Abstract: A laser survey instrument, which comprises at least a main unit for emitting a laser beam and an object reflector for reflecting the laser beam from the main unit toward the main unit, whereby said main unit comprises an emitter for emitting the laser beam, a rotating unit for rotating and scanning the laser beam, a tilting mechanism for tilting the laser beam at an arbitrary angle at least in one direction with respect to a horizontal plane, a rotating angle detector interlocked with the rotating unit and for detecting irradiating direction of the laser beam, a reflection light detector for detecting reflection light from the object reflector, and an alignment display unit for detecting a deviation of direction with respect to the object reflector and a deviation of tilt angle based on a signal from the reflection light detector and for obtaining information on the deviation of direction or the tilt angle, the laser beam emitted from the main unit is irradiated to scan, the center of the object reflector is

Abstract: An intraoral camera connects to a shade analyzer subsystem, e.g., a digital video processor, and a color display monitor. The camera captures a digital color image of the patient's tooth and the subsystem compares that image to a stored plurality of tooth shades. Each tooth shade is represented in a block of data, including color image data, a tooth shade digital word, and a manufacturer type. The patient's tooth image includes an RGB chromaticity representation that is scanned and compared with the several tooth shades stored in memory, and a match is determined and communicated to a user of the system. The methodology includes the specification of fractional tooth shades, if needed, corresponding to a plurality of porcelain films for manufacturing a reconstructed tooth.

Abstract: A rotating laser beam projector includes a power controller having a micro controller coupled to a laser power circuit which determines whether the laser beam emitted by the projector is rotating or stationary. When the laser beam is rotating, the laser power circuit delivers a first level of continuance power to the laser. When the laser beam is stationary, the laser power circuit delivers a second level of continuance power to the laser which is less than the first level of power. The micro controller communicates messages from the laser beam projector to a remotely positioned sensor assembly by rotating the laser beam at a first speed when no message is to be communicated and rotating the laser beam at a second speed, different from the first speed, when a message is to be communicated. The laser beam projector includes a bridge for delivering electrical power to a pendulum-supported device from a stationary source.

Abstract: In an analysis system including as light sources an incandescent lamp and a blue light emitting diode, the light of the two sources is combined and directed through filters and a test tube with material to be examined to a photodiode array spectrometer. The filters are so selected that they counteract the intensity drop of the incandescent lamp and the sensitivity decrease of the photodiode array of the spectrometer at short wave lengths.

Abstract: An elevation measurement instrument including a support ruler, an optical instrument and a bracket pivotally coupling the optical instrument to the support ruler. The optical instrument includes a first ocular mount having a telescope with a horizontal crosshair and a second ocular mount having a horizontal alignment level device. The bracket couples the optical instrument to the ruler along a horizontally balanced axis. The bracket includes a position indicator colinearly aligned with the horizontal crosshair.

Abstract: A laser beam receiver is provided wherein the position of a laser beam incident upon an array of a plurality of photosensitive cells is calculated by coupling the plurality of photosensitive cells to a plurality of signal amplifiers, wherein each subset of adjacent photosensitive cells is coupled to a distinct subset of amplifiers among the plurality of signal amplifiers and wherein each non-adjacent mutually-coupled cell subset is connected to a single one of the plurality of signal amplifiers; and calculating the position of the laser beam based upon amplified signals read at the plurality of signal amplifiers.

Abstract: A color comparator system is described which avoids the use of liquid reference standards and glass vials. In a preferred embodiment the system includes (a) a clear lens piece including a plurality of lens sections equal to the desired number of color steps or intensities to be measured or observed; (b) background color for visually separating the lens sections and providing a controlled background color for samples between lens sections; and (c) at least one lens color means positioned behind the lens piece. The visual perception when using this comparator system is the same as viewing a series of glass tubes filled with colored liquid. Ambient light passes through each lens and is then reflected back toward the viewer.

Abstract: Two detectors are effectively positioned at a predetermined lateral position in a rectangular illumination field at a wafer plane. The ratio of the signals from the two detectors is calculated. This ratio is indicative of the quality of the illumination field and any lamp instability which may effect the illumination field, and therefore image quality. In a photolithographic device, a short arc mercury xenon lamp provides illumination for projecting the image of a reticle onto a photosensitive resist covered substrate or wafer. The desired illumination intensity profile is sensitive to lamp instability. This instability may alter the desired illumination intensity profile which may adversely effect image quality, and therefore the resulting product. The ratio of the signals received from predetermined locations laterally along the illumination intensity profile improves the detection of unstable lamps.

Abstract: A laser survey instrument, which comprises at least a main unit for emitting a laser beam and an object reflector for reflecting the laser beam from the main unit toward the main unit, whereby said main unit comprises an emitter for emitting the laser beam, a rotating unit for rotating and scanning the laser beam, a tilting mechanism for tilting the laser beam at an arbitrary angle at least in one direction with respect to a horizontal plane, a rotating angle detector interlocked with the rotating unit and for detecting irradiating direction of the laser beam, a reflection light detector for detecting reflection light from the object reflector, and an alignment display unit for detecting a deviation of direction with respect to the object reflector and a deviation of tilt angle based on a signal from the reflection light detector and for obtaining information on the deviation of direction or the tilt angle, the laser beam emitted from the main unit is irradiated to scan, the center of the object reflector is

Abstract: In a horizontal position error correction mechanism for an electronic level according to the present invention, a collimation optical system collimates a level rod, and a calculation processing device processes an output signal of a photoelectric converter by calculation to calculate a difference of elevation and so forth. A compensator device formed on a telescope optical system for maintaining a horizontal position corrects an inclination of the electronic level to maintain the horizontal position of the electronic level, and a suspended optical member suspended from the compensator device is rocked in forward and backward directions and leftward and rightward directions in response to an inclination of the compensator device.

Abstract: A technique for making precise spectrophotometric measurements illuminates a sample with two or more modulated light sources at two or more, typically closely spaced, wavelengths. Light from the sources is combined, homogenized, and directed to the sample, and the light from the sample is collected and detected by a photodetector. The optical output powers of two sources are modulated with the same periodicity and with a reversed amplitude. Variations in the concentrations of species in the sample affect the modulation amplitude representing the sum of the optical powers from two sources in such a way as to produce an output signal. That output signal, based on an electrical component varying with a periodicity at the fundamental frequency, provides a measure of the difference in the transmissions (or other optical properties) of the sample at the two wavelengths. Feedback methods, such as null-point detection, provide stable, sensitive measurements.

Abstract: An intraoral camera connects to a shade analyzer subsystem, e.g., a digital video processor, and a color display monitor. The camera captures a digital color image of the patient's tooth and the subsystem compares that image to a stored plurality of tooth shades. Each tooth shade is represented in a block of data, including color image data, a tooth shade digital word, and a manufacturer type. The patient's tooth image includes an RGB chromaticity representation that is scanned and compared with the several tooth shades stored in memory, and a match is determined and communicated to a user of the system. The methodology includes the specification of fractional tooth shades, if needed, corresponding to a plurality of porcelain films for manufacturing a reconstructed tooth.

Abstract: An electronic distance measurement EDM apparatus (41) for attachment to a range pole (42), having a GPS antenna (12) having a circular exterior (46) with a reflective outer surface (54) for reflecting an EDM light beam (56) over an angular azimuth range of 360.degree.. The reflective outer surface (54) is a thin material such as tape or paint. A GPS receiver (16) connects to the GPS antenna (12) for providing a GPS-derived location of a phase center (18) of the GPS antenna (12). An optional radio transmitter (20) transmits information for the GPS-derived location in a GPS location data signal (22). An optional radio receiver (24) receives a differential GPS (DGPS) correction signal (26) and/or a GPS real time kinematic signal (28) for use in improving the accuracy of calculation of the GPS-derived location. An integrated global positioning system / electronic distance measurement (GPS/EDM) surveying system (40) includes the EDM apparatus (41), the range pole (42), and a total station (58).

Abstract: A digitally filtered laser receiver includes a plurality of radiation sensors spacially arranged in a manner which identifies a relative position of the sensors with respect to a rotating laser radiation source. The digitally filtered laser receiver includes a microcomputer having inputs which are responsive to impingement of the sensors by radiation. The microcomputer is programmed to process data from the inputs only when the radiation sensors are impinged by radiation from the rotating laser radiation source. The microcomputer processes the data and provides an output which is indicative of the position of the rotating laser radiation source and the sensors.

Abstract: An electronic leveling apparatus and associated leveling staff are designed to form an image of scale patterns of the leveling staff on a photo-electric transducer by means of a telescopic optical system, convert the image into an electrical signal with the transducer and implement the Fourier transformation for the signal with a signal processor, thereby having functions of focusing control and abnormality detection. The leveling staff has an alignment of the first and second (and third) scale patterns aligned in order cyclically at a constant pitch along the length measuring direction, with the first and second patterns having their widths varied in different cyclic periods and the third pattern having a constant width.

Abstract: The colorimetric value at a specified temperature is determined by measuring the colorimetric value of a colored material sample at an arbitrary temperature using a color meter such as a spectrophotometer, colorimeter, or densitometer, and by correcting the measured colorimetric value on the basis of the change in colorimetric value with temperature, which change in colorimetric value is computed from the difference in colorimetric values observed for a single colored material sample at a minimum of two different temperatures. When a spectrophotometer is applied, the spectral reflectance or the spectral transmittance of the colored material sample is measured. On the other hand, spectral reflectance or spectral transmittance is measured in advance for a dye or pigment at a minimum of two different temperatures. The difference (.DELTA.K) of absorption coefficient (K), the difference (.DELTA.S) in the scattering coefficient (S), and the difference (.DELTA.

Abstract: A first embodiment of the invention includes a light source (1) lighting two parallel optical branches (b1, b2) controlled respectively by two optical shutters (4, 6), one comprising a transparent cell (3) containing a substance to be studied, and the other being used to divert the light from the source. The light coming successively from one and from the other branch is applied selectively to three color filters (F1-F3) filtering three wavelengths selected according to the substance to be studied. The successive luminous intensities which have crossed each of the filters are measured through three detectors (D1 to D3) and the measurings are combined by means of a control (0). Analogous measuring sequences may be achieved with an embodiment comprising three light sources and a single detector. The device can be used for determination of the pH value of a substance.

Abstract: Method of assay of enzymatic activity, comprising projecting excitation light to a sample containing an enzyme, a substrate which forms a product by action of the enzyme, and a reference substance which is insensitive to the action of the enzyme but emits fluorescence; obtaining a first measured value of fluorescence intensity of the sample at a first wavelength region which includes fluorescence emitted by the substrate or the product at least, obtaining a second measured value of fluorescence intensity at a second wavelength region which is different from the first wavelength region for the first measured value and includes fluorescence emitted by the reference substance; and assaying the enzymatic activity from the ratio of the first measured value to the second measured value and apparatus for performing the method. The method assures high accuracy and high sensitivity of measurement in enzyme labeled immunoassay and enzyme labeled DNA hybridization.

Abstract: A new method of measuring the soiling of floor surfaces or the like, capable of numerically and objectively measuring and grasping the soiling of floor surfaces and wall surfaces, in particular, the soiling of fiber floors, such as carpet floors, comprising the following steps: a step of illuminating a measurement surface of a floor surface in all directions by using diffused light from a diffusion chamber and a diffusion plate, a step of receiving light reflected by the measurement surface at the opening end of an optical fiber bundle disposed in the direction perpendicular to the measurement surface, a step of obtaining a color difference value between the surface color of the measurement surface obtained by measuring the received light and the surface-color of a standard plate obtained by making measurement in the similar way, and a step of numerically measuring the soiling of the floor surface depending on the change with time in the color difference value.

Abstract: The invention comprises a method, apparatus and equipment for detecting the hit location of a projectile passing through a target plane. A light source generates at least two zones of light which subtend between them a specified angle. The light zones sweep the target plane, illuminating a projectile crossing the target plane and casting a shadow of the projectile onto a screen, preferably a difuse, ground-glass screen.

Abstract: A laser beam projection apparatus is capable of supplying laser beams finely converged on an object at all times irrespective of a distance to the object. The laser beam projection apparatus has a laser beam generator, including a focus adjusting device, for supplying laser beams periodically swept within one plane and, at the same time, converged at a controllable distance, a light receiving element for receiving reflected laser beams from a predetermined object and generating an output signal, a distance calculating unit for calculating a distance to the object on the basis of the output signal and a controller for operating the focus adjusting device so that the swept laser beams are converged in a position corresponding to the calculated distance. The controller can change a sweep speed of the laser beam in accordance with a change in the calculated distance. The controller cna change a sweep speed of the laser beam in accordance with a change in the calculated distance.

Abstract: The present invention provides a spatial positioning and measurement system and a reference station for determining the instantaneous position of a dynamic reference point. The reference station emits a primary laser beam, determines the terrestrial position of a local reference point located on the reference station using a satellite based global positioning system and transmits the terrestrial position. The system detects the primary laser beam and the terrestrial position of the local reference point and responsively determining the terrestrial position of the dynamic reference point.

Abstract: The process for measuring relative angles between a measuring platform and measuring points provides at least one light ray (f.sub.1, f.sub.2) fanned into a flat band. This light fan is swivelled around an axis of the measuring points light is reflected back to the measuring platform, as soon as the light fan impinges on these reflecting means. The measuring platform has counters, which count continuously until the arrival of a reflecting signal at the measuring platform. The respective next reflecting signal stops at the next provided counter. A counter is provided to count with the same counting pulse, during the entire, predefined angular range, in which the measuring points are to be acquired. From the ratios of the counts stopped by the reflecting signals, to the count of the counter that is still counting, the angle of the corresponding measuring point is calculated. Preferably two light fans (f.sub.1, f.sub.2) that are preferably at right angles to each other are provided.

Abstract: Improved transmitter and receiver units for use in spatial measurement system that are easy and inexpensive to manufacture while providing a high degree of reliability are disclosed. Specifically, the laser transmitter includes a laser emitter, a bearing/motor assembly coupled to the laser emitter, the bearing/motor assembly including a rotatable hollow spindle shaft through which a laser beam generated by the laser emitter passes and a motor for driving the spindle shaft, a prism assembly coupled to the spindle shaft, wherein the prism assembly divides the laser beam generated by the laser emitter into a pair of fanned laser beams, and reflecting means for reflecting the fanned laser beams generated by the prism assembly as counter-rotating fanned laser beams. The receiver unit preferably includes at least one optical receiver coupled to an extension member, a processing unit coupled to the optical receiver, and a receiver interface coupled to the processing unit.

Abstract: A method for calibrating an automatic chemical analyzer whereby an improved baseline value is calculated. The analyzer uses a photodetector to detect the amount of light passing through a flow cell and correlates this value to the amount of analyte present in a sample solution. In the preferred embodiment, silica is the analyte under investigation. A baseline solution of a specified (preferably zero) analyte concentration, or a sample solution of unknown analyte concentration, is introduced into a chemical module after chemical reagents have reacted with themselves to form a color complex. The resulting solution is passed to the photodetector which determines the amount of analyte present. This value corresponds to the analyte contaminants within the reagents and can be subtracted out by further calculations.

Abstract: An electronic leveling system, which is intended to enhance the efficiency of leveling work, is capable of sending various data generated on the part of the electronic level unit from it to the electronic leveling staff and sending various data generated on the part of the leveling staff from it to the leveling unit. The system includes a function of compensating automatically the tilt of the leveling unit and leveling staff.

Abstract: An electronic leveling apparatus and associated leveling staff are capable of measuring the height difference of the positions automatically through the opto-electric conversion of the image of a pattern formed on the leveling staff. The apparatus has a turning drive means for turning it on a horizontal plane, a light emission means for emitting a light beam to the outside, a light reception means for receiving a reflected light of the emitted light beam, and a signal processor for controlling the turning drive means in response to the received signal so that the apparatus is oriented to the leveling staff automatically.

Abstract: The present invention concerns a new optical photometry system for on-line analysis of industrial fluid streams. The invention is a general purpose optical photometer, capable of absorption, fluorescence and reflectance measurements at single wavelengths in the ultraviolet, visible and near infrared spectral ranges. Light signals generated by the light source are carried between a central photometric console and remote analysis sites by fiber optic cables. The return light signals are compared with a standard to make the desired analysis.

Abstract: For a given set of dyes, chosen to match a target (standard) color, by combining the a priori percent reflectance and concentration data of primary (calibration) dyeings with that of one or more trial dyeings, a calculated formulation can be obtained which agrees with one of the trial formulations used, or the average, as precisely as desired. A match, color or spectral, to a target color, near to the color of the trial dyeing in color space, is obtained that is, for all practical purposes, as accurate as those dyes permit.

Abstract: Described herein is an automated quality inspection station for evaluating color component characteristics of a product. The inspection station includes a color video camera, for capturing video frames of product images, and a control system for analyzing those video frames. The control system is programmed to perform a reference calibration and then a sample calibration. During the reference calibration an operator identifies component type areas from a displayed reference frame of a typical product assortment. The control system calculates color value density curves from the identified areas. The density curves are then calibrated to each other by scaling each of the density curves by a scaling factor. The scaling factors can either be provided directly by the operator or default values can be calculated by the control system. Default scaling factor values are calculated by summing the product of the corresponding density curve and an overall histogram of a sample video frame over a range of color values.

Abstract: A dual wavelength optical sensor for measuring chemical properties of a particular quantity, the optical sensor including a sensor probe having a thin sensing film whose optical characteristics are responsive to the chemical properties of the measured quantityThe United States Government has certain rights in this invention pursuant to Contract No. ITA87-02 between the U.S. Department of Commerce and Iowa State University.

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: A heating apparatus for use in the process of coating workpieces with an aqueous colored material such as a water-base paint. Radiant heaters are used in a flash-off operation to remove moisture from the coating material on the workpieces while the workpieces are transported between the heaters. The coating color is specified in advance, and an optimal moisture removal operation is performed by automatically regulating the radiant heat intensity suitable for the specified color.

Abstract: A reflection plate for a biochemical measuring instrument which is adapted to evaluate a biochemical value by obtaining a reflective property of a reflection surface of the reference reflection plate, obtaining a reflective property of test paper impregnated with biochemical sample and mounted on a test stick, and comparing the two reflective properties, wherein: the reflection surface of the reference reflection plate is depressed from the periphery thereof. Thereby, even though the test stick is required to be placed adjacent to the reflection surface to achieve a uniformity the optical arrangement in obtaining the two reflective properties, the contamination of the reflection surface from the sample can be prevented. Preferably, the reference reflection plate itself may be provided with a depression to defined the reflection surface at the bottom of this depression.

Abstract: A photomultiplier (10) with an elongated rectangular, cathode (20) tilted with respect to the inlet opening (14) is alternately illuminated by a measuring light beam (36) and a reference light beam (40). The measuring light beam (36) and the reference light beam (40) extend in a plane parallel to the longitudinal sides of the cathode (20) and impinge upon the cothode (20), such that they illuminate the same areas of the cathode (20).

Abstract: A chemical sensor, such as a fiber optic chemical sensor, is self-calibrated by measuring two output values which behave differently in response to an analyte, and forming a ratio between the two measured output values to cancel out effects of variations in external factors such as temperature variations, differences between coatings, light (illuminator) variations, fouling, bleaching, leaching or the like. An indicator material may be used which produces both fluorescence and phosphorescence, both monomer and aggregate emission or absorption bands, emission or absorption bands with or without an isosbestic point, emission peaks at one wavelength at two different excitation bands, or emission peaks at two wavelengths for excitation at two wavelengths.

Abstract: Herein disclosed is a method for mutual transformation between the data of a light-source color on a color CRT monitor and the light-source color. The transformation can be performed by using any of the following two formulas:R.sub.c (.lambda.)=[I.sub.c (.lambda.)/I.sub.g (.lambda.)]R.sub.G (.lambda.);and ##EQU1## wherein: Both R.sub.c (.lambda.), and X, Y and Z express the non-luminous object color data which are designated at a spectral reflectance factor and the CIE tristimulas values, respectively; andBoth I.sub.c (.lambda.), and R.sub.c, G.sub.c and B.sub.c express the light-source color data, which are designated at a spectral distribution and the RGB video drive signals, respectively.Unknown parameters R.sub.G (.lambda.) and I.sub.G (.lambda.), and K.sub.R, K.sub.G and K.sub.

Abstract: A portable hand held instrument is capable of making accurate colorimetric measurements in the field. The instrument has a body which houses the electronic circuitry and a door which allows a vial having a solution to be measured to be placed therein. The vial is illuminated lengthwise by a light beam of two wavelengths, one of which serves as a reference. The light emerging from the top of the vial is spatially integrated and directed to a detector. The detector measures the intensity of the transmitted light, and the electronic circuit determines the difference between the logarithms of the detected signals. This difference is multiplied by a constant to produce a signal representative of the concentration and is displayed. The resolution of the measurement is automatically increased when the processor senses that the signals are too small.

Abstract: Test carrier analysis system for the analytical determination of a component of a sample fluid, in particular of a body fluid. The system comprises test carriers (1) with a color formation layer (5) which is attached movably to the test carrier. The color formation layer is in the initial state of the test carrier not in fluid contact with a fluid reservoir layer (4) likewise attached to the test carrier, but can be pressed against the latter by external manipulation. The system also incorporates an evaluation apparatus with a pressure element (10a) for the pressing of the color formation layer (5) and a control unit (25) for controlling the apparatus functions.

Abstract: An apparatus including a measuring head, equipped with light sources for lighting one part of a bodywork of which the color is to be reproduced with a receiver for picking up the light reflected in each of a plurality of preset wavelength in order to produce a signal representing the reflectance of the surface in each wavelength. The apparatus also includes a device for calculating, for each wavelength, the reflectance for any combination of basic shades or bases from among a predetermined set off bases, and apparatus for continuously comparing the measured reflectance with the calculated reflectance in order to find a suitable paint formulation. A starting formulation given by the particular combination of bases corresponding to the color reference of the bodywork to be repaired may be modified, until the difference between the calculated reflectance values and measured reflectance values reaches a minimum or becomes smaller than a preset threshold.

Abstract: A color signature sensor for color recognition or discrimination utilizing a spectral analysis system for use as a process control for automation and on-line quality assurance. An object to be observed is illuminated by a suitable light source, light collected from the object under examination is routed into a monochromator. The output of the monochromator is fed to an analog-to-digital converter and analyzed by a microprocessor.

Abstract: The object of the present invention is the improvement of logarithmic amplifiers and/or converters and the applications of such devices in particular to photometric analyzer apparatuses.These amplifiers are characterized by the fact that they are linear with an amplification gain programmable by the .mu.P computer and that they may be preceded optionally by a reference voltage system.Application to the measurement of light transmitted by samples.

Abstract: A color measuring apparatus including a photoelectric conversion device for outputting basic color signals corresponding to quantities of light of basic color components of a sample, respectively, a calculating device for calculating a color value of the sample in a predetermined colorimetric system, a target setting device for setting a target color value of the sample in the predetermined colorimetric system, a region setting device for setting a predetermined region containing the target color value, a region decision device for deciding whether or not the color value falls within the predetermined region, an approximation decision device for deciding whether or not the color value has most approximated to the target color value and an output device for outputting a result of the decision of the approximation decision device.

Abstract: Method and apparatus for matching a selected color with predetermined available paint colors wherein a portable color meter is used to analyze a selected color and store chromaticity data representing the hue, chroma and brightness of the selected color. That stored chromaticity data is coupled to a computer which compares it with stored chromaticity data in the computer representing available color formulas and then selects one of the stored paint formulas most closely matching the chromaticity data representing the selected color.

Abstract: An offset drift correction method for use in in a color film inspection apparatus includes the steps of; measuring the changes of various amounts of light at intervals of a predetermined amount of light as density signals by using a green standardized logarithmic-transforming curve; providing table data by shifting the green standardized logarithmic-transforming curve as to inputs in such a way that the changes become equal to one another; writing the table data in a green look-up table; measuring input signals for red and blue at intervals of the predetermined amount of light; and substituting the measured inputs with the table data of the shifted green standardized logarithmic-transforming curve at corresponding amounts of light.

Abstract: A device for making accurate, reproducible light reflectance measurements on an optically nonuniform specimen comprises means for holding the specimen in a fixed position. In one embodiment the specimen is illuminated by light sources that are arranged at acute angles relative to the specimen and (360.degree./N.+-.1.degree.) apart in azimuth, where N=the total number of light sources. The light sources are sequentially energized and deenergized to illuminate the specimen. A light detector receives light reflecting from the surface and generates an electrical signal, which is subsequently processed. In another embodiment the light sources are arranged in pairs in which the two light sources in a pair are simultaneously energized and deenergized and the pairs are sequentially energized and deenergized. A method for measuring reflected light is also provided.

Abstract: Adjustment of color density of a color picture to be recorded on a photosensitive material is performed in a color picture output device in such a manner that a test pattern print is outputted from the device and the density of the test pattern print is then compared with a standard pattern plate preliminarily prepared. After the actual output picture color density is measured by the standard pattern plate, the gain and offset for obtaining the standard density can be automatically calculated so as to thereby perform in smooth and high speed color picture outputting operation.

Abstract: Method for the measurement of the difference in the color contents of two samples (1, 2) or of two component areas of a sample, in which method one or several sources of light (3 to 6) as well as one light detector (7) are used. According to the invention, both samples (1, 2), or component areas of a sample, are illuminated simultaneously and, from both samples (1, 2) or component areas of a sample, the light is passed simultaneously to the light detector (7). The lights to be measured from the samples (1, 2) or component areas of a sample are of different colors, as compared with each other, so that the light to be measured from the first sample or component area is absorbed weakly in the coloring agent and the light to be measured from the second sample or component area is absorbed strongly in the coloring agent. The colors of the lights to be measured from the samples (1, 2) or component areas of a sample are alternated with each other at an appropriate frequency, such as, e.g.

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.