Abstract: An assay for photometrically detecting and/or quantitating the presence of an analyte in a sample in which the signal generated by a label associated with the analyte is photometrically detected in the presence of a suspended solid support.

Abstract: The invention provides a method capable of determining the presence or absence of each of a plurality of different ligands in a specimen. The specimen is contacted with a predetermined number of different homogeneous populations of fluorescence beads having one or more predetermined antiligands affixed to their surface. The specimen and bead mixture is analyzed using a means having a single parameter for measuring the fluorescence per ligand to determine the number of nonagglutinated beads, the number of agglutinated beads, the number of bead aggregates, and for each aggregate, the number of beads it comprises. This information is used to correlate the presence or absence in the specimen of each of the different ligands analyzed for. The method of the invention thus provides for the simultaneous determination of a predetermined number of ligands in a specimen using only a single bead contacting step.

Abstract: Particle pattern judging method in which a particle pattern formed on the bottom surface of a reaction vessel by an immunological agglutinated reaction is measured in an optical manner; a variation ratio of light intensity of the border of the particle pattern is obtained and the particle pattern is judged whether it is agglutinated or not on the basis of the variation ratio: or a two-dimensional image of the particle pattern is picked up; the two-dimensional image of the particle pattern is differentiated to obtain differentiated values concerning pixel compositions consisting of the particle pattern; and the particle pattern is judged whether it is agglutinated or not on the basis of a distribution of the thus obtained differentiated values.

Abstract: A system for rapid microbead calibration of a flow cytometer including a suspension of quantitative fluorescent microbead standards and analytical software. The software is used to take information on the microbead suspension from a flow cytometer and analyze data, smooth curves, calculate new parameters and notify of expiration of the system.

Abstract: The mean particle size of a dispersed phase, such as a liquid dispersed in a carrier liquid, is determined by selecting a particulate solids material which, when dispersed in the carrier liquid, has the same refractive index as the dispersed liquid in the carrier liquid, measuring the turbidity of selected particle sizes of the particulate solid for different concentrations of each particle size in the carrier liquid and developing a relationship of the ratio of the turbidity to the concentration for each particle size as a function of particle size which may be referenced when measuring the turbidity and concentration of the dispersed liquid in the carrier liquid to determine the actual particle size of the dispersed liquid.

Abstract: In a method and apparatus for examining samples comprising individual objects (28) of macromolecular or similar size, or smaller, an instrument element (14) comprises a substrate (16) overlaid with a thin film layer (18) of a material that is electrically conductive and/or at last partly optically opaque. A discontinuity comprising an aperture (26) or an asperity is formed in or on the element (14) in a known location, and the sample (28) is brought to this discontinuity so that it is not necessary to search for the sample by scanning. Energy (e.g. electrical energy or light) is applied to the element (14) and, with the latter and the sample in intimate association, e.g. with the sample inside the aperture (26), changes in the radiation from the sample site resulting from the presence of the sample are detected.

Abstract: Detecting light in a capillary electrophoresis optical system includes input and output windows in the outside surface of a capillary tube. The width of the windows is not substantially greater than the bore of the tube. A fiber optic input is spaced from the capillary tube so that the light is directed to the tube and is matched to the window width. The light output from the tube is matched to be received by a fiber optic output spaced from the capillary tube. The optical light envelop from the fiber input through the tube and to the fiber output is governed by the LaGrange Invariant. The matching is effected in accordance with the Numerical Aperture of the fiber optics.

Abstract: An x-ray sedimentation particle size analyzer in which data is taken only at particular positions along the sedimentation cell, and each such position is individually calibrated. Presentation of the data in the form of a particle size distribution curve can be accomplished very accurately using interpolation techniques. The sedimentation cell design is free of the effects of undesirable density gradients, capable of detecting and removing bubbles, capable of attaining a highly uniform dispersion of sample prior to sedimentation, and including a safety interlock device for blocking x-ray projection when the cell is being accessed.

Abstract: Particle pattern images of the sample are optically measured by an image reader of a particle agglutination pattern judgment apparatus, and the measured particle pattern images are retrieved by a data processing controller to be able to execute pattern judgment processing. The data processing controller obtains predetermined parameters on the basis of the particle pattern images read by the image reader, and automatically judges an agglutination, non-agglutination, or unidentified attribute of each particle pattern on the basis of the obtained parameters. An operator visually observes the particle pattern images of the sample to visually determine an agglutination, non-agglutination, or unidentified attribute of each particle pattern of the sample. The operator inputs the visual judgment results in the particle agglutination pattern judgment apparatus using an input unit.

Abstract: Methods and apparatus employing optical spectrometry techniques to measure metallic wear debris contamination in used motor oil, even in the presence of carbon particulates. Measurement results based on optical spectrometry as disclosed herein correlate closely with results of laboratory analysis based on atomic spectrometry. Variation in transmittance of a sample of oil as a function of wavelength within the approximate range of 300 nm (violet) to 1300 nm (near-infrared) is measured as an indicator of metallic wear debris contamination. Conveniently, measurements may be taken at just two wavelengths within the range, for example 565 nm (green) and 660 nm (red). The ratio of transmittance at the shorter of the two wavelengths to transmittance at the longer of the two wavelengths is determined as an indication of the amount of metallic wear debris contamination, decreases in the ratio from a ratio of unity indicating increasing levels of contamination.

Abstract: Automatic particle pattern judging method, in which particles to be tested, such as blood cell particles, are delivered into not only a reaction vessel but also a reference vessel, and an amount of the particles delivered into the reference vessel is measured and a judgement whether the particle pattern formed in the reaction vessel is agglutinated or not is conducted by correcting values of a reaction liquid contained in the reaction vessel concerning parameters for the judgement or correcting threshold values, with which the values of the test liquid concerning the parameters should be compared in accordance with the amount of the particles delivered into the reference vessel. Therefore, by the method according to the invention, even when the amount of particles to be tested delivered into the reaction vessel is varied for some reason, it is possible to judge correctly whether the particle pattern is agglutinated or not.

Abstract: The visual monitoring apparatus includes a transparent tube section with coupling flanges at each end for coupling to adjacent conduit sections carrying a stream of conditioned sludge which includes agglomerated solid bodies. Control rods extend between the coupling flanges to strengthen the tube. A strobe light is mounted in a housing which is mountable alongside the tube and closely conforms to the shape thereof for confining the strobe light to a predetermined area of the tube and isolating that area from ambient light. The housing accommodates the control rods therethrough and contains a mirror which directs light reflected from the illuminated contents of the tube along a viewing path through a view port in the housing which is closed by a door or hatch. The frequency of the strobe can be adjusted to correspond to the flow rate of the fluid in the tube for creating the visual impression of substantially stopping the movement of the solid bodies in the tube.

Abstract: A kit of highly uniform size microbead standards for flow cytometer alignment, compensation, and/or calibration, comprising a blank microbead population and/or an auto-fluorescent microbead population, together with two or more series of calibrated microbead populations labeled with fluorescent dye(s) which (i) prior to fluorescent dye(s) labeling, match the fluorescence spectra and fluorescence intensity of the blank and/or autofluorescent microbead population, and (ii) after fluorescent dye(s) labeling, match the fluorescence spectra and fluorescence intensity of fluorescently labeled samples to be measured on the flow cytometer. Also disclosed is a corresponding method to align, compensate, and/or calibrate a flow cytometer so as to make measurements on samples comparable and independent of the specific instrument and instrument settings.

Abstract: An optode designed to prevent washing away of the indicator and reagent from a membrane is located within an optical device that measures substance concentrations. The reagent and indicator materials are covalently bound on the membrane. The membrane can be a polysaccharide, especially cellulose, an acid glycol ester, or it can contain silicon. The indicator and/or reagent can be covalently bound to the membrane by a bridge molecular, particularly a multifunctional aldehyde, glutaraldehyde or a silane.

Abstract: Apparatus is provided for measuring non-absorptive scattering with an exceptionally high degree of accuracy. In the preferred mode, the apparatus can also be used to measure absorptive scattering, thus providing a method of distinguishing absorptive scattering from scattering due to transparent moieties (i.e. non-absorptive scattering). The approach of the invention promises to significantly expand the use of optical systems in quality control. The general concept of the invention relies on symmetric heterodyne scattering. Specifically, two beams at slightly differing optical frequencies are directed to intersect at some arbitrary angle. Transparent objects within the intersection volume scatter light from each beam into the other. After intersecting, the two beams are directed to separate photodetectors which mix each transmitted beam with the scattered light from the other beam.

Abstract: The invention relates to a measuring cell (1) designed for measuring the contents of the components present in slurries which are in a flowing motion, the measuring cell comprising an inlet pipe (2) and an outlet pipe (9) for the slurry and a measuring window (3). According to the invention, the inlet pipe (2) is placed at a given distance from and in an inclined position with respect to the plane contained in the measuring window (3), in order to direct the slurry jet entering from the inlet pipe (2) to a point that is approximately one internal radius of the inlet passage (2) in front of the center of the measuring window (3).

Abstract: Agglomeration or solubilization of particles of a suspension can be determined during a scanning sedimentation analysis of particle-size distribution by monitoring respective values of extinction determined in two successive scans or from one scan and a fixed light curtain at a common ratio h/t where h is the distance of the measurement by the light curtain from the surface of the suspension and t is the time at which the measurement is taken.

Abstract: In a method and apparatus for detecting the presence of contaminants in a liquid stream which may also contain gas bubbles, the gas bubbles are detected by mechanically generating an alternating hydraulic pressure in the liquid stream, and monitoring the response of gas bubbles in the stream to the alternating hydraulic pressure.

Abstract: An apparatus and method for automatically measuring and recording erythrocyte sedimentation rates (ESR) of blood samples according to the Westergren method includes a controllable specimen device member which measures sedimentation data of blood samples, and a data processor which controls the specimen device analyzes the sedimentation data and reports the results of its analyses. The specimen device is equipped with a controllable camera which measures the opacity of light passing through a specimen being analyzed. The camera has a high dynamic range, meaning that it is sensitive over a blood spectrum of light intensities, so that it guarantees an accurate reading even when the blood sample is hemolyzed or has turbid plasma. The apparatus makes an initial sedimentation height measurement on a specimen sample, and after a given amount of time makes a final sedimentation height measurement on that specimen.

Abstract: A method and apparatus for determining the level of particulate contamination in a plurality of liquid sources. The apparatus comprises first and second control valves each having a number of valve elements equal in number to the number of liquid sources, with analytical equipment to determine the amount of particulate contamination in a fluid sample, disposed therebetween. Samples are withdrawn from and returned to the same liquid source. A common valve controller insures that the control valves are maintained at a common valve setting. The analytical equipment is capable of detecting particulate contaminants as small as 0.3 micron.

Abstract: An x-ray sedimentation particle size analyzer in which data is taken only at particular positions along the sedimentation cell, and each such position is individually calibrated. Presentation of the data in the form of a particle size distribution curve can be accomplished very accurately using interpolation techniques. The sedimentation cell design is free of the effects of undesirable density gradients, capable of detecting and removing bubbles, capable of attaining a highly uniform dispersion of sample prior to sedimentation, and including a safety interlock device for blocking x-ray projection when the cell is being accessed.

Abstract: In a contaminant detector for processing paper pulp including sticky contaminants, a pulp sample is diluted to less than 0.5% consistency and passed through a concentrator from a plurality of classified samples having heavy and light particles. The inclined classified samples are again diluted to less than 0.5% consistency and passed as thin sample flow through an open channel having a light transmitting base. The flow is back lighted and a photodetector includes a linear array of sensitive elements aligned to receive the transmitted light. The sensitive elements aligned with particle creates a signal proportional to the width. By rapid sequential activation of the elements, a digital data stream is created which is processed by a microprocessor to determine the particle size and produce a plurality of contaminant relative signals related to different classified size ranges, such as heavy, medium and small contaminant particles.

Abstract: A method for analyzing impurities in liquid and an apparatus therefor are disclosed, which are adapted to classify impurities contained in various liquids to be measured into soluble substance, insoluble substance and impurities in the form of bubbles and to measure their concentration separately; especially the impurities in liquid are analyzed by the method such that photoacoustic signals obtained by irradiating a liquid to be measured with intensity-modulated light are measured; the correlation between the modulation frequency of the intensity-modulated light (light modulation frequency) and the phase of the intensity-modulated light, with which the liquid to be measured is irradiated, as well as that of their photoacoustic signals are obtained; and impurities in the liquid to be measured are detected, while classifying them into soluble and insoluble ones and those in the form of bubbles on the basis of the information thus obtained; and the apparatus comprises a light source, at least one light modulator

Abstract: A medium including particles to be analyzed is contained in a cell through which excitation rays are passed. The excitation rays are focused and have a predetermined wave form. A period in time of the excitation rays is set substantially equal to and preferably longer than the attenuation time of an acoustic pulse which is generated when the excitation rays are absorbed in the particle and when the particle release heat. The acoustic pulse is used to analyze particle size and number of particles.

Abstract: A method and apparatus for making paper by refining fibrous stock. The stock is passed through an adjustable refining means and a sample of the refined stock is analyzed using a fibre fineness distribution analyzer to produce, over a range of fibre widths, counts of the number of fibres in the sample which have a selected fibre width. Fibre width is plotted against fibre count at intervals of 1 .mu.m over the range of from 7 .mu.m to 64 .mu.m to obtain a fibre fineness distribution curve. The fibre fineness distribution curve is compared with a reference fibre fineness distribution curve obtained by the prior analysis of stock known to have produced paper of desired quality. The refining means is then adjusted to produce a stock the analysis of which produces a distribution curve substantially the same as the reference curve.

Abstract: The method and apparatus permit analyses, by optical means, of properties of gaseous suspensions of particles, by measuring radiation that is emitted, transmitted or scattered by the particles. Determinations of composition, size, temperature and spectral emittance can be performed either in-situ or by sampling, and Fourier-transform infrared spectrometric techniques are most effectively used. Apparatus specifically adapted for performing radiation scattering analyses, and for collecting radiation from different sources, are provided.

Abstract: A measuring device for measuring the concentration of particles in a liquid advanced through a tube (2) includes a transducer where the tube in a measuring zone has an area change implemented such that the pipe wall is kept clean from deposits. Probes (8, 9) are inserted in the tube wall (6, 7) so that the measuring surfaces of the probes are in contact with the liquid and form a part of the tube wall. The measuring device is compensated for temperature by means of a reference apparatus (13, 14) coacting with said probes electrically and mechanically.

Abstract: In order to improve the selectivity of an indicator chamber or optode conting of an indicator and a membrane impermeable to the indicator and surrounding it, for use in the measurement of concentration of component particles by means of an optical light measurement system including a light source, a light receiver and a readout device, a substance which reacts with the particle to be measured is provided within the indicator chamber, and the reaction product then modifies the optical properties of the indicator.

Abstract: In an indicator chamber (e.g., optode) arrangement including an indicator d a membrane which surrounds it and is impermeable to it, a carrier substance is provided within said membrane for transport of particles to be measured into the indicator chamber. Said carrier is mobile within said membrane. This improvement allows for the preparation of highly selective indicator arrangements and broadens the range of applicability of the method of measurement.

Abstract: A device for determining the susceptability of microorganisms, i.e., bacteria, to antibiotics is provided. The device utilizes a layer of light transmissive material having a plurality of flat, opaque louver elements set in a transparent matrix which permit transmission of visible light and illumination of a sample being tested. A method for determining the susceptability is also provided.

Abstract: A device for constituting in the wall of a pipe an optical pick-up window which may be scavenged by a protective fluid. A chamber is provided with an inlet for said fluid and an outlet for said fluid, said chamber passing through said wall and opening into said pipe through an open end, the opening of which constitutes said outlet, and a tube introduced into the chamber so as to constitute in the chamber about the tube an annular conduit starting near the said inlet of the chamber and leading towards said outlet, one end of the tube being provided with said window and being placed in the chamber opposite said outlet, the other end of the tube opening outside the chamber, wherein the distance between the window and the outlet is sufficiently short for the flow of protective fluid in front of the window to be a sheet of fluid.