Abstract: A sensor for gaseous and vaporous species is disclosed. The sensor comprises an electrically insulated substrate which contains small pores passing completely through it. Electrodes consisting of metallic or semiconductor material are deposited onto the top surface of the substrate. In a first embodiment of the invention, an electrolyte is placed on the top surface of the substrate in such a manner as to create a gas or vapor permeable electrolyte layer on top of the electrodes. In a second embodiment of the invention, the electrolyte is applied to the bottom surface of the substrate and seeps up through the porous holes of the substrate until it makes contact with the electrodes. Both embodiments result in a gas sensor with a response time dependent upon the gas flow rate rather than the time required for the gas to be dissolved in the electrolyte layer and be detected.

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: The electrode of the present invention has metallic surface within a laser produced opening where the metallic surface extends into an electronic metallic conductive pathway and the pathway is covered for electric insulation by an encapsulant layer. The encapsulant layer around the metallic surface has the opening to allow the exposure of the metallic surface from the encapsulant layer. The metallic pathway and encapsulant are resident on a substrate, and are produced from layered circuitry. The electrochemical cell has the aforementioned electrode juxtaposed to another electrode. This electrode is part of the patterned metallic layer that is produced by layered circuitry. The electrode extends into an electronic metallic conductive pathway that is spaced apart and electronically insulated from the other pathway. The insulation can be supplied by a covering of encapsulant material that covers the pathway except does not cover the second electrode.

Abstract: In order to simplify the performance of serial measurements by means of a measuring device for determining chemical parameters of an aqueous sample, with at least one symmetrical, ion-sensitive membrane being located between the sample and an electrolytic medium and the sample and the electrolytic medium being in contact with reference electrodes connected to an evaluation unit, a measuring element is provided which can be inserted into a measuring device and which has a sample chamber connected with a reference chamber via a bore. At least one measuring chamber is provided, which is separated from the sample chamber by a symmetrical, ion-sensitive membrane. The reference chamber and all measuring chambers contain electrolytic media into which are dipped the reference electrodes located in the measuring device.

Abstract: In connection with a method for generating a constant derivation potential in analytical chemistry by means of a pH measuring chain containing a reference electrode, in particular for a pH test electrode for use in the meat-processing industry or for measurements in semi-solid substances such as cheese, pastes, in which for carrying out the measurement at least the pH measuring electrode is introduced into the medium to be measured by a corresponding movement, it is proposed that every time the pH measuring electrode is introduced into the medium to be measured, the electrolyte solution of the reference electrode, which is to be brought into contact with the medium to be measured via a diaphragm, be compressed whereby the diaphragm of the reference electrode, which gets into contact at least with the outer surface of the medium to be measured, is subjected to a cleaning action due to the pressure rise in the electrolyte solution occurring simultaneously with such compression.

Abstract: The invention is directed to an electrochemical measuring cell for detecting gaseous components with an electrolyte which is disposed between a counter electrode and a measuring electrode provided with gas permeable pores. The pores are configured as channels partially or completely filled with the electrolyte and these channels have a diameter which does not exceed 10 micrometers with a channel length of up to 300 micrometers and a web thickness of not more than 5 micrometers. With this configuration, drift and memory effects are suppressed and the measuring sensitivity is increased and, on the other hand, the response time and the residual current are reduced. When the measuring cell is used as a dosimeter, the counter electrode and the measuring electrode are decoupled with respect to a mass transport in the electrolyte.

Abstract: A planar oxygen sensor has an insulating substrate, a cathode formed on the insulating substrate generally at the center thereof; another electrode formed on the insulating substrate in a region other than the region of the cathode, a gas permeable membrane stretched to cover these electrodes and having its peripheral portion supported on the insulating substrate, and an electrolytic solution charged between the gas permeable membrane and the insulating substrate. A surface of the cathode is substantially in contact with the gas permeable membrane and is formed at a position higher than the gas permeable membrane support portion of the insulating substrate. A portion of the insulating substrate surface other than the region where the cathode is formed is recessed. Because the layer of electrolytic solution on the cathode is thin, oxygen molecules passing through the gas permeable membrane can immediately serve for the reduction at the cathode, thereby increasing the response speed of the planar oxygen sensor.

Abstract: Precalibrated, disposable electrochemical sensing devices can be constructed so as to utilize a housing shaped so as to internally include at least two separate half cells, one of which is capable of serving as a reference half cell and the other of which is capable of serving as a sensing half cell. The housing is shaped so as to include a top depression capable of being used as a container which is in communication with the interiors of the half cells. The depression is capable of holding for a sample to be analyzed using the device. The housing is preferably mounted on a board which is capable of being plugged into a female socket. This board carries electrodes which are connected to electrodes in the half cells.

Abstract: A miniature, solid-state long-life reference electrode in which the amount of outflow of an internal electrolyte containing a halogen ion is reduced includes a conductor on the periphery of which is formed a sintered body consisting of a silver halide and silver oxide, a water-containing gel enveloping the conductor and including a halogen ion electrolyte, and a hollow tubular body closed by a liquid-junction portion comprising a porous ceramic, or by a partitioning wall having an ion permeable portion of a predetermined diffusion coefficient and volume. In another embodiment, the tubular body of the reference electrode is partitioned by a partitioning wall having an ion permeable portion of a predetermined diffusion coefficient and volume.

Abstract: A testing module is provided having units which can be arranged seriatim to provide narrow through passageways linked to each other for quantitative determination of analytes passing through the units as by electrical testing with electrodes. Auxiliary passageways are preferably used in one unit to allow flushing of a first sample chamber without contamination from a second sample chamber. An electrode holder carries a membrane backed by a gel to aid in electrically linking the membrane to an electrode and to support the membrane in a substantially planar condition in use.

Abstract: A detection system for the detection of e.g. chlorine in a gas stream comprises an elongate support (14) which has electrolyte distributed along its length and is provided with a pair of electrodes (18,20), the electrolyte being chemically reactive with the gas to be detected to produce an electric current detectable by the electrodes. The electrolyte may be distributed along the support by capillary action or it may incorporate a viscosity-enchancing agent to allow the electrolyte to remain in place along the length of the support thereby avoiding loss of electrolyte by dripping.

Abstract: In a sheet type reference electrode having a gelatinized internal solution, a liquid junction surface of the gelatinized internal solution is coated with a hydrophilic porous thin film. Alternatively, a liquid junction member contacts the gelatinized internal solution and is coated with a hydrophilic porous thin film. In either event, the thin film controls the diffusion of ions from the gelatinized internal solution. A liquid junction portion is also provided by impregnating a chemically stabilized, hydrophilic, high molecular porous material with a gelatinized composition which remains wet.

Abstract: Miniaturized Clark-type oxygen electrodes includes a substrate having at least one recess groove formed on a surface thereof for receiving an electrolyte solution, and two electrodes acting as a cathode and an anode formed through an insulating layer on the surface of the substrate. Each of the electrodes is at least partially disposed in a bottom area of the recess. A solid or semi-solid, porous, electrolyte solution-containing material fills the recess, and an oxygen gas-permeable membrane covers and seals the recess and porous material received therein. Miniaturized biosensors are made using the oxygen electrode as a transducer. The oxygen electrodes and biosensors, which are extremely accurate, can be mass-produced and can be widely used in various fields such as clinical analysis, industrial processing, and in the determination of environmental conditions. The biosensors can be particularly used in clinical diagnosis and in monitoring devices for both in vivo and in vitro measurements.

Abstract: A measuring probe in which the electrolyte is in the form of a highly viscous gel produced in situ from an ion-permeable polymer and a neutral salt suspension. Homogeneously suspended neutral salt particles in the gel cause the gel to have a turbid appearance which disappears progressively as the suspended neutral salt particles pass into solution, thus indicating at all times the state of aging of the electrolyte. The additional presence of silica gel renders the probe potential resistant to pressures in excess of 10 bars.

Abstract: An oxygen sensor includes an electrically conductive substrate directly coated with an electrolytic oxidative polymeric membrane, which contains a porphyrin compound and a metal complex thereof. Also provided is an oxygen sensor capable of being subjected to a temperature calibration and including an oxygen electrode consisting of an electrically conductive substrate directly coated with a porphyrin derivative compound and a metal complex compound thereof, a reference electrode, a gelled polymeric electrolyte in which the oxygen electrode and reference electrode are immersed, and an oxygen-selective permeable membrane coating the gelled polymeric electrolyte. The electrically conductive substrate according to the present invention is formed from a material inactive with oxygen gas, such as indium tin oxide, iridium oxide, nickel or gold.

Abstract: An electrochemical sensor comprising an electrolyte and an analyte separated by a selectively permeable membrane preferably characterized in that the electrolyte is an electrically conductive solid comprising a homogeneous dispersion of a polymeric matrix phase and an electrically conductive salt and substantially free of water. Preferably the polymeric matrix phase is plasticized, the plasticizer forming a continuous phase in which the conductive salt is dissolved. The sensor is used, for example, for sensing and measuring gases especially in transcutaneous measurement of blood gases.

Abstract: A method and apparatus for electrical testing of membrane tissue employs a pair of rack sections which have cavities for receiving opposing end portions of the culture cup. The culture cup and rack sections are clamped together to form test chambers at opposing sides of the cup substrate on which the experimental tissue is grown. Electrode cartridges are inserted into axial bores of the receiving cavities to provide a test current through the membrane tissue. Integral connectors connect with conduits for passing irrigation streams through the test chambers.

Abstract: A method and an apparatus for measuring concentration of a dissolved substance are disclosed. In accordance with the method, measurements are made with two instruments having different permeability characteristics to obtain two readings, and these readings are corrected in accordance with a pre-determined relationship. The apparatus provides an electrochemical cell wherein a common anode is surrounded by closely-spaced cathodes. The cathodes are in at least two groups, wherein the first group has a first response characteristic to the dissolved substance and the second group has a second response characteristic. In the preferred embodiment, the two characterisitcs are produced by providing different distances between a substance-selective membrane and respective cathodes. In one embodiment, the cathodes are annular and surround the anode at different radii, while in another embodiment the cathodes are discrete and are spaced from the anode by equal distances.

Abstract: An analysis system including an ion selective electrode assembly, a sample container and a transport mechanism. The electrode assembly includes a reference electrode within a reference gel-filled well and ion selective electrodes disposed on an elongated portion of the electrode assembly. The sample container includes a body defining a plurality of reservoirs and a slot retaining an absorbant wiping and/or blotting material. The electrode assembly may be removably fixed relative to the transport mechanism. The transport mechanism includes a support table adapted to receive the sample container. The support table moves relative to the electrode assembly under the control of a cam to sequentially position the elongated portion of the electrode assembly within the reservoirs and the slot of the sample container.

Abstract: An improved electrode assembly of a modular configuration for sensing ion concentration includes a substrate mounted in a housing and being sandwiched by a first and second support layer of non-conductive material. A gelantinized solution is positioned in an opening between the first support layer and a substrate, while a second gelatinized solution is positioned in an opening between a second support layer and a substrate. Electric leads and electrodes are appropriately positioned on the substrate for operative contact with the respective gelatinized solutions. An ion-responsive member contacts one gelatinized solution, while an acqueous junction member extends through the respective support layers and substrates to contact another gelatinized solution.

Abstract: An oxygen sensor includes an electrically conductive substrate directly coated with an electrolytic oxidative polmeric membrane, which contains a porphyrin compound and a metal complex thereof. Also provided is an oxygen sensor capable of being subjected to a temperature calibration and including an oxygen electrode consisting of an electrically conductive substrate directly coated with a porphyrin derivative compound and a metal complex compound thereof, a reference electrode, a gelled polymeric electrolyte in which the oxygen electrode and reference electrode are immersed, and an oxygen-selective permeable membrane coating the gelled polymer electrolyte.

Abstract: An electrochemical system for the detection of carbon dioxide includes a single cell chamber exposed to the sample medium through a polymeric barrier membrane, a single set of electrodes and utilizes an aprotic non-aqueous, gelled solvent/electrolyte medium which allows measurement of CO.sub.2 in the presence of both oxygen and water vapor.

Abstract: A reference electrode is disclosed for use in potentiometric analysis of ion activity in a solution.

Abstract: A flat shaped composite electrode includes a flat substrate having a high electrical insulating property. A flat inside pair of electrodes and a flat outside pair of electrodes are fixed on the substrate. A flat support layer having a high electrical insulating property overlays the electrodes and substrate. The support layer describes two holes into which a gelatinized internal solution is placed. An ion response glass membrane is mounted on the support layer and over one hole, while a liquid junction membrane is similarly mounted over the other hole.

Abstract: An ion selective microelectrode in which the reference solution is an aqueous solution of formamide (or methyl formamide) and in which the ionophore-containing membrane covering the reference solution is PVC dissolved in water-insoluble 3-methylcyclohexanone (or equivalent substituted cyclic ketone). The reference solution may be gelled with PVA and preferably is buttressed to assure against incursion of membrane components.

Abstract: An improved electrode assembly for measuring ions, such as a pH electrode, and method of forming the same is provided. A plastic support layer with an aperture is mounted over a base member having electrodes. A gelatinized internal solution is mounted in the aperture over the electrodes in a plasticized solution containing a hydrogen ion-responsive material is formed into a paste and is positioned over the gelatinized internal solution and the adjacent surrounding areas of the support layer. When the paste solidifies it forms a thin film plastic ion-selective response membrane that is integrally sealed to the support layer.

Abstract: Disclosed is an ion sensor having an ion-sensitive substrate provided within a tube at a position recessed from an open end of the tube and having an ion carrier membrane, which is selectively permeable to an ion of interest, filling the space between the opening of the tube and the surface of the ion-sensitive substrate on the open-end side of the tube. A method of manufacturing the ion sensor includes steps of inserting and retaining the ion-sensitive substrate in the tube, filling the space between the ion-sensitive substrate and the tube with a sol-like ion carrier membrane composition, and gelling the sol-like ion carrier membrane composition.

Abstract: An electrochemical method and apparatus for detecting polar toxic species is disclosed which uses a conductive polymer coated sensing electrode. The conductive polymers may be polyquinoline or substituted polyquinolines.

Abstract: A lipid membrane is used as a chemo-receptive transducer for quantitative and semi-quantitative analysis of chemical test species in an electrolyte. The lipid membrane is contacted with an electrolyte containing the test species, and an electrical potential difference is applied across the membrane. From measurements of the trans-membrane ion current variation due to the presence of the test species, a quantitative analysis of the test species may be conducted, on a highly selective basis. Receptors showing a high degree of selectivity towards the test species are included in the membrane.

Abstract: An electrochemical sensor device providing long term signal stability through a structure and relation of components effective to provide substantially uniform current flux at all points across a working electrode and a counter electrode of a three electrode system within an electrolyte container having a hydrophobic membrane permeable to a selected component to be measured and accessible to a fluid to be monitored.

Abstract: A testing module is provided having units which can be arranged seriatim to provide narrow through passageways linked to each other for quantitative determination of analytes passing through the units as by electrical testing with electrodes. Auxiliary passageways are preferably used in one unit to allow flushing of a first sample chamber without contamination from a second sample chamber. An electrode holder carries a membrane backed by a gel to aid in electrically linking the membrane to an electrode and to support the membrane in a substantially planar condition in use.

Abstract: A combination pH/reference electrode is provided with the two electrochemical references being symetrically thermally insulated from the sensing membrane and being thermally adjacent each other. The portion of the pH fill buffer in contact with the inner surface of the sensing membrane is thermally insulated, as by KCl crystals, to rapidly equilibrate in temperatures with the sample solution.

Abstract: An improved flow through ion sensing electrode and a method for producing it. The electrode is formed of bilumen plastic tubing using one lumen as the sample path and the other lumen as a sensing chamber. By permeating a portion of the tubing with an ion selective material, an ion selective membrane integral with the chamber wall is produced. A preferred embodiment also incorporates a reference electrode.

Abstract: An improved flow through ion sensing electrode and a method for producing it. The electrode is formed of bilumen plastic tubing using one lumen as the sample path and the other lumen as a sensing chamber. By permeating a portion of the tubing with an ion selective material, an ion selective membrane integral with the chamber wall is produced. A preferred embodiment also incorporates a reference electrode.

Abstract: A combination ion sensing and reference electrode and a method for producing it. The electrode is formed of bi-lumen plastic tubing using one lumen as sensing chamber and the other as a reference chamber. A portion of the sensing chamber extends distally relative to the reference chamber, and is permeated with an ion selective material by soaking that portion in a solution containing the ion selective material. The method of manufacture is thereby simplified and sealing of the chambers is improved.

Abstract: Apparatus and method for an electrochemical sensor for carbon monoxide detection in a gelled aprotic organic nonaqueous electrolyte solution.

Abstract: An improved method for producing ion-selective membranes having a desired shape and of a desired plastic, for incorporation in ion-sensing electrodes, and the electrodes incorporating these membranes. This method allows the use of preformed polymeric members having the desired shape to produce ion-selective membranes, allowing simplified production of ion-sensing electrodes, as well as combination ion-sensing and reference electrodes.

Abstract: A galvanic cell type oxygen sensor comprising a galvanic cell comprised of a cathode made up of metal effective for the electrolytic reduction of oxygen, an anode made up of lead material and an electrolyte made up of an aqueous mixed solution of organic acid and organic acid salt, which has a long life and a high output voltage, is not at all affected by carbon dioxide and which can prevent the generation of hydrogen from the cathode, is disclosed.

Abstract: A combination ion sensing and reference electrode and a method for producing it. The electrode is formed of bi-lumen plastic tubing using one lumen as sensing chamber and the other as a reference chamber. A portion of the sensing chamber extends distally relative to the reference chamber, and is permeated with an ion selective material by soaking that portion in a solution containing the ion selective material. The method of manufacture is thereby simplified and sealing of the chambers is improved.

Abstract: An electrochemical electrode device comprising a tubular member having a bottom end adapted to be inserted into a liquid sample to be measured, and a top end which is closed by a cap member including electrical conductors by means of which the electrodes of the electrode device are connected to an outer cable. In order to facilitate the introduction of liquid or gel into an inner space defined within the tubular member as well as withdrawal of liquid or gel from that space, a longitudinally extending passage is formed within the cap member. This passage may be selectively opened and closed by means of a closure member which is received in a cavity extending transversely to and intersecting the longitudinal passage. The closure member is preferably in the form of a swingably mounted slide valve member or a rotatable cock member.

Abstract: A conductimetric gas sensor consists of a ptfe body forming an electrolytic cell; two threaded silver electrodes screwed into the ptfe body and bridged by a layer of a hydrophilic gel in contact with an electrolyte in the cell; a reservoir for supplying deionized water to the cell, so that the volume of water between the electrodes is maintained; and a gas-permeable hydrophobic layer through which the hydrophilic gel can be exposed to the gas.

Abstract: Early fatigue damage in aluminum is assessed by detection of microcracks in an anodized surface film using a hand-held electrode having a contact tip formed of a gel containing an iodide salt and starch. The gel tip is pressed against the anodized film and an electrical pulse is applied to pass current through the microcracks to oxidize iodide in the gel to form black iodine-starch complex. Thus, dark spots in the gel indicate the sites of fatigue-induced microcracks in the oxide and thus the extent of fatigue damage in the metal.

Abstract: A probe for measuring electrical conductance to determine water concentration in a fluid is disclosed. The probe comprises a pair of spaced apart electrodes and a bridge of protein gel between the electrodes. The probe is especially useful for monitoring water concentration in the lubrication oil for a compressor drive train of a hermetic vapor compression refrigeration system. In such a refrigeration system the water concentration in the lubrication oil corresponds to water concentration in the refrigerant of the refrigeration system.

Abstract: Early fatigue damage in aluminum is assessed by detection of microcracks in an anodized surface film using a hand-held electrode having a contact tip formed of a gel containing an iodide salt and starch. The gel tip is pressed against the anodized film and an electrical pulse is applied to pass current through the microcracks to oxidize iodide in the gel to form black iodine-starch complex. Thus, dark spots in the gel indicate the sites of fatigue-induced microcracks in the oxide and thus the extent of fatigue damage in the metal.

Abstract: A reference electrode catheter for use for in vivo measurement of body fluids. The catheter includes a small diameter cylindrical tube having a reference electrode assembly disposed on the distal end thereof. The reference electrode assembly includes a hollow cylindrical housing and an electrode element positioned within the housing mounted on and supported by a retainer member. The electrode element is connected to an electrical conductor which extends out of the housing and through the passageway of the tubing to the proximal end of the tubing. An electrolytic material, such as gelled Ringer's solution, is disposed within the housing, and a membrane formed of hydrogel is positioned across an aperture in the housing so as to form an ion diffusion barrier between the body fluids to be measured and the electrolytic material within the housing.

Abstract: A sensor consists of a catalytically active measuring electrode communicating with a non-polarizable atmospheric oxygen electrode by way of an aqueous acid electrolyte. The electrolyte used is an aqueous gelatinous polymeric adhesive in which ionogenic substances are dissolved. Due to the adhesive properties of the electrolyte, a 3-phase boundary of air-catalyst-electrolyte is formed at the transition to the measuring electrode and substantially determines the measuring process.