Abstract: Presented is a gas sensor and method for detecting the quantity of a measurement gas contained in a gas mixture. The sensor includes a prechamber, a first pump device disposed in the prechamber configured to set the partial pressure of a free gas component of a detection gas to a predetermined value, and a measuring chamber separated from the prechamber by a diffusion barrier. The measuring chamber includes a detection device configured to determine the concentration of the detection gas. The sensor further includes an inlet chamber separated from the prechamber by a diffusion barrier, a second pump device disposed in the inlet chamber configured to set the partial pressure of the free gas component of the detection gas to a predetermined value, and a third pump device disposed in the measuring chamber and configured to set the partial pressure of the free gas component to a predetermined value.

Abstract: Metal-oxide gas sensor. According to one embodiment, the sensor includes a layer or pellet of tungsten trioxide (WO3) substituted with one or more added metals. Preferably, the added metals are substituted in a concentration between about 0.005 and 10%, have an oxidation state less than +6, and possess a similar ionic radius to W6+. The substituted metal oxides are preferably formed as nanoparticles and sintered into a dense structure or coating possessing a surface-depletion layer sensitive to the surface adsorption of gas molecules and whose resistance changes in a predictable manner with gas adsorption. The extent of resistance change, rate of change and rate of desorption can be different for different gases, depending on the gas molecule's polarizability, dipole moments and electron configuration. The sensor can be used in a wide range of temperatures and corrosive conditions because of the intrinsic stability of the substituted metal oxides.

Abstract: A micro fuel cell sensor having laminated gas permeable membrane. The sensor comprises a housing, first and second gas diffusing electrodes spaced from one another, a fuel-cell spacer having an acidic electrolyte disposed between said first and second electrodes, and two gas permeable membranes. The first gas permeable membrane comprises a polymer laminated on a metal substrate, wherein the substrate comprises pores that have dimensions at least less than one-half the thickness of the polymer film.

Abstract: A flow head for a gas sensor having a sensing element is provided. The flow head includes a body at least partially defining a cavity in thermal communication with the sensing element. The body includes an inlet port located within an annular surface of the body and an outlet port located within the annular surface of the body. The body also includes an inlet passage offset from and parallel to the cavity, wherein the inlet passage configures the inlet port and the cavity to be in fluid communication with one another. The body further includes an outlet passage offset from and parallel to the cavity, wherein the outlet passage configures the outlet port and the cavity to be in fluid communication with one another.

Abstract: A sensor for determining the concentration of a gas in gas mixtures, which has a measuring and a reference electrode as well as a polymer layer, which is in contact with the gas mixture and with the measuring electrode. A pH sensitive electrode is provided as the measuring electrode.

Abstract: An electrochemical sensor comprising sensing and counter electrodes and first (sensor) and second (reservoir) matrices of respectively different porosity, each matrix containing electrolyte, the surface of the first matrix adjacent and in contact with the second matrix having a catalytic coating applied thereto as sensing electrode and the electrolyte contained within the second matrix being capable of flow to or from the first matrix.

Abstract: A gas sensor is constructed as follows. A protector (4) covering around a gas sensing element (2) has an inner hollow-cylindrical portion (6) and an outer hollow-cylindrical portion (7) that is provided coaxially with the inner hollow-cylindrical portion (6) with an air space (8) in between. Outer-wall gas inlet openings (13) are formed in the outer hollow-cylindrical portion (7), and guiding bodies (10) extending inward are attached to the outer-wall gas inlet openings (13). Inner-wall gas inlet openings (11) are formed in the inner hollow-cylindrical portion (6) at positions nearer to the gas sensing element (2) than the outer-wall gas inlet openings (13). A side wall (9) face of the inner hollow-cylindrical portion (6) opposite the outer-wall gas inlet openings (13) is formed so as to be parallel to a side wall (12) of the outer-hollow cylindrical portion (7) or so as to have a slop-like shape with a diameter enlarging in the axial direction toward a bottom wall (17) of the protector (4).

Abstract: An electrochemical sensor for organic molecules such as ethylene includes an electrochemical cell, gas sample inlet means and means for detecting current produced by the oxidation of the organic molecule at the anode of the cell. The sensor is capable of sensing multiple organic molecules in some embodiments. A voltage is applied to the anode of the cell to provide energy to drive the oxidation reaction and produce a corresponding current. The sensor of the invention can be made as a small, hand-held unit that is capable of real-time detection of various organic species.

Abstract: A gas sensor is disclosed. The gas sensor includes a gas sensing layer including at least one chemical compound with the general chemical formula M?O62N?, wherein M is at least one chemical element selected from the group consisting of W, Ti, Ta, Sr, Mo, and combinations thereof, and ?, ?, ? are self-consistent, said gas sensing layer being capable of detecting at least one gas selected from the group consisting of NO, NO2, SO2, O2, H2O, CO, H2, and NH3, at least one electrode positioned within a adhesion layer composed of a material selected from the group consisting of Ti, Cr, and combinations thereof, and a response modification layer composed of a material selected from the group consisting of Mg, Ti, V, Cr, Mn, Co, Ni, Zn, Nb, Ru, Rh, Pd, Ta, W, Re, Pt, and combinations thereof. The at least one electrode is in communication with the sensing layer. A method of fabricating the gas sensor is also disclosed.

Abstract: Disclosed herein is a composition for use in a NOx electrode comprising: Tb(1-x)Ln(x)E(1-y)Q(y1)X(y2)Z(y3)O3 wherein Ln is a lanthanoid or a combination of lanthanoids, E is a metal selected from chromium, iron, and a combination thereof, Q is an element selected from magnesium, calcium, strontium, and a combination thereof, X is an element selected from boron, lead, phosphorus, germanium, and a combination thereof, Z is an element selected from barium, silicon, aluminum, and a combination thereof, x is from 0 to about 0.5, y is from about 0.05 to about 0.8, and y1, y2, y3 are independently from 0 to about 0.8, with the proviso that y=y1+y2+y3, and y2+y3 is greater than 0. Also disclosed are a method of making it, electrodes and sensors comprising it, and a method of detecting NOx.

Abstract: A process is provided for distinguishing between wet from dry gas with a breath alcohol measuring device, in which a defined sample volume from a gas blown in is fed for sampling to an electrochemical sensor (6), which generates a sensor signal that depends on the reaction of ethyl alcohol. The sensor signal is sent to a control and evaluating unit (4) and is evaluated there to determine the alcohol concentration. To distinguish dry gas from wet gas, provisions are made for the sensor signal to be detected in its time dependence and for the presence of wet gas to be determined when it is observed that a sensor signal of a polarity opposite the polarity of the sensor signal caused by the reaction of ethyl alcohol appeared at first at the beginning of sampling. The process may be used, e.g., in conjunction with the calibration of breath alcohol measuring devices or in so-called interlock systems with a breath alcohol measuring device in order to recognize attempts at manipulation.

Abstract: The present invention uses a sensor electrode (3) in a nitrogen oxide sensor (10) which includes a nitrate or nitrite of an alkali metal and an oxide of a rare-earth element. The nitrate/nitrite of the alkali metal replaces part of the lattice of the oxide of the rare-earth element, forming a solid solution. The sensor electrode (3) therefore exhibits highly practical features, especially high water-insolubility and capability of nitrogen oxide measurement in a hot and humid atmosphere containing water vapor. Thus, a highly practical nitrogen oxide sensor electrode and nitrogen oxide sensor are provided which are usable in measurement in a hot and humid atmosphere containing water vapor.

Abstract: An electrochemical gas sensor which comprises an electrode assembly, including a catalytic sensing electrode and a counter electrode, mounted inside a housing provided with at least one gas entrance, a reservoir for containing electrolyte in use, a compressible wick for supplying the electrode assembly with electrolyte and a wick compression component. A first end of the wick extends into the reservoir and a second end of the wick contacts the electrode assembly. The wick compression component compresses the wick in a direction substantially radial to an axis joining its first and second ends.

Abstract: The present invention provides a unique solution to the problems of both steady-state and transient signals produced by a variety of interfering stimuli, including humidity, which relies upon the inclusion in a gas sensing electrode in an electrochemical gas sensor of a catalyst material, in addition to a first catalyst material reactive to the target gas, the additional, or second, catalyst material producing a response to an interfering stimulus which is of the opposite polarity to that generated by the first catalyst material.

Abstract: A sensor supervision system for periodically providing a test to accesses the status of a gas detection sensor, such as a carbon monoxide (CO) sensor, is provided. To access the status of the CO sensor, a processor provides a voltage to the sensor supervision system, such that a voltage is applied to CO sensor, charging the CO sensor. The status of the CO sensor is accessed by determining the change in the voltage charge of the CO sensor between two sampling time points. If the first sample voltage is substantially equal to the second sample voltage, i.e., a substantially constant voltage, the carbon monoxide sensor fails the test. However, if there is an change is the voltage change between the first and second sampled time points, the CO sensor passes the test.

Abstract: The present invention generally relates to carbon dioxide (CO2) sensors. In one embodiment, the present invention relates to a carbon dioxide (CO2) sensor that incorporates lithium phosphate (Li3PO4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li2CO3) and barium carbonate (BaCO3). In another embodiment, the present invention relates to a carbon dioxide (CO2) sensor has a reduced sensitivity to humidity due to a sensing electrode with a layered structure of lithium carbonate and barium carbonate. In still another embodiment, the present invention relates to a method of producing carbon dioxide (CO2) sensors having lithium phosphate (Li3PO4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li2CO3) and barium carbonate (BaCO3).

Abstract: A hydrogen sensitive composite sensing material based on cerium oxide with or without additives to enhance sensitivity to hydrogen, reduce cross-sensitivities to interfering gases, or lower the operating temperature of the sensor, and a device incorporating these hydrogen sensitive composite materials including a support, electrodes applied to the support, and a coating of hydrogen sensitive composite material applied over the electroded surface. The sensor may have in integral heater. The sensor may have a tubular geometry with the heater being inserted within the tube. A gas sensor device may include a support, electrodes applied to the support, and a dual sensor element to cancel unwanted effects on baseline resistance such as those resulting from atmospheric temperature changes. The hydrogen sensitive composite material or other gas sensitive materials may be used in the dual element gas sensor device.

Abstract: A fuel gas analyzer for measuring the concentration of oxygen in fuel gas, comprising an electrochemical oxygen sensor and water vapor 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 vapor, which would otherwise lead to damage of the electrochemical oxygen sensor,

Abstract: An electro-catalyst for the oxidation of ammonia in alkaline media; the electrocatalyst being a noble metal co-deposited on a support with one or more other metals that are active to ammonia oxidation. In some embodiments, the support is platinum, gold, tantalum, or iridium. In some embodiments, the support has a layer of Raney metal deposited thereon prior to the deposition of the catalyst. Also provided are electrodes having the electro-catalyst deposited thereon, ammonia electrolytic cells, ammonia fuel cells, ammonia sensors, and a method for removing ammonia contaminants from a contaminated effluent.

Abstract: Devices for generating and storing ozone. A device for generating ozone includes: at least one elongated electrode unit including an outer tubular dielectric member and an inner conducting member having a longitudinal axis; and one or more elongated electrode tubes disposed circumferentially about the longitudinal axis. Each of the electrode tubes is arranged in parallel to the electrode unit. When an electrical potential is applied across the conducting member and electrode tubes during operation, plasma is established between the dielectric member and electrode tubes. The plasma converts oxygen gas into ozone gas.

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: An analyzer includes a reforming unit which reforms fuel containing an organic compound which contains carbon and hydrogen into a reformed gas containing hydrogen, a flame ionization detector which is connected to the reforming unit, and detects an ion generated by combusting the reformed gas supplied from the reforming unit and a sample gas, or ionizing a sample gas by reaction with the reformed gas supplied from the reforming unit, and outputs an output signal representing the ionic amount, and an analysis controller which analyzes the output signal from the flame ionization detector, and provides data capable of identifying a component contained in the sample gas.

Abstract: A gas sensor has a sensor element of a cup shape and an insulation electrical heater for heating the sensor element. The insulation electrical heater is placed in an inside of a hollow part of the sensor element. An insulation length extension area is formed on an outer peripheral surface of the insulation electrical heater between electrodes of the insulation electrical heater and a reference electrode metal member tightly bonded onto the sensor element. The insulation length extension area is composed of a plurality of flanges, a rectangle flange part formed in one body, a taper shaped flange part, or a bended flange part.

Abstract: The present invention provides a unique solution to the problems of both steady-state and transient signals produced by a variety of interfering stimuli, including humidity, which relies upon the inclusion in a gas sensing electrode in an electrochemical gas sensor of a catalyst material in addition to a first catalyst material reactive to the target gas, the additional, or second, catalyst material producing a response to an interfering stimulus which is of the opposite polarity to that generated by the first catalyst material.

Abstract: A gas sensor is used in particular for determining a physical property of a measuring gas, preferably for determining the concentration of a component of an exhaust gas in an exhaust branch of an internal combustion engine. The gas sensor has a sensor element situated in a housing. The housing includes a protecting tube having apertures through which the measuring gas may reach the sensor element. At least on its side facing the sensor element, the protecting tube has an absorptivity which is subject to only minor changes during the intended operation of the gas sensor in an exhaust branch of an internal combustion engine.

Abstract: A method and instrument capable of accurately detecting the presence of a gas and accurately measuring the concentration of the gas in, for example, the environment. The method and instrument sense the presence of a gas with a sensing element whose output is linear to the concentration of the gas in the environment, and process the output of the sensing element through a nonlinear amplifier having a higher gain at lower levels of the output than at higher levels of the output so that the nonlinear amplifier amplifies the output of the sensing element at the lower levels thereof and avoids signal saturation at the higher levels thereof. The method and instrument then deliver the amplified output of the nonlinear amplifier to an audio circuit that produces an audio output having a property in proportion to the amplified output of the nonlinear amplifier.

Abstract: A MEA 6 having a proton conductive membrane is sandwiched by metal plates 14, 15 and they are further sandwiched by heat pressable films 20, 21. An opening 24 and an opening 18 are formed in the heat pressable film 20 and the metal plate 14, respectively so that an electrode 10 is used as the sensing electrode and exposed to atmosphere to be measured. Openings 25, 19 are formed in the heat pressable film 21 and metal plate 15, respectively so that an electrode 11 is used as the counter electrode, and water vapor is supplied to the electrode from a water pack.

Abstract: A gas sensor is equipped with a built-in ceramic heater. The gas sensor detects the concentration of a predetermined gas component contained in the exhaust gas. The ceramic heater has a heater base member made of ceramic, a heating element formed in the inside of the heater base material, and a pair of external electrode pads that is electrically connected to the output terminals for the outer leads. The external electrode pads, the heating element, and the heater leads are made of base metal. The outer surface of each external electrode pad is covered only with a dense protective film made of noble metal such as gold (Au), silver (Ag), platinum (Pt), rhodium (Rh), and palladium (Pd).

Abstract: A NOx sensing system having a NOx sensor and a method for determining a NOx concentration utilizing the NOx sensor are provided. The NOx sensor utilizes a second chamber communicating with ambient atmosphere with ambient oxygen for allowing an electrochemical cell to accurately measure an oxygen concentration in a first chamber communicating with an exhaust stream to more accurately control the oxygen concentration in the first chamber, without disassociating NOx therein. The more accurate control of the oxygen concentration in the first chamber, subsequently allows for a more accurate measurement of the NOx in the exhaust system.

Abstract: A gas sensor for detecting NOX is provided. The gas sensor may have a plurality of substrate members, a first sensing electrode, and a second sensing electrode. The gas sensor may also have a first heater element associated with the first sensing electrode and being located on a first side of one of the plurality of substrate members, and a second heater element associated with the second sensing electrode and being located on a second opposing side of the one of the plurality of substrate members.

Abstract: An electrochemical gas sensor (9) has improved electrochemical measurement properties and housing tightness for an electrolyte at the sites at which the connection lines (11, 21, 31) pass through. The sensor (9) includes a housing (4), containing at least one measuring electrode (1) and a counterelectrode (2) and with electric connection lines (11, 21, 31) from the electrodes (1, 2, 3) to a measuring unit (8) arranged outside the housing (4). The electric connection lines (11, 21, 31) include carbon nanotubes (CNT, Carbon Nanotubes) at least in some sections in the housing (4) in the area of the electrolyte wetting.

Abstract: A system to detect a presence of a specific gas in a mixture of gaseous byproducts comprising moisture vapor is disclosed. The system includes an electrochemical cell, a transport to deliver the mixture of gaseous byproducts from the electrochemical cell, a gas sensor in fluid communication with the transport, the sensor responsive to a presence of the specific gas to generate a signal corresponding to a concentration of the specific gas, and a membrane to prevent transmission of liquid moisture, the membrane disposed between the transport and the gas sensor.

Abstract: A miniaturized gas sensor including film type electrodes, and a solid ionomer electrolyte, for the detection of toxic gases, i.e., carbon monoxide, and other oxidizable or reducible gases and vapors is described. The all-solid planar sensor cell has two or more film type electrodes arranged on a non-conductive planar surface of a supportive material. The electrodes are discrete and in intimate contact with the same solid polymer ionomer membrane. The sensor cell contains no liquid electrolyte and is operated in a potentiostatic or potentiodynamic mode. The unique feature of the sensor cell is that high sensitivity to a select gas or vapor is achieved by a novel three-phase contact area design for a sensing electrode which is easily accessible to the gas sample via small diffusion openings or holes that penetrate through the solid polymer ionomer membrane layer above the sensing electrode.

Abstract: A proton conductor gas sensor whose durability at high temperature is enhanced by using gel not converted to sol even at high temperature in a water reservoir. Fine particles of silica are gelled by adding water thereto and agitating the mixture under shear force. The thus obtained gel (34) is placed in a water reservoir of proton conductor gas sensor (2) and fed through steam introduction port (30) to MEA (10).

Abstract: The invention comprises novel apparatuses and testing methods for evaluating a fluid diffusion component. The apparatus includes a fluid capable of undergoing oxidation or reduction, a half-cell electrode assembly able to receive the fluid, and a change in acidity indicator in communication with the assembly. An inventive method of the invention includes the steps of passing a fluid capable of undergoing oxidation or reduction through a half-cell electrode assembly to form a sample, contacting the sample with an indicator, and detecting a change in acidity in the indicator.

Abstract: An aqueous solution of a Na salt of a phenol sulfonic acid polymer as a liquid electrolyte is held in a separator of a liquid electrochemical gas sensor. A sensing electrode and a counter electrode are connected to the separator to detect CO at a range from about ?40° C. to about 70° C.

Abstract: A multi-gas sensor device for the detection of dissolved hydrocarbon gases in oil-filled electrical equipment. The device comprising a semiconductor substrate, one or more catalytic metal gate-electrodes deposited on the surface of the semiconductor substrate operable for sensing various gases, and an ohmic contact deposited on the surface of the semiconductor substrate. The semiconductor substrate comprises one of GaN, SiC, AlN, InN, AlGaN, InGaN and AlInGaN. A method for sensing gas in an oil-filled reservoir of electrical equipment, comprising providing a sensor device, immersing the sensor device in the oil-filled reservoir, allowing the gases emitted from the oil to interact with the one or more catalytic metal gate-electrodes, altering the gas as it contacts the catalytic metal gate-electrodes and altering the sensitivity of the sensor.

Abstract: In a method of manufacturing a sensor, firstly, a plate-type detection element is inserted through an element-insertion through-hole of a first powder-compacted ring. Secondly, a flange section including at least the first powder-compacted ring is integrally assembled to the plate-type detection element, applying axially compressive pressure to the first powder-compacted ring so as to compressively deform the first powder-compacted ring such that the cross-sectional area of the element-insertion through-hole is reduced. Thirdly, the flange section is engaged, directly or via an intermediate member, with the stepped portion of the metallic shell at the time of disposing of the plate-type detection element in the through-hole of the metallic shell. A sensor prepared by the method is also disclosed.

Abstract: A gas sensor comprises an electrically conductive housing including a shelf member and a chamber containing an electrolyte. A conductive cathode mounted on the shelf member has a plurality of holes therein and a conductive tail element. A gas permeable membrane overlying the cathode prevents electrolyte from escaping the chamber but allows gas to permeate the membrane. An anode within the chamber is in electrical contact with the electrolyte and the conductive housing. The tail element is adapted to be connected to the anode through an electrical circuit including the conductive housing.

Abstract: An electrochemical sensor for organic molecules such as ethylene includes an electrochemical cell, gas sample inlet means and means for detecting current produced by the oxidation of the organic molecule at the anode of the cell. The sensor is capable of sensing multiple organic molecules in some embodiments. A voltage is applied to the anode of the cell to provide energy to drive the oxidation reaction and produce a corresponding current. The sensor of the invention can be made as a small, hand-held unit that is capable of real-time detection of various organic species.

Abstract: It is an object of the present invention to minimize the power for heating of an FET-type gas sensor using an FET to ensure a long operating life. Two terminals 10 and 11 are arranged at a sensitive electrode 31 formed on a gate insulation film of an FET, and different potentials are applied thereto to cause a current to flow. The sensitive electrode 31 functions as a heating element by causing a current to flow in the sensitive electrode 31 which needs to be heated, allowing the FET-type gas sensor to be heated most efficiently. Furthermore, the terminals 10 and 11 configure a part of a temperature detector which measures the temperature of the heated sensitive electrode 31.

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 detector with a compensated electrochemical sensor exhibits altered sensitivity in response to decreasing stochastic noise in an output thereof. A gain parameter can be adjusted to alter sensitivity. A life-time estimate can be made based on sensitivity.

Abstract: A gas sensor and method of manufacturing the gas sensor are disclosed. The gas sensor comprises a gas sensing element, an insulating element holder having an element inserting bore through which the gas sensing element axially extends, a housing fixedly supporting the insulating element holder, an airtight sealant and a cushioning filler. Ceramic slurry, composed of at least ceramic powder and binder, is filled in an area between the gas sensing element and the insulating element holder on a leading end portion of the element inserting bore and fired to form a cushioning filler. The ceramic slurry contains 47 to 53 wt % of ceramic solids for a gross weight of ceramic slurry and a binder laying in a value ranging from 5 to 10 wt % for a weight of the ceramic solids.

Abstract: A gas sensor assembly comprises a housing (65) including a bore (61). A pin (50) extends through the bore (61) and an O-ring (100) is located in the bore. The O-ring (100) contacts the pin (50) and parts of the bore (61) so as to be restrained against movement in both lateral and axial directions. Two- and three-shot molding processes are described for fabricating the assembly.

Abstract: Electrolytic solution which contains sulfuric acid and is stored in an electrolytic solution storage 2 of a case 3 is caused to be retained in an electrolytic solution retainer 25. A reference electrode 18 and a counter electrode 19 are printed on the underside of the electrolytic solution retainer 25. The reference electrode 18, the counter electrode 19, and the electrolytic solution retainer 25 are thus formed into a single component, with the reference electrode 18 and the counter electrode 19 being formed simultaneously. Electrode pins 32,33,34 are brought into contact with the reference electrode 18, the counter electrode 19, and a detection electrode 17. The electrode pins 32,33,34 are made of tantalum. A contact portion 32b,33b,34b and a lead portion 32a,33a,34a of each electrode pin 32,33,34 are formed as a seamless, integral body.

Abstract: In a planar oxygen sensor having a pump cell, a reference cell, a sensor chamber and a heating device, a ground plane electrode is provided and includes a sensing portion having a first sense lead and a second sense lead and a measuring portion having a first measuring lead and a second measuring lead, wherein the first measuring lead and the second measuring lead have increased surface area relative to said sensing portion such that the resistance between the first measuring lead and the second measuring lead is reduced and wherein the first measuring lead is disposed so as to be communicated with the first sense lead and the second measuring lead is disposed so as to be communicated with the second sense lead.

Abstract: This invention provides an assembly comprising a sensing electrode and a counter electrode in contact with a membrane body formed from a solid polymer electrolyte system comprising a fluorinated polymer matrix and a charge carrying component which is dispersed in the matrix the electrodes and membrane being housed in a housing having a gas diffusion barrier through which gas may flow. The charge carrying components are fluorinated organic proton conductors (such as heptadecafluorooctane sulphonic acid, bis-trifluoromethane sulphonamide, N-(2,6-diethylphenyl)-1,1,1-trifluoromethane sulphonamide, N-benzyltrifluoromethane sulphonamide and N, N-1,2-cyclohexanediylbis (1,1,1-trifluoromethane sulphonamide)). The polymer matrix is a homopolymer or copolymer of vinylidene fluoride preferably with fluorinated comonomers. The solid polymer electrolyte system preferably contains plasticising additive(s) and is cast as a coating onto one or more electrodes eg.

Abstract: An electrochemical sensor, especially for gases, is provided having a mediator compound based on transition metal salts of polybasic acids and/or transition metal salts of polyhydroxycarboxylic acids. The electrochemical sensor also contains a DLC, BDD or a precious metal thin-layer measuring electrode (3). The electrochemical sensor may be used for determining SO2 and H2S.

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.