Abstract: A method and suitable apparatus for periodically analyzing pulp stock, including wood pulp and water, in a pulp digester, to determine the amount of cooking to which the pulp has been subjected. The method includes taking a sample of the pulp stock from the digester, diluting the sample to a predetermined range of consistency, and determining the exact consistency of the sample. Next, the sample is transferred to a reaction chamber. A reagent is then added to the sample and allowed to react with the sample at a predetermined temperature. The light absorbance of the reagent during the reaction is continuously monitored during the reaction. After the light absorbance has clearly passed a peak, the value of the peak is combined with the consistency of the sample, previously determined, to arrive at the amount of cooking to which the sample had been subjected prior to the test, from a known relationship thereof to the light absorbance of the reagent and the consistency of the sample.

Abstract: This invention relates to an apparatus and a method of high performance liquid chromatography comprising irradiating a high performance liquid chromatography column and detecting separation conditions and separation patterns of a material charged onto said column by measuring the intensity of transmitted light, reflected light or fluorescent light from the column by means of a line sensor.

Abstract: A detector cell assembly for spectrophotometry has a radiation transparent spherical ball closing the opening in a cell body through which radiation passes. The spherical ball is of fused silica or sapphire and is pressed the cell body in a direct seal. The radiation has a crossed ray pattern within the cell.

Abstract: A pump colorimetric analyzer is described including: (a) a sample cell through which a light beam is transmitted, (b) a light source, (c) a photodetector, and (d) a piston which reciprocates between first and second positions in the cell. The piston includes a sample chamber which permits the light beam to be transmitted therethrough when the piston is in its second position. When the piston is in its first position the light beam is transmitted through the sample cell. The novel analyzer uses a single light source, a single sample cell and a single photodetector.

Abstract: An analyzer for acid-soluble aluminum in a steel sample precisely controls the etching charge by monitoring the etching current level and integrating the current with time. Once a predetermined charge is reached, the etching current is terminated. In a preferred embodiment, the etching cell is stacked above the mixing and developing chamber such that etching fluid flow is by gravity between these elements.

Abstract: For measurement of chlorine concentration in a process stream, an improved device is set forth measuring light transmission in a selected frequency range. The preferred embodiment uses a light source, a light filter and an optical fiber extending to a pipe or other vessel with flowing chlorine. The light is transmitted from a lens system to another lens system and into a second optical fiber. The second fiber extends to a measuring device.

Abstract: Light in two different wavelengths, only one of which is attenuated by the presence of a substance to be tested for, is passed through a light path which includes a fluid path. The two wavelengths are equally attenuated by particulate contamination and all other conditions except for the presence of the tested for substance. A light path through a reference cell provides a reference for each wavelength. The presence of the tested for substance provides a differential attenuation which is indicative of the presence of the substance and the degree of differential attenuation is a measure of the concentration of the substance.

Abstract: A method for measuring the color difference betweeen a sample dye and a standard dye by testing the color properties of both dyes, which comprises determining, in advance, the relation of the color difference of dyeings (between the standard dye and the dyes of the same family) to the color difference of dye solution (between a standard dye and the dyes of the same family) using the standard dye and two or more, preferably several, representative samples arbitrarily selected from plural lots of dyes, then calculating the color difference of dye solution between the standard dye and a sample dye, and predicting the color difference of dyeings from the calculated color difference of dye solution by referring to the relation obtained.

Abstract: A method and apparatus for analysis of liquid samples is described. The method involves simultaneously introducing a predetermined quantity of a given sample and a predetermined quantity of a selected reagent therefor directly into separate flow lines by aspiration from separate containers; bringing the extracted sample and the extracted reagent together into a common flow channel; and causing the sample/reagent mixture to travel along the flow channel as a discrete liquid slug interposed in the stream of a carrier liquid to the measurement cell of an analytical instrument. Another aspect of the method is characterized in that a single pump is used to draw sample and reagent into separate arms of the flow channel which subsequently merge, and to drive the sample/reagent mixture along the flow channel; and in that a carrier liquid is drawn into the flow channel by said pump so that the material within the flow channel is carried along as a continuous liquid phase.

Abstract: Apparatus in which a sample and a reagent solution are introduced into a stream of carrier liquid, whereby reaction proceeds between the sample and the reagent solution during their transfer through a passage. When a zone of the reaction solution passes successively through two flow cells provided in series, light absorbancy based on the reaction solution in each flow cell is measured, and rate assay is made from a difference between light absorbancies. A period of time for observing a specific sample can be changed by changing the length of a reaction tube connecting a flow cell at the upstream side to a flow cell at the downstream side.

Abstract: A fluid sample cell for spectroscopic analysis of a fluid sample includes a fluid-tight compartment for the containment of a fluid sample which is defined by a radiant energy transmissive top, a side wall and a bottom. The bottom comprises a plurality of sectors and a Fresnel disc, whereby radiant energy passing through the compartment impinges upon at least one of the sectors and is specularly reflected from a reflecting surface of the sectors to respective focal points of the sectors.

Abstract: A liquid chromatography apparatus comprises a detector part having as a light source a metal halide lamp filled with tantalum halide, mercury and rare gas.

Abstract: An apparatus for the inspection of fluids, particularly paints, having a housing with a cavity and enclosed with a light transmitting window and having an insert member positioned in the cavity which provides a fluid chamber where fluid flows by the window and wherein the flow is laminar and undirectional. This provides a view area of the liquid whose color parameter can be accurately measured by a colorimeter of spectrophotometer. The apparatus is particularly useful in the manufacture of paints so that the color of the paint being made can be accurately matched to a standard color.

Abstract: A micro-polarimeter interfaced with a system for high performance liquid chromatography, for quantitatively analyzing micro and trace amounts of optically active organic molecules, particularly carbohydrates. A flow cell with a narrow bore is connected to a high performance liquid chromatography system. Thin, low birefringence cell windows cover opposite ends of the bore. A focused and polarized laser beam is directed along the longitudinal axis of the bore as an eluent containing the organic molecules is pumped through the cell. The beam is modulated by air gap Faraday rotators for phase sensitive detection to enhance the signal to noise ratio. An analyzer records the beams's direction of polarization after it passes through the cell. Calibration of the liquid chromatography system allows determination of the quantity of organic molecules present from a determination of the degree to which the polarized beam is rotated when it passes through the eluent.

Abstract: A method and apparatus for analysis of liquid samples is described. The method involves simultaneously introducing a predetermined quantity of a given sample and a predetermined quantity of a selected reagent therefor directly into separate flow lines by aspiration from separate containers; bringing the extracted sample and the extracted reagent together into a common flow channel; and causing the sample/reagent mixture to travel along the flow channel as a discrete liquid slug interposed in the stream of a carrier liquid to the measurement cell of an analytical instrument. Another aspect of the method is characterized in that a single pump is used to draw sample and reagent into separate arms of the flow channel which subsequently merge, and to drive the sample/reagent mixture along the flow channel; and in that a carrier liquid is drawn into the flow channel by said pump so that the material within the flow channel is carried along as a continuous liquid phase.

Abstract: Photometric cuvette for optical analysis of through-flowing medium, made as a thin and narrow transparent tube requiring minimum sample amounts. Light, substantially parallel to the tube length, is led obliquely into the tube through its wall, is reflected and led obliquely out through the tube wall to a detector. The angle of incidence is selected so that after entry, the light is totally reflected against the outer tube wall where the wall is in contact with surrounding atmosphere, the light being supplied essentially uniformly around the tube.

Abstract: Improved optical systems for liquid chromatographic apparatus comprise flow cells with light transparent portions through which one or more beams of light may be passed through an effluent stream flowing in the cell, one or more light sources on one side of the flow cell to project light through the cell and its contained effluent stream, one or more light limiting apertures positioned on the opposite side of the cell in the paths of the light beams, one or more positive light focusing elements positioned in the path of the light beams from the cell to the apertures to image the center of the cell at the apertures and a light sensor positioned in the path of the light beam on the side of each aperture opposite to its respective light focusing element.Improved methods of chromatographic analysis using the new optical systems are also disclosed.

Abstract: A gas chromatograph Fourier transform infrared (GC/FTIR) system includes a GC oven having a flexible capillary column therein for separating components of a sample. The column discharges effluent directly into a light pipe associated with an FTIR spectroscope. An auxiliary flow of carrier gas is added to the effluent at the light pipe to convey constituents through the light pipe free from tailing or peak broadening.

Abstract: A halogen mass flow rate detection system having an absorption cell through which a halogen entrained inert gas can be passed. An electromagnetic beam of preselected wavelength in the bound-continuum absorption region is passed through the cell while the halogen entrained inert gas is passed therethrough and also while only an inert gas is passed through the cell. By measuring the intensity of the beam passing through the absorption cell, molecular absorption can be utilized for determining the concentration and, therefore, the mass flow rate of the halogen passing through the absorption cell. By incorporating the halogen mass flow rate detection system in an iodine/oxygen chemical laser, for example, the mass flow rate of the iodine into the resonant cavity of the laser can be simply, accurately and reliably ascertained.

Abstract: A stopped-flow apparatus is disclosed which includes one or a pair of flow systems mounted in separate thermostatically controlled baths and actuated by a single driving system thus permitting differential rate of determinations. The reaction or observation cell is easily changed to modify the apparatus without the necessity of changing the entire flow system. This is accomplished by screw threaded connection to the cell so that a variety of different cells can be inserted readily and easily into the thermostatically controlled bath. Stopping is accomplished by means of an adjustable block system on the main driving system or by a stopping syringe operatively connected to the cell. Efficient mixing is accomplished in a mixing chamber screw threadably secured to the cell and utilizing a double bifurcated feed block.

Abstract: A colorimeter in which a light source, a collimating lens and a band pass filter are supported by a housing that is movable with respect to a stationary beam dividing assembly in a direction at least substantially transverse to the optical axis of the light from the source. The assembly separates the incoming collimated and filtered light into a sample beam and a reference beam which are directed back toward the housing in directions parallel to the optical axis. The movement of the housing toward or away from the sample produces an increase or decrease in the intensity of the light illuminating the sample and a corresponding decrease or increase in the intensity of the light at the reference detector. The arrangement is such that the apparatus may be readily adjusted to obtain accurate colorimeter readings even for samples having abnormally high or low density characteristics.

Abstract: A method and apparatus for sensing the presence of bubbles in a liquid wherein radiation is directed through said liquid toward a radiation responsive sensor and the differential between the response of the sensor when a bubble is not present in the radiation path and the response thereof when a bubble is present in the radiation path is markedly increased by limitation of the radiation which can reach said sensor to wavelengths strongly absorbed by said liquid.

Abstract: Spectrum analyzer for the light absorption of a solution comprising a small transparent measuring cell containing the solution; a light source; means for dividing the beam of light of the source into two beams, one being the reference beam and the other the measuring beam transmitted respectively to a reference absorber element and to the measuring cell; means for selecting the measuring wavelength; means for modulating the reference and measuring beams which have respectively traversed the absorber element and the measuring cell; means for detecting the energies of each of the modulating beams after they have traversed the reference absorber element and the sample; the modulation means comprising alternate transparent and bireflecting sectors in front of each of the beams which have passed through the reference absorber and the measuring cell, said sectors being associated with means for selecting the wavelength of the beams in such a way that, as a function of the successive positions of the sectors relativ

Abstract: A copper liquor analyzer includes a sample cell through which a portion of a copper liquor stream passes. Light of a predetermined wavelength is passed through the copper liquor in the sample cell. A detector circuit receives the passed light from the sample cell and provides an output corresponding to the strength of the copper liquor in accordance with the received light.

Abstract: In a flow metering apparatus a bubble detector for detecting bubble formation in tubing subject to deformation from internal fluid pressure includes a light source and a light detector. The light detector is positioned on the opposite side of the tubing from the light source such that the light transmitted through the tubing to the detector is dependent on the presence of fluid in the tubing and on the shape of the lumen of the tubing. A control circuit responsive to the output of the detector interrupts operation of the metering apparatus when the light transmitted through the tubing falls below a predetermined minimum level. False interruptions resulting from deformation of the tubing by pressure changes in the fluid are prevented by forming members which engage the wall of the tubing adjacent the light source and light detector.

Abstract: The present invention includes an apparatus for measuring radiation from a sample. The apparatus includes means for axially focusing radiation from an excitation monochromator at the sample. The present invention further includes a novel sample cell holder useful with the fluorescent radiation measuring apparatus.

Abstract: A serum and a reagent are supplied into a reaction tube to prepare a reactive solution or a sample solution which is sucked up at a predetermined position into one of a plurality of flow cells. The flow cells are mounted on a thermostatic block to be heated to a predetermined temperature and alternatively supplied with the sample solution. After a sample solution has been introduced from a specified reaction tube into one of the flow cells and heated to the predetermined temperature, the sample solution in the one flow cell is irradiated with light to measure changes in absorbance of the sample solution for a predetermined time. During a period when the absorbance changes of the sample solution in one flow cell is measured, another sample solution is introduced from another reaction tube into another flow cell and heated to the predetermined temperature.

Abstract: A flow cell for optical analysis of a fluid sample has a cell chamber whose volume is not limited by considerations of fluid residue carryover. A piston movable within the viewing region and having a conduit through its face is used to collapse the volume of the viewing region to substantially zero while maintaining a flow path between inlet and outlet conduits so that residue can be removed from the flow cell and its conduits with a minimum of cleaning fluid.

Abstract: An improvement in analytic instruments which measure liquid properties by optical techniques, the improvement providing an optical path through the liquid under test as low as about 0.1 mm by presence of a flat transparent surface across the optical beam and by flowing a film of the liquid under test down the surface, the depth of the film being the optical path through the liquid.Desirably the surface is normal to the beam, but at an acute angle to horizontal. A matted surface is desirable for spreading high viscosity solvents across the surface.

Abstract: A colorimeter in which a beam dividing assembly is supported on a movable carriage intermediate the sample and reference detectors. The assembly separates the incoming collimated light into a sample beam and a reference beam. The movement of the carriage toward or away from the sample produces a decrease or increase in the intensity of the light illuminating the sample and a corresponding increase or decrease in the intensity of the light at the reference detector. The arrangement is such that the apparatus may be readily adjusted to obtain accurate colorimeter readings even for samples having abnormally high or low density characteristics.

Abstract: A flow cell for location intermediate a light source and a photosensitive device for light measurement of a fluid therein in a light path. The flow cell has an elongated tubular body member, a debubbler unit, and a tubular fluid outlet tower. The body member has an open-ended bore therethrough constituting a sight passageway. A pair of light transmitting quartz rods are positioned in the respective open ends of the bore to close them. One end of the debubbler unit functions as a fluid inlet conduit and a tubular neck portion extends from the bottom of the debubbler unit and is transversely connected to the open-ended bore of the body member intermediate its ends. A tubular fluid outlet tower has its bottom end transversely connected to the open-ended bore of the body member intermediate its ends.

Abstract: Contamination between successive aqueous samples in a continuous-flow analytical system is eliminated by the careful and precise application of a thin, uniform film of immiscible fluid upon the outer surface of an aspirating probe of a metering system. The immiscible fluid is selected to preferentially wet the inner and outer probe surfaces and the inner wall surfaces of the conduits of such system, to the substantial exclusion of the aqueous samples. The immiscible fluid is aspirated, along with an air segment, between aspirations of successive samples, each aspirated air and sample segments are encapsulated by such immiscible fluid while passed through such system. A selective valve is utilized to isolate and transfer each fluid sample from the probe to such system.

Abstract: The optical detector is particularly adapted for use with an apparatus for separating blood into its components and is of the type including a centrifuge for centrifuging whole blood to separate same into the components thereof and of the type wherein plasma is withdrawn from the centrifuge through a flexible, light transmitting tubing and the spillover of red blood cells into the plasma withdrawn is monitored by the optical detector. The optical detector comprises a block having a slot across the top face thereof, the inner portion of the slot having a width less than the outer diameter of the tubing which is received in the slot such that when the tubing is pressed into the slot, it is squeezed from a circular cross section to an oval cross section to present two flat portions of the tubing adjacent opposite sidewalls of the slot. A first cavity is situated in the block behing a first sidewall of the slot and a second cavity is situated in the block behind a second sidewall of the slot.

Abstract: A spectrophotometer detector cell assembly having improved sensitivity, has a cell defined by a bore through a body and closed at the ends by radiation transparent windows with inlet and outlet passages through the body to the bore, so that radiation passed through the sample fluid flowing through the bore is detected by a photodetector. The body, which is made of a thermally conductive material, is a large thermal mass is relation to the volume of the cell and a tubular inlet conduit, also made of a thermally conductive material, wraps around the body and connects to the inlet passage so that fluid flowing into the bore will tend to reach a stable temperature due to the heat sink effect of the body and conduit thereby stabilizing the refractive index of the fluid in the bore and enhancing the sensitivity of the photodetection.

Abstract: An improved gas analyzer for measuring the presence of one or more gaseous compounds in a gas sample. The gas analyzer has an infrared source stabilized against temperature variations by a radiation loading scheme in combination with a selected source environmental temperature sensitivity to provide a stable source temperature without a conventional temperature controller. A rotating interference filter assembly is disposed in the optical path. This assembly alternately totally blocks radiation, passes radiation in a wave length band which will not be absorbed by a random gas sample, and sequentially passes radiation in one or more additional bands which will be absorbed by one or more gases in the sample cell. The sample cell features a unique enclosed cell with infrared transparent windows which are substantially free of impingement of contaminants of the gas sample thereon. A unique detector provides protection against deterioration from moisture while allowing easy and inexpensive assembly.

Abstract: The density of chlorine dioxide gas in a wet acid atmosphere may be continuously monitored with a photometer energized by a constant voltage incandescent light source illuminating a 0.5 inch thickness, continuous flow sample spaced between quartz glass windows. The emergent light is filtered to pass approximately 4400 Angstrom wavelength light to a selenium photocell. Photocell power output measuring means is calibrated to correspond with chlorine dioxide gas density. The concentration strength of an aqueous solution of chlorine dioxide is continuously monitored with a similar photometer having a 0.125 inch sample space between windows and a 4600 Angstrom filter for the emergent light.

Abstract: Process and device for detecting impurities in the atmosphere by an inteny-time rate technique whereby chemiluminescent reaction curves are developed and found to be representative of specific materials. Hence, by comparing known intensity-time rate curves with curves had by actual measurings, the invention enables the user to discern many more materials never before detected.