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: A wavelength meter having a single mode fiber optics input is disclosed. The single mode fiber enables a plurality of laser beams to be multiplexed to form a multiplexed input to the wavelength meter. The wavelength meter can provide a determination of the wavelength of any one or all of the plurality of laser beams by suitable processing. Another aspect of the present invention is that one of the laser beams could be a known reference laser having a predetermined wavelength. Hence, the improved wavelength meter can provide an on-line calibration capability with the reference laser input as one of the plurality of laser beams.

Abstract: Light filter apparatus for receiving a light beam having wavelengths in a selected band and for dispersing the light into a plurality of rays, with each ray having a different wavelength for which the intensity peaks. The peak wavelength varies approximately continuously with displacement of spatial position in a chosen direction along the filter's light-receiving plane. In one embodiment, the filter is a modified etalon structure having at least two reflecting surfaces whose separation distance is not constant but increases or decreases monotonically with distance in a chosen direction in a light-receiving plane of the etalon. Each of these two reflecting surfaces may be planar or non-planar but continuous, or may have a step or staircase configuration. This structure may operate using transmitted light or reflected light.

Abstract: A method for the quantitative determination of antigen (or antibody) which comprises adding a sample containing an antigen (or antibody) to a dispersion of an insoluble carrier of fine particle size with an antibody (or antigen) fixed thereto to effect an antigen-antibody reaction, measuring absorbance of the reaction mixture, A.lambda..sub.1 and A.lambda..sub.2, at two different wavelengths, .lambda..sub.1 and .lambda..sub.2, and calculating the concentration of said antigen (or antibody) in the sample from the absorbance ratio A.lambda..sub.1 /A.lambda..sub.2. This method is suitable for the measurment of the amount of an antigen or antibody in samples taken from living bodies using a simple procedure which has high sensitivity.

Abstract: A spectrophotometer is composed of a spectrofilter, a plurality of bandpass filters for cutting unnecessary transmission bands, and a CCD photosensor. The photosensor is composed of two sets of photosensors having different sensitivity ranges that overlap at some portion to increase the dynamic range of the device. The handling amount of charges is increased at every portion of the CCD photosensor in order to reduce the influence of the shot noise. Further, various technologies are used to enhance the accuracy and stability of the spectrophoto-measurement.

Abstract: A monochromator utilizing a single light source productive of a uniformly intense, single beam, single wavelength coaxial beam output or alternatively, a single beam selected dual wavelength coaxial beam output.

Abstract: An electrophoresis instrument includes a capillary tube mounted in an air cooled cartridge. The cartridge also supports a spherical lens which is part of the optical detection apparatus. The cartridge rests in a manifold which includes the sample and buffer reservoirs. The temperature of the capillary tube is controlled by measuring the electrical resistance of the capillary tube during the electrophoresis process and then cooling or heating the cartridge by circulating temperature controlled air over the tube. The optical path associated with the instrument is a fiber optic bundle bifurcated close to dual detectors into a reference arm and a sample arm so as to provide similar reference and sample optical paths. The instrument may be used for controlling temperature in gradient electrophoresis and detecting neutral markers in determining electro-osmotic flow.

Abstract: What is disclosed is a method and a system for (trace) gas analysis, specifically NH.sub.3 analysis in flue gases exhausted from power plants or in industrial waste gases. In this method and system, a laser is reversed between two of its intrinsic resonance lines whereof one wavelength corresponds to an absorption maximum and the other corresponds to an absorption minimum of the gas to be detected. The extinction E and thus the concentration of the gas under analysis is derived from the ratio of the values of intensity attenuation at the two wavelengths.

Abstract: The method of the present invention employs an enzyme immunoassay for measuring the concentration of an analyte in a sample by indirect colorimetric detection. An incident light beam at a plurality of wavelengths is directed into a liquid solution containing an analyte of interest. The solution is capable of attenuating the amount of light at a first wavelength received from this solution as a function of the increasing concentration of the analyte present. A light signal from the solution at the first wavelength is detected, and light at a second wavelength, at which substantially no attenuation of light signal occurs as the concentration of the analyte increases, is also detected. The ratio of the two respective wavelengths is formed and that ratio is compared with ratios of known amounts of the analyte to determine the amount of the analyte in the sample.

Abstract: In a method wherein sets of measured values of the intensity of electromagnetic radiation, which has been subject to optical interference, absorption or scatter by a sample, are correlated with different sets of known values derived from either a model of the optical properties of the sample, or from an analogue technique, correlation is by means of either a zero dependent correlation function, or a normalized residual function. Both functions are unaffected by gain factors, thereby avoiding any need to determine and to maintain absolute sensitivities of optical detectors; provide greater variation of correlation than with techniques employing a conventional correlation coefficient, thereby increasing the precision with which the optimum correlation can be determined, especially when either the measured value, or known values are subject to error; enable the method to be carried out with only two radiation components; and can enable a reduction in computing time.

Abstract: A conversion and kit for a dual beam spectrophotometer permitting it to operate in dual wavelength mode and thereby obtaining resolution heretofore unavailable from similar machines. The present invention provides for a second light source and directs it through the sample. By eliminating the reference path of the dual beam machine, the second light source permits the converted dual beam spectrophotometer to work in dual wavelength mode and thereby generate higher resolution while using the same instrument. The conversion allows the spectrophotometer to be operated in dual beam mode and for the easy/rapid changing between dual beam and dual wavelength modes.

Abstract: In an optical system for measuring sample absorption of light at a primary wavelength output from a monochromator, a method of subtracting the effect of secondary wavelength components of light from the monochromator. The sample absorption of light at the primary wavelength including the effect of the secondary wavelength components and at the secondary wavelength are determined. The results are used to obtain the sample absorption of light at the primary wavelength without the effect of the secondary wavelength components.

Abstract: A device for distributing signals within a sensor system used for monitoring the presence of a specific analyte in a composition by means of an analyte-sensitive indicator molecule is disclosed. The sensor system includes a signal-generating component, a single-fiber sensor tip that houses the indicator molecule and a signal-measuring component. In one embodiment, the signal-generating component generates a first optical signal of a wavelength that is sensitive to the indicator molecule, and a second optical signal of a wavelength that is predictably altered by the indicator molecule. The distribution system includes lengths of optical fiber, a dividing connector, a mixing connector, a transmitting connector and a tip connector. The dividing connector connects at least three intermediate fibers to the signal-generating component to receive intermediate signals. The mixing connector connects a mixing fiber to the intermediate fibers to receive the intermediate signals and blend them into a single mixed signal.

Abstract: An automatic analyzer of a single-line and multi-item type having a circular reaction line along which a number of reaction vessels are transported in the stepwise manner, and a photometering apparatus in which white light is divided into a plurality of light beams having different wavelengths, by means of a diffraction grating, and the light beams are transmitted by means of light guides whose exit ends are arranged along the reaction line with a pitch which is different from that with which the reaction vessels are arranged. While the reaction vessels are moved by one pitch, a plurality of reaction vessels are photometered in time sequential manner.

Abstract: This disclosure relates to a method for measuring the concentrations of sugars in liquids by the use of near infrared as well as an apparatus for practicing said method.The method comprises a step wherein the absorption spectrum of the sugar under investigation existing at a first depth relatively close to the surface in a sample is computed by using relatively weak power of near infrared, a step wherein the absorption spectrum of the sugar under investigation existing at a relatively deep second depth in the sample is computed by using relatively strong power of infrared, and a step wherein the concentration of the sugar under investigation in the sample is determined by computing the absorption spectrum of the sugar at a different depth between said first and second depths on the basis of the results of measurement in said first and second steps. The wavelengths for the use for said absorption spectrum are selected from anyone of wavelength bands of 950-1,150 nm, 1,150-1,300 nm, and 1,300-1,450 nm.

Abstract: An analyzing apparatus provided with a spectroscopic photometer, in which light emitted by a deuterium lamp enters a flow cell; light transmitted by the flow cell is divided into two light beams by means of a beam splitter, one of which is received by a detecting element for sample measurement and the other of which is received by a detecting element for monitoring through a filter transmitting only light in a predetermined wavelength region, which is not essentially absorbed by the sample; and a signal processing device compares the output signal of the detecting element for sample measurement with that of the detecting element for monitoring and effects necessary operations.

Abstract: A device for the individual adjustment of the intensity of several spectral lamps (1, 2), the radiation of which is combined into a common ray path (4), is distinguished by the fact that a device is provided for the modulation of the emission of each of the spectral lamps (1,2) with a different frequency, a beam-splitting mirror (8) for extraction of a part of the total radiation is inserted into the common ray path (4), a photoelectric receiver (9) is provided for the generation of an electrical signal which is proportional to the intensity of the extracted radiation, and frequency filters (11, 23) which are tuned to the modulation frequencies of the spectral lamps (1, 2) are arranged behind the photoelectric receiver (9), regulators, comprising a phase-locked loop (PLL) (12, 22), an automatic gain control (AGC) (13, 23) and a power amplifier (10, 20), for control of the intensity of the respective spectral lamp (1, 2) being allocated to the frequency filters.

Abstract: A spectrophotometric method is described of quantitatively determining the concentration of a dilute component in either a clear or a strongly light-scattering environment containing same in unknown concentration together with a reference component of known concentration, by a series of contemporaneous radiation-directing and measurement steps of radiation of selected varying wavelengths. Specific applications are disclosed involving the in situ, in vivo, non-invasive spectrophotometric determination of blood-borne as well as tissue species, e.g., hemoglobin, and oxyhemoglobin, and intra-cellular enzyme cytochrome c oxidase, in human body parts such as fingers, hands, toes, feet, earlobes, etc., as well as organs such as the brain, skeletal muscle, liver, etc.

Abstract: A dual wavelength spectrophotometer produces a relatively small, high power, high duty cycle light spot from a single relatively low power multi-chromatic light source. A Xenon arc lamp light source is focused by an ellipsoidal mirror onto a rotating partially reflective optical chopper. The chopper comprises a wheel having mirrored segments alternately separated by transparent segments. Light reflected by the mirrored segments passes through a first monochromator which produces a first monochromatic light beam. Light transmitted through the transparent segments passes through a second monochromator and emerges as a second monochromatic light beam having a wavelength different from the wavelength of said first monochromatic light beam. The first and second monochromatic light beams are recombined into a single dual wavelength light beam that is reflected through a sample to be analyzed. Reflective front surfaces are employed throughout the system in order to minimize power loss.

Abstract: An absorption photometer for measuring the absorption by conducting the light to a thin flow cell in which a liquid sample flows, wherein the sample light for measuring the absorption peak is superimposed on the reference light selected from the transparent (window) range of the liquid and the absorbance is detected by separating the sample light and reference light after transmission of the flow cell. Changes in the light path conditions can be monitored accurately, and therefore high-accuracy measurement immune to noises is made possible even using an elongated flow cell.

Abstract: Optical apparatus and methods are employed in the determination of impurity components present in both homogenous and non-homogenous light-scattering products. Light sources having wavelengths in the visible and near-infrared regions are preferred.

Abstract: A system for measuring the density of certain ions or neutrals within a plasma without probe intervention. When cylindrical symmetry is present, the system also provides measurement of spatial distribution of excited ionic states within the plasma. The system allows spatial distribution of contaminant ions in magnetic confinement thermonuclear fusion devices to be monitored. These functions are accomplished by directing two laser beams through a region containing a plasma. The laser means are at respective wavelengths chosen to be in and closely adjacent to a spectral region near the electronic transition frequency of the ionic species of interest in the plasma. The intensities of the two wavelengths are then measured and compared to obtain the desired data and characterization.

Abstract: In the monitoring of gas or vapor concentrations in a gas sample by comparing the transmission of light through the sample at different wavelengths corresponding to behaviorial maxima and minima of the gas, the different wavelengths are selected by permitting light to fall alternately on different sets of slits in an entrance mask of a spectroscope so that light diffracted by a grating in the spectroscope at the wavelengths represented by the slits in the two sets will fall on an exit slit in an exit mask of the spectroscope and thence pass to a photodetector. This arrangement enables the shift between the different sets of wavelengths to be achieved without introducing mechanical jitter, since the photodetector output may be electronically gated so as to be measured only for predetermined periods when light is passing first through one and then through the other set of slits.

Abstract: In a flow injection analysis method of injecting a predetermined amount of a sample into a continuous flow of a carrier solution and introducing a reaction zone of the sample and the carrier solution into a flow cell, signals representative of the respective absorptions of the reaction zone for a plurality of wavelengths are produced when the reaction zone is passing through the flow cell. The signals are subjected to an at least two-wavelength processing or differentiation processing, thereby providing a desired absorbance of a substance of interest for analysis free of the influence of a ghost component.

Abstract: A densitometer wherein a sample to be measured is illuminated and the light transmitted through or reflected by the sample is passed through a slit and dispersed by a dispersing element so that a spectral image of the sample as defined by the slit is formed on the image plane of the dispersing element. A plurality of image sensors each comprising a linear array of photodiodes are disposed on the image plane in such a manner that each of the image sensors substantially conform to one of the images of the slit formed by different wavelengths. The outputs from the photodiodes are processed by a computer to provide desired information about the sample.

Abstract: A spectrophotometer producing a derivative spectrum of a looked-for component of a sample includes means for producing an output signal which is directly representative of the concentration of the looked-for element.

Abstract: A gaseous mixture containing a number of molecular gases is analyzed to establish the amount of each individual gas by directing a light beam along a measurement path 11 through the gas. Each of the spectral component is selected to coincide with a respective vibrational-rotational-excitation band of one of the gases. The attenuation produced in each of the spectral components in its passage along the measurement path 11 serves as an indication of the concentration of the associated gas. The spectral components are generated either from distinct light sources 12, 13, 14 or are alternatively produced by spectral division of light from a multiple line or broad band source. Different marking frequencies f1, f2 and f3 are used to modulate each of the spectral components so that the signal received from the single photoelectric receiver 18 can be subsequently demodulated by three demodulators 19, 20, 21 to recover information relating to the individual spectral components.

Abstract: Method and apparatus for monitoring the deposition of a material or materials upon a substrate using atomic absorption techniques. Radiant energy is directed through a flow of evaporant during a deposition process. The radiation contains spectral emission lines absorbable by the evaporant as well as emission lines not absorbable by the evaporant. Changes in the transmission of one or more non-absorbable lines are used to compensate for changes in the absorption of absorbable lines of interest that are caused by misalignment or displacement of the optical elements during the deposition process.

Abstract: A photometric system for determining the absorbance ratio, in a sample, of two different wavelength lights. First and second lights, each having a different wavelength, are passed through the sample in alternation with each other. The radiation intensity from each light that has passed through the sample is detected. A comparator, up/down counter and digital to analog converter are coupled so that a scaling factor is derived which, when multiplied with an analog signal proportional to the intensity of the first light after it has passed through the sample, is equal to an analog signal proportional to the intensity of the second light after it has passed through the sample. The output of the counter comprises a digital word corresponding to the ratio of the absorbance ratio of the first light and the second light.

Abstract: An improvement in a spectrophotometer of an improved apparatus for automatic initialization of the wavelength indexing function of the spectrophotometer. A drive mechanism drives the wavelength indexing movement of the spectrophotometer diffraction grating. The grating is initialized to a grating initialization position by physical opposition of a stop mechanism to the driving when a drive linkage reaches a drive linkage initialization position.

Abstract: An automatic rate analyzing method for determining a concentration of an item in concern contained in a sample to be analyzed comprises steps of irradiating the sample with light thereby to produce a transmitted light signal at a specific wavelength, converting the transmitted light signal into a corresponding electric signal and sampling the electric signal at a given interval thereby to produce a plurality of sample values. The plurality of sample values are grouped into groups each containing a predetermined number of sample values selected for every given number of the sample values. Each of the groups is deviated from the adjacent ones by a number of sample values smaller than the given number. The sample values in each of the groups are added together to produce sums associated with each of the groups.

Abstract: A method of and device for analyzing one ingredient in a mixed solution with two light beams of different wavelengths are disclosed which include the following processes. A light beam from a light source are divided into a first light beam having a wavelength of .lambda..sub.1 and a second light beam having a wavelength of .lambda..sub.2. The wavelength .lambda..sub.1 is fixed, and .lambda..sub.2 is variable, for example, a scanning wavelength. Reference signals E.sub..lambda..sbsb.1 and E.sub.(.lambda..sbsb.2.sub.) respectively corresponding to the fixed wavelength .lambda..sub.1 and the variable wavelength (.lambda..sub.2) are produced from photometric signals resulting from the passage of the first and second light beams through only a solvent. After having been normalized by the reference signals E.sub..lambda..sbsb.1 and E.sub.(.lambda..sbsb.2.sub.), the photometric signals Ib.sub..lambda..sbsb.1 and Ib.sub.(.lambda..sbsb.2.sub.

Abstract: In a method for measuring chlorophyll of a leaf of a plant, the light having passed through the leaf is divided into a light component of a shorter wavelength the amount of which changes with the amount of chlorophyll and another component of a longer wavelength the amount of which does not change with the amount of chlorophyll. The amount of these two components are measured at the same time and the difference therebetween is used for determining the amount of chlorophyll contained in the leaf. A chlorophyll meter utilizing the method is provided with a spectroscopic dividing means for dividing the light which has passed through the leaf into the two components.

Abstract: Color former is added to blood serum sample color it, and measurements for specific components are determined based on the light absorbance caused by coloring. For one sample, a differential light absorbance between two wavelengths at each of long wavelength region, middle wavelength region and short wavelength region within a visible wavelength band is determined. The degree of chyle is determined from the measurements for the long wavelength region, the degree of hemolysis is determined from the measurements for the middle wavelength region, and the degree of icterus is determined from the measurements for the short wavelength region. The measurements for the specific components are then corrected by the degree of chyle, degree of hemolysis and degree of icterus to obtain highly correct measurements.

Abstract: In the double-beam spectrophotometer, two light beams, a reference beam and a sample beam, are used. Optical signals in the light beams are converted into electrical signals. The magnitudes of a reference signal and a sample signal are compared. A voltage to be applied to a photoelectric converting means is adjusted on the basis of the difference signal between the larger signal of the compared signals and a reference voltage so that the magnitude of the larger signal is substantially constant. The spectrum displayed by a recorder is obtained by the ratio of the reference signal to the sample signal. Since the larger signal is controlled to be substantially constant, when the sample signal is larger than the reference signal as in the case of a difference spectrum, the photoelectric converting means is not saturated and a wide photometering range is secured.

Abstract: A calibration system is provided for spectrophotometers of the type in which two or more wave lengths of light are caused to be transmitted through a sample cell. The calibration system may be used to calibrate spectrophotometers in which the beams are sequentially transmitted through the sample. In the practice of the invention, the sample is replaced with a number of accurately known optical attenuators which are introduced into the system in synchronism with the two light beams. The system provides calibration for both the scaling and linearization of the spectrophotometer, or conversely provides for the generation of tables and graphs which permit the operator to correct the photometer reading into an accurate representation.

Abstract: The reflectivity compensating apparatus is utilized in a dual wavelength spectrophotometer wherein a chopper mirror, having alternating mirror segments and open spaces equal in area, cuts through a light beam from a light source and the mirror segments reflect light through a liquid sample in a sample container to a photodetector having an output channel. The reflectivity of each mirror segment varies slightly from the other segments.

Abstract: Monochromatic light emitted from a monochromator is split into two light beams. These light beams are detected by a photodetector and converted into corresponding electric signals after having been transmitted, respectively, through a sample to be analyzed and a reference placed in the respective beam paths. The signal corresponding to the light beam transmitted through the sample and the signal corresponding to the light beam transmitted through the reference are converted into digital signals which are subsequently stored in respective digital storages or memories. The signal corresponding to the light beam transmitted through the reference is compared with a value in a predetermined range. The resultant value is then converted into an analog signal for operating a sensitivity regulator thereby to adjust the sensitivity of the photodetector. Thus, the signal corresponding to the light beam transmitted through the reference (reference light signal) is so controlled as to lie in a predetermined range.

Abstract: In an element analyzer exploiting a magneto-optic effect, when a concentration of the element in a sample material to be detected is high, two peaks are produced in the wave form of the signal obtained during the measurement. The present invention provides a discriminating technique to indicate whether two peaks appear in the wave form of the signal, with the object of reducing the error produced in the element analysis exploiting a magneto-optic effect.

Abstract: A pair of optical beams of radiant energy from separate paths in a spectrophotometer are coaxially merged into a single composite beam with an optical member which resembles a coarse echelette grating. A reflective surface which includes the surfaces of sidewalls within a plurality of parallel grooves is disposed on the optical member. The grooves are arranged in a lateral array and are generally V-shaped cross-sectionally. The beams to be combined are directed upon the sidewalls and the composite beam is emitted therefrom in accordance with the law of reflection. When the beams to be combined include non-collimated rays, shadowing is provided by the portion of the optical member between adjoining sidewalls of adjacent grooves to reduce flare. Furthermore, image aberrations as caused by off-axis operation due to use of a spherical mirror in the beam combining arrangement, are substantially corrected by the optical member.

Abstract: A scanning spectrophotometer employes fixed optics to produce a dispersion f optical energy. The dispersed optical energy is scanned by a fixed position surface acoustic wave photoelectric transducer. The scan rate of the surface acoustic wave photoelectric transducer is determined by associated electronic circuitry to produce scan rates permitting real-time spectral measurements from a moving platform.