Abstract: An optical concentrator increases the power density from diffuse optical energy remitted by an optically diffusing surface by at least partially recollimating the diffuse optical energy. The concentrator includes an optical diffuser element illuminated at a first point by optical input energy and remitting incident optical energy. A reflective element has a reflective surface with a concentration point located at the first point and the reflective surface reflects diffuse optical energy incident on it from the diffuser element. At least one aperture is provided for the transmission of an output beam formed by a portion of the diffuse optical energy from at least the diffuser element.

Abstract: A conical illuminator for use in colorimetry, spectrophotometry, densitometry or sensitometry. In a preferred embodiment, light from a source such as a pulsed xenon lamp is integrated within a integrating chamber. The light source may be placed in a second integrating chamber adjacent to the aforementioned integrating chamber. Alternatively, the lamp may be placed directly within the integrating chamber. The light is emitted through an exit port and conformed to a conical configuration, according to a pre-selected standard, via an annular stop. An imaging optic relays the conformed light uniformly onto a sample plane. The annular stop is placed at or near the tangential focal length of the imaging optic. The annular stop may be coated with a light absorbing coating, or can be formed with a grooved or mirrored surface. Alternatively, in lieu of an integrating chamber, a diffuser may be employed for homogenizing the light. Various configurations of the imaging optic and annular stop are possible.

Abstract: Primary and secondary mirrors constitute a collimator which permit measurements to be made within a reasonably sized equipment enclosure. An incoming laser beam, from a unit undergoing test, has its light dispersed by an integrating sphere from which radiometric measurements may be made. Further, the output from the sphere passes through an avalanche photo diode for detecting laser beam pulse envelopes. These envelopes may be measured for such parameters as pulse width, and interval. A focal plane array camera is provided to measure boresight deviation from the unit undergoing test.

Abstract: A high efficiency integrating sphere that can be used in a large variety of scientific instruments. The sphere having an efficiency gain obtained by using a superconducting material, acting as a perfect reflector, on the inside hollow surface of the sphere. The sphere is operated with a delay between the incident and sensed light, heretofore not possible, and yielding substantial improvement in the signal-to noise ratio of the integrating sphere.

Abstract: An improved power meter for measuring the energy and wavelength of light emanating from an optical fiber. The meter is an integrating sphere having a source aperture for receiving the tip of an optical fiber and coupling the light from the tip into the sphere's central cavity. The source aperture is modified to include a sterilizable, liquid-fillable insert which mimics the optical environment within tissue. The sphere also has improved baffling and the sensitivity of wavelength verification is improved by means of a rotatable interference filter placed between an exit aperture and a light detector.

Abstract: A high efficiency optical mixer includes a source of focused radiant energy. The focused radiant energy is concentrated by a parabolic concentrator onto an exit port. A diffuse reflector, which can be planar or arcuate, is maintained in contact with the output port thereby minimizing optical losses and diffusely reflecting light from the concentrator. The reflected light can be transmitted, by fiber optics, to an optical system. A method is providing for concentrating focused radiant energy onto a selected area and diffusely reflecting same from that area.

Abstract: Apparatus for scanning an information medium, such as laser scanning apparatus, includes a light collector which has high light collection efficiency, which is easy and economical to manufacture, and which efficiently shades photodetectors from scattered transmitted light. The collector includes first and second members joined together to form a light collecting cavity, with diffusely reflecting surfaces facing the cavity. The members extend the length of the scanning region and are formed from longer lengths of extrudable material. The members have ends which form a slot adjacent to the light scanning region for receiving light transmitted through the information medium into the collection cavity and which have information medium guiding features.

Abstract: A sorting apparatus is disclosed which utilizes transmitted light to determine whether or not an article under inspection is defective in order to reject any article determined to be defective. A light irradiator is provided on irradiating an article being inspected with a light beam having a smaller diameter than that of an article, and a light condenser is provided for condensing the rays of light transmitted through the article while being diffused. Two light detectors respectively detect two specific kinds of light having different wavelengths from among the condensed rays of light transmitted through the article. A ratio is obtained between the intensities of the two specific kinds of light detected by the light detector and compared with a predtermined ratio in order to determine whether the article under inspection has undergone deterioration in quality.

Abstract: A laser film scanner scans film as it is translated in a substantially horizonally plane past a diffuse light collector. The light collector includes an elongated housing enclosing a collection cavity having a slot at its top through which light enters. The cavity has diffuse reflective surfaces to diffusely reflect light to a photodetector communicating with the cavity. Positioned opposite the slot is a slanted face from which light entering the cavity is directly reflected. The slanted face avoids streak artifacts in a detected image by permitting dirt particles falling through the slot to roll down to a lower region in the cavity. The slaned face may be formed from a removable insert of low adhesion fluorocarbon material to permit cleaning without disassembling the collector.

Abstract: The invention is directed to an arrangement for measuring the absorption of a transparent specimen. The arrangement includes: a radiation source for supplying radiation; a radiation-integrating device defining a space enclosed by a wall having a reflective surface for multiply reflecting the radiation substantially uniformly throughout the space to diffusely illuminate the transparent specimen whereby diffused radiation passes through the transparent specimen; a photometric measuring unit for measuring the radiation passed through the specimen; and, a mount for mounting the specimen between the reflective surface and the measuring unit. The arrangement of the invention enables the absorption of transparent specimens to be measured which have unfavorable outer forms such as where the specimen contains no surfaces which are mutually parallel.

Abstract: The apparatus and method of the invention are applied to the generation of alternating sample, dark, reference and dark beams for direction of said sample and reference beams into an integrating sphere which comprises detecting means and a reference source, for spectroscopic analysis of a sample contained in a sample cell which is operatively associated with said integrating sphere; to the generation of digital control signals attendant the generation of said beams; and to the processing of the multiplexed, sample analysis results analog data signal, as provided by the detecting means, by aligning a digital control signal therewith in time and further operating upon the thusly aligned data signal to precisely calculate the sample analysis results therefrom.

Abstract: An electro-optical technique for the efficient scanning of many different forms of transparent media. The method utilizes synchronous closed loop scanning (integrated scanning). The subject is illuminated with a predetermined light source level. The source is directed by a scanner to the transparent media. The illumination is then electro-optically processed and immediately fed back through the same scanner to the subject media. The resulting feedback creates an image signal that actively illuminates the media, providing only as much light as is required to detect the image. The signal thus created can be used to create a very high resolution reproduction of the subject image. The image can be reproduced immediately for viewing and transmission or stored as a video record. In addition, the image can be manipulated or integrated with other images for analysis, measurement, or presentation purposes.

Abstract: Apparatus and method are described for determining the transmission factor or the density of a translucent element, such as an optical filter, using the cosine-to-the-fourth law. The apparatus includes a source of light of constant color and intensity. A detector is mounted on a track for movement along rectilinear path with the plane of the operative face of the detector parallel to the path. A reading of the intensity of light from the source sensed by the detector is taken in one position with the element in the light path and in another position with the element absent. The positions being such that the two readings are equal. The angles .THETA. and .alpha. of incidence of light on the detector in the two positions are determined and computer means determine value of ##EQU1## to give the value of the transmission factor.

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: A colorimeter comprises a light source, a mixing box formed of non-coated light diffusing surface manufactured by molding sintering white ceramics or white resin for diffusing and reflecting light from the light source to guide the same to a sample, first light receiving means for receiving light reflected from the sample when light is emitted from the light source, and second light receiving means for receiving light other than the light reflected from the sample emitted from the light source.

Abstract: Apparatus for determining the effective surface roughness of polished optical samples, by measuring the total integrated scattering, only operates for non-light-transmissive samples. For a transmissive sample, the invention adds a light trap behind the sample for transmitted light, and a diaphragm in front of the sample. The rear surface of the diaphragm is provided with a non-reflective wafing which traps secondary light reflected or scattered by the inside rear surface of the sample.

Abstract: A portable spectrophotometer is disclosed which is provided with a holding case accommodating opto-mechanical color-reading devices and an electronic control device provided with a microprocessor having data and program memories. The spectrophotometer further includes a power source which enables its self-sustained field use.

Abstract: A light collection device for use in a flame emission detection system such as an on-line, real-time alkali concentration process stream monitor is disclosed which comprises a sphere coated on its interior with a highly diffuse reflective paint which is positioned over a flame emission source, and one or more fiber optic cables which transfer the light generated at the interior of the sphere to a detecting device. The diffuse scattering of the light emitted by the flame uniformly distributes the light in the sphere, and the collection efficiency of the device is greater than that obtainable in the prior art. The device of the present invention thus provides enhanced sensitivity and reduces the noise associated with flame emission detectors, and can achieve substantial improvements in alkali detection levels.

Abstract: In a color measuring instrument, an integrating sphere is used to illuminate the sample and fiber optics are used to carry light diffusely reflected from the sample and from an interior wall of the sphere to a spectrometer. The transmitting ends of the fiber optic bundles are fixed in the housing of the spectrometer as entrance slits for the spectrometer, which includes a fixed grating and one or two arrays of photodetectors to detect the spectra dispersed by the grating from light received from the two transmitting ends.

Abstract: The present invention is drawn to a spectrophotometer using a pulsed xenon flashtube as a light source. The energy to be applied to the light source of the spectrophotometer is set within a range of 0.03 joules to 1.0 joule. Therefore, the intensity of light emitted from the light source is not too great, which allows the spectrophotometer to measure a spectral reflectance under the presence of natural light or equivalents thereof. Further, the charging period of time required for the spectrophotometer to provide a desired light emission intensity is short, so that the light source is capable of emitting many flashes of light per second, wherein the amount of data produced within a predetermined measuring period is increased. Thus, accurate data can be generated.

Abstract: A multichannel optical sensing device is disclosed, for measuring the outr sky luminance or illuminance or the luminance or illuminance distribution in a room, comprising a plurality of light receptors, an optical shutter matrix including a plurality of liquid crystal optical shutter elements operable by electrical control signals between light transmitting and light stopping conditions, fiber optic elements connected between the receptors and the shutter elements, a microprocessor based programmable control unit for selectively supplying control signals to the optical shutter elements in a programmable sequence, a photodetector including an optical integrating spherical chamber having an input port for receiving the light from the shutter matrix and at least one detector element in the spherical chamber for producing output signals corresponding to the light, and output units for utilizing the output signals including a storage unit having a control connection to the microprocessor based programmable control

Abstract: The etendue (throughput or area-solid angle product) of a high resolution interferometer is maintained at a substantially high level by use of a transparent chamber defined by a highly reflective internal surface, the chamber being located at the input to the interferometer. The chamber has an input aperture to admit light into the chamber and an output aperture or exit opening to pass light to the interferometer. By integrating the input light through multiple reflections thereof within the chamber until it exits to the interferometer, the etendue of the latter is substantially enhanced.

Abstract: The invention is directed to a reflectance measuring apparatus having a predetermined aperture for the receiving optic. A light-conducting device arranged between the measuring aperture and the specimen enlarges the effective measuring surface of the latter so that even specimens having a large surface structure can be measured without difficulty.

Abstract: The invention relates to photometric apparatus and method for determining a characteristic of individual ones of a plurality of samples contained within a plurality of sample chambers. The photometric apparatus includes an enclosure; a substantially uniform source of radiation coupled to the enclosure such that a plurality of sample chambers, disposed within the enclosure, are simultaneously illuminated by the uniform source; and apparatus for detecting an amount of radiation which is transmitted through individual ones of the sample chambers, the detecting apparatus having an output signal having a magnitude which is a function of the amount of radiation which is transmitted through an individual one of the sample chambers.

Abstract: A probe, for use with a spectrophotometer, which senses the reflectance of a sample remote from the spectrophotometer. The probe includes a housing having a probe portion positionable proximate the sample, and an integrating chamber disposed within the probe housing and having a radiation input port, a sample port for passing diffused radiation to the sample and returning reflected radiation from the sample, a reference port, and an exit port to receive radiation reflected from the sample through the sample port. The probe further includes a guide for directing radiation to the radiation input port from a radiation source, and an element, responsive to the exit port and the reference port, for selectively conveying reflected radiation from the sample and the wall of the integrating chamber in the probe to the remote spectrophotometer.

Abstract: A linear light source for a film scanner includes means for generating an intense beam of light and an elongated cylindrical integrating cavity having diffusely reflective walls, and defining an input port through which the intense beam is introduced into the cavity and an output slit parallel to the long axis of the cylindrical integrating cavity to emit a uniform line of light.

Abstract: An apparatus for monitoring the light energy power level of a beam of light, includes beamsplitters on the axis of the light beam for directing portions of the light beam in first and second paths respectively orthogonal to the axis while transmitting the remaining portion of the light beam therethrough. First and second photodetectors having similar spectral responsivity intercept the first and second light beam portions respectively, and detect and signal the light energy power level of the respective first and second light beam portions. Analysis circuitry coupled to the first and second photodetectors and responsive to the output signals therefrom to calculate the total light energy power level of the light beam. The apparatus resolves linearly polarized light into two orthogonal components while permitting most of the light to exit. This exit beam can be analyzed in terms of the incident beam or monitored for measurement or control purposes.

Abstract: A high sensitivity fluorescence and absorption detector comprising an elongated substantially cylindrical flow cell connected to and receiving the outflow of a fluid chromatography column; a mechanism for projecting a fluorescence generating beam of electromagnetic energy along on an axis substantially coincident with the axis of the flow cell; the flow cell including an elongated substantially cylindrical midsection housed by a tubular capillary transparent to the fluorescent radiation generated by the beam; a fluorescence integrating sphere completely surrounding the midsection of the capillary, the integrating sphere collecting at least about 3 pi steradian of the fluorescent radiation emanating through the capillary tube and into the sphere; the beam being projected to enter one end of the cylindrical flow cell, focus at about the center point of the axis of the cylindrical midsection, emanate through the other end of the flow cell and impinge upon a photodetector for detecting the portion of the beam whi

Abstract: An apparatus for measuring the relative coverage of a predetermined portion of a sheet of translucent material with an opaque medium such as ink or photographic emulsion, comprising: a light source for providing a relatively constant intensity source of light over a predetermined measuring area; a positioning device for positioning the predetermined portion of the sheet of material to be measured over the predetermined measuring area of the light source; a light measuring device for measuring the relative amount of light from the light source which is transmitted through the predetermined portion of the sheet of material to be measured, whereby the relative amount of opaque medium coverage of the portion of the sheet to be measured is readily determinable by comparison of the measured amount of light transmitted through the predetermined portion of the sheet to be measured with predetermined calibration values.

Abstract: An apparatus for determining and displaying selected characteristics of a film formed on the surface of a glass ribbon includes a scanning head mounted on a track for movement above the filmed surface of the glass ribbon. The scanning head has a source of light pulses generated from a tungsten lamp and chopper, filtered to simulate daylight and focused on the filmed surface. An integrating sphere is also mounted on the scanning head and has an entrance port formed in a wall thereof for collecting a portion of the light being reflected from the surface. Optically filtered detectors mounted in detector ports formed in the wall of the sphere generate output signals representing the "Y" and "Z" components of the collected light on the CIE X,Y,Z, tristimulus scale.

Abstract: A spectrophotometer provided with a plurality of integrating spheres of different types which can be selectively and exchangeably used in accordance with the type of a sample to be measured and the purpose of the measurement.

Abstract: A method and apparatus for calculating the equivalent blackbody color temperature of incandescent lamps. A lamp analyzer having photosensors which detect the red and blue components of lamp radiation and convert the components to analog currents. The currents pass through a multiplex system and are converted into a signal with voltages proportional to the photosensor currents. A signal conditioner circuit removes switching transients, damped oscillations and cell noise from the circuit, and an automatic gain controller system insures linearity in the signal. The ratio of the blue component of the signal to the red component is then determined by a ratio computer, producing an output which is linearized and scaled by a translator to display the corresponding color temperature of the lamp in Kelvins.

Abstract: Apparatus for monitoring the intensity of light comprising an optical waveguide having a light-collecting tip end with a diffusing surface which is shaped so that it can collect and transmit light rays into the waveguide. The structure of the tip is such that it is capable of collecting rays which are directed toward the tip from all angles within a 360.degree. arc. The tip may be conical, hemispherical, ellipsoidal or variations of these geometrical forms.

Abstract: Optical measurement apparatus includes a cell (12) adapted to receive fluid for testing and a light source (16) arranged to direct an incident light beam (5) into the cell. A hollow intergration sphere (14) and light-sensitive detector (26) are provided to detect at least a pre-determined portion of light emitted by a segment (13) of the cell transversely of the direction of said incident light beam.The light source (16) and the cell (12) are arranged so that the light incident on the cell is not collimated but, as it traverses segment of the cell, is confined to the cell by total internal reflection, unless otherwise scattered by particles in the cell.

Abstract: A radiation dispersing cavity has its interior surface covered by a plurality of deformations, each of which acts as a dispersing element which is small with respect to the effective diameter of the cavity and yet large with respect to the wavelengths processed by the integrating cavity. The interior surface of the cavity is coated with a material which provides the proper reflectivity for the wavelengths of interest. The interior of the cavity is covered with at least two different sets of interlocking deformations producing at least two different apparent planes of reflection. Use of alternating concave-inward, concave-outward deformations facilitates smooth transitions between deformations, preventing development of hot spots at sharp discontinuities.

Abstract: The apparatus measures the transmission of light in successive falling objects. A beam is projected, wide enough to bathe all the facing surface of the object. An integrating sphere is on the other side of the object and its inlet and outlet apertures provide cut-offs so that only a hollow cone of flux scattered from the object is trapped in the integrating sphere, this flux being measured by a detector. The detector is connected to a micro-processor whose output is a measure of the clarity of the object. When the object is not in the beam, the beam falls on a detector so that the reduction in flux sensed by the detector is a measure of the projected area of the object. The micro-processor divides the signal from the detector by the reduction in flux, thereby making the output substantially independent of the size of the object.

Abstract: There is disclosed a reflectometer which uses an integrating cavity interposed between a pulsed light source and a test element. The cavity has enhanced efficiency by reason of its construction wherein a diffusely-reflecting surface is connected at opposite edges to mirrored surfaces that reflect back to the diffusely-reflecting surface, at least the majority of diffusely-reflected rays that are non-aligned with selected rays from the diffusely-reflecting surface that impinge unimpeded on the test element.

Abstract: A lens for utilization in the radiation energy exit port of a radiation energy integrating sphere is provided, and functions to prevent instrumental specular radiation energy reflections from striking the interior wall surfaces of the sphere and being collected thereby. The instrumental specular radiation energy reflections include those from the lens, per se, and those from instrumentation disposed without the integrating sphere.

Abstract: In order to color sort objects such as peas or sweets, they are dropped in succession through two integrating spheres. In the first sphere, the object absorbs infra-red radiation and the peak reduction in infra-red flux is detected in order to provide a signal responsive to the size of the object. In the second sphere, the object is illuminated with white light and the peak reduction in flux is detected by at least three detectors for three colors determined by filters. To make the illumination more uniform in the sphere, there is a step around the sphere almost half way down, with light sources equi-spaced around the step. The size signal is divided into the respective color signal in a micro-processor to produce a size-corrected color signal.

Abstract: The holding mechanism holds an object under inspection in a manner that the substantially entire surface of the object may relatively be scanned by a laser beam. A spherical integrating light collector has an opening disposed close to the inspected surface of the object held by the holding mechanism. A laser beam illuminating mechanism is coupled with the other end of the spherical integrating light collector, and illuminates the inspected surface of the object with the laser beam through the opening. A photo-electric converter receives the scattered light as is reflected by the inspected surface and collected by the spherical integrating light collector, and converts the scattered light into an electrical signal representing an amount of light. An analog to digital converter converts the electrical signal derived from the photo-electric converter into a digital signal. A peak detector receives the digital signal derived from the analog to digital converter to detect peak values at predetermined periods.

Abstract: A system for measuring radiation in the laboratory or at a site to aid in determining whether to erect a solar energy installation at that site includes a positioner and a sensor. The sensor, which is mounted on the positioner, includes a rotating semispherical chopper and an integrating sphere for collecting radiation in three modes. A broad-band detector measures the irradiance from the integrating sphere to monitor for anomalies. A pair of monochromators simultaneously measure, one in the visible range and the other in the infrared range, the spectral irradiance from the integrating sphere. Processing electronics process the measured spectral irradiance from the monochromators and generate data signals for providing an absolute irradiance spectra at the plane of the entrance aperture. The absolute irradiance spectra is inputted to an X-Y plotter and a magnetic disc and tape. The system further includes internal reference sources providing continuous wavelength and irradiance calibration.

Abstract: An integrating sphere (10) comprised of a uniform diffusely reflecting spherical cavity (24) having mutually transverse input and output ports (42, 46) and a linear sample transport mechanism (12) secured thereto so that the multiple samples (136) can be brought into registration with the input port, one at a time, without having to open or disassemble the apparatus when a change of a sample (136) is desired. A vacuum tight seal (72) is provided between the cavity (24) and transport mechanism (12) for maintaining the integrity of a vacuum generated within the sphere when attached to source of optical energy. The device is utilized, for example, to test the emissive characteristic such as the relative fluorescence quantum efficiency of a dye sample placed in the path of a monochromatic optical energy source coupled to the input port (42) while having a light detector coupled to the output port (46).

Abstract: Apparatus for measuring the absolute reflectance of a sample, which comprises an integrating sphere provided with four windows the centers of which lie in a plane including the center of the integrating sphere. A first one of the four windows has its center coinciding with a diametrical line of the integrating sphere included in the plane while a second and a third window are arranged symmetrically with respect to the diametrical line, with a sample set in the fourth window so as to face inwardly of the integrating sphere. A light source is so arranged as to introduce a beam of light into the integrating sphere and a light measuring device is so arranged as to receive the light emerging from the integrating sphere. The integrating sphere is rotatable for 180.degree.

Abstract: A method and device for detecting and evaluating the optical properties of a specimen, utilizing a light source that has alternating light and dark phases, a detector that picks up light from the light source by way of the specimen being examined, and a circuit that integrates and digitalizes the signals received from the detector, that includes an integrator, and that can be connected to the detector. The signals emitted from the detector are integrated both during at least part of the light phase and during at least part of the dark phase. The integral obtained during the dark phase is subtracted from that obtained during the light phase in order to determine the results. The integrator that is used to integrate the signals is used like an analog-to-digital converter of the double-integration type to convert the integral into a digital signal.

Abstract: A radiation dispersing cavity has its interior surface covered by a plurality of deformations, each of which acts as a dispersing element which is small with respect to the effective diameter of the cavity and yet large with respect to the wavelengths processed by the integrating cavity. The interior surface of the cavity is coated with a material which provides the proper reflectivity for the wavelengths of interest.

Abstract: A double-beam spectrophotometer which uses an integrating sphere for measurement of the total reflected light from a sample or only the diffuse reflection component thereof. The sphere is provided with a first pair of windows in which a sample and a reference are detachably and exchangeably set and a second pair of windows through one of which one of a sample and a reference light beam enters the integrating sphere so as to impinge perpendicularly on said sample or reference set in one of said first pair of windows, while through the other of said second pair of windows the other of said sample and reference light beams enters said integrating sphere to impinge aslant on said reference or sample set in the other of said first pair of windows. The positions of said sample and reference are exchanged in accordance with the type of measurement to be made.

Abstract: Apparatus and method for biological fluid analysis involving radiation measurement. The apparatus includes a pipetting dispenser having means for directing radiation from the piston thereof generally axially through the liquid in the pipette tube such that the pipetting dispenser serves not only as a means for measuring and mixing liquids, but also serves as a cuvette. The apparatus and method provide maximum radiation path length to accommodate liquids of different optical density. Still another feature of the apparatus and method is the provision of means for removing liquid from the outer surface of a pipette tube, which means are readily adapted to automated procedures. The apparatus in one embodiment is adapted for absorbance measurement of analyte samples, and in another embodiment is adapted for measurement of fluorescent radiation from analyte samples.

Abstract: In a reflectance measuring instrument, an integrating sphere is provided to illuminate the sample of which the reflectance is to be measured. A first fiber optic cable is provided to receive a light beam reflected by the sample and a second fiber optic cable is positioned to receive a light beam reflected from the wall of the integrating sphere. The transmitting ends of the fiber optic cables are mounted in a pivoted plate to selectively position the transmitting ends to emit light into the entrance slit of a monochromator.

Abstract: The color of gemstones or the like is assessed by projecting light onto the stone, using an interrupting member to regularly interrupt the path of the light shortly before it reaches the stone, the member having a normally white, diffusing interrupting surface, and using a detector for detecting the color of the light coming from the gemstone and from the interrupting surface of the interrupting member. Preferably, the stone is mounted in a chamber having normally white, diffusing internal walls and the diffusing interrupting surface is within the chamber.

Abstract: A system for measuring radiation in the laboratory or at a site to aid in determining whether to erect a solar energy installation at that site includes a positioner and a sensor. The sensor, which is mounted on the positioner, includes a rotating semispherical chopper and an integrating sphere for collecting radiation in three modes. A broad-band detector measures the irradiance from the integrating sphere to monitor for anomalies. A pair of monochromators simultaneously measure, one in the visible range and the other in the infrared range, the spectral irradiance from the integrating sphere. Processing electronics process the measured spectral irradiance from the monochromators and generate data signals for providing an absolute irradiance spectrum at the plane of the entrance aperture. The absolute irradiance spectrum is inputted to an X-Y plotter and a magnetic disc and tape. The system further includes internal reference sources providing continuous wavelength and irradiance calibration.