Abstract: An injection fluid composition includes a treatment agent and a carrier fluid. The treatment agent includes a material having a reactive surface functionality. The material having a reactive surface functionality is selected from the group consisting of graphite, graphene, activated carbon, and combinations thereof. Additionally, a method of treating a sludge in production tubing is presented. The method includes injecting a first fluid including a treatment agent in a carrier fluid into the production tubing, contacting the sludge with the treatment agent, maintaining the first fluid downhole such that the treatment agent adheres on a surface of the sludge, injecting a second fluid comprising a stimulating agent to stimulate the treatment agent, and extracting compounds of the sludge from the production tubing.

Abstract: A solid state, carbon dioxide (CO2) sensor configured for sensitive detection of CO2 in both dry and moist conditions. The CO2 sensor utilizes a composite sensing material that detects CO2 in the range of 100 ppm to 10,000 ppm. The sensing material is composed of O-MWCNTs and a metal oxide functionalizing agent, such as iron oxide (Fe2O3) nanoparticles. The material has an inherent resistance and conductivity that is chemically modulated as the level of CO2 increases. The CO2 gas molecules that are absorbed into the carbon nanotube composites cause charge-transfer and changes in the conductive pathway causes changes in conductivity of the composite sensing material. This change in conductivity provides a specificity and sensitivity for CO2 detection. The CO2 sensor can be easily integrated into existing electronic circuitry and hardware configurations, including the hardware of a mobile computing device, such as a smart phone or tablet device.

Abstract: An electric meter includes a meter shell configured to be within an outer utility box. A meter socket and blades are for coupling to openings of the socket. The openings include utility-side and premises-side openings for the blades to extend into. A meter processor is coupled to measurement circuitry, and to a communications unit including a transceiver. A gas sensor is positioned proximate to the blades for sensing ?1 gaseous compound product resulting from an arc discharge across air involving the blades. During operation of the electric meter, responsive sensing a presence of the gaseous compound product, the gas sensor generates an output signal. Responsive to the output signal being above a predetermined threshold level, the electric meter triggers an alert signal that is transmitted to an advanced metering infrastructure (AMI) which indicates an identity of the electric meter and that the electric meter had experienced the arc discharge.

Abstract: The claimed invention is an apparatus and method for performing impedance spectroscopy with a handheld measuring device. Conformal analyte sensor circuits comprising a porous nanotextured substrate and a conductive material situated on the top surface of the solid substrate in a circuit design may be used alone or in combination with a handheld potentiometer. Also disclosed are methods of detecting and/or quantifying target analytes in a sample using a handheld measuring device.

Abstract: A reference electrode includes a metal body, a lead disposed within the metal body, an insulator disposed between the lead and the metal body, the insulator including a ceramic material, and a porous metal chamber coupled to the metal body, the lead extending into the porous metal chamber. The porous metal chamber is configured to maintain an electrolyte solution within the porous metal chamber to establish a redox couple with the lead.

Abstract: In a polyurethane gel 1 including a gel layer 2 and a coat layer 3 covering the gel layer 2, the gel layer 2 is produced by allowing at least aliphatic polyisocyanate having an average functionality of more than 2.0 to react with polyol having an average functionality of 3.0 or less, and the coat layer 3 is produced by allowing at least aliphatic diisocyanate and/or alicyclic diisocyanate to react with bifunctional active hydrogen compound.

Abstract: According to one aspect of the invention, a potentiometric sensor having a cathode and an anode. The cathode is configured to provide a summary voltage representative of at least two voltage points. The anode is configured to provide a first voltage. The cathode is in communication with the anode by a first electrolyte forming an open circuit having an open circuit potential. Within the first electrolyte is a concentration of a target ion. The open circuit potential mathematically corresponds to the concentration of the target ion.

Abstract: An electrode includes a structure comprising a porous material and an electrically-conductive liquid covering at least a portion of the porous material, wherein the electrode is configured to be immersed in fluids of interest, the electrically-conductive liquid being immiscible in the fluids of interest.

Abstract: A plug-in module for a liquid- or gas-sensor comprised of a sensor module (SM) and a sensor module head (SMH), which can be releasably connected together, and which, when connected, enable data and energy transfer via a galvanically decoupled transfer section, wherein the sensor module head (SMH) includes an energy supply unit for operating the sensor module head (SMH) and the sensor module (SM), as well as a data memory (MEM), in order to store sensor data received from the sensor module (SM).

Abstract: A sulfur concentration detection system for detecting a sulfur concentration in a liquid includes a sensor having a conductive metal substrate and zinc oxide microstructures deposited on and protruding from the conductive metal substrate, a current source, and a voltage detector. An electrical resistivity of the zinc oxide microstructures is configured to change as a function of an amount of sulfur in the liquid available to react with zinc in the zinc oxide microstructures. The current source and the voltage detector are connected to the conductive metal substrate and configured to detect a change in the electrical resistivity of the zinc oxide microstructures.

Abstract: An apparatus for real-time, in-situ monitoring of actinide ion concentrations which comprises a working electrode, a reference electrode, a container, a working electrolyte, a separator, a reference electrolyte, and a voltmeter. The container holds the working electrolyte. The voltmeter is electrically connected to the working electrode and the reference electrode and measures the voltage between those electrodes. The working electrode contacts the working electrolyte. The working electrolyte comprises an actinide ion of interest. The reference electrode contacts the reference electrolyte. The reference electrolyte is separated from the working electrolyte by the separator. The separator contacts both the working electrolyte and the reference electrolyte. The separator is ionically conductive to the actinide ion of interest. The reference electrolyte comprises a known concentration of the actinide ion of interest. The separator comprises a beta double prime alumina exchanged with the actinide ion of interest.

Abstract: A device is provided for collection of gases in molten metals, the device having an immersion end with a gas collection body, a gas supply line opening at the immersion end, and a gas discharge line for gases penetrating the gas collection body. The gas collection body is impermeable to molten metal and has an end face arranged on the immersion end and side walls of the collection body. At least a portion of the gas collection body has a gas impermeable layer arranged on a surface of the side walls of the gas collection body. A measurement method is also provided using the device.

Abstract: A method for operating an ion-sensitive sensor with a measurement circuit which includes an ion-sensitive electrolyte-insulator-semiconductor structure (EIS); wherein the measurement circuit is embodied to issue an output signal which is dependent on ion concentration, especially a pH value, of a measured liquid; and wherein the method comprises the steps of: introducing the ion-sensitive electrolyte-insulator-semiconductor structure into a measured liquid; accelerating charging processes in the region of an insulator layer of the ion-sensitive electrolyte-insulator-semiconductor structure by operating the sensor over a predetermined time span at least a first working point; and dynamically adapting the working point to set a second working point, and registering and processing the output signal of the measurement circuit at the second working point.

Abstract: A sensor is disclosed for determining a sulfur concentration in a liquid, such as a liquid fuel. The sensor includes a substrate that is at least partially coated with zinc oxide and, more specifically, zinc oxide microstructures. The zinc oxide microstructures have a crystal lattice structure that is oriented in the (002) plane, are oxygen-deficient and have a rod-like microstructure. If the substrate is conductive, it may be connected directly to a working electrode which is connected to a potentiometer which, in turn, is connected to a reference electrode. If the substrate is non-conductive, the conductive layer can be deposited on the substrate prior to deposition of the zinc oxide to form a working electrode. An application of a constant current (or voltage) to either electrode will result in a voltage across (or current flow between) the working and reference electrodes.

Abstract: A measurement system is disclosed for determining a sulfur concentration in a liquid, such as a liquid fuel. The measurement system includes a first electrode that is at least partially coated with zinc oxide and, more specifically, zinc oxide microstructures. The zinc oxide microstructures have a crystal lattice structure that is oriented in the (002) plane. The first electrode may be connected to an electrometer which, in turn, may be connected to a second electrode. The second electrode may be disposed on a common substrate with the first electrode or may be in the form of a plate disposed substantially parallel to the first electrode.

Abstract: An array-type sensor that senses NH3 includes non-Nernstian sensing elements constructed from metal and/or metal-oxide electrodes on an O2 ion conducting substrate. In one example sensor, one electrode may be made of platinum, another electrode may be made of manganese (III) oxide (Mn2O3), and another electrode may be made of tungsten trioxide (WO3). Some sensing elements may further include an electrode made of La0.6Sr0.4Co0.2Fe0.8O3 and another electrode made of LaCr0.95Mg0.05O3.

Abstract: This disclosure relates to a method of detecting an analyte. The method includes (1) contacting an aqueous solution containing the analyte with an electrochemical detector having a working electrode, a counter electrode, and a solid electrolyte, where the analyte includes a halogen or an oxy-halogen species and the solid electrolyte provides an electrical pathway between the working and counter electrodes; (2) applying a voltage to the detector; and (3) measuring the resultant current change in the detector.

Abstract: A method is provided for influencing the properties of cast iron by adding magnesium to the cast iron melt and measuring the oxygen content of the cast iron melt. Magnesium is added to the cast iron melt until the oxygen content of the cast iron melt is approximately 0.005 to 0.2 ppm at a temperature of approximately 1,420° C. A sensor for measuring the oxygen content in cast iron melts contains an electrochemical measuring cell containing a solid electrolyte tube.

Abstract: A water detection device comprising at least one fuel cell comprising a first electrode, a layer of electrolyte, a second electrode and an electrical measurement device characterized in that the first electrode of the cell is in contact with a first face of a porous silicon substrate comprising Si—H bonds, in such a manner as to liberate a flow of hydrogen in the presence of water. Advantageously, the substrate of porous silicon is incorporated into a first housing permeable to water, the fuel cell being incorporated into a second housing said second housing being impermeable to water and permeable to oxygen.

Abstract: A system and method for online monitoring of molten salt corrosion of a component of an apparatus is disclosed. First and second electrodes are electrically isolated from each other within the component and exposed to a corrosive operating environment of the apparatus. The first and second electrodes are electrically coupled such that when an electrical potential difference exists between the first and second electrodes an electrical current flows between the first electrode and the second electrode. The electrical potential difference between the first electrode and the second electrode is based at least in part on molten salt corrosion at the first electrode or the second electrode. At least one of the electrical potential difference or the electrical current flowing between the first electrode and second electrode is measured and analyzed such that a corrosion characteristic of the component can be predicted.

Abstract: A system and method for the high temperature in-situ determination of corrosion characteristics of a molten metal on an alloy under study is provided which takes place within an insulated furnace. A graphite crucible provided in the furnace contains an electrolyte formed from a molten salt of a metal halide. A reference electrode formed from the same metal as the electrolyte is immersed in the electrolyte solution in the graphite crucible. A beta-alumina crucible containing a molten metal is also provided within the furnace and preferably within the graphite crucible. A measuring electrode formed from the alloy under study is immersed in the molten metal. Standard electrochemical techniques are used to measure and analyze the electrochemical effects of corrosion of the molten metal on the alloy.

Abstract: The present invention concerns a probe for measuring hydrogen concentration in molten metals comprising a probe body and a hydrogen sensor. The sensor structure is based on a sensor body having a wall within which a sealed cavity is defined. The cavity contains a solid reference material for generating a reference partial pressure of hydrogen within the cavity. At least a portion of the wall of the cavity is formed from a solid electrolyte material carrying a measurement electrode on a surface of the solid electrolyte outside the cavity and a reference electrode on a surface of the solid electrolyte within the cavity, exposed to the reference partial pressure of hydrogen. An electrical conductor extends from the reference electrode through the wall of the cavity to an external surface of the sensor body. The probe body comprises a chamber for receiving the sensor and a reference-signal connection for connecting to the electrical conductor when the sensor is received in the chamber.

Abstract: The method for detection of cyanide in water is a method for the detection of a highly toxic pollutant, cyanide, in water using ZnO2 nanoparticles synthesized locally by an elegant Pulsed Laser Ablation technique. ZnO2 nanoparticles having a median size of 4 nm are synthesized from pure zinc metal target under UV laser irradiation in a 1-10% H2O2 environment in deionized water. The synthesized ZnO2 nanoparticles are suspended in dimethyl formamide in the presence of Nafion, and then ultrasonicated to create a homogenous suspension, which is used to prepare a thin film of ZnO2 nanoparticles on a metal electrode. The electrode is used for cyanide detection.

Abstract: A method and apparatus for depositing a coating material on a surface of a substrate by an ion plasma deposition process using a hollow cathode is disclosed. The cathode may be a substantially cylindrical hollow cathode. A plasma arc is formed on the outer circumference of the cathode to remove coating material from the cathode, which is then deposited on a surface of a substrate. An internal arc drive magnet is contained within the hollow bore of the cathode and cooling is provided to the magnet during operation.

Abstract: A device is provided for measuring the gas content in a molten metal, the device including an immersion end having a gas-collecting body, a gas supply line opening on the immersion end, and a gas discharge line for the gases passing through the gas-collecting body. The gas-collecting body contains materials, which in contact with the molten metal do not form liquid reaction products.

Abstract: A method is provided for influencing the properties of cast iron by adding magnesium to the cast iron melt and measuring the oxygen content of the cast iron melt. Magnesium is added to the cast iron melt until the oxygen content of the cast iron melt is approximately 0.005 to 0.2 ppm at a temperature of approximately 1,420° C. A sensor for measuring the oxygen content in cast iron melts contains an electrochemical measuring cell containing a solid electrolyte tube.

Abstract: The present invention relates to a multi-functional sensor system that simultaneously measures cathode and anode electrode potentials, dissolved ion (i.e. oxide) concentration, and temperatures in an electrochemical cell. One embodiment of the invented system generally comprises: a reference(saturated) electrode, a reference(sensing) electrode, and a data acquisition system. Thermocouples are built into the two reference electrodes to provide important temperature information.

Abstract: The present invention concerns a probe for measuring hydrogen concentration in molten metals comprising a probe body and a hydrogen sensor. The sensor structure is based on a sensor body having a wall within which a sealed cavity is defined. The cavity contains a solid reference material for generating a reference partial pressure of hydrogen within the cavity. At least a portion of the wall of the cavity is formed from a solid electrolyte material carrying a measurement electrode on a surface of the solid electrolyte outside the cavity and a reference electrode on a surface of the solid electrolyte within the cavity, exposed to the reference partial pressure of hydrogen. An electrical conductor extends from the reference electrode through the wall of the cavity to an external surface of the sensor body. The probe body comprises a chamber for receiving the sensor and a reference-signal connection for connecting to the electrical conductor when the sensor is received in the chamber.

Abstract: This invention provides a system and method for efficient reformulation of an initial gas with associated characteristics into an output gas with desired characteristic parameters, within a substantially sealed, contained, and controlled environment. The gas reformulating system uses a gas energizing field to disassociate the initial gas molecules and molecules of injected process additives of appropriate types and amounts, into their constituents that then recombine to form the output gas with the desired parameters. The gas reformulating system further comprises a control system that regulates the process and thereby enables the process to be optimized. The gas energizing field may be provided at least partly by hydrogen burners or plasma torches.

Abstract: A measuring probe is provided for measurement in molten metal, the probe having a measuring head arranged on an immersion end of a carrier tube. A bath contact and at least one sensor for determining a component of the molten metal are arranged on the immersion end. The bath contact, viewed in the immersion direction, has a first bath contact region with two surface areas extending parallel to the immersion direction on opposite sides of the bath contact.

Abstract: An electrochemical gas probe capable of measuring an amount of gas in a molten metal. The probe comprises a sensing unit that includes a reference electrode, a sensing electrode, a solid-state reference mixture adjacent to the reference electrode, and a conductor between the reference electrode and a sensing electrode. The probe also comprises a supporting unit that includes a main support, a protection cover and a stabilizing material, wherein the stabilizing material is between the sensing unit and the protection cover of the supporting unit. By using a solid-state reference material, the change of hydrogen content in molten aluminum may be conveniently monitored during a degassing process.

Abstract: The present invention relates to an electrochemical sensor for determining the concentration of a group IA metal in a fluid such as molten metal. The sensor comprises a substantially pure quantity of the group 1A metal as a reference electrode (13) contained in a sensor housing (3), and a solid electrolyte constituting at least part of the sensor housing (3). The electrolyte is in electrical contact with the reference electrode (13) and the sensor is capable of operating at temperatures in excess of 973K. In a preferred arrangement, the sensor comprises a two part elongate conductor (15), a first part (17) of which extends from the reference electrode (13) into a refractory seal (11a), and a second part (19) of which extends from within the refractory seal (11a) externally of the sensor, the two parts (17, 19) being welded together.

Abstract: A skin penetrating system is provided with a drive force generator and a disposable housing member. A plurality of penetrating members are positioned in the disposable housing member. Each penetrating member is coupled to the drive force generator. A plurality of analyte detecting members are each associated with a penetrating member and are positioned in the disposable housing member. Each analyte detecting member is positioned in a sample chamber with a volume of less than 1 ?L, The sample chambers have openings for transport of a body fluid into the sample chamber. Each analyte detecting member is configured to determine a concentration of an analyte in a body fluid using a sample of less than 1 ?L of a body fluid disposed in the sample chamber. A user interface is configured to relay at least one of, skin penetrating performance or a skin penetrating setting.

Abstract: An ion sensor has a flow path through which a sample flows. An ion-exchange membrane is in contact with the sample in the sample flow path. An internal solution is provided on one side of the ion-exchange membrane. An internal electrode is provided so as to come in contact with the internal solution. The surface of the ion-exchange membrane that does not come in contact with the sample is coated with a two-liquid-mixed epoxy resin.

Abstract: Disclosed is an electrochemical sensor comprising a work electrode and a reference electrode, said sensor adapted to measure the characteristics of a liquid under test, based on the relative electric potential difference and electric current between the work electrode and the reference electrode both immersed in the liquid under test, said work electrode comprising a substrate that reacts to the liquid under test for generating an electric potential according to the concentration of the liquid under test, and said reference electrode comprising a substrate that reacts to the liquid under test for generating a fixed electric potential. According to the present invention, at least one of the work electrode and the reference electrode comprises said substrate coated with a function film for serving to generate the electric potential through the intervention of the film between said substrate and the liquid under test.

Abstract: A measurement device is provided for determining the oxygen activity in molten metal or slag with a measurement head, which is arranged on one end of a carrier tube and on which an electrochemical measurement cell is arranged. The electrochemical measurement cell has a solid electrolyte tubule, which is closed on one side and which contains on its closed end a reference material and an electrode, which projects from the opposite end of the solid electrolyte tubule. The solid electrolyte tubule has on its outer surface a coating made from a mixture of zirconium silicate with a fluoride. The measurement head may also have a thermo-element, and the device may be used to determine the concentration of silicon and/or carbon in the melt, based on the oxygen activity measurement.

Abstract: A measurement device is provided for determining the oxygen activity in molten metal or slag with a measurement head, which is arranged at one end of a carrier tube and on which an electrochemical measurement cell is arranged. The electrochemical measurement cell has a solid electrolyte tube, which is closed at one end and which contains a reference material and an electrode at its closed end. The electrode projects from the opposite end of the solid electrolyte tube. The outer surface of the solid electrolyte tube has a coating of a mixture of calcium zirconate with a fluoride. The measurement device can be used for calculating the sulfur, silicon and/or carbon content of the molten metal or slag from reaction of the sulfur with the calcium zirconate, which releases oxygen, and measurement of the resulting change in oxygen activity of the melt or slag at the outer surface of the solid electrolyte tube.

Abstract: A novel process and apparatus to combinatorially screen a large number of discrete compositions for electrocatalytic activity have been developed. The apparatus contains a cell body adjacent to a fluid permeable catalyst array support supporting multiple solids. A catalyst mask having holes that are in alignment with the multiple locations for supporting solids is placed over the catalyst array support, masking the solids. A cell cover is positioned adjacent to the catalyst array support, with the cell cover having a passage for monitoring the solids through the mask. A detector may be in alignment with the passage of the cell cover.

Abstract: A sensor for use in monitoring electrochemical potentials, includes (a) a crucible made of ceramic material having a closed end and an open end, the close end containing metal/metal oxide powder mixture retained therein by mineral insulating packing, the open end having a metallized band fired in the ceramic material; (b) an annular metal sleeve formed of a metal exhibiting a coefficient of thermal expansion compatible with the crucible, and having a distal open end brazed to the open end of the crucible, and a proximal open end; (c) an insulated electrical conductor having a distal end in electrical connection with the metal/metal oxide powder and extending through the mineral insulation packing and into the first annular sleeve, and having a proximal end terminating near the proximal open end of the annular sleeve; and (d) a signal transfer assembly sealingly associated with the proximal end of the annular sleeve including an electrical cable connected to the electrical conductor.

Abstract: A measuring device for determining the oxygen activity in metal melts or slag melts has a measuring head arranged on the end of a carrier tube, on which head an electrochemical measuring cell is arranged. The electrochemical measuring cell has a solid electrolyte tube closed on one end, which is surrounded on the closed end and at least on a portion of its periphery by a steel tube closed on one end. A reference material and a filler material adjoining the reference material are arranged inside the solid electrolyte tube on its closed end. A metal rod is arranged as an electrode along the solid electrolyte tube in such a manner that, on the one hand, it stands in contact with the reference material and, on the other hand, it projects out of the open end of the solid electrolyte tube. The open end of the solid electrolyte tube has a closure which is constructed as a cap, which fits on the exterior of the steel tube or the solid electrolyte tube, and the closure is gas-permeable.

Abstract: The use of impedance measurements to detect the presence of pathogens attached to antibody-coated beads. In a fluidic device antibodies are immobilized on a surface of a patterned interdigitated electrode. Pathogens in a sample fluid streaming past the electrode attach to the immobilized antibodies, which produces a change in impedance between two adjacent electrodes, which impedance change is measured and used to detect the presence of a pathogen. To amplify the signal, beads coated with antibodies are introduced and the beads would stick to the pathogen causing a greater change in impedance between the two adjacent electrodes.

Abstract: A compact ceramic fuel property sensor comprises a plurality of laminated ceramic layers. The heater, temperature sensor, and capacitance measurement electrodes are embedded between the layers. The capacitance electrodes include interdigitated electrodes and fuel traps for containing a sample of liquid fuel disposed between the interdigitated electrodes. The dimensions of the fuel traps are selected so that the fuel traps remain filled with liquid after said sensor has been bathed in fuel. A method for monolithically preparing the sensors provides a reduced cost method and a sensor that can survive indefinitely in liquid fuel.

Abstract: A diagnostic method and device for use in detecting or quantitating an analyte present in a liquid sample. The method includes reacting an analyte-containing sample with reagents capable of generating a first coil-forming peptide in solution form. This peptide is then contacted with a biosensor whose detection surface has surface-bound molecules of a second, oppositely charged coil-forming peptide, under conditions effective to form a stable &agr;-helical coiled-coil heterodimer on the detection surface. The formation of the coiled-coil heterodimer produces a measurable change in biosensor signal, which is measured to detect the presence of or quantitate the amount of analyte in a sample. Also disclosed is a biosensor device for carrying out the reaction.

Abstract: The present invention relates to an electrochemical sensor for determining the concentration of a group IA metal in a fluid such as molten metal. The sensor comprises a substantially pure quantity of the group 1A metal as a reference electrode (13) contained in a sensor housing (3), and a solid electrolyte constituting at least part of the sensor housing (3). The electrolyte is in electrical contact with the reference electrode (13) and the sensor is capable of operating at temperatures in excess of 973K. In a preferred arrangement, the sensor comprises a two part elongate conductor (15), a first part (17) of which extends from the reference electrode (13) into a refractory seal (11a), and a second part (19) of which extends from within the refractory seal (11a) externally of the sensor, the two parts (17, 19) being welded together.

Abstract: A sensor for determining the concentration of sulphur compounds in a liquid includes: a working electrode in contact with the liquid to be analyzed; a referenced electrode insulated from the liquid to be analyzed; a liquid-impermeable membrane located between the working electrode and the reference electrode and permeable to an ion that may form a chemical compound with the sulphur compounds in the liquid to be analyzed; and a reference material in contact with the reference electrode or forms the reference electrode.

Abstract: A device in accordance with a present invention includes at least one of a stainless steel anode and transition metal oxide cathode.

Abstract: The present invention relates to a filtration-detection device for detecting or quantifying an analyte in a test sample including a filtration device having a first binding material immobilized thereto, wherein the first binding material is capable of binding to a portion of the analyte, and a detection assembly positioned relative to the filtration device to detect or quantify analyte bound to the first binding material. The present invention also relates to methods of using the filtration-detection device.

Abstract: A sensor for detecting chemical properties of a liquid, for example in an oil well, includes a glass pH electrode (22a) and a reference electrode (22c). The glass electrode (22a) consists of a narrow sensor electrode (30) on the surface of an electrically insulating substrate (20), a layer of glass (36) covering the sensor electrode (30), and two cleaning electrodes (32, 33) one extending along each side of the sensor electrode along its entire sensing length. The cleaning electrodes (32, 33) are not covered by the layer of glass, and are no more than 3 mm apart from each other. Application of a voltage between them generates gas bubbles by electrolysis that dislodge any fouling from the glass electrode (22a). The sensor electrode (30) may be of zigzag form, with the cleaning electrodes (32,33) interdigitated between the successive parts of the zigzag. A hydrophilic membrane (24) of sulphonated microporous PVdF provides further protection against fouling of the electrodes (22) by oil.

Abstract: The measuring range of a fuel cell based concentration sensor can be extended by decreasing the load across the fuel cell terminals and by increasing the amount of oxidant supplied to the fuel cell. In this way, such a sensor avoids saturation, for example, when measuring methanol concentrations from 0 M to over 4 M in liquid aqueous solution. Such a sensor is suitable for use in measuring fuel concentrations in the recirculating fuel stream of certain fuel cell stacks (for example, direct methanol fuel cell stacks).

Abstract: An electrochemical sensor to measure the activity of a metallic component in a molten metal, comprising the molten metal as the measuring electrode, a reference electrode containing the metallic component to be measured, separated from each other by a liquid ion-conducting halide comprising the metallic component to be measured and immobilized in a non-conducting porous support fabricated from a material inert or almost inert to the molten metal, the halide and the reference electrode material, and whereby the reference electrode further comprises an external connection comprising an electric wire held in an electric isolating material which is chemically inert or almost inert to the molten metal and the reference electrode material, characterized in that the sealing of the reference electrode which is adapted to be sealed is done by a high temperature cement and by the molten metal itself and by a gas tight sealing of the external connection above the melt, and the reference electrode is introduced by a melt