Abstract: A carbon dioxide gas detection element includes a solid electrolyte of a sodium ion conductor made of a ceramic/glass composite material.

Abstract: An automatic ion concentration analyzing apparatus including a plurality of ion concentration measuring cells each having an ion selective electrode and a reference electrode; a single pair of sample suction nozzle and nozzle driving device for picking up the sample to be measured; a sample supplying device for selectively supplying the sample sucked in the nozzle to the ion concentration measuring cells; and calculation and display section, which is commonly used for calculating the ion concentration concerning samples to be measured by comparing the measurement results of electric potentials induced on the ion selective electrode and the reference electrode. In the apparatus according to the invention, although the apparatus can be made small in size, the ion concentration of the samples to be measured can be analyzed in an effective manner.

Abstract: A biosensor device for detecting electrolytes in liquid samples includes a capillary tube having a lumen extending therethrough. This lumen receives and retains liquid to be sampled for electrolytes. A tube holder is engaged at one end of the tube. This tube holder includes a bore therethrough in fluid communication with the lumen of the tube. A biosensor is positioned within the lumen of the tube. The biosensor is capable of generating an electrical signal responsive to the presence of one or more electrolytes in the liquid sample. Electrical contact elements are associated with the biosensor for measuring the electrical signal for the detection of electrolytes in the sample.

Abstract: This invention relates to a pH measuring electrode having a sensor film which is sensitive to a hydrogen ion (H+) in the solution and method of manufacturing the same. The pH measuring electrode of this invention has a sensor film of a metal oxide deposited on an electrically conductive support so that the sensor film can be very miniaturized in its size. Therefore, the entire pH measuring electrode can be made considerably small and simple in construction. Also, this invention provides another pH measuring electrode which further includes a porous film of an insulation material coated on the surface of the metal oxide sensor film so that the sensor film is not affected by any coexistent substances.

Abstract: An amperometric biosensor and method for the detection of hydrogen peroxide, NADH, or NADPH with high sensitivity includes an electrode having on its testing surface a three-dimensional redox polymer network in which peroxidase is immobilized.

Abstract: An electrochemical measuring cell has a three-electrode system including electrode, counter electrode and reference electrode in an electrolyte. The measuring cell has an additive promoting the electrochemical reaction and is selective and highly sensitive for the detection of hydrogen halides and also provides a stable measuring signal. A measuring cell of this kind has an additive of tetrachloroauric acid in the electrolyte for detecting hydrochloric acid with all electrodes being made of gold. The counter electrode is protected by a cation exchange membrane to provide a further improvement.

Abstract: An apparatus and method for a cleaning process control is disclosed. The apparatus includes two parallel plates of glass that have a plurality of shims positioned therebetween and a means for clamping these plates of glass firmly against the shims. A contaminant is positioned between the plates of glass and the apparatus is cleaned using a selected cleaning process. The apparatus can then be inspected to determine the effectiveness of a particular cleaning process by peering through the transparent glass plates to inspect for any remaining contaminant. The apparatus can then be cleaned more extensively and used again to check a different cleaning process.

Abstract: The concentration of an ionic species (e.g. K.sup.+) is determined using an ion sensitive electrode having an appropriate membrane (e.g. valinomycin in plasticised PVC). In place of a conventional reference electrode, the half cell is completed with an electrode having an identical membrane but lacking the constituent producing the ion-selective response (e.g. plasticised PVC). The working and reference electrodes can then be made in substantially the same manner to null of interferents. The difficulties associated with double junctions are avoided.

Abstract: An improved compact ion-concentration measuring apparatus having a removable sample testing module with gelatinized electrodes. The gelatinized portion of the electrodes can be formed with a jelly containing an acrylic polymer with sodium.

Abstract: A sensor for measuring the concentration of an analyte in a solution is disclosed. The sensor may be adapted for use as either an amperometric or a potentiometric sensor. It includes a membrane having a biologically active protein immobilized within. The membrane is attached and reliably sealed to a housing by means of ultrasonic welding, either directly or indirectly. Further, the membrane may be compressed to a fraction of its original dimensions. Metallic parts of the device may, optionally, be physically isolated from the sample solution to reduce corrosion. These features operate synergistically so that the claimed device exhibits relatively fast response and recovery times, is reliably leak-proof, and may be constructed in relatively small sizes.

Abstract: Ion sensor having an ion-selective electrode and a reference electrode, both being unified, without internal liquid solution. The ion-selective electrode part has a solid solution of halogenide of conducting ions of solid electrolyte and halogenide of metal for an internal electrode, e.g., NaCl-AgCl solid solution. The reference electrode part has a solid solution of halogenide of the group Ia or IIa, e.g., Na, K, and a halogenide of metal for an internal electrode, e.g., NaCl-AgCl solid solution. The electrode parts are supported by an insulating substrate. A solid electrolyte such as NASICON or ionophore such as valinomycin is used as an ion-sensitive membrane.

Abstract: A corrosion sensor array incorporating individual elements for measuring various elements and ions, such as chloride, sulfide, copper, hydrogen (pH), etc. and elements for evaluating the instantaneous corrosion properties of structural materials. The exact combination and number of elements measured or monitored would depend upon the environmental conditions and materials used which are subject to corrosive effects. Such a corrosion monitoring system embedded in or mounted on a structure exposed to the environment would serve as an early warning system for the onset of severe corrosion problems for the structure, thus providing a safety factor as well as economic factors. The sensor array is accessed to an electronics/computational system, which provides a means for data collection and analysis.

Abstract: In a miniaturizable, capacitively measuring chemical semiconductor-based sensor system consisting of a sensor and a reference element which are to be brought into contact with the electrolyte to be measured, the reference element being connected in series with the sensor, the reference element consists of a highly doped semiconductor substrate or metal/semiconductor substrate which is covered with a membrane, and the sensor consists of an insulator/semiconductor substrate which is coated with a sensitive membrane, and the sensitive membrane of the sensor is more sensitive than that of the reference element.The sensor and the reference element of this sensor system may either be applied to one and the same chip or consist of individual components which are readily interchangeable with one another.

Abstract: A glass pH electrode which comprises a silver-silver chloride or a mercury-mercurous chloride inner electrode and an electrode filling solution for the inner electrode which is a zwitterionic buffer solution containing chloride ions.

Abstract: The present invention relates to a combined semiconductor gas sensor, this sensor is constituted by combining two portions, each of the portions is made of a different gas sensitive material, their resistance exhibit different variation with the variation of the density of a specific gas, a detecting signal is led out from the junction of the two portion. Because of the mutual compensation and propagation effect of the two portions of the above mentioned gas sensor, the stability and/or sensitivity as well as the stability to temperature and humidity and the initial relaxation time can be improved. Gas sensors of different characteristics can be obtained by different combinations of two different gas sensitive materials selected according to need.

Abstract: Small quantities of liquid are conveyed, either for the purpose of filling micropipettes or to function as an electrolyte in an ion selective electrode, in a flexible non-metallic capillary tube which is mounted, at a first end, in an adapter fitting. The fitting defines a socket for coupling to a source of liquid, a hypodermic syringe for example, or for receiving an electrochemical half-cell which will contact an electrolyte in the tube. A filter may be interposed between the fitting and hypodermic syringe so as to frictionally engage both when the device is employed for filling micropipettes.

Abstract: A combination sampling/electrochemical analysis cell comprises an enclosure having a hollow therein, at least one inlet leading to the hollow, a vent leading from the hollow, at least one testing electrode, at least one counter electrode, and at least one reference electrode, all disposed at least in part in the hollow. A testing reagent is also contained in the hollow.

Abstract: The invention relates to measuring the concentration of ions in a medium. The potentiometric sensor of the invention comprises a body (7) in the form of a matrix body made of a single type of material which does not conduct electricity, which is chemically inert, and which is suitable for being filled with various materials in the dispersed, the dissolved, or the grafted state. A sensitive zone of the matrix body comprises a layer or thickness (9) of an ionically conductive material for being put into contact with the measurement solution, an underlayer or thickness (10) of an electronically conductive material, and an intermediate layer or thickness (11) providing intimate connection between said layer (9) and said underlayer (10). A conductor (12) passes through a portion of the matrix body (7) in sealed manner and is inserted into the underlayer (10). The sensor is particularly applicable to measuring biological fluids.

Abstract: An improved solid-state ion-selective electrode has greater uniformity of asymmetric potential and high sensitivity and selectivity for the cation of interest. The electrode comprises: (1) a porous element comprising graphite; (2) an electrochemical reference in substantially dry form on at least a portion of the element, the reference comprising: (a) an oxidant and (b) a reductant that is the conjugate of the oxidant, the oxidant and reductant being present in about equimolar quantities; and (3) a polymeric membrane comprising an ion-selective ionophore in electrochemical contact with the electrochemical reference. The electrode can be prepared to be selective for one of a number of cations, including lithium and ammonium. Methods for preparing these electrodes are also disclosed.

Abstract: A readily disposable ion selective electrode assembly, free of onboard reagents, for use in analyzers has a reference element and plural sensor elements linearly positioned in parallel on a substrate. An elastomeric flow channel member containing two parallel grooves creates flow channels on the substrate above the elements. The substrate holds the elastomer in compression and is retained by snaps injection molded into a housing. Electrical contacts and leakfree fluidic connections are provided by spring loaded connectors through the housing. Reference and sample fluids are drawn through the respective flow channels and come together to form a liquid junction downstream from the sensor elements. Bubbles, that might otherwise cause erroneous results, are detected.

Abstract: A glass pH electrode which comprises a silver-silver bromide inner electrode and an electrode solution for the inner electrode which is a zwitterionic buffer solution.

Abstract: A sensor 13 is inserted into a connector 14. A constant voltage required to obtain a response current is applied across the connector 14 by a voltage applying source 15 at timings required. A response current of the sensor 13 inserted into the connector 14 is converted into a voltage by a current-to-voltage converter 16, and the amount thereof is determined by a microcomputer, the analysis results being displayed onto a display unit.

Abstract: A method of producing an ion sensitive working electrode for a heavy metal ion sensor, the ion sensitive working electrode including a mixture of Ag.sub.2 S and MeS in which Me represents a heavy metal to be determined in a solution to be measured, the method including applying a conductive layer onto a substrate using at least one thick-film technique selected from the group consisting essentially of screen printing and film casting; applying a layer comprised of a plurality of juxtaposed sections on top of the conductive layer, each section of the plurality of juxtaposed sections being comprised of a mixture of Ag.sub.

Abstract: An iodide-doped, polythienylene coated electrode suitable for a potentiometric iodide ion sensor and a method for its manufacture are disclosed. The electrode is prepared by polymerizing the polythienylene on a working surface thereof. To this end, the working surface is contacted with a monomer solution of thiophene monomer and an electrolyte dissolved in organic solvent. Thereafter the solution is subjected to either a substantially constant potential of about 1.6 volts to about 1.8 volts vs. Ag/AgCl or to a cycling potential between -0.1 volts and +1.8 volts vs. Ag/AgCl for a time period sufficient to polymerize a polythienylene film of the desired thickness onto the working surface of the electrode.The polythienylene film on the working surface is then doped with I.sub.2 by placing the coated electrode in an aqueous solution of iodide salt under applied potential conditions of about +0.6 volts to about +1 volt vs. Ag/AgCl for a period of time sufficient to dope the polymer.

Abstract: Disclosed is an integrated ion sensor, which comprises at least one ion selective membrane sensitive to ions contained in a solution to be measured for detecting the concentration of the ions, a signal processing circuit for inputting a detected signal obtained by the ion selective membrane through a conductive member and fetching the detected signal through MOSFETs or the like included in an input stage to process the same, a reference electrode disposed in the measuring environment made by the solution to be measured and to be set to a predetermined voltage relationship between the reference electrode and the ion selective membrane, and a power supply having negative and positive terminals for supplying a driving power to the signal processing circuit through the terminals, one of the terminals being connected to the reference electrode, wherein the signal processing circuit is set to an active state at a voltage set to the reference electrode by controlling the threshold value of at least one of the MOSFET

Abstract: A removable gelatinized calibration member is provided for use in storing or calibrating an ion concentration measuring device having measuring electrodes located in a concave measuring portion. The gelatinized calibration member is provided in the same shape as the concave measuring portion so that it may be removably placed onto the measuring device electrodes. The gelatinized calibration member may be a discrete pad or it may be provided in a rod-like configuration that can be moved in and out of a cylindrical housing.

Abstract: Switching devices (10) comprise a micro-electrode (12 or 16a') coated with a templated polymer (14). For example, the template molecule is glucose and the bulk polymer is a thiophene/boronic acid-substituted thiophene copolymer. The switch is activated or inactivated by the concentration of glucose in a solution (38) contacting the coated micro-electrode. Advantageously, the dimensions of the switch may be very small, 10.sup.-6 or less.

Abstract: Phosphate ion-sensitive composition and ion-selective electrode are disclosed incorporating an ionophore having the formula:R.sub.1 -X (a)orX-Z-X (b)wherein R.sub.1 is H or a hydrophobic substituent, Z is a spacing unit and X is represented by the formula: ##STR1## wherein n=0 or 1 and R.sub.2 and R'.sub.2 are independently selected from the group consisting of CH.sub.2, C(O) or C(S).

Abstract: An ionophore according to the general formula I wherein the substituents are chosen such that the ionophore is either also polymerized in the matrix of a membrane selective for metal ions or interwoven therewith. Thus obtained is a membrane having a long useful life for use in diverse sensors such as ISFET, ion-selective electrode, and the like.

Abstract: A blood loss monitoring apparatus is disclosed. The system includes a tank having a solution which removes blood from blood containing materials which are deposited in the tank and also hemolyzes the blood. Blood and blood containing materials are deposited into the tank during surgery, and the volume of liquid in the tank as well as the hemoglobin concentration in the tank are then determined. From this information, the total amount of hemoglobin lost is determined, and by measuring the patient's hemoglobin level immediately prior to the surgery, the total amount of blood lost is then calculated. The amount of blood lost can be continuously monitored and updated throughout the course of the surgical procedure or operation.

Abstract: An anion exchange membrane for ionic macromolecules, specifically heparin, which is formed of a polymeric matrix material, an anion exchange material suitable for heparin detection, and a plasticizer can be employed in an electrochemical sensor arrangement to directly measure the concentration of heparin ions in blood or blood fluid. Potentiometric response to heparin has been observed with membranes comprising 30-70 wt. % polymeric matrix material, such as polyvinyl chloride, 0.1-12 wt. % quaternary ammonium salt, such as tridodecyl methyl ammonium chloride, and 30-70 wt. % of a plasticizer, such as dioctyl sebacate.

Abstract: An apparatus for the simultaneous measurement of a plurality of ionic concentrations can utilize a test station having a common support sheet for supporting a plurality of ion selective electrodes, reference electrode and pH responsive electrode. Simultaneous measurements can be taken at the same time from a single sample and the pH reference electrode can validate the operative range of an ion selective electrode.

Abstract: The present invention provides a biosensor comprising at least one lipid membrane, each membrane including at least one gated ion channel. The membranes comprise a closely packed array of self-assembly amphophilic molecules and the gated ion channel has a conductance which is dependent upon an electric field applied across the membrane. The biosensor of the present invention may comprise a plurality of discrete membranes each including at least one gated ion channel. The conductance of each of the membranes is measurable independently of the conductance of the other membranes.

Abstract: An accurate, low cost temperature control system for a disposable cartridge carrying including a sample chamber for a portable medical diagnostic device or other electrochemical analytical device is disclosed. The disposable cartridge may include its own heating element on a sensor chip and plugs into a terminal which contains electrical input/output connections. The outer surface of the chip is exposed. A remote temperature sensor which senses the temperature of the outer surface of the chip of the measuring cell and generates a control signal which is used with conventional temperature control circuitry as the basis for thermostatic control of the cell temperature.

Abstract: A polyviologen modified electrode which comprises an insoluble film of polyviologen polymerized on a base electrode by electrochemical reduction and electrodeposition of monomer represented by the formula (I) ##STR1## Wherein R.sup.1 is a divalent group selected from the groups consisting of alkylene, cycloalkylene, arylene and arylalkylene or a trivalent group selected from the groups consisting of alkanetriyl, cycloalkanetriyl, arylalkanetriyl and aryltriyl; X.sup.- is a counter anion; m is 2 or 3, which electrode has no performance problem in connection with the solubility to water and organic solvent and the annealing phenomenon.

Abstract: A body fluid sample is diluted with a diluent which comprises an aqueous solution containing bis(2-hydroxyethyl)-iminotris(hydroxymethyl)methane and boric acid to obtain a diluted body fluid sample, and the ion concentration in the diluted body fluid sample is determined with ion-selective electrodes, whereby the variation width of pH in the diluted body fluid sample can be held down to a narrow range. As a result the determination can be made without exerting adverse effects on the ion-selective electrodes, and errors in determination can be markedly reduced as compared with cases where the conventional diluents are used.

Abstract: An enzyme electrode is prepared with a composite coating on an electrical conductor. The composite coating is formed from a casting solution of a perfluorosulfonic acid polymer, an enzyme, and a carbon supported catalyst. The solution may be cast directly on the conductor surface or may be formed as a membrane and applied to the surface. The perfluorosulfonic acid ionomer formed from the casting solution provides an insoluble biocompatible protective matrix for the enzyme and acts to retain the enzyme for long term availability in the electrode structure. The carbon supported catalyst provides catalytic sites throughout the layer for the oxidation of hydrogen peroxide from the enzyme reactions. The carbon support then provides a conductive path for establishing an electrical signal to the electrical conductor.

Abstract: This invention relates to a semiconductor substrate having a porous surface nd to the amperometric receptor-based sensors formed with the substrate. More specifically, this invention pertains to the substrate in the form of a bipolar junction transistor having a porous hydrophilic surface directly on its base wherein the surface forms a support for an amperometric sensor. The invention also pertains to the methods of making and using the substrate and sensor.

Abstract: Self-assembly of a chemically insensitive redox material, such as ferrocenyl thiol, and a chemically sensitive redox material, such as a quinone thiol, onto microelectrodes forms the basis for a two-terminal, voltammetric microsensor having reference and sensor functions on the same electrode. Detection is based on measuring the potential difference of current peaks for oxidation and reduction of the reference (ferrocene) and indicator (quinone) in aqueous electrolyte in a two-terminal, linear sweep voltammogram using a counterelectrode of relatively large surface area. Use of microelectrodes modified with monolayer coverages of reference and indicator molecules minimizes the size of the counterelectrode and the perturbation of the solution interrogated. Key advantages are that the sensor requires no separate reference electrode and the sensor functions as long as current peaks can be located for reference and indicator molecules.

Abstract: A system for analyzing the ion level of a fluid sample including an analyzer instrument, containing electrical circuitry for analyzing the ion level of the fluid sample, in electrical communication with a sensor unit having an ion selective electrode in communication with the fluid sample and electrical contacts for communication with the analyzer instrument. A recharger unit for the analyzer instrument is also disclosed.

Abstract: A pH sensor has a core of an electrochemically inert insulating or semi-conductive material, and is coated with an electrically conductive, electrochemically sensitive coating. The preferred core is insulating and made of alumina, with a thin coating of iridium oxide deposited over at least a portion of the outer surface of the core. The coating is carried to a surface remote from the sensing surface and is used for making electrically conductive connections that lead to remote circuitry. The core is made in a form that can be supported and held in an insulating, electrochemically inert, deformable material that is sealed around the outer surface of the coating on the core to prevent leakage of chemicals being sensed. The body also permits sealing quite easily onto access ports on which the sensor housing is mounted. Various connections to the electrode coating can be made quite easily to provide for a unique sensor assembly.

Abstract: A tapered carbon microelectrode is produced by extruding an organic material or a composition composed of crystalline carbon fine powder and an organic binder into a thin rod form, carbonizing said rod by calcining to produce a pure carbon thin rod, soaking the resulting thin rod as an anode in an electrolytic solution, gradually pulling up the thin rod while electrochemically oxidizing the tip portion of the thin rod. Then a lead wire is connected with the thick portion of the thin rod followed by coating all the surface except the conically sharp tip portion.The tapered carbon electrode can be used for various electrochemical measurements and scanning tunneling microscope.

Abstract: A method and apparatus for the monitoring and control of concentration of an ion in a solution at an elevated temperature of at least 100.degree. C. are disclosed. The method comprises the steps of contacting a first electrode with a flowing first solution containing said ion at the elevated temperature, and contacting a second electrode with a second flowing solution containing said ion at the elevated temperature. The rate of flow of the second solution is substantially lower than the rate of flow of the first solution. The first and second solutions are then contacted or admixed. The electrodes must be capable of detecting the ion at the elevated temperature and have the same response characteristics to changes in concentration of the ion at the elevated temperature.

Abstract: A reference electrode for generating a reference potential on an ion sensor is disclosed. The reference electrode has a lamination film covering a surface of an electrically conductive substrate and formed by alternately laminating silver halide thin films and hydrophobic resin thin films.

Abstract: A sheet-type, highly polymerized composite electrode used for measuring ionic concentration includes a thin film ion-selective responsive membrane formed on an upper surface of an insulating support layer by sequentially dripping an ion-selective responsive membrane paste containing solvent onto the support layer. The ion-selective responsive paste has a polymerization degree sufficient to provide an enduring ion-responsive membrane without any reinforcing structure.

Abstract: A reference electrode according to the present invention includes a silver layer (2) and an insulating hydrophobic material layer (5) which is formed by atomic beam sputtering and containing silver halide dispersed therein, on the surface of a conductive substrate (1).The resulting reference electrode is of a solid type, is almost free from outflow of silver halide, can be miniaturized easily, is not affected by ion concentration, provides a stable potential and has high durability.The conductive substrate (1) may be a field effect transistor having a gate insulator film and the layer (5) may be a laminate film obtained by laminating alternately a thin layer or layers of silver halide and a thin layer or layers of insulating hydrophobic material.

Abstract: An ion concentration analyzer for determining ion concentration in blood or urine. This analyzer comprises a flow cell provided with an ion selecting electrode and a syringe having a metal piston rod for introducing sample liquid into the flow cell. A metal member is disposed at a mid portion of a pipe connecting the flow cell and the syringe, and is electrically connected to the piston rod.

Abstract: The present invention comprises an electrochemical metering apparatus that provides for convenient storage and presentation of the analytical electrode, simple assembly, and two calibration modes. The apparatus includes an electrode storage and presentation assembly that permits the user to introduce the electrode into a sample solution while simultaneously observing the meter's output, and store the electrode when not in use. All structural components are intended to fit together with interlocking tabs and windows. A serial port fits within the construction of the main housing without the need for bolts, and battery clips that depend directly from the circuit board obviate the need for wiring connections. The present invention also features two calibration modes. A "segment addition" mode permits separation of the voltage/concentration curve into individually plotted regions, the number of which depends on the number of reference solutions used in the calibration procedure.

Abstract: A gaseous carbon dioxide detection sensor comprising a detection electrode and a reference electrode opposed on both sides of an ionic conductor, wherein a mixture comprising one mol of an alkali metal carbonate more than one mol of an alkaline earth metal carbonate is used as the detection material for the detection electrode. The detection sensor has the electromotive force characteristic relative to the gaseous carbon dioxide less undergoing the effect of moisture in the gas to be measured and has a high sensitivity.

Abstract: The biosensor of the present invention quantifies a substrate contained in a sample liquid by reducing electron acceptors using electron generated in a reaction of the substrate to enzyme and then by measuring the reduced amount of the electron acceptors electrochemically. The biosensor has an electrical insulating substrate, an electrode system including at least a working electrode and a counter electrode, a reaction layer including the enzyme provided on the electrode system and a hydrogen ion concentration control layer, and the reaction layer is in contact with the electrode system. According to the present invention, the hydrogen ion concentration in the sample liquid can be made most appropriate in accordance with the type of the enzyme contained in the reaction layer, without the adjustment of the hydrogen ion concentration in the sample liquid beforehand. Thus, the specific substrate contained in the sample liquid can be easily quantified with accuracy and speed.