer in electrical communication with the one or more layers of metal, wherein the one or more layers of metal are each independently selected from a layer of chromium, platinum, gold, nickel, cobalt, tungsten, rhodium, iridium, silver, tin, titanium or tantalum, or an alloy thereof. Methods of using the devices (e.g., to detect one or more analytes in a sample, to detect and/or diagnose a disease or condition in a subject), and methods of making the devices are also provided.

Abstract: Breath sensor apparatus and methods of use are described herein where a flow control apparatus may generally comprise a sampling chamber defining a volume and one or more openings into the sampling chamber, at least one sensor in fluid communication with the sampling chamber, wherein the at least one sensor is configured to detect the analyte. The sampling chamber may also be configured to receive the breath sample into the sampling chamber and into contact with the at least one sensor via diffusion into the sampling chamber.

Abstract: A gas sensor comprises a support structure with a cavity (6), a sensing element (1) sensitive to a gas and arranged in the cavity (6), and a filter (3) spanning the cavity (6). The filter (3) is a size selective filter.

Abstract: A gas sensor includes know types of electrodes such has 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: A plenum assembly configured for electrophysiology assays, such as patch clamp techniques, includes one or more ground electrode assemblies. The ground electrode assemblies are individually removable from a plenum base of the plenum assembly in a non-destructive manner, and may be reinstalled in the plenum base in a manner that reestablishes electrical contact with ground circuitry without requiring soldering or other additional steps. A rejuvenating apparatus is provided for rejuvenating one or more ground electrode assemblies removed from the plenum base.

Abstract: A sensor and a corresponding method measure the pH of a solution without using an external reference electrode. The pH sensor has at least one functionalized electrode with an attached first redox active molecule and an attached second redox active molecule that are differently sensitive to pH and oxidize/reduce at different voltages, and a difference in peaks of a response of the two molecules to applied electrical parameter is measured and correlated to a particular pH.

Abstract: A physiologic sensor for measuring the partial pressure of carbon dioxide is provided. The sensor includes a generally C-shaped in cross-section sensor cover, the sensor cover defining an opening on an underside thereof; a membrane body housed within the opening, the membrane comprising an amorphous fluoroplastic, the membrane including a first end and a second end and defines a chamber therewithin; a sensor body for coupling the membrane to the sensor cover; two or more electrodes positioned within the membrane chamber; and a substantially electrolyte-free liquid contained within the membrane chamber and in contact with the two or more electrodes.

Abstract: This invention is to provide an electrode device whose manufacturing cost is suppressed and whose surface is difficult to be polluted. The electrode device comprises an internal electrode, an enclosure that houses the internal electrode, an internal solution that is housed in the enclosure and that electrically communicates a liquid junction formed in the enclosure or a response glass that forms a part or all of the enclosure with the internal electrode, and an antifouling mechanism that has a light source to irradiate ultraviolet rays on a sample contact surface of the enclosure as being a surface that makes contact with a sample and that prevents the sample contact surface of the enclosure from being polluted, and the light source is directly or indirectly mounted on an outside of the enclosure, or the light source is housed inside of the enclosure.

Abstract: An electrode for lithium ion secondary batteries, including a porous glass particle and a positive electrode active material or negative electrode active material that is capable of occluding and releasing lithium ions wherein the pore volume of the porous glass particle is from 0.1 ml/g to 2 ml/g, is used to provide a lithium ion secondary battery excellent in a charge rate property.

Abstract: In a circular cross section obtained by cutting a protector along a plane which is orthogonal to an axial direction and passes through gas introduction holes, the gas introduction holes are arranged asymmetrically in the circumferential direction of a circumferential wall of the protector. When the circular cross section is bisected into first and second divisional regions by a straight line which passes through the center of the circular cross section and does not pass through any gas introduction holes, the total opening area of gas introduction holes located in the first divisional region is smaller than the total opening area of gas introduction holes located in the second divisional region.

Abstract: To provide a gas sensor device having improved measurement accuracy. This gas sensor device is provided with: a sensor element that detects the concentration of a gas by means of heat dissipation from a heat generating body; and a cover with which the sensor element is covered. The cover has a plurality of ventilation sections, which are disposed by being separated with each other in the direction perpendicular to the flowing direction of the gas, and the sensor element is disposed between the ventilation sections.

Abstract: Provided is a gas sensor which is capable of preferably sensing an ammonia gas, and has excellent durability. A mixed-potential gas sensor includes a sensor element composed of an oxygen-ion conductive solid electrolyte, and a heater provided inside the element. The sensor element includes on a surface thereof a sensing electrode formed of a cermet including Pt, Au and an oxygen-ion conductive solid electrolyte, and also includes a reference electrode formed of a cermet of Pt and an oxygen-ion conductive solid electrolyte, and a porous electrode protective layer whose porosity is 5 to 40% covering at least the sensing electrode. The Au abundance ratio in a surface of noble metal particles forming the sensing electrode is 0.4 or more. The concentration of an ammonia gas is determined on the basis of a potential difference occurring between the sensing electrode and the reference electrode when the sensor element is disposed in a measurement gas and heated to 400° C. to 800° C.

Abstract: Electrochemical sensors for the detection of select analytes are provided. The electrochemical sensors include a barrier layer having a substantially uniformed thickness disposed between a sensing layer and an ion exchange membrane. The barrier layer includes a two-dimensional nanomaterial. The barrier layer has a thickness of less than or equal to about 1 nm. The sensing layer has a thickness of less than or equal to about 10 nm. The sensing layer generates ions in response to select analytes. The barrier layer allows the generation ions to pass therethrough and travel into the ion exchange membrane. The barrier layer acts as a physical barrier to contaminants and larger molecules.

Abstract: A gas sensor includes a first electrode having a first main surface and a second main surface opposite to the first main surface; a second electrode having a third main surface facing the second main surface and a fourth main surface opposite to the third main surface; a metal oxide layer disposed between the first electrode and the second electrode, and being in contact with the second main surface and the third main surface; and an insulating film covering at least a part of the first electrode, a part of the second electrode, and at least a part of the metal oxide layer. At least a part of the fourth main surface is exposed to gas which contains a gas molecule including a hydrogen atom. A resistance value of the metal oxide layer decreases when the second electrode is in contact with the gas molecule.

Abstract: An electrochemical gas sensor (10) includes a housing (20) and with at least one electrode (21, 22). The housing (20) has a gas inlet (23). An at least strongly acidic, liquid electrolyte (30) is present in the gas sensor (10). The electrolyte (30) partly wets the electrode (21, 22). Provisions are made in such a gas sensor (10) for the electrolyte (30) to contain an additive that contains at least one surfactant. An electrolyte (30) is also provided for a gas sensor (10), which electrolyte (30) contains at least one surfactant as an additive.

Abstract: An electrochemical cell for sensing gas has added mechanical support for the working electrode to prevent flexure of the working electrode due to pressure differentials. The added mechanical support includes: 1) affixing a larger area of the working electrode to the body of the cell; 2) a gas vent to a cavity of the body to equalize pressures; 3) a rigid electrolyte layer abutting a back surface of the working electrode; 4) infusing an adhesive deep into sides of the porous working electrode to enhance rigidity; 5) supporting opposing surfaces of the working electrode with the rigid package body; and 6) other techniques to make the working electrode more rigid. A bias circuit is also described that uses a controllable current source, an integrator of the varying current, and a feedback circuit for supplying a voltage to the counter electrode and a bias voltage to the reference electrode.

Abstract: A method produces a multilayer film for covering a bone defect site. The film comprises at least one substantially completely bioresorbable covering layer, and the at least one covering layer is placed on a thermally deformable and substantially completely bioresorbable molding layer. The at least one covering layer is connected to the molding layer thermally and/or mechanically, preferably in a compressed manner. Mandrel-like protrusions are arranged on the molding layer, and the protrusions are pressed into the at least one covering layer by the placement of the at least one covering layer on the molding layer and/or pushed through the at least one covering layer. Alternatively or in addition to the protrusions, substantially completely bioresorbable connection devices, preferably rivets or pins, are pushed through the molding layer and the at least one covering layer.

Abstract: A method of operating a sensor system including at least one sensor for detecting an analyte gas and a control system includes electronically interrogating the sensor to determine the operational status thereof and upon determining that the operational status is non-conforming based upon one or more predetermined thresholds, the control system initiating an automated calibration of the sensor with the analyte gas or a simulant gas.

Abstract: The subject matter of the present disclosure generally relates to systems and methods for sensing analytes with a high selectivity and low responses to interferences in an environment. In one embodiment, a sensor was developed which comprises a sensor electrode, a coupling element operationally coupled to a discrete segment of the sensor electrode, and an activation material in operational contact with the coupling element and configured to induce an irreversible sensor response for a selected sensing application.

Abstract: The principles and embodiments of the present invention relate to methods and systems for safely providing NO to a recipient for inhalation therapy. There are many potential safety issues that may arise from using a reactor cartridge that converts NO2 to NO, including exhaustion of consumable reactants of the cartridge reactor. Accordingly, various embodiments of the present invention provide systems and methods of determining the remaining useful life of a NO2-to-NO reactor cartridge and/or a break-through of NO2, and providing an indication of the remaining useful life and/or break-through.

Abstract: A gas detection device including a vessel, wherein the vessel contains an aqueous solution, and a sensing element operably coupled to the vessel, wherein the sensing element is not in direct contact with the aqueous solution.