Abstract: A device for humidifying gases without oxygen comprised of a gas conduit for passing the gases through the device to be humidified having a portion of the conduit being permeable to water but a barrier to electrolytes. The portion of the gas conduit is positioned closely adjacent the anode of a galvanic cell also having a cathode. A reservoir is provided for placement of the galvanic cell and the portion of the gas conduit therein which is at least partially filled with an electrolyte solution.

Abstract: A highly sensitive and selective electrochemical detector has been developed for the liquid chromatograph analysis of carbohydrates. This detector includes copper particles and copper particles coated with copper oxide particles dispersed in a perfluorosulfonate ionomer film which is cast onto the surface of a glassy carbon electrode. The copper is electrochemically dispersed into the perfluorosulfonate ionomer by a constant potential method. The response of the detector is based on the electrolytic generation of a higher oxidation state species of copper catalytically oxidizing carbohydrates in alkaline solutions at a pH greater than 13.

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: An apparatus for measuring the properties of a sample includes a sensor block with at least one sensor module whose housing contains a measuring chamber in contact with a sensor, the housing of the sensor module M including a mixing chamber for indirect measurement of a sample property, which chamber is placed upstream of the measuring chamber, and is connected with a sample channel and a reagent channel. Due to the modular design of the sensor block, the sample and reagent paths in the sensor block or sensor module may be kept short; along with the compact arrangement of mixing chamber and measuring chamber this permits the required sample and reagent volumes to be kept to a minimum.

Abstract: The apparatus employs a method for accurate, reproducible analytical solution evaluation eliminating the need for a reference sensor by determining the activity of selected species employing species specific sensors and species combination sensors in conjunction with Nernst-type equations. The apparatus includes sensor structures for elimination of edge effects to signals thereby yielding accurate, reproducible measurements, and a cartridge structure adapted to incorporate an array of the new sensors for employment of the new method where the cartridge is particularly adapted for miniaturization, maintaining a fixed volume of solution for analysis and providing an anaerobic testing environment. Lastly, a compact instrument embodying miniaturization especially adapted for field use and use of the cartridge is provided herein.

Abstract: In a measuring device for determination of the activity or the concentration of ions in solution comprising a flow channel (24) having a reference electrode and at least one measuring electrode, said flow channel having a first end (22) and a second end (23); a first line (18) connecting said first end of said flow channel to at least one calibrating liquid container (1,2,3) through first valve means (5,6,7); a first pumping means (14A) interposed in said first line (18) between said first valve means (5,6,7) and said first end (22) of said flow channel (24); a discharge line (19) connected to said first line adjacent said first end (22) of said flow channel (24), said discharge line having second pumping means (14B); a sample feed line (25) connected to said second end (23) of said flow channel for providing a sample to said flow channel; first and second sensors (10,11) arranged in said first and second ends of said flow channel, respectively, for detecting the flowing fronts of liquids, said sensors being

Abstract: The instant invention provides in one aspect porous frit electrodes having improved efficiencies. In another aspect the invention provides inert metal reference and/or counter electrodes a method of reducing diffusion effects on a metal terminal counter or reference electrode and the electrodes so produced.

Abstract: A continuous on-line blood monitoring system for determining the ionic concentrations of certain ions within blood is disclosed. By use of a synchronized valving mechanism within the device, as well as locating the amplification electronics away from the sensor elements, a relatively small, but highly efficient analyzing system is provided.

Abstract: An oxygen detection device utilizing a water permeable humidifier and two galvanic cells connected in series gas flow connection, each of the galvanic cells having an anode and cathode; the respective cathodes being connected to a common connection between two load resistors, and the respective anodes being separately connected across one each of the load resistors; the device further having a third galvanic cell in close proximity to a water permeable tube to provide an oxygen getter and humidifier.

Abstract: An electrochemical cell for measuring the activity of one or more ionic species such as pNa, pK, pCa, pNH.sub.4, pCl etc. consisting of two sensors selective to the actual ionic species, one of which is used as the reference electrode and the other as the measurement electrode.The two sensors are chosen preferably identical.The electrode used as the reference electrode is brought into contact with a solution of known ionic activity and an ionic strength which is greater, equal to or substantially greater than that of the unknown solution to be measured.The measurement electrode is brought into contact with the unknown solution to be measured, while a third electrode is used purely for instrumental reasons and does not participate in the measurement.

Abstract: An electrochemical detection device comprising a cell unit that has a cell therein and a supporter that rotatably supports said cell unit and that is made in one piece with said cell unit, wherein said cell unit has a cell block that has a test solution introduction route through which a test solution flows after being introduced into the inside of said cell block and that has a test solution outlet route through which the test solution leaves the inside and that has a reference electrode and a counter electrode provided so that they come into contact with the test solution flowing from said test solution introduction route to said test solution outlet route; a gasket that has an opening constituting said cell, and that is in contact with said cell block so that said opening is connected with both the test solution introduction route and the test solution outlet route; a working electrode that faces said opening of the gasket, and said supporter has a pressure means that pushes said working electrode onto sai

Abstract: A two-part test cartridge for use in a centrifugal analyzer for measuring the concentration of different electrolytes in blood or blood serum samples has one part which is disposable and which is characterized by a sample entry port, one or more filled calibrant chambers, a waste chamber and passages between various chambers; and a second, mating part which is reusable and which is characterized by an ISE, a power supply and circuitry therefor, and a series of chambers and passages adapted for communication with the series of chambers and passages in the disposable part.

Abstract: A flow through type ion electrode apparatus including a number of interconnectable block structures. Each block structure includes recesses in respective faces thereof, which lead to a through hole extending between the faces. A membrane electrode is located within each block structure so as to communicate with the through hole. A spacer having a through hole therein is inserted in a recess of each of a pair of adjacent block structures to interconnect the adjacent block structures.

Abstract: A modular multi-channel automated medical analyzer device is disclosed, characterized by use of an ion selective electrode and/or enzymatic electrode/wash cell system which permits rapid analysis of various substances of interest contained within undiluted body fluids such as whole blood, serum and/or plasma. The ion selective electrode and/or the enzymatic electrode are disposed upon a probe which automatically axially reciprocates downwardly in a simple manipulative motion between an open-ended reference wash cell and a sample cup bearing the body fluid specimen to be analyzed. The wash cell includes an inlet port and one or more outlet ports through which is circulated an aqueous solution bearing a known concentration of the substance to be measured to provide a reference calibration medium as well as a probe washing medium.

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 improved ISE is provided for measuring the concentration of an electrolyte in a sample in a centrifuge-type analyzer utilizing a multichamber test pack. The reference cell and sensor cell of the ISE are each comprised of an electrode, fill solution, housing and membrane in a fully self-contained configuration. Each cell is of sufficiently small size to fit in the test pack. The electrode of each cell is provided with screw threads to allow each cell to be screwed directly into the test pack thereby securing the cell to the test pack and at the same time providing a convenient electrical contact to the readout electronics of the test pack. With the present design manipulation of the ISE sensor output voltage can be achieved by varying the known ion concentration of the fill solution. Also provided is a novel method of introducing a fill solution into the cell after all of the cell components are in place.

Abstract: An ion selective electrode flow cell includes a first fluid conduit and at least two ion sensing electrodes each having ion sensing surfaces disposed within the first fluid conduit. A second fluid conduit and an ion sensing electrode having an ion sensing tip is disposed within the second conduit. There is an electrically conducting bridge connecting the first and second fluid conduits. A conductive member is disposed within the first fluid conduit proximate the ion sensing surfaces of two ion sensing electrodes and the bridge. A third fluid conduit may intersect the first fluid conduit and can include grounding for grounding fluid flowing through the third fluid conduit. Capacitors between exit and entry ports of the first and second fluid conduits and ground reduce electrical noise within the flow cell.

Abstract: An electrochemical differential resistance measurement arrangement usable for detecting low concentration ionic impurities such as chemical warfare agents in liquids such as water. The disclosure includes details of electrochemical cells used in the liquid resistance measurement arrangement including one cell with fixed electrode positions and a selective ion transmitting membrane one cell with adjustable electrode position, and a combination cell. A differential bridge electrical circuit, together with a preferred form of alternating current energization therefor, an effluent circuit therefor and a balancing method sequence of steps for the bridge, are also included.

Abstract: This invention relates to solid-state electrode or micro-electrode sensor apparatus for measuring certain characteristics of an aqueous sample such as a body fluid or a blood sample and more particularly to such apparatus which employs a disposable cartridge containing a sensor or a bank of sensors for such characteristics and reagents used to calibrate the sensors.

Abstract: An improvement of a device for measuring ion activity in a liquid sample comprising at least a pair of ion-selective electrode sheets, liquid-guiding portions for guiding a reference liquid and a liquid sample to each active surface of the pair of ion-selective electrode sheets respectively, and a bridge for electrically connecting both liquids supplied on the electrode sheets to each other is disclosed.

Abstract: A method for establishing a treatment protocol for correcting an abnormal condition of disease in a living organism is described. The method comprises the steps of analyzing body fluids from normal and abnormal individuals to generate analysis patterns of the normal and abnormal fluids, comparing the patterns to determine differences in the patterns, and establishing a treatment protocol for the abnormal individual through chemical or metabolic therapy which treating will normalize the abnormal pattern.

Abstract: An automatic analyzing apparatus for effecting chemical analyses for various sample liquids such as blood, urine, and the like, comprising a sample delivery pump for metering a sample liquid into a reaction cuvette, a reagent delivery pump for delivering to the reaction cuvette a given amount of a given reagent selected from a plurality of reagents contained in a reagent cassette, to form a test liquid, a feed mechanism for successively supplying reaction cuvettes along a circular reaction line, a plurality of photometering sections arranged along the reaction line for effecting a plurality of photometric and/or nephelometric and/or fluorometric measurements for each test liquid at different time instances to produce a plurality of photometric results, and circuitry for receiving the photometric results and selecting therefrom given quantitative analytical data of a given test item.

Abstract: The effectiveness of organic additives acting as inhibitors during the electrolytic deposition of metals from aqueous electrolytes, which contain organic additives for improving the deposition of metal, is electrically measured. In order to permit an improved and more reliable check of the effectiveness of the inhibitor and to permit a controlled supply of makeup inhibitors at the required rate, a partial stream of the electrolyte is supplied to flow at a constant velocity in a measuring cell provided with at least three wire electrodes having a fresh conductor surface, a measuring current of 5 mA to 1.0 A is supplied to the electrodes and is maintained, and the slope of the plotted cathode potential-time curve in the range from 0.1 to 50 minutes is taken as a measure of the effective conecentration of the inhibitor.

Abstract: A combination pH and CO.sub.2 sensor employs separate sensors. Each sensor has a wire with an electrochemically active layer, an electrolyte layer and a membrane between the electrolyte layer and the fluid to be tested. Each electrolyte layer is constructed of a dried residue which can be easily stored and which must be rehydrated prior to the first use. The electrolyte layer in the pH sensor when hydrated forms an aqueous solution buffered against changes in pH due to changes in the dissolved CO.sub.2 concentration and is preferably formed of 2-(n-morpholino) ethanesulfonic acid, 2-(n-morpholino) ethanesulfonic acid - sodium salt and potassium chloride. The electrolyte layer in the CO.sub.2 sensor when hydrated forms an aqueous solution having bicarbonate ions and is preferably formed of polyvinyl alcohol, sodium chloride and sodium bicarbonate. The electrical potential at the pH sensor is proportional to the pH of the fluid. The electrical potential difference between the CO.sub.

Abstract: A portable instrument for use in the field in detecting, identifying, quantifying, and monitoring gas, liquid or solid materials is disclosed. The instrument may analyze either liquids or gases depending upon the type of sensor array therein. The instrument also includes means for changing a gas, liquid or solid to a fluid material. The instrument further includes an array or small sensors which, upon exposure to the unknown material, form a pattern of electrical responses, a source of previously formed response patterns characteristic of various materials, and microprocessor means for comparing the sensor-formed response pattern with one or more previously-formed response patterns to thereby identify the material on a display. The number of responses may be increased by changing the operating voltage, temperature or other condition associated with one or more sensors to provide a plurality of responses from each of one or more of the sensors.

Abstract: The instant invention provides in one aspect porous frit electrodes having improved efficiencies. In another aspect the invention provides inert metal reference and/or counter electrodes a method of reducing diffusion effects on a metal terminal counter or reference electrode and the electrodes so produced.

Abstract: A method and apparatus for determining electrochemically active components in a process stream. The method comprises the steps of providing a sample in which the components are contained, and depositing the components onto a working electrode, altering the environment of the working electrode so that it is immersed in a supporting electrolyte by effecting a matrix exchange and stripping the deposited electrochemically active components from the working electrode into the supporting electrolyte. The method and apparatus utilize a measurement cell which comprises a vessel (10) for containing the supporting electrolyte and a mercury drop electrode (150).

Abstract: Disclosed is a process and device for facilitating the differentiation of particles in a medium. The particles, which belong to at least two different groups of particles, are enclosed in a chamber bounded by electrodes which produce a rotating electrical field. A means for producing two rotating electrical fields having opposite directions of rotation and variable rotational frequency is provided to be attached to the electrodes. The particles exposed to the rotating electrical field forces with opposite directions of rotation can be differentiated on the basis of their rotational behavior.

Abstract: Measuring device for determination of the activity or of the concentration of ions in solutions, which has an electrode block having several electrodes and with a flow channel, the flow channel being in connection at its one end with a sample vessel and is connected at its other end to a line, in which a pump is interposed, with calibrating solution containers.Between the pump and the outlet of the electrode block branches off a discharge line, in which a further pump is interposed. Preferably, both pumps are combined into a peristaltic pump, the lines being laid in the segments of the pump.According to a second embodiment, the electrode block is again in connection with the calibrating solution containers. The delivery of the sample is performed however on the same side through a septum. Advantageously, the other side of the electrode block opens out into a pressure equalization vessel, into which a withdrawal line opens in which in turn the above mentioned peristaltic pump is interposed.

Abstract: In a method of measuring ion activity of a liquid sample comprising steps of spotting a reference liquid and the liquid sample on surfaces of ion-selective membranes, respectively, of at least a pair of ion-selective electrode sheets which is electrically insulated from each other, said ion-selective membranes being provided on the top of said ion-selective electrode sheets; and measuring a potential difference between the ion-selective electrodes under the conditions that both liquids are electrically connected to each other by a bridge, the improvement wherein:said each ion-selective electrode sheet is arranged upside down in such a manner that the ion-selective membrane is positioned on the lowest side;andsaid each liquid spotted from the upper side is temporarily conveyed downwardly to the lower level than the surface of the ion-selective membrane or the spotting is done on the lower level than the surface of the ion-selective membrane, and then conveyed upwardly to the surface of the ion-selective membra

Abstract: A clinical chemistry analyzer system for blood chemistry analysis is disclosed. Two major parts comprise the system. One part is a discardable sensor cartridge which contains a bank of sensors, calibration fluid containers, conduit means and an external peristallically pumpable tube section. The other part is an analysis machine which interfaces with the discardable cartridge and has means to drive the peristaltic pump as well as means to interface with the sensors of the cartridge to provide a readout therefrom. The system is adapted to be made part of a heart/lung machine sustaining a patient in order to sample and monitor the venous and arterial blood flow thereof.

Abstract: There are disclosed an ion selective electrode comprising a polyvinyl chloride series resin plate having a through hole; conductive member disposed along the through hole; ion sensitive membrane of a polyvinyl chloride series resin membrane; and a lead wire connected to the conductive member, and the flow type ion sensor comprises a plurality of the ion selective electrodes mutually integrally associated with each other with the interposition of electrical insulating members so that through holes of the respective ion selective electrodes may define a flow passage for a liquid to be measured, and a flow type ion sensor using the same.The ion selective electrode and flow type ion sensor using the same of this invention allow the measurement in a smaller amount of the sample to be measured and are excellect in the adhesion of the ion sensitive membranes, therefore they have effects of a stable potential supply and a prolonged life time, and these industrial merits are highly great.

Abstract: This invention relates to solid-state electrode or micro-electrode sensor apparatus for measuring certain characteristics of an aqueous sample such as a body fluid or a blood sample and more particularly to such apparatus which employs a disposable cartridge containing a sensor or a bank of sensors for such characteristics and reagents used to calibrate the sensors.

Abstract: A sensor and a method are disclosed for the potentiometric determination of the ion content or activity of a sample and the concentration of other components (e.g., glucose, urea, triglycerides, enzymes, drugs) of a sample. The sensor comprises ion-selective electrodes which are held in a frame and have porous material between them; the porous material provides a means to establish ionic flow between the electrodes. Each ion-selective electrode is comprised of a membrane which is selectively permeable to the ion or other substance whose activity or concentration is being determined; a reference electrode; and an internal reference material.

Abstract: In a method of measuring ion activity of a liquid sample comprising steps of spotting a reference liquid and the liquid sample on surfaces of ion-selective membranes, respectively, of at least a pair of ion-selective electrode sheets which is electrically insulated from each other, said ion-selective membranes being provided on the top of said ion-selective electrode sheets; and measuring a potential difference between the ion-selective electrodes under the conditions that both liquids are electrically connected to each other by a bridge, the improvement wherein:said each ion-selective electrode sheet is arranged upside down in such a manner that the ion-selective membrane is positioned on the lowest side; andsaid each liquid spotted from the upper side is temporarily conveyed downwardly to the lower level than the surface of the ion-selective membrane, and then conveyed upwardly to the surface of the ion-selective membrane so as to reach the surface of the ion-selective membrane.

Abstract: A single-use sensing device for a clinical chemistry analyzer system includes a carrier which supports a capillary passage. Species selective sensors are located within a test chamber portion of the capillary passage. A rotatable multichamber reservoir having a calibrant chamber for holding calibrant fluid and a sample chamber for containing a sample fluid is rotated first to a calibrant test position and then to a sample test position. In the calibrant test position, the calibrant chamber is connected to the inlet end of the capillary passage to draw calibrant fluid into the test chamber. In the sample test position, the sample chamber is connected to the inlet end to draw sample fluid into the test chamber and purge the calibrant fluid from the test chamber. A set of sensor readings are taken at each position, and concentration values are derived from the two sets of readings.

Abstract: An ion selective electrode device is used to electrochemically detect several ion concentrations of an ion-containing liquid. The ion selective electrode device comprises a plurality of ion selective electrodes. These ion selective electrodes each include a substrate of insulating material having a small-diameter through hole, a metal layer formed in one body on an inner peripheral surface of the through hole and both major surfaces of the substrate, and ion sensitive layer formed on the metal layer of the inner peripheral surface. Those ion selective electrodes are connected by insulating plates for maintaining electrical insulation between the adjoining ion selective electrodes in such a manner that these through holes define a flow path for liquid to be examined.

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: The present method and apparatus set forth an improved measuring device and system of measuring to determine hypochlorite concentration from electrolyte discharge from a chlor-alkali cell. In the preferred and illustrated embodiment, a container means suspended at the lower end of a wand captures electrolyte. It enables electrodes to be submerged with the electrolyte to obtain a measurement of the hypochlorite concentration. The electrodes include a current emitting electrode, a reference electrode and a gold sensing electrode having an external surface which is etched to increase the surface area and has a coating of hypochlorite thereon to maintain uniform calibration and measurement during operation.

Abstract: A measuring system comprises ion-selective electrodes adjoining a measuring passage, which has an inlet and an outlet. The measuring passage has bends, which are adjoined by the sensing electrodes, which are flush with the boundary surface of that measuring passage. Said bends extend also before and behind each electrode. The sensing electrodes are provided at the outside surface of each bend so that they will be effectively rinsed and errors due to entrained impurities will be avoided. The measuring passage is suitably substantially circular but has entrance and exit portions offset from the circular line. The electrodes are provided on the outside particularly in a star-shaped array. The measuring system is provided with a shield consisting of a closed, electrically conducting covering, which preferably consists of a metallic cover. Contact and contact pressure springs are subjected to a uniform stress because the cover is mounted with play by means of a hinge so that self-alignment will be effected.

Abstract: A device for measuring the velocity of flow of a liquid comprises electrodes over which the liquid flows. A chemical emitting electrode is mounted so as to contact the liquid at a first point and is supplied with periodic input pulses by a current pulse generator such that chemicals are caused to be periodically generated on its surfaces. A second chemical detecting electrode is mounted downstream of the first point. The second electrode is connected to a potentiostatic circuit which produces an output signal when it detects the arrival of chemicals produced by the first electrode. A circuit measures the time between an input pulse and the corresponding output signal such that the velocity of the flow of the liquid can be determined.

Abstract: A dual working-electrode electrochemical detector includes two working-electrodes disposed in parallel, opposed and closely spaced relationship. The electrodes comprises a low temperature isotropic carbon, and the electrodes are spaced by a Teflon spacer. A channel is formed in the Teflon spacer for the flow of the biological fluid to be tested. The electrodes are mounted on hollow members, and the entire arrangement is held in fluid-tight engagement by a pair of yokes which overlie the hollow members.

Abstract: A coulometric flow cell having a defined flow path, and a working electrode in the form of a porous conductive matrix of a selected electro-conductive material in finely divided or powdered form, confined within a segment of the flow path, is described. The cell has particular utility for use with a liquid chromatography separation, and when placed in line upstream of sample injection, will remove selected electroactive components in the carrier fluid, and thereby reduce background level of contaminants reaching the column and eluting from the column. The cell may also be placed in line following sample injection whereby it may be employed to electrochemically modify selected materials in the mobile phase whereby to change their chromatographic characteristics. The cell also may be advantageously employed for direct testing or measuring of a sample solution.

Abstract: An ion selective electrode device is used to electrochemically detect several ion concentrations of an ion-containing liquid. The ion selective electrode device comprises a plurality of ion selective electrodes. These ion selective electrodes each include a substrate of insulating material having a small-diameter through hole, a metal layer formed in one body on an inner peripheral surface of the through hole and both major surfaces of the substrate, and ion sensitive layer formed on the metal layer of the inner peripheral surface. Those ion selective electrodes are connected by insulating plates for maintaining electrical insulation between the adjoining ion selective electrodes in such a manner that these through holes define a flow path for liquid to be examined.

Abstract: Rapid and accurate whole blood analysis measurements are made with analysis systems of the potentiometric type that employ restricted diffusion type liquid junctions where the whole blood sample is flowed past sensing electrode and liquid junction at a velocity of at least one centimeter per second during a data acquisition interval that is at least twenty-five milliseconds in duration.

Abstract: Between a substance to be analyzed and a sensor there is placed at least one membrane, forming part of a sample vessel containing a sample to be analyzed and being permeable for a species depending on the substance to be analyzed. This membrane constitutes at least one wall of the sample vessel, through which the active sensor surface may be brought into contact with the substance to be analyzed. The sensor is designed as a separate unit which is movable relative to the sample vessel, with which its membrane may be brought into contact. For the purpose of measurement the sensor is contacted by the membrane stretching over the active sensor surface which in itself does not carry a membrane.In this way the sensor cannot be contaminated by the sample, and the device may be successfully used for series measurements.

Abstract: The salinometer is based on a direct determination of the conductivity ratio R.sub.t =(Cx/Cs).sub.t of sample water to standard seawater in a two channel, dual-cell, continuous-flow system. Each of the channels includes a conductivity cell with four electrodes immersed in sequence in the water flow. Two of the electrodes are current electrodes and the other two electrodes are potential electrodes. The standard water and the sample water pumped into their respective channels, are maintained at a common temperature by heat exchangers and a common bath. The salinometer circuitry include a first current source for driving a controlled current into the current electrodes of the conductivity cell to maintain a constant voltage across the potential electrodes. A second current source drives a current which is a linear function of the first controlled current into the current electrodes of the conductivity cell in the reference channel. The conductivity ratio R.sub.

Abstract: An improved apparatus for electrochemically analyzing a sample in solution is described. The apparatus comprises an electrochemical detector comprising a plurality of electrochemically isolated flow cells arranged in series so as to define at least one flow path. Each of the electrochemical flow cells in turn comprises at least one working electrode, at least one reference electrode, and at least one counter electrode. Electrical potentials are applied to the various working electrodes so that the sample solution is cyclically subjected to oxidation and reduction conditions whereby selected substances contained in the sample solution may be electrically screaned or modified prior to detection and measurement on a downstream sensing electrode.

Abstract: A device for transporting and distributing a liquid comprising at least one internal liquid passage, a liquid introducing hole extending from the outer surface of the device to the liquid passage, and at least one liquid distribution opening extending from the liquid passage to the outer surface. The inlet of the liquid introducing hole is adapted to receive a port of a liquid injector in airtight relation therewith. At least one air discharging hole may extend from the liquid passage to the outer surface. An ionic activity measuring device is constructed by a combination of such devices. It comprises solid electrodes in contact with the liquid distribution openings and provided in a number equal to the number thereof, and at least one bridge extending between the liquid introducing holes, between the liquid passages or between the liquid distribution openings. The respective pairs of solid electrodes are able to selectively respond to a predetermined ion.

Abstract: An electrochemical measuring system which effects, measures and sorts charge transfer reactions of selected substances in a sample solution is provided. The system includes a novel electrode which is adapted to measure simultaneously on at least two electrodes at least two electrolytic potentials with reference to a reference potential. In a preferred form the electrode comprises a hollow, cylindrical body formed of an electrically insulating material. The electrode is open at least at one end and has a generally smooth cylindrical inner surface. A plurality of electrically discrete active electrode segments are mounted on the inner surface of the electrode with their active surfaces substantially flush with the generally smooth cylindrical inner surface.