Abstract: A method and apparatus are described for an accurate determination of the concentration of a gas, vapor or a gas dissolved in a sample which compensate for variations in temperature and light - source intensity. The apparatus comprises a sensor containing a fluorescent reagent connected to a transfer optic, such as fiber optics prism or glas pipes, and to a reference sensor containing the same fluorescent reagent. The reference sensor is encapsulated in an environment containing air. The light emitted from the first sensor and the reference sensor is determined and recorded automatically, the concentration of the gas being calculated based on the output from said light detectors using calibration data of the fluorescent reagent present in the sensors. The reagent is immobilized in the sensor by a glue, such as a silicon glue.

Abstract: A method and apparatus using a frequency tunable laser to generate a beam which passes through a sample cell and onto an optical detector wherein the tunable laser is modulated at a predetermined frequency which has the undesired effect of producing a periodic interference fringe near an absorption induced signal. An additional level of modulation is applied to the laser beam by a triangular waveform having a predetermined peak-to-peak amplitude and frequency. The triangular waveform peak-to-peak amplitude produces a frequency swing of the laser beam so as to generate from the periodic interference fringe, a signal having reduced components near the absorption induced signal. The signal at the optical detector is demodulated by a lock-in amplifier tuned to a predetermined harmonic of the frequency of the triangular waveform.

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: Method for making a probe with a plurality (one or more) of optical fiber sensors containing colorimetric chemical indicators in gaps in the fibers, the fibers bent to provide good light transmission qualities. Apparatus for making a probe with a plurality of such optical fiber sensors. A probe with a plurality of such optical fiber sensors. A vacuum chuck for holding the ends of such fibers.

Abstract: A Method and Apparatus for identifying and distinguishing fluids and for recognizing contamination of a fluid, which method and apparatus utilizes spectrographic analysis of control samples of known fluids and then spectrographic analysis of unknown fluids to generate optical signatures, finger prints and/or profiles of data and processed data relating to the relative intensities of light at selected wavelengths; and then, through comparison of the various signatures, fingerprints and/or profiles, provides determinative information as to contamination or non-contamination of the unknown fluids; after which appropriate operation control is effected and/or exercised.

Abstract: A method and apparatus for identifying and distinguishing fluids and for recognizing contamination of a fluid, which method and apparatus utilizes spectrographic analysis of control samples of known fluids and then spectrographic analysis of unknown fluids to generate optical signatures, finger prints and/or profiles of data and processed data relating to the relative intensities of light at selected wavelengths; and then, through comparison of the various signatures, fingerprints and/or profiles, provides determinative information as to contamination or non-contamination of the unknown fluids; after which appropriate operation control is effected and/or exercised.

Abstract: Measurement of the color properties of wet paint, such as lightness by colorimetry or photospectrometry, is carried out on a sample volume contained in a vessel and while the sample volume is subjected to shearing forces and advantageously also turbulence. The shearing and turbulence are created by a rotating disc having a spiral rib configuration on one surface which faces a window through which the measurements are made by a spectrophotometer.

Abstract: The disclosure relates to an apparatus and method for increasing the sensitivity of laser absorption detection of gas phase atoms and molecular species within a gaseous medium. An active optical element in a laser absorption detection system is translationally (longitudinally) vibrated a selected amplitude along the optical axis and at a desired frequency to eliminate fringes produced by interference fringe producing optical elements. The vibration frequency is preferably asynchronous with other modulation frequencies in the system.

Abstract: A device for measuring transmittance of light comprises a light source, photodetector and signal processor. The concentration of a substance in a fluid sample can be accurately determined by coating the light source with a reagent that is chemically reactive with the substance and measuring light transmitted from the coating before and after the substance is applied to the coating. The coating can contain a solid support matrix, such as a translucent nonwoven paper web of the type used in reagent test strips and similar indicator devices. The invention is useful for making clinical analyses on body fluids.

Abstract: A comparitive colorimeter for use in the field which simultaneously compares the color densities of two liquid samples and designates the degree of difference. The apparatus includes two major subsystems, optical and electronic. The optical subsystem is designed to provide identical light beams through both the sample and standard solutions and to minimize the effect which imperfect sample tubes have on the output. The electronic subsystem includes a log conversion and differential amplifier circuit for generating a difference signal representative of the difference between the optical densities of the sample and standard solutions. The difference signal is evaluated by a comparative circuit consisting of a resistive chain having a plurality of node voltages and hex inverters connected to the node voltages. The hex inverters drive a series of LED indicator lights to designate the relative degree of difference between the optical densities of the sample and standard.

Abstract: Near infrared instrument for measuring constituents such as moisture, protein and oil in materials has a movable sample holder of predetermined thickness depending upon the particular material being measured. The sample holder is moved past a source of near infrared radiation and detector by a mechanical drive.

Abstract: A simple optomechanical method and apparatus is described for substantially reducing the amplitude of unwanted multiple-interference fringes which often limit the sensitivities of tunable laser absorption spectrometers. An exterior cavity is defined by partially-transmissible surfaces such as a laser exit plate, a detector input, etc. That cavity is spoiled by placing an oscillating plate in the laser beam. For tunable diode laser spectroscopy in the mid-infrared region, a Brewster-plate spoiler allows the harmonic detection of absorptances of <10.sup.-5 in a single laser scan. Improved operation is achieved without subtraction techniques, without complex laser frequency modulation and without distortion of the molecular lineshape signal. The technique is applicable to tunable lasers operating from UV to IR wavelengths and in spectrometers which employ either short or long pathlengths, including the use of retroreflectors or multipass cells.

Abstract: A fiber optical probe for colorimetric measurement of chemical properties suitable for the insertion into living tissue. A chemical to be colorimetrically measured is introduced into a sample chamber on the side of the probe near the probe tip. A colorimetric substance contained in the sample chamber changes colors in response to chemical properties of the chemical to be colorimetrically measured, thereby changing the amount of light transmitted through the sample chamber by the optical fibers.

Abstract: A fluid sample cell for the spectroscopic analysis of a sample includes a fluid-tight sample compartment defined by a radiant energy transmissive top, a side wall, and a bottom having a reflective surface. The bottom is heat conductive and comprises an external surface which defines a hollow well adapted to receive a hot plate. A fluid sample cell is also provided wherein a side wall of a sample compartment defines an entry port and an exit port such that, when the cell is in a substantially vertical position, one of the ports is located above and one below the compartment. A fluid sample cell is also provided wherein a side wall of the sample compartment is provided with a pocket for collecting impurities when the cell is in a substantially vertical position, wherein the pocket is disposed above and/or below the sample compartment.

Abstract: A radiation beam, having passed through the mixture containing the component whose spectral composition contains at least one characteristic spectral line of the component, is caused to pass alternately along two channels one of which comprises a definite amount of the gaseous component and the other of which serves as reference. The second channel over which the radiation beam travels is limited to a diaphragm having a radiation transmission substantially equal to that of the first channel in the absence of said component in the mixture. The output beam from the two channels is directed towards a detector for detecting the variation of intensity of the beam through a filter for selecting said characteristic radiation.

Abstract: In a colorimeter for use in a biochemistry field, an amount of transmitted light impinging upon a light receiving device is decreased corresponding to an absorbance of a reagent to be used by arranging a light adjusting device in the optical path. The amount of light transmitted through a blank cuvette is made substantially equal to an amount of light transmitted through the reagent. Therefore, even when the analysis is performed for an item using a high absorbance reagent, the deviation of the amount of transmitted light does not affect measured absorbance values, and thus it is possible to perform the color measurement in an accurate manner regardless of the reagent absorbance.

Abstract: A photometric measurement method for producing readout signals indicative of light absorption of samples contained in a series of cylindrical cuvettes arranged in a movable cuvette carrier for successively conveying said cuvettes into the path of a measuring light beam directed onto a radiation detector, wherein readings are taken at precisely measured intervals as a function of the width of the cuvette, the rate of movement of the cuvette and the required number of measurements, and a selected reading is taken at the same distance from the leading wall of each cuvette.

Abstract: In accordance with the present invention, apparatus for photometric light absorption measurements of liquid samples contained in reaction cuvettes comprises a temperature controlled bath unit in which at least one light path conversion means is immersed in the fluid bath medium and is provided with at least two layers, one light-reflective layer and one non-corrosive layer on a surface thereof.

Abstract: Apparatus (FIG. 1) for non-dispersive optical determination of the concentration of an identifiable gas, such as a hydrocarbon, in a mixture such as atmospheric air comprises a sample chamber 13 to contain a sample of the mixture, a source 21 of IR radiation at a wavelength absorbed by the gas beamed through the sample chamber to a detector 22 and transducer means to change the gas pressure within the chamber to determine the change in radiation intensity detected at different pressures. One wall of the sample chamber is formed by a flexible diaphragm 25 driven by a voice-coil type transducer 26 whereby the pressure is switched repetitively between the values above and below atmospheric. Atmospheric gas is admitted to the chamber by a porous plug 24 which restricts flow to a low level permitting a pressure change in the chamber. Absorption by the gas relates the intensity of source radiation I.sub.S and measured radiation I.sub.M by I.sub.M oc I.sub.S .multidot.e.sup.-.alpha. o.sup..multidot.g.multidot.p.

Abstract: A device and method for measuring blood characteristics and parameters, especially arterial, venous, or differential blood oxygen saturation levels uses one or two probes containing a unique configuration of light emitters of two different wavelengths, and sensors which alternately illuminate and read reflected light from blood passing through a specially-designed cuvette. Electronic comparison of reflected radiation received by the probes produces a voltage which is linearly related to blood oxygen saturation level. An opto-electronic feedback network compensates for differences in blood optical density.

Abstract: A portable photometer for measuring the transmission properties of a fluid contained in a container having a transparent bottom is disclosed which is characterized in that there is provided: a monochromatic light source and a collimator assembly, both of which are contained within the base of a moveable member; a locating member arranged to contact the top of the container to thereby locate the end of the tubular member at a predetermined position with respect to the bottom of the container; and a photodetector device positioned beneath the container to receive the light from the collimator.

Abstract: The present invention concerns a device for analyzing chemical substances and monitoring chemical reactions in which cuvettes on a turntable are rapidly scanned by light at test and reference wavelengths and intensity of the light after passage through the cuvettes monitored by a photodetector. The output of the photodetector is logically processed so that measurements can be made of the varying optical densities in the samples scanned.

Abstract: A method of measuring mean particle size and/or standard deviation of particles involves illuminating a suspension of the particles with three beams of radiation of wavelengths R.sub.1, R.sub.2 and R.sub.3 and measuring the beam intensities passing through the suspension. The results are compared with those of the liquid medium free of particles and attenuation ratios of the beams at wavelengths R.sub.1 and R.sub.3 and at R.sub.2 and R.sub.3 are compared with previously calculated values for these ratios.This comparison enables the desired parameters to be obtained easily; preferably by using a spectrophotometer in which two or more optical densities at two or more wavelengths are compared simultaneously.The method is of particular use for aqueous suspensions of titanium dioxide pigment using wavelengths R.sub.1, R.sub.2 and R.sub.3 of 480 to 520 nanometers, R.sub.2 of 600 to 800 nanometers and R.sub.3 of 400 to 480 nanometers and not greater than (R.sub.1 -40) nanometers.

Abstract: A novel combination and a method are disclosed for detecting and measuring a predetermined substance capable of being specifically bound. The combination comprises a novel adapter which eliminates contact of a light conducting and receiving probe with the sample.

Abstract: An apparatus and a method for standardizing a gas measuring device has a source capable of emitting a beam of radiation aligned to impinge a detector. A housing means encloses the beam. The housing means has a plurality of apertures permitting the gas to enter the housing means, to intercept the beam, and to exit from the housing means. The device further comprises means for closing the apertures and a means for purging said gas from the housing means.

Abstract: The rate of enzyme reaction is determined by determining of the quantity of enzyme, and deriving the rate of reaction per unit time of a reaction solution having an absorbance which is proportional to the time. A temperature correction coefficient which is used during the determination of the enzyme quantity is derived by temperature information which is supplied by a temperature sensor disposed within the reaction solution to be determined.

Abstract: The photometer for automatic sample analysis comprises an optical bench emitting a measuring lightbeam, a series of transparent cells containing the samples for analysis and for sucessive presentation in the beam and result recording and processing means. A set of rectilinear presentation means each supporting a juxtaposed row of cells is arranged in parallel side by side in a magazine. Means for selecting and extracting each presentation means successively from the set of the latter are provided. A movable carriage supports the optical bench with means for moving said carriage at reading speed parallel to the row of cells selected such that the measuring beam of the bench sucessively traverses each cell of said row.

Abstract: Improved components, such as a cuvette, are disclosed in the specification.

Abstract: An apparatus for automatically measuring the light transmission factor of liquid test samples in which a number of transparent vats is arranged around the circumference of a stationary table over which rotates a photoelectric measuring device which successively scans each vat to determine the light transmission factor of the samples. The various samples are automatically transferred by sucking them into the measuring vats from a bank of test tubes via a bank of probes with flexible hose connections to each vat; a central control valve drains the vats after testing. Electronic timing circuits provide the control commands for the operative sequences of the device, and logic circuitry, in combination with a data storage and retrieval system, provides comparative data between reference measurements and sample measurements for each vat.