Abstract: A method and device have an electrode rod (1; 21) for a pH meter. The electrode rod (1; 21) has a measuring end (2; 22) for immersion into a liquid test sample (31), wherein the measuring end (2; 22) has a pH measuring element, and wherein electrical feed lines (5) in the electrode rod (1; 21) extend towards the pH measuring element. A plurality of capillaries (8, 9, 10; 23) for feeding liquids and gas into the test sample (31) extend in the electrode rod (1; 21) and have outlet openings (11, 12, 13; 24) in the area of the measuring end (2; 22). The method and device facilitate and accelerate preparation of liquid test samples and adjustment of a pH value for small amounts of test samples or narrow sample containers in NMR spectroscopy applications.

Abstract: A combination electrode, including: A first tube; a measuring membrane, which sealedly closes the first tube to form a measuring chamber; a second tube, which surrounds the first tube and is connected borderingly with the first tube to form an annular reference chamber; a buffer solution located in the measuring chamber; an electrolyte solution located in the reference chamber; a first tapping electrode in contact with the buffer solution; and a second tapping electrode in contact with the electrolyte; wherein, additionally, arranged in the reference chamber is an axially shiftable, annular, sealing element, which bounds the volume occupied by the electrolyte solution, the sealing element is biased by means of an electrically conductive, elastic, deformation element, which surrounds the first tube, and the second tapping electrode is electrically connected with the deformation element, in order to tap the potential of the second electrode via the deformation element.

Abstract: An improved combination ion-selective electrode has a thin ion-sensing body extending from an outer reference body. The exposed portion of the ion-sensing body is encompassed by a sleeve which effectively forms an extension of the reference body and also provides mechanical stability to the ion-sensing body. One or more fluid channels are formed interior to the sleeve to provide an electrically conductive path from the reference solution within the reference body to the tip of the electrode.

Abstract: A potentiometric sensor device for measuring pH value is provided, which sensor device has two electrodes situated on a substrate and applied with the aid of thick-film technology. The two electrodes form an interdigital comb structure on the substrate. The interdigital comb structure allows the sensor device to be manufactured without a reference electrode having a glass body, so that the sensor device may easily be used where the sensor device is subjected to high mechanical loads.

Abstract: Glass pH electrode with integrated optical sensor, characterized in that said electrode can be sterilized without substantial alteration of its optical characteristics, in particular in respect to gamma ray irradiation sterilisation.

Abstract: A system for monitoring a pH level of a sample medium is disclosed herein as including a pH probe having a pH-sensitive electrode, a reference electrode and a temperature electrode arranged within a housing of the pH probe. The probe housing generally includes a flexible inner tube and a flexible outer tube, the inner tube being concentrically arranged within the outer tube. Preferably, a size of the probe housing minimizes the amount of trauma introduced by insertion of the pH probe into physiological tissues, muscles or fluids. The system also includes a processing means, which is coupled to the pH probe for determining the pH of the sample medium. A method of forming a pH-sensitive electrode, a method of manufacturing a pH probe, and a method for using a pH probe are also disclosed herein.

Abstract: An ion concentration measurement system is provided. The ion concentration measurement system has: at least an end system having a sensing unit for measuring the ion concentration of a test solution to generate at least a sensing signal; a control unit for controlling the acquisition of the sensing signal; a display unit for displaying the sensing signal in real time; and an end wireless transmission interface for transmitting the sensing signal wirelessly.

Abstract: An electro-chemical sensor is described having two molecular redox systems sensitive to the same species and having an detector to detect relative shifts in the voltammograms of the two redox systems.

Abstract: A modular potentiometric sensor includes a housing having measuring and reference half-cells, a temperature sensor, and solution ground combination assembly. An electrical conductor of the combination assembly extends through the housing, while remaining electrically isolated from the housing and half-cells, terminating at an electrically and thermally conductive end cap. Seals at opposite ends of the housing permit portions of the half-cells and the combination assembly to extend therethrough. The seals, measuring half-cell, and the combination assembly define an electrolyte compartment for the reference half-cell. The end cap provides close thermal coupling to the test fluid while also serving as a test fluid ground that is electrically isolated from the electrolyte compartment.

Abstract: An electrochemical sensor is provided that includes a housing defining a cavity for a reference electrolyte and defining an opening to the cavity configured to be proximate to a target fluid. The sensor further includes a junction plug comprising a porous material and a cross member impermeable to a target fluid positioned between the junction plug and the cavity. The cross member includes a planar portion disposed against the junction plug that defines an aperture to enable electrochemical communication between the target fluid and the reference electrolyte.

Abstract: A pH sensor is provided. The pH sensor includes a body, a glass electrode, a reference electrode and a solution ground. The glass electrode is disposed on the body to contact a liquid sample. The reference electrode has a reference fill solution disposed within the body. The solution ground electrode is operably coupled to the body and has a portion of the solution ground electrode that is disposed within a harbor such that a portion of the solution ground electrode is configured to contact the liquid sample. The body has a passageway that extends from the reference fill solution to an aperture proximate the liquid sample.

Abstract: The invention provides a method for measuring a pH value of a sample solution, which is performed by a pH sensing device, including: providing a pH sensing device and a sample solution, wherein the pH sensing device includes a pH sensor array, and the pH sensor array comprises m pH sensors, and m is an integer greater than 1; measuring the sample solution with the pH sensor array for n times, wherein n is an integer greater than 1, n measurement values are generated, each pH sensor generates a measurement value for each measurement, and the total amount of measurement values generated is n×m; and generating a pH value of the sample solution by all of the measurement values generated by the pH sensor array.

Abstract: A system of measuring pH of a solution having a calibration device to counteract time-drift effect. The calibration device of the system adjusts a compensation voltage to zero a measuring voltage of a first sensor and only respond to time-drift voltage of the first sensor. The calibration device has a differential operation amplifier receiving measuring voltages from the first sensor and a second sensor of the system to eliminate the time-drift voltages of the first and second sensors, thereby achieving calibration of the time-drift effects.

Abstract: A method and device have an electrode rod (1; 21) for a pH meter. The electrode rod (1; 21) has a measuring end (2; 22) for immersion into a liquid test sample (31), wherein the measuring end (2; 22) has a pH measuring element, and wherein electrical feed lines (5) in the electrode rod (1; 21) extend towards the pH measuring element. A plurality of capillaries (8, 9, 10; 23) for feeding liquids and gas into the test sample (31) extend in the electrode rod (1; 21) and have outlet openings (11, 12, 13; 24) in the area of the measuring end (2; 22). The method and device facilitate and accelerate preparation of liquid test samples and adjustment of a pH value for small amounts of test samples or narrow sample containers in NMR spectroscopy applications.

Abstract: An ion concentration sensor produces a signal reflective of the ion concentration within a solution. The ion concentration sensor is based on an ion sensitive transistor having a solution input, a reference input, a diffusion input, and a diffusion output. The ion sensitive transistor is connected as a pass transistor, such that the diffusion output provides an electrical signal indicating an ion concentration in a solution contacting the solution input.

Abstract: pH-change sensors and related methods are disclosed. One such sensor may have a first ion-sensitive transistor-operational-transconductance-amplifier (the “first IOTA”) and a second ion-sensitive transistor-operational-transconductance-amplifier (the “second IOTA”). Each IOTA may have an ion-sensitive transistor, a load transistor, and an output. In each IOTA, the drain region of the ion-sensitive transistor may be connected to the drain region of the load transistor. A differential sensor may be connected to the IOTAs, and an output from the differential sensor may indicate a voltage difference between the IOTA outputs. The output from the differential sensor may be used to provide an indication of a change in pH.

Abstract: An electrochemical suspended element-based sensor system includes a solution cell for holding an electrolyte comprising solution including at least one electrochemically reducible or oxidizable species. A working electrode (WE), reference electrode (RE) and a counter electrode (CE) are disposed in the solution. The CE includes an asymmetric suspended element, wherein one side of the suspended element includes a metal or a highly doped semiconductor surface. The suspended element bends when current associated with reduction or oxidation of the electrochemically reducible or oxidizable species at the WE passes through the suspended element. At least one measurement system measures the bending of the suspended element or a parameter which is a function of the bending.

Abstract: A reference electrode for potentiometric measurements has a housing (2) with a hollow space (4) containing a liquid reference electrolyte (6) as well as a conductor element (8) immersed in the reference electrolyte. In addition, the housing has a diaphragm (12) through which the reference electrolyte can be brought into contact with a measuring medium (10) outside of the housing. Furthermore, means are provided to effect an outflow of the reference electrolyte through the diaphragm. A first electrical contact element (20, 36) is arranged in the hollow space in such a manner that the contact element is immersed in the reference electrolyte as long as the fill level (18) of the reference electrolyte does not fall below a threshold value (FS), and that the contact element is not immersed in the reference electrolyte if the fill level falls short of the threshold value.

Abstract: The invention relates to a measuring device having a penetrating electrode. Said elongated electrode of the measuring device is movably mounted in axial direction thereof. In case of a load or a shock, it can absorb said load to a given degree in the housing of said measuring device. Said shock-absorbing characteristic makes it possible to largely prevent breaking of the first electrode that is preferably configured in the form of a glass electrode. The invention also relates to a measuring device, to a method for the production and the application of said measuring device.

Abstract: A pH half-cell method and apparatus includes an electrode, a pH sensitive glass membrane and an electrolyte in electrolytic contact with the electrode and membrane. The membrane includes at least about 15 mole percent lithium, and the electrolyte includes a lithium salt as the predominant monovalent cation. The pH half-cell is used with a reference half-cell and meter to provide an electrochemical potential measurement sensor, optionally with both half-cells disposed within a single housing. The lithium salt electrolyte is also used in a method for storing, conditioning, preserving and/or rehabilitating a pH half-cell.

Abstract: A method and a device for developing an electrochemical measuring system, in particular a sensor, is provided. A plurality of different electrode materials are applied to at least one substrate and introduced into a medium together with at least one reference electrode. Subsequently, the electrochemical potentials of the individual electrode materials in relation to the reference electrode are determined.

Abstract: An ionic probe is provided according to the invention. The ionic probe includes an active electrode configured to generate a measurement signal for an external test fluid, a first reference electrode configured to generate a first reference signal, and an at least second reference electrode configured to generate at least a second reference signal. The measurement signal is compared to the first reference signal and the at least second reference signal in order to determine an ionic measurement of the external test fluid.

Abstract: Carbon nanotubes have been reversibly and readily oxidized and reduced with common chemicals in solution, thereby allowing the nanotubes to be used as catalysts for chemical reactions and as stable charge storage devices.

Abstract: Provided are fabrication, characterization and application of a nanodisk electrode, a nanopore electrode and a nanopore membrane. These three nanostructures share common fabrication steps. In one embodiment, the fabrication of a disk electrode involves sealing a sharpened internal signal transduction element (“ISTE”) into a substrate, followed by polishing of the substrate until a nanometer-sized disk of the ISTE is exposed. The fabrication of a nanopore electrode is accomplished by etching the nanodisk electrode to create a pore in the substrate, with the remaining ISTE comprising the pore base. Complete removal of the ISTE yields a nanopore membrane, in which a conical shaped pore is embedded in a thin membrane of the substrate.

Abstract: A system of measuring pH of a solution having a calibration device to counteract time-drift effect. The calibration device of the system adjusts a compensation voltage to zero a measuring voltage of a first sensor and only respond to time-drift voltage of the first sensor. The calibration device has a differential operation amplifier receiving measuring voltages from the first sensor and a second sensor of the system to eliminate the time-drift voltages of the first and second sensors, thereby achieving calibration of the time-drift effects.

Abstract: A method for producing a pH measuring probe includes: providing an electrode wire protruding out of both sides of a recording device, the electrode wire being fixed to the recording device with the first end thereof, placing a glass tube over a second end of the electrode wire until reaching a cavity of the recording device, the glass tube and the recording device being fixed together; providing another electrode wire protruding from both sides of a base plate including a recess for the recording device, the other electrode wire being fixed to the base plate with its end protruding; providing a casing comprising first and second openings, the casing and base plate being sealed together, forming the housing; and guiding the glass tube through the recess in the base plate until it protrudes out of an opening in the casing and the recording device is inserted into the base plate.

Abstract: An object of the present invention is to suppress an electric potential drift as described above and improve pH measurement precision in order to obtain practical measurement precision in the dry-type multilayered film-type pH electrode. The present invention provides a complex pH electrode which has at least two ion-selective electrodes comprising a non-conductive support, a pair of electrode layers, an electrolytic layer and an ion-selective membrane where at least one of the ion-selective electrode is a hydrogen ion-selective electrode, wherein the hydrogen ion-selective membrane is saturated with carbon dioxide gas.

Abstract: The system concerns an electrode system for an electrochemical sensor, comprising, arranged on a conductive substrate (10), a plurality of micro-discs (22) electrically connected to the substrate and a generating electrode (20) insulated from the substrate by an insulating layer (14) and including a plurality of orifices (24) concentric with said micro-discs. A conductive layer (12) and connections (26, 28) enable to connect the electrodes to power sources. The generating electrode enables to modify locally, at the micro-discs, the concentrations of species present in solution opposite said electrodes.

Abstract: A system for monitoring a pH level of a sample medium is disclosed herein as including a pH probe having a pH-sensitive electrode, a reference electrode and a temperature electrode arranged within a housing of the pH probe. The probe housing generally includes a flexible inner tube and a flexible outer tube, the inner tube being concentrically arranged within the outer tube. Preferably, a size of the probe housing minimizes the amount of trauma introduced by insertion of the pH probe into physiological tissues, muscles or fluids. The system also includes a processing means, which is coupled to the pH probe for determining the pH of the sample medium. A method of forming a pH-sensitive electrode, a method of manufacturing a pH probe, and a method for using a pH probe are also disclosed herein.

Abstract: The present invention describes a new electrochemical biosensor comprising (i) a biocatalyst producing a pH change when interacting with the analyte to be determined and (ii) a compound exhibiting different redox properties both in its protonated and non-protonated forms (pH-sensitive redox compound). The elements described above are integrated in a biosensor system composed of a working electrode and a reference electrode connected to an ammeter. When the analyte is present, the system produces a current change that is proportional to the concentration of the analyte. The biosensors described herein can be used in the accurate detection of a wide range of analytes. They can be used in diagnostics, industrial processes, food and feed quality control, biotechnology, pharmaceutical industry, environmental monitoring and so on.

Abstract: A method and apparatus for treating an aqueous electroplating bath solution. The method comprises continuously agitating the solution; adjusting the pH of the solution, adjusting the temperature of the solution while adding an amount of hydrogen peroxide sufficient to promote dissolution of the hydrogen peroxide and generation of hydroxyl radicals; and adding an amount of an iron-containing compound so as to increase the rate of dissolution of the hydrogen peroxide to hydroxyl radicals so as to oxidize the organic compounds; whereby the total amount of organic carbon compounds in the solution is reduced. The apparatus comprises a treatment vessel, a pump for transferring a portion of the solution from the vessel to a mixing tank and for transferring a second portion of the solution to a heat exchanger for heating or cooling the second portion of the solution and a pump for transferring hydrogen peroxide to the vessel.

Abstract: A pH electrode having a pH-sensitive region on an electrically conductive support, said pH-sensitive region comprising a mixture of between 50% and 85% of the total mixture by weight of particles of a Group VA or Group VIII metal incorporated in, or applied to, a polymer substrate of a non-shrinking plastic selected from polyimides, the polymer substrate having a resistivity of 10 to 100 Kohms/square the metal particles including antimony particles and, when said particles are incorporated into said resistive polymer substrate, having said pH-sensitive region abraded to expose said particles.

Abstract: A method and apparatus estimate hydrogen concentration in a reformate stream produced by a fuel processor of a fuel cell. A sensor measures carbon monoxide, carbon dioxide, and water in the reformate stream. A fuel meter controls fuel input to the fuel processor. An air meter controls air input to the fuel processor. A water meter controls water input to the fuel processor. A transport delay estimator recursively estimates transport delay of the fuel processor. A hydrogen estimator associated with the transport delay estimator, the air, water and fuel meters, and the sensor estimates hydrogen concentration in the reformate stream. The hydrogen estimator includes a fuel processor model that is adjusted using the estimated transport delay. The carbon monoxide, the carbon dioxide and the water are measured using a nondispersive infrared (NDIR) sensor.

Abstract: The invention relates to methods of preparation of highly sensitive potentiometric sensors with an electroconductive polymer film as a sensing element.

Abstract: The system concerns an electrode system for an electrochemical sensor, comprising, arranged on a conductive substrate (10), a plurality of micro-discs (22) electrically connected to the substrate and a generating electrode (20) insulated from the substrate by an insulating layer (14) and including a plurality of orifices (24) concentric with said micro-discs. A conductive layer (12) and connections (26, 28) enable to connect the electrodes to power sources. The generating electrode enables to modify locally, at the micro-discs, the concentrations of species present in solution opposite said electrodes.

Abstract: A galvanic probe comprises a sensor electrode and a reference electrode. The sensor electrode has an exposed surface that comprises a noble metal or antimony or bismuth, and, optionally, an oxide or hydroxide thereof. The reference electrode is spaced apart from the sensor electrode and has an exposed surface that comprises zinc or magnesium, and, optionally, an oxide or hydroxide thereof. The probe may be incorporated into a device for controlling the pH and/or ORP of a fluid in a vessel to a desired pH and/or ORP level, incorporated into methods for measuring the pH and/or ORP of a fluid, or used as a galvanic cell.

Abstract: A pH measurement system automatically measures the pH of samples in purge and trap sample concentrators, autosamplers or other sample delivery devices. The pH measurement system includes a pH sensor that is positioned in a pH sample reservoir. The pH sample reservoir may be automatically filled with sample from a sparge vessel, calibrated using liquid having known pH, or rinsed. A controller enables and disables the valves and pump to transmit the liquid to the pH sample reservoir.

Abstract: An object of the present invention is to suppress an electric potential drift as described above and improve pH measurement precision in order to obtain practical measurement precision in the dry-type multilayered film-type pH electrode. The present invention provides a complex pH electrode which has at least two ion-selective electrodes comprising a non-conductive support, a pair of electrode layers, an electrolytic layer and an ion-selective membrane where at least one of the ion-selective electrode is a hydrogen ion-selective electrode, wherein the hydrogen ion-selective membrane is saturated with carbon dioxide gas.

Abstract: The present invention provides a metal electrode stabilised by a coating, the coating comprising a sulfur containing moiety in its molecular structure. The coating may also include a hydrophilic group and a spacer between the sulfur containing moiety and the hydrophilic group. Preferably, the sulphur-containing moiety is selected from the group comprising thiol, disulphide and SOx, and the hydrophilic group is selected from the group comprising hydroxyl, amine, carboxyl, carbonyl, oligo (ethylene oxide) chain, and zwitterionic species. Compounds useful in the present invention include 2-mercaptoethanol, 2-mercaptoethylamine, 3-mercaptopropionic acid, thiophene, 4-carboxythiophene, cysteine, homocysteine, and cystine.

Abstract: Disclosed is a microchip-based differential-type potentiometric oxygen gas sensor, which comprises a working electrode and a reference electrode. The working electrode is composed of a cobalt-plated electrode, a buffered hydrogel, and an ion sensitive gas permeable membrane while the reference electrode is composed of an oxygen non-sensitive silver chloride electrode and the same ion-selective gas-permeable membrane of working electrode. By taking advantage of the corrosion potential, the microchip-based oxygen gas sensor can accurately and quickly detect the content of dissolved oxygen in a sample solution. With this structure, the oxygen gas sensor is applied to a microchip-based all potentiometric multi-sensor capable of detecting two or more ions and gas species on a single chip.

Abstract: A galvanic probe comprises a sensor electrode and a reference electrode. The sensor electrode has an exposed surface that comprises a noble metal or antimony or bismuth, and, optionally, an oxide or hydroxide thereof. The reference electrode is spaced apart from the sensor electrode and has an exposed surface that comprises zinc or magnesium, and, optionally, an oxide or hydroxide thereof. The probe may be incorporated into a device for controlling the pH and/or ORP of a fluid in a vessel to a desired pH and/or ORP level, incorporated into methods for measuring the pH and/or ORP of a fluid, or used as a galvanic cell.

Abstract: A chemical sensor (1) for selectively detecting an analyte in a solution as described. The sensor comprises a flow-through chamber (2), a selective membrane (3), a transducer means (4), an inlet (5) for a liquid flow containing a recognition element, and an outlet (6). There is also described a method of selectively detecting an analyte in a solution, wherein a recognition element is contacted with the solution containing the analyte via a selective membrane, said contact resulting in a response detectable by transducer means. The recognition element is injected into a flow, the flow is passed into a flow-through chamber comprising a transducer means and the selective membrane, where it is contacted with the analyte passing from the solution outside the selective membrane, whereby the recognition element and the analyte interact to provide a signal which is detected by the transducer means.

Abstract: A reference junction for a reference half-cell, the reference junction including an ion-barrier membrane and being sized and shaped for removable receipt within a receptacle of a reference half-cell housing. The reference junction may be included in an electrochemical potential measurement sensor for use in making pH, other selective ion activity, oxidation-reduction potential, and other electrochemical potential measurements.

Abstract: A reference electrode (1) for electrochemical measurements includes a metallic palladium-containing electrode component (3) which is covered by a layer (4) formed of or containing a palladium compound poorly soluble in aqueous media. Positioned on layer (4) is a reference electrolyte (5) which contains anions of this palladium compound in dissolved form (FIG. 4).

Abstract: A test method and apparatus for determining the content of carboxylic acid-based corrosion inhibitors in a coolant or heat exchange fluid. The amount of acidic reagent added to the coolant or fluid between two pH equilibrium points is measured to determine the amount of inhibitors. The refractive index can be measured to determine the amount of freezing point depressant.

Abstract: A pH sensor is provided capable of readily determining the pH of a solution of a small amount. The pH sensor includes a semiconductor substrate, an oxide film provided on the semiconductor substrate, a solution storage part for holding a solution on the oxide film, and an electrode to be in contact with the solution in a vicinity of the oxide film. To determine the pH of a solution, a capacitance-voltage characteristic is initially monitored by the sensor between the electrode in contact with the solution and another electrode provided on the back surface of the semiconductor. Then the pH of the solution is derived from a flat band voltage which is obtained based on the capacitance-voltage characteristic.

Abstract: A pH electrode having a pH-sensitive region on an electrically conductive support, said pH-sensitive region comprising

Abstract: The present invention is drawn generally to an improved electrochemical sensor. The reference cell within the sensor can be a salt bridge comprising at least two chambers for containing an electrolyte fluid, preferably containing a semipermeable plug impregnated with an electrolyte, an essentially fluid impermeable plug for separating the at least two chambers, and a narrow opening through the plug providing a non-axial flow path for ionic communication between the at least two chambers when the electrolyte fluid is present.

Abstract: A polymeric material which to form a stable, reproducible interface between the ionic and electronic domains of an ion selective sensor, or an ion selective field effect transistor, or the like is provided. When employed in an ion selective sensor, the polymeric material is advantageously provided over a solid internal reference electrode and an ion selective material is provided thereover. According to one embodiment, the polymeric material of the invention includes less than about 1.63×10<immobilized charged sites per gram (less than about 2.72 millaequivalents/gram). According to another embodiment, the polymeric material includes immobilized sites of charge opposite that of mobile ions involved in the redox couple. A preferred polymeric material comprises a copolymer of methacrylamidopropyltrimethylammoniumchloride and methylmethacrylate.

Abstract: A sensor for measuring pH of a solution includes a housing with an exterior surface for exposure to the solution. A measuring glass electrode within a tubular circuit ground electrode extends through the exterior surface. A reference glass electrode is received in a neutral pH solution in the housing and is coupled by a salt bridge to the exterior surface. An electric circuit within the housing has a first preamplifier connected by a first conductor to the measuring glass electrode and has a second preamplifier connected by a second conductor to the reference glass electrode. The first and second conductors have substantially equal lengths so that ambient electrical noise equally affects signals from the electrodes. The electrical cable that carries output signals from the electric circuit passes through a ferrite sleeve which inhibits high frequency electric noise that is induced in the cable from reaching the electric circuit.