Abstract: An apparatus for analyzing particles in a sample liquid which classifies or counts components in the sample liquid by image processing. The liquid sample can be urine or the like and is passed in a flattened flow. The apparatus comprises sheath liquid supply apparatus sample liquid discharge apparatus a, temperature sensor for detecting the ambient temperature and temperature measuring circuit for measuring the temperature depending on the output of the temperature sensor, and a driving circuit for driving the sample liquid discharge apparatus by correcting the sample liquid discharge flow rate depending on the signal from the temperature measuring circuit. The sheath liquid is supplied at a specific pressure, and the sample liquid discharge quantity is corrected depending on the ambient temperature. When changed to the high scale factor taking state or low scale factor taking state, a different correction rate is set.

Abstract: A system for coulometric TCO.sub.2 analysis wherein a sample bottle is pressurized by a head space gas having a CO.sub.2 composition which approximates the dissolved CO.sub.2 concentration in the sample. The head space gas transfers to sample to a pipette. The sample is then transferred to a stripper where the sample is degassed. Two carrier gas lines flush the stripper and transfer the CO.sub.2 to a coulometer.

Abstract: A plunger homing mechanism for use in automated chromatography. A plunger cap holder holds the plunger cap of a syringe within a housing. The housing is biased with an isolation spring within a casing. The casing is raised and lowered to move the syringe plunger held within the housing. When the casing is lowered and the plunger hits bottom, the relative movement between the housing and the casing is detected by a sensor. The casing movement is then caused to stop. This permits the detection of a home or reference position for the accurate and precise withdrawal of a sample to be analyzed. Additionally, damage to the syringe from over driving the plunger rod is prevented.

Abstract: An apparatus and a method for analyzing particles suspended in a liquid are described, which particles are of a type or are prepared so as to emit radiation characteristic of the particles when exposed to radiation. Particular fluorescence-photometrical flow cytometry is described in connection with biological cell populations.The apparatus comprises an elongated flow area in the shape of a channel provided in a cuvette comprising a first body member having a planar facial surface and a second body member having a planar facial surface. The first and the second body members are adapted to be moved relative to one another between a first position, in which the planar facial surfaces are in fluid-tight contact with one another, and a second position, in which the planar facial surfaces are spaced apart. At least one of the planar facial surfaces of one of the body members is provided with an elongated groove.

Abstract: An endless loop calibration system comprising a sensor cassette having a flow-through passage and at least one sensor to be calibrated, a chamber coupled to the sensor cassette to define an endless loop, a calibration liquid in the endless loop, and a valve element which is employed to prevent the flow of calibration liquid through the endless loop. This valve element, preferably carried by a housing, urges a tube compressor to squeeze a compressible tube against a curved wall surface sufficiently to prevent fluid from flowing in the compressible tube across the zone, and to maintain the at least one sensor in the sensor cassette wet with calibration liquid for long term storage of the calibration system.

Abstract: Automation of the coulometric Karl Fischer titration has allowed for the accurate, precise determination of moisture content of lyophilized hGH formulations. The system of the present invention utilizes a vented, two-hole sampling/dispensing probe that dispenses titrant and withdraws sample solution through the closed container rubber septum into the Karl Fischer titration reaction vessel. This approach eliminates erroneous results due to environmental moisture contamination or loss of material during the sample transfer process. The system of the present invention is also equipped with a fixed loop valving system, which facilitates the precise measurement of a defined amount of water as a standard. This allows for an accurate accessment of system suitability that was lacking with commercial water standards due to inaccurate moisture content presumably from moisture contamination of the standard under storage and/or at the time of manufacture.

Abstract: An electropneumatic apparatus for sampling rapidly predetermined volumes of a mixture, to be connected to a computer.

Abstract: The centrifugation chamber serves in particular for liquor testing, the liquid to be tested being arranged in a vessel whose bottom area is formed by a slide retained in a bottom part, there being arranged at least at the outer circumference of the vessel a suction element which lies on the lower part. The upper part is clampable on the lower part by means of a clamping device, so that different size upper parts can be used with a single lower part.

Abstract: A device for the extemporaneous and continuous preparation of a solution for dialysis by the dissolution of several substances in powder form in water. The device includes a number of independent cartridges each containing a salt of a substance necessary for the preparation of the dialyzate, such as sodium chloride, potassium chloride, calcium chloride, magnesium chloride, and sodium bicarbonate.

Abstract: an automated synthesizing apparatus which comprises a raw material, reagent and solvent supply unit, a reaction unit, a purification unit provided with HPLC and CPC, and a freeze-drying unit for freeze-drying a purified product supplied from the purification unit. The raw material, reagent and solvent supply unit includes a plurality of reservoirs for containing raw material, reagents and solvents; volumetric tubes and gas-liquid boundary sensors for the quantification of the raw material, reagents and solvents from the reservoirs; flow-lines for supplying the raw material, reagent and solvent from the reservoirs towards subsequent steps; and solenoid valve assemblies disposed on the respective flow-lines for selectively closing and opening such respective flow-lines.

Abstract: Apparatus and methods for processing liquids are provided. The apparatus include open-ended, hollow reactor compartments which are detachably connected to receptor ends of tube systems. In preferred embodiments, a portion of the tube system is fixed to a rotor arm which can be rotated in a circle and moved up and down. Another portion of the tube system is coupled to a metering syringe which serves for drawing in or ejecting fluids into or from the reactor compartment and/or the tube system. A plurality of process stations such as bottles containing reagents or solvents can be arranged on a circular tray such that they can be accessed by the reactor compartment or by the receptor end if the reactor compartment has been detached from the tube system. The invention can be used, for example, for automatic protein sequencing, whereby the proteins to be sequenced are held in place by a matrix in the reactor compartment.

Abstract: The flow-injection system includes a microwave oven having a flow-through reactor having a flow-through conduit located in windings around a conduit carrier for absorbing microwaves. The windings extend through the radiation cavity of the microwave oven only with a part of their length and transversely to the radiation direction. The microwave oven includes programmable adjusting means for the heating power and the heating period. Thus, in connection with a reduction flow-through reactor and an atomic absorption spectrometer, a determination of hydride formers and mercury in a material sample is possible, independently of the valence state.

Abstract: A syringe is depressurized to suck a slight amount of air into the tip portion of a probe of a probe assembly, forming an air layer. Then, the syringe is depressurized again to suck into the probe assembly a sample to be discharged into a reaction container. Accordingly, the target sample to be discharged, the air layer and extruding water are placed into the probe assembly in the named order from the tip portion of the probe.

Abstract: A chemical sensor and method for in-line chemical analysis including a body having a central cavity. The body also has a pair of openings through it to the cavity. A porous plug, such as a ceramic frit, is sealed into each of these openings so that there is a space between the plugs in the cavity. A vent passageway through the body to the cavity is also provided. A pressurized sample is flowed through one porous plug into the cavity while a pressurized reagent is flowed through the other porous plug into the cavity. A component of interest of the sample reacts with a reactive component of the reagent in the cavity to produce a reaction product. The reaction product is analyzed in the cavity by, for example, absorption spectroscopy. As fresh sample and reagent flow into the cavity, the reaction products flow out of the cavity by way of the vent passageway.

Abstract: An improved automated pipetting system for programmingly pipetting predetermined quantities of liquid between preselected groups of test tubes, vials or wells arranged on a horizontal table. A substantially rigid overhead frame mounted over the table on which the test tube arrays or the like are arranged. A pair of parallel X-axis guide shafts mounted in the rigid frame. A pair of helical screws rotatably mounted in the frame parallel to the pair of X-axis guide shafts. Each helical screw is driven by a stepper motor coaxially connected thereto. A pair of X-axis roller sections are movably mounted on the pair of X-axis guide shafts and support a Z-axis probe mechanism via a pair of Y-axis guide shafts and a parallel Y-axis helical screw. A stepper motor is drivingly and coaxially connected to the Y-axis screw for moving the Z-axis probe mechanism along the Y-axis guide shafts. The Z-axis probe mechanism is movably mounted on the pair of Y-axis guide shafts.

Abstract: An optical agglutination assay device for detecting cocaine. The device includes a hollow reaction cell defining a generally planar liquid receiving reaction chamber having a thickness which is insufficient to diminish the intensity of a ray of light passing through an aqueous reaction system in the chamber in a first direction transversely of the plane of the latter. The device also includes a pusher assembly for delivering an aqueous agglutination reaction system and an unknown substance suspected of containing cocaine into the chamber. The agglutination system is such that agglutination is inhibited in the presence of cocaine. The device also includes an optical transmitting and receiving unit aligned with the reaction cell for measuring the intensity of light reflected from the chamber as a measure of the occurrence of agglutination in the reaction system.

Abstract: A system collects fluid waste within a closed waste vessel where a waste disposal cycle is determined based upon the pressure level within the waste vessel. In the preferred embodiment, a closed liquid waste vessel accepts waste solutions through conduits having valves controlling conduit fluid communication with treatment vessels. A pressure sensor determines the level of pressure within the waste vessel. A pressurizing device reduces the level of pressure within the vessel. When the pressure within the vessel is lowered to a predetermined level, the valve is opened. When the pressure sensed within the liquid waste vessel then rises above an appointed value, the valve is closed, completing the waste collection of a treated sample. This corresponds to the point in time when the treatment vessel is empty, allowing a sudden rush of air into the waste vessel, raising the vessel pressure to ambient and closing the valve.

Abstract: An apparatus that provides controlled volumetric delivery of particulate material, particularly for delivery of a particulate sample for analysis. The apparatus includes a sample receiving tubular member that is vibrated or rotated relative to the sample container to agitate and fluidize a surface portion of the sample placed in an elongated container. A transporting gas carries the fluidized sample from the container through the tubular member. Sample delivery rate is controlled by a traversing mechanism that gradually inserts the moving tubular member into the upper fluidized portion of the sample. The apparatus allows total delivery of a known mass of a particulate sample at a predetermined delivery rate.

Abstract: A continuous flow analysis system measures the cholesterol distribution among different lipoprotein classes in a blood sample. A blood plasma sample is separated into different lipoprotein classes by single vertical spin density gradient ultracentrifugation. The sample is then introduced in a continuous succession into a continuous reagent stream which flows through a detector. A signal of the reaction, such as the absorbance of the reaction product, is continuously monitored as the reaction mixture flows through the detector. The detector measures a transient signal thus allowing a relatively short reaction period. The absorbance data is digitized and analyzed with the help of a computer to generate a cholesterol profile indicative of the cholesterol concentration in each lipoprotein class.

Abstract: Apparatus is provided for coupled liquid chromatography and nuclear magnetic resonance (NMR) spectroscopy measurements. The apparatus includes a liquid chromatograph, an intermediate storage device for intermediately storing of components of a probe eluent and an NMR spectrometer. Selected intermediately stored components are fed to an NMR measurement unit. The intermediate storing device includes a number of capillary tubes, which are switchable by an automatically controlled valve arrangement for selectively receiving and delivering desired eluent components.

Abstract: Methods are disclosed for detecting the effects of cell affecting agents on living cells. The method steps include providing living cells that are retained in a micro flow chamber. The micro flow chamber is adapted for either continuous or intermittent flow of solutions or suspensions in intimate contact with the cells. The solutions or suspensions, which contain a cell affecting agent, are then flowed in intimate contact with the cells and at least one effect of the cell affecting agent on the cells is measured by an appropriate detecting means, which is operatively associated with the micro flow chamber.

Abstract: A calibration system comprising a sensor cassette including at least one sensor to be calibrated and a housing having a liquid passage including a chamber. The housing is coupled to the sensor cassette to place the liquid passage in fluid communication with the sensor cassette. The housing has a gas injection passage through which a gas can be injected into the liquid passage to mix with a calibration liquid in the housing. A gas vent vents the gas from the housing. Porous media is provided in the chamber. The gas and calibration liquid pass through the porous media, and the porous media assists in rapid mixing of the gas and the calibration liquid.

Abstract: An analyzer system for improving quality of a reaction product, wherein a liquid sample must be maintained at an elevated temperature to prevent precipitation of titratable species, comprises a heated sample and dilution section, an autotitrator and a programmable controller. In operation a liquid sample to be analyzed is withdrawn from a reactor and maintained at reactor temperature while being diluted. The diluted sample is then cooled and passed to an autotitrator for analysis. The analyzer system includes a programmable controller for automatic unattended dilution of successive samples.

Abstract: An apparatus for receiving chemical compounds carried in a high pressure effluent fluid stream from supercritical fluid extraction. The apparatus includes a heated conduit connected to supercritical fluid extraction device through which an effluent stream flows. The exit port of the heated conduit is located within the airspace of a decompression zone which is free of liquid. A liquid solvent chamber is provided in open communication with the downstream end of the decompression zone into which the effluent stream flows for the recovery of chemical compounds therein.

Abstract: An analytical method which comprises sampling a predetermined amount of a liquid sample, bringing the sample to a vapor-liquid equilibrium at a predetermined temperature and pressure, separating the resultant gaseous and liquid fractions from each other, and analyzing the gaseous fraction as a gas sample and the liquid fraction as a liquid sample, and an apparatus for practicing the analytical method. By this method or apparatus, the light and heavy fractions of a substance can be simultaneously analyzed in composition and chemical structure. This enables the modification and the service life of a chemical substance like a lubricating oil, in which the qualities may change with the passage of time, to be estimated or foreseen.

Abstract: An analyzing device, in particular for examining body fluids, with a measuring module, at least one gas feed tube for a calibrating gas, a moistening device for the calibrating gas as well as a washing water tube connectable to the measuring channel of the measuring module, is simplified and improved in that the moistening device for the calibrating gas is integrated in the washing water conduit through a water inlet and a water outlet. The calibrating gas can be led over the water surface in the moistening device and moistened in this way.

Abstract: Apparatus and method for practice in an over-the-road vehicle to determine whether effluent water released in an operating water treatment system (plant installation) can be adequately treated to remove contaminants so the effluent may be reused at the plant rather than discharged to the environment with inimical effect. The frame of the vehicle supporting a plurality of clean holding tanks, a plurality of functionally different water treating units, an analysis laboratory, a pilot cooling tower simulator, and a pilot boiler simulator. The effluent is transferred from one of the holding tanks to at least one of the water treating units to reduce the contaminant level. When the contaminant level has been reduced to a level appropriate for reuse at the plant, the effluent is transferred to one of the simulator apparatus for evaluation of the treated water in the corresponding plant process.

Abstract: Sample liquid analysis apparatus and method for the formation and supply to a conduit of a stream of successive sample liquid test packages, and the repeated bi-directional displacement of the sample liquids test package stream in the conduit, sample liquid analysis apparatus operatively associated with the conduit for repeated, time-spaced analyses in turn of the sample liquids in each of the sample liquid test packages. Each of the test packages comprises a first segment of a sample liquid and a first reagent liquid, and a second segment of a second reagent liquid spaced from the first segment by a different fluid in the test package.

Abstract: Dispensing apparatus for an automatic chemical analyzer including a reaction turntable having a plurality of reaction vessels arranged along a periphery thereof, a sample turntable having a plurality of sample vessels arranged along the periphery thereof, a reagent turntable having a plurality of reagent bottles in which different kinds of reagents are contained, a sample delivery mechanism for delivering a given amount of a sample into a reaction vessel, and a reagent delivery mechanism for delivering a given amount of a reagent into the sample to form a test liquid in the reaction vessel.

Abstract: A method and apparatus for practicing solid phase extraction of samples for analysis where the method comprises the steps of providing a cassette having a plurality of tubes, each containing an absorbent substrate and having an upper and a lower opening; applying a preconditioning liquid reagent to each tube of the cassette through the upper opening to render the substrate therein hydrophilic and drawing the liquid through the substrate until the liquid is at a predetermined height about the substrate; applying a liquid sample to be analyzed to each of the tubes of the cassette and drawing the sample through the substrate until the liquid is at a predetermined height in the tube with respect to the substrate; applying an eluate to each tube of the cassette to remove an eluent therefrom; and collecting the eluents from the cassette tubes. The apparatus automates this process and provides accurate and rapid separation of compounds in the sample.

Abstract: In blood examinations, first basic items such as the number of red blood cells, the number of white blood cells and the volume of hemoglobins are measured (primary examination), then, on the basis of the results thereof, further specific additional items are measured such as leukocyte classification and measurement of reticulocytes (secondary examination). In this case, the basic items are measured by the basic analyzing module and the results of the measurement are analyzed to judge whether additional items are necessary or not, and only specimens requiring additional items are measured in the additional analyzing module. The additional analyzing module is provided with a temporary sump for temporarily retaining the measuring solution from the measuring solution preparing device. Thus, the blood examination may be done efficiently.

Abstract: The number of bacteria in a cell population comprising bacteria and somatic cells is determined by concentrating the bacteria and the somatic cells on the surface of a substrate of a filter material, such as a membrane filter, rupturing the somatic cells by treatment with a medium which is not in osmotic balance with the medium inside the cells, such as water which here constitutes a hypotonic medium, and removing or inactivating their ATP, establishing an extraction chamber having an inner wall which is partly defined by the bacteria-bearing surface of the filter material and therein extracting the ATP from the bacteria with a medium containing a surfactant, such as a quaternary ammonium compound, capable of perforating the cell walls of the bacteria, adding luciferin and luciferase and transferring the medium to a measuring chamber, determining the amount of ATP by measuring the light emitted as a result of the luciferin/luciferase reaction and expressing the amount of ATP as the number of bacteria present

Abstract: A microprocessor-based, control unit for analysis of a fluid sample, and for especially biomedical analysis of a body fluid, is provided. Also provided is the combination of a roller assembly and a compartmentalized pouch containing certain chemicals, with the rollers functioning to break rupturable seals of compartments and to push fluids from one compartment to another. Apparatus in accordance with the present invention, is useful, for example, in monitoring urea concentration during dialysis.

Abstract: A method for diluting and mixing specimen such as blood and a reagent, which is designed to prepare a mixed solution of a specimen and a reagent at a specific ratio by discharging the reagent in a passage for quantitative determination in a sampling valve by a specified amount of the reagent. The method is such that specimen is discharged by reagent first at a low speed and thereafter at a usual speed by a reagent discharge device. The reagent discharge device may comprise a syringe, a pump having a thin film for forming air and liquid chambers, or the like. As constructed, the specimen is not damaged due to fluid pressure.

Abstract: A method and apparatus are provided for use with a centrifuge to analyze reactants. The apparatus includes at least one cuvette having at least one chamber. The chamber has a radially outward wall which provides a base upon which reactants can be pelleted when the device is rotated about a centrifugal axis. Each cuvette includes one or more openings for introducing fluids to the cuvette and includes a channel positioned adjacent to the radially outward wall for removing fluids from the chamber. Pressure is applied to the chamber to force fluids therefrom, through the channel. A hold down device is also provided through which fluid and/or pressure may be passed with respect to the cuvette. The invention also provides a method for determining the existence and degree of agglutination of reactants in a first fluid suspension and contained in a single reaction vessel using a photodetector.

Abstract: A method of determining populations of live, whole bacteria electrochemically. The bacteria are filtered, and the filtrate is employed in association with an electrochemical measuring unit to determine the bacteria density. In accordance with a flow-through method, the average signal over the predetermined time period of the test is employed, in conjunction with a constant, to determine the population. In accordance with the bypass method, reagent is passed through a bypass line to the electrochemical measuring unit, and the resulting signal is subtracted from the signal resulting from the filtrate, a constant being employed to correlate the resulting remainder with bacteria count. A changing-concentration method employs a changing concentration of bacteria in the same fluid to determine populations of bacteria. A saved-sample method employs a second test of the same filtrate, after a predetermined time period, to compensate for any contaminants that may be present.

Abstract: An apparatus for diluting and mixing specimen such as blood and a reagent, which is designed to prepare a mixed solution of a specimen and a reagent at a specific ratio by discharging the reagent in a passage for quantitative determination in a sampling valve by a specified amount of the reagent. The apparatus is designed so that specimen is discharged by reagent first at a low speed and thereafter at a usual speed by a reagent discharge device. The reagent discharge device may comprise a syringe, a pump having a thin film for forming air and liquid chambers, or the like. As constructed, the apparatus is not damaged due to fluid pressure.

Abstract: An automatic continuous multinominal analyzer comprises suction tubes to be inserted into vessels containing a reagent, each suction tube having a pair of electrode lines. The contacts of each pair of electrode lines are located above the suction port of the suction tube. Hence, the contacts are isolated from each other when the level of the reagent in a vessel is lower than the contacts, even if the reagent still remains in the vessel. If it is detected that the contacts in a vessel are isolated, this indicates that the vessel is almost empty. A display indicates a vessel which is almost empty on the basis of the result of the detection as to whether the contacts in the vessel are isolated. After a vessel is indicated on the display, the controller continues suction of the reagent and an analysis operation until the reagent in the indicated vessel is reduced to the minimum level which can be extracted through the suction tube.

Abstract: An apparatus (1) for processing or preparing liquid samples for a preferably quantitative chemical analysis, especially for flow-injection analysis, is, for the purpose of miniaturisation and reducing the necessary sample volume while at the same time reducing the analysis time, assembled from a set of plate-like components (8). Each of the components (8) includes channels to form pipe pieces (9) and/or branches (13) with orifices and/or values, for example non-return valves, and/or pumps (6,7) in order to be able to feed the carrier liquid and sample to a detector (3) in the desired manner. Depending on the purpose of the analysis, the components (8) with the pipes and functional parts contained in them may be stacked in varying number and/or sequence and/or angular orientation relative to one another and can be connected in a sealing manner in the operative position.

Abstract: An apparatus for drawing a specimen of a body fluid, such as urine from a sample tube. The specimen is drawn through a slide assembly for examination. A sample tube with a special plug and ball valve is described to provide a solids collection chamber with which a uniform amount of body liquid is provided for the specimen.

Abstract: A system is provided for the detection of transition elements and/or rare earth elements in an aqueous sample which also contains high concentrations of alkali and alkaline earth metals. The system is effective for determination of transition elements and/or rare earth elements in sea water, industrial waste streams, biological fluids and biological issue samples.

Abstract: An automated apparatus for use in cleaving, deprotecting and purifying synthesized polypeptides immobilized on solid phase particles. The apparatus includes cleavage and extraction vessels where peptide cleavage from solid-phase particles, and extraction of scavenger reagents occurs, respectively, and structure for automated transfer of (i) reaction solutions into and out of the cleavage vessel, (ii) peptide solution from the cleavage vessel to the extraction vessel, and (iii) extraction solvent into the extraction vessel, in dispersed form. Excess extraction solvent is removed from a side arm in the extraction vessel.

Abstract: A method for flow injection analysis of total inorganic phosphate contained in an aqueous system such as a cooling tower or boiler is described which uses a reducing agent and preservative composition therefore as the carrier for the sample to be analyzed, thereby creating a facile process which permits conversion of the various polyphosphates to orthophosphate and development of the molybdenum blue complex color reaction at 60.degree.-95.degree. C. and under 2-10 psi. This method has less stringent pressure and temperature requirements than those employed heretofore, thus permitting the use of more reliable and economic devices for measuring total inorganic phosphate in the field.

Abstract: In a blood gas analyzer, a substantially oxygen-free measurement solution is fed through a measuring cell as far as a diffusion cell in which the measurement solution is brought into contact with a blood sample to be tested. The gases dissolved in the blood sample diffuse through a membrane in the diffusion cell into the solution. The measurement solution is then propelled in the reverse direction to feed into the measuring cell. In the measuring cell, the measurement solution is electrochemically measured to determine a value which is related to the partial pressure of oxygen (pO.sub.2) in the sample.

Abstract: A dispenser which can deliver precise small amounts of a liquid is disclosed. The dispenser is particularly suited to applying reagents in a biological test such as an immunoassay. It includes a reservoir chamber linked to a dispense chamber via a check valve, the two chambers preferably being in the form of syringes. An outlet line leading from the dispense chamber to a nozzle includes a delay check valve (preferably a ball inside a cylindrical chamber) which allows continuous outward flow, but shuts off flow in the reverse direction after allowing a predetermined volume to pass. The process of refilling the dispense chamber from the reservoir chamber creates reverse flow in the nozzle and causes a hanging drop of liquid at the tip of the nozzle to be withdrawn.

Abstract: Liquid transport system with constant fluid flow rate provided by cam driven pump. Multiple cams on common cam shaft are driven by a source of constant power and coordinate timing and operation of multiple system elements.

Abstract: A capillary stop-flow junction located in a housing at an end of a capillary passageway used to transport a liquid and at the beginning of a non-capillary internal chamber in the housing, in which the stop-flow junction contains an improvement which comprises 1) means for selectively trapping a gas in the capillary passageway and non-capillary chamber, wherein when the means for trapping is activated and the liquid enters the capillary passageway, the gas is compressed by the liquid as the liquid flows through the capillary channel and stops flowing at the stop-flow junction; or 2) a stop-flow nozzle surrounding the capillary passageway and projecting into the chamber; or 3) the stop-flow junction being formed from a single housing body member; or 4) a rupture junction in the capillary pathway, wherein the rupture junction is a stop-flow junction providing less maximum available back pressure than the capillary stop-flow junction.

Abstract: An automatic chemical analyzer includes containers for chemical reagents, a standard (full scale) solution and a baseline solution. An overflow sampler provides a test sample having a chemical concentration to be measured. Computer controlled valve means connect either the baseline solution, standard solution or test sample to an output tube, and a peristaltic pump couples the reagents and the liquid in the output tube to a chemical module where the chemical reaction takes place. The output of the chemical module is coupled to a flow cell in the form of a stream of liquid segments separated by air bubbles. Light at a selected optical frequency is passed directly through the flow cell to a photodetector the output of which is converted to digital form by a computer which stores baseline and full scale values corresponding to the color values of the liquids in the baseline and standard containers.

Abstract: An automatic chemistry analyzer includes a flow cell mounted so that flow through the cell and tubing connected to the cell is visible from the front of the housing. The electrolytes to the cell are removably plugged into the cell from their rear. The probe aspirating sample fluid into an injection cell is simultaneously washed by diluent and the diluent mixes with the fluid sample. Waste fluid from the flow cell is fed to a basin which then feeds under gravity to a waste drain. A ratio pump is formed by selected syringes which are band driven to deliver accurately prerequisite volumes of reagents to the flow cell. The solution ground to the system is on the inlet line for sample adjacent the entrance to the flow cell of fluid thereby minimizing electronic noise. Only two motive means are necessary, one to effect horizontal and rotational movement of the sample tray, and a second to effect vertical motion of a crane mounted probe operative between sample cups and an injection cell.

Abstract: A sensor arrangement for flow injection analysis, includes an enzyme reactor and a chemical/physical sensor. The sensor arrangement is designed as a sealed module and a flow channel of great length is accommodated in the module. By this sensor arrangement, gases generated or consumed in the enzyme reactor are detected without interfering gas exchange with the environment.