Abstract: An FTIR measurement is conducted on a background gas to obtain a single beam spectrum SB(BG) [C] and a synthetic single beam spectrum SSB(BG)[D], and an FTIR measurement is conducted on a sample gas to obtain a single beam spectrum SB(Samp)[E] and a synthetic single beam spectrum SSB(Samp)[F].

Abstract: The invention is directed to a system and method for detecting substances, such as explosives and/or drugs, using, in part, short bursts of energy light from a relatively low energy strobe. Embodiments include coupling the strobe with a detector for use in a portable hand-held unit, or a unit capable of being carried as a backpack. Embodiments further include placement of one or more stroboscopic desorption units and detectors in luggage conveyors systems, carry-on X-ray machines, and check-in counter locations.

Abstract: A method for detection of a peroxide-based compound includes directing ultraviolet light from an ultraviolet light source toward a location remote from the ultraviolet light source, where the ultraviolet light induces photodissociation of a peroxide-based compound located at the remote source into hydroxyl radicals and excitation of the hydroxyl radicals to fluoresce, capturing any fluorescence from the remote location that has been induced by the ultraviolet light directed from the ultraviolet light source toward the remote location, and analyzing the fluorescence that has been captured from the remote location to determine the presence of the peroxide-based compound at the remote location. A system for detection of a peroxide-based compound that performs such method steps is also described herein.

Abstract: An analysis system, tool, and method for performing downhole fluid analysis, such as within a wellbore. The analysis system, tool, and method provide for a tool including a spectroscope for use in downhole fluid analysis which utilizes an adaptive optical element such as a Micro Mirror Array (MMA) and two distinct light channels and detectors to provide real-time scaling or normalization.

Abstract: A process (300) is disclosed to measure predetermined wavelength reflectance spectra of a photo resist coated wafer (305,310,315,320) at a nominal thickness. After coating, the predetermined wavelength reflectance (325,330) is measured and the peak heights and valleys in the vicinity of the predetermined wavelength are tabulated. The relative swing ratio is computed (335) as the average peak height of the spectra at the exposure wavelength. This relative swing ratio is then compared to similar computations on other processes to determine which provides the best critical dimension (CD) control.

Abstract: An air quality instrumentation system for a concentrated solar power generation system using a fluid heat transfer medium includes a pipe, a window and a spectroscope. The pipe extends from the concentrated solar power generation system and contains system air from within the concentrated solar power generation system. The window is positioned within the pipe to permit light to pass through the pipe and the system air. The spectroscope is positioned adjacent the window to assess concentration of a constituent within the system air, the concentration of the constituent providing an indication of an operating condition of the concentrated solar power generation system.

Abstract: A spectrophotometer includes a plurality of LEDs arranged in a circular array, each having a calibrated power input determined by the use of pulse width modulation and each having a unique wavelength band determined by the utilization of a unique fluorescent phosphor coating or lens. At least one of the LEDs comprising a phosphor-free high energy UV LED. Light reflected to the spectrophotometer is divided into predetermined wavelength ranges through the utilization of a linear variable filter and photo detectors wherein the analog signal from a photo detector is converted to a digital value through the use of auto-ranging gain technique.

Abstract: Methods and apparati for fluorescence imaging using multiple excitation-emission pairs is revealed. A target object is illuminated by light in at least two spectral regions, causing fluorescence emission in at least two spectral regions. The emitted light is collected and separated for analysis.

Abstract: Emitting illumination light and auxiliary light having a wavelength range different from that of the illumination light onto an observation target simultaneously, obtaining an image formed of reflection light of the illumination light and reflection light of the auxiliary light reflected from the observation target, calculating, with respect to each pixel of the obtained image signal, estimated spectroscopic data in the wavelength range of the auxiliary light using a value of the image signal and estimated matrix data in the wavelength range of the auxiliary light stored in advance, obtaining quasi reflectivity information reflecting a reflectivity of the observation target in the wavelength range of the auxiliary light based on the estimated spectroscopic data in the wavelength range of the auxiliary light, and generating a special image based on the quasi reflectivity information.

Abstract: The invention discloses a multi-wavelength semiconductor light source comprising a plurality of semiconductor light sources mounted on a silicon sub-carrier and emitting radiation spanning a wavelength range. In preferred embodiments, these sources are configured in a linear and circular array. The radiation is coupled to a waveguide array disposed on the same silicon subcarrier, with a lower cladding of silicon dioxide and deposited core layer which is preferably the spin-on epoxy resin SU-8. Output from the waveguide array provides a compact multi-wavelength laser source with wide tuning range via a plurality of laser sources. An output spatial span of the waveguide array is smaller than an input spatial span and sufficiently small to probe the properties of a sample.

Abstract: A method and system for simultaneously measuring strain and temperature characteristics of an object involves the attachment to the object of a pair of optical fibers having different refractive indices, the fibers being connected together at least one end thereof, and directing laser light into at least one end of the fibers. The Brillouin frequency of each of the fibers is measure and the strain and temperature characteristics are calculated based on the coefficients of strain and temperature and the measured Brillouin frequencies of the fibers.

Abstract: A Method for identifying one or a small number of molecules, especially in a dilution of ?1 ?M, using laser excited FCS with measuring times ?500 ms and short diffusion paths of the molecules to be analyzed, wherein the measurement is performed in small volume units of preferably ?10?14 l, by determining material-specific parameters which are determined by luminescence measurements of molecules to be examined. The device which can be preferably used for performing the method according to the invention is a per se known system of microscope optics for laser focusing for fluorescence excitation in a small measuring compartment of a very diluted solution and for imaging the emitted light in the subsequent measurement through confocal imaging wherein at least one system of optics with high numerical aperture of preferably ?1.2 N.A.

Abstract: A chemical imaging and process monitoring device which utilizes a computer controlled tunable laser to provide light at discrete wavelengths in the near infrared band and a focal plane array to image or a single-point photo detector to detect the intensity of light reflected from a sample illuminated at various wavelengths of light. The device also provides light intensity reference detectors at the source and terminus of the light delivery pathway for normalizing the collected data and for detecting defects in the light delivery pathway.

Abstract: Spectral information may be employed in process control and/or quality control of goods and articles. Spectral information may be employed in process control and/or quality control of media, for example financial instruments, identity documents, legal documents, medical documents, financial transaction cards, and/or other media, fluids for example lubricants, fuels, coolants, or other materials that flow, and in machinery, for example vehicles, motors, generators, compressors, presses, drills and/or supply systems. Spectral information may be employed in identifying biological tissue and/or facilitating diagnosis based on biological tissue.

Abstract: A chemical imaging device which utilizes a computer controlled tunable laser to provide light of wavelengths in the near infrared band and a focal plane array to image a sample illuminated at various wavelengths of light. The device also provides light intensity reference detectors at the source and terminus of the light delivery pathway for normalizing the collected images and for detecting defects in the light delivery pathway.

Abstract: Method and apparatus for spectrophotometric characterization of turbid materials are provided. An incident light beam is used to illuminate a turbid material sample and optical signals of coherent reflectance, diffuse reflectance, collimated transmittance and diffuse transmittance are measured from the sample as functions of wavelength. The following optical parameters are determined as functions of wavelength for spectrophotometric characterization of the turbid material sample in the spectrum of interest: absorption coefficients ?a, scattering coefficient ?s, anisotropy factor g and real refractive index n.

Abstract: A spectrophotometer, in which an emission spectrum of the light source is measured. Based on the measured emission spectrum, a threshold is set to allow only an outstanding spectral intensity in a specific wavelength region to be greater than the threshold. Then, a ratio between the setup threshold and a peak spectral intensity in the specific wavelength region greater than the threshold is calculated. Then, an electric-charge accumulation time for a light-receiving element corresponding to a wavelength region equal to or less than the threshold is set at an upper limit of electric-charge accumulation time causing no saturation in any light-receiving element. Based on the ratio between the threshold and the peak spectral intensity in the specific wavelength region greater than the threshold, an electric-charge accumulation time for the light-receiving element corresponding to the specific wavelength region greater than the threshold is set.

Abstract: A first light source has a first wavelength corresponding to an excitation wavelength of a fluorophore. The excitation wavelength and an emission wavelength of the fluorophore delineate a predetermined interval. A second light source has a second wavelength offset with respect to the first wavelength so as to be outside said predetermined interval. The offset between the first and second wavelengths is comprised between 30 nm and 100 nm. A camera comprises a filter opaque to the first and second wavelengths and transparent to the emission wavelength and to wavelengths substantially higher than the higher of the first and second wavelengths. The light sources and camera are synchronized to alternately activate one of the light sources and make the camera alternately acquire a fluorescence image and a background noise image.

Abstract: Detection sensitivity is improved by increasing the amount of light of beams that irradiate a sample cell without causing saturation of a detector with ultraviolet beams or visible beams. This spectrophotometer includes a sample cell, which stores a sample to be measured, a visible light source and an ultraviolet light source each for supplying an incident beam that enters the sample, a spectroscope, which disperses a beam that has passed through the sample, an optical detector, which detects beams dispersed from such beam (spectrum), and a dichroic element which reflects or transmits ultraviolet beams from the ultraviolet light source and which transmits or reflects visible beams from the visible light source. Optics are configured such that ultraviolet beams and visible beams that have passed through or have been reflected by the dichroic element enter the sample cell.

Abstract: A method and apparatus for calibrating an NIRS system which includes a sensor portion (42) and for evaluating an NIRS system for proper functioning is provided that includes an enclosure (40) with at least two windows (16,18) disposed in a wall of the enclosure (40) The windows (16,18) allow the light source (22) and one or more detectors (24) of an NIRS system sensor (42) to interface with the enclosure (40) One window (16) is dedicated to the light source (22) while each light detector (24) has a window (18) dedicate thereto Thus, the enclosure (40) includes a number of windows (16,18) equal to the number of light detectors (24) in the NIRS system sensor plus one The inner surface of the wall(s) of the enclosure (40 is of a light-absorbing color, e.g., black A diffuse reflectance member (28) of a light-reflecting color, e.g.

Abstract: Objects such as manufactured goods or articles, works of art, media such as identity documents, legal documents, financial instruments, transaction cards, other documents, and/or biological tissue are sampled via sequential illumination in various bands of the electromagnetic spectrum, a test response to the illumination is analyzed with respect to reference responses of reference objects. The sequence may be varied. The sequence may define an activation order, a drive level and/or temperature for operating one or more sources. Illumination may be in visible, infrared, ultraviolet, or other portions of the electromagnetic spectrum. Elements of the evaluation system may be remote from one another, for example coupled by a network.

Abstract: A spectral photometer intended for integration purposes includes a measurement head equipped with illumination arrangement including at least one light source for the illumination at an angle of incidence of 45° of a measured object and located in a measurement plane, a pickup arrangement for capturing the measurement light remitted by the measured object at an angle of reflection of essentially 0° relative to the perpendicular to the measurement plane, a spectrometer arrangement including an entry aperture for the spectral splitting of the measurement light captured and fed through the entry aperture, and a photoelectric receiver arrangement exposed to the split measurement light for conversion of the individual spectral components of the measurement light into corresponding electrical signals. It further includes an electronic circuit for control of the light source and forming digital measurement values from the electrical signals produced by the photoelectric receiver arrangement.

Abstract: An imaging apparatus for obtaining spectral image data from an object that includes: a) a light source; b) an input optics section; c) a programmable spectral filter that conditions the multispectral image bearing light according to a predetermined spectral transmission function; d) a detector array in the path of the conditioned multispectral image bearing light and providing a corresponding output signal; and, e) a control logic processor in communication with the spatial light modulator for modulating addressable areas of the spatial light modulator to provide the spectral transmission function thereby.

Abstract: The disclosure generally relates to a multimode imaging apparatus for simultaneously obtaining multiple wavelength-discriminative spectral images of a sample.

Abstract: An optical apparatus in which multiplexed holograms are used to achieve wavelength selectivity and polarization manipulation is used to facilitate near-normal incidence of light on the holograms. The polarization manipulation allows light reflected from the holograms to be separated from the light incident on the holograms. In one application, the apparatus can be used to extract spectral lines of an analyte from radiation scattered from a sample.

Abstract: A wavelength correction function provides corrected reflectance values from actual reflectance values taken in a reflectance-base instrument. The correction is provided as a function of measured reflectance values and a predefined set of high resolution reflectance values established for the reflectance-based instrument implementing the wavelength correction function.

Abstract: A Method for identifying one or a small number of molecules, especially in a dilution of ?1 ?M, using laser excited FCS with measuring times ?500 ms and short diffusion paths of the molecules to be analyzed, wherein the measurement is performed in small volume units of preferably ?10?14 l, by determining material-specific parameters which are determined by luminescence measurements of molecules to be examined. The device which can be preferably used for performing the method according to the invention is a per se known system of microscope optics for laser focusing for fluorescence excitation in a small measuring compartment of a very diluted solution and for imaging the emitted light in the subsequent measurement through confocal imaging wherein at least one system of optics with high numerical aperture of preferably ?1.2 N.A.

Abstract: In order to improve spectral measurement accuracy during high-speed wavelength shifting, the appropriate sensitivity of the detection system is maintained by, prior to measurement of a sample, measuring the voltage value, then storing this value into a table, and maintaining the voltage value to be applied to the photodetector, and during measurement of the sample, reading out the maintained voltage value and applying it to the photodetector.

Abstract: The inventive bioprocessing system (and technique) relies on non-invasive optical chemical sensing technology wherein an optical excitation source excites an optical chemical sensor. The optical chemical sensor then emits luminescence or absorbs light which is measured by a detector. The luminescence emitted from the chemical sensor or the amount of light absorbed by the chemical sensor is related to the concentration of an analyte, such as oxygen. If the luminescence emitted changes, or if the amount of light absorbed changes, then the concentration of the analyte has changed. Using such a system to measure and adjust multiple parameters at one time allows one to efficiently and cost-effectively determine optimal conditions for a given cell type and/or cell environment, for example.

Abstract: A method is described that includes measuring, at each of a set of W wavelength bins, a spectral response of at least one region of a sample stained with multiple stains, and determining the concentration of at least one of the stains in the region of the sample based in part on the spectral responses, the wavelength bins being chosen so that a matrix of elements that represent the responses of the stains at the wavelength bin has an inverse for which a mathematical stability is maximum relative to the inverses of other matrices of elements that represent the responses of the stains for other possible sets of wavelength bins.

Abstract: An illumination subsystem for use in optical analysis which provides spatially and angularly homogenized radiation to the sample being analyzed. The system eliminates the illumination system as an interferent in the overall optical analysis. Thus, modest translations or rotations of the illumination source or changing the illumination source does not require recalibration of the instrument or prior modeling of illumination variability due to such changes. Illumination stability is achieved by incorporating a light pipe which both angularly and spatially homogenizes the light. Further, a series of filters and/or lenses are incorporated to provide bandpass filtering which eliminates unwanted wavelengths or bands of wavelengths from contacting the tissue and allows for a higher signal-to-noise ratio when the sample is tissue, while preventing thermal damage.

Abstract: The invention is concerned with a method for the determination of the charging state of filtrates of fiber masses used in the manufacturing of paper and cardboard. In the method, a sample is filtrated from fibers through a filter, and indicator color is added to the filtrate. The absorbance of the filtrate is measured and the charging state of the solution is read from an earlier made calibration curve that corresponds to the measured absorbance. In the first embodiment of the invention, the calibration curve is made by taking a sufficient amount of samples from the same anionic sample and such different known amounts of cationic agent are added to these samples, that at least a part of the samples are cationic and at least a part of the samples are anionic. The charging states of the filtrated samples are determined in a previously known way, e.g.

Abstract: Systems and methods for filter based spectrographic analysis are provided that permit rapid analysis of bioanalytes. Systems include devices for illuminating a sample with electromagnetic radiation and capturing radiation emitted from the sample. Emitted radiation can be collected by a plurality of waveguides each associated with a filter for a particular wavelength of radiation. Focusing devices are associated with filters and waveguides in certain embodiments. Radiation captured by waveguides can then be transmitted to a remote detector, which can determine the intensity of radiation for each waveguide. The use of a plurality of filters having different, band pass characteristics can permits the simultaneous detection of a plurality of different wavelengths of radiation emitted by a sample, thereby providing spectrographic information about the sample under study. Systems can include computers for storing acquired spectrographic information, addressable arrays of samples, and information security measures.

Abstract: A surface plasmon resonance apparatus for detecting a soluble analyte (e.g. a protein) or a particulate analyte (e.g. a cell), the apparatus comprising: (a) a sensor block adapted to receive a sensor, said sensor, for example a sensor slide, having a metallized sensor surface capable of binding the analyte; (b) a light source capable of generating an evanescent wave at the sensor surface of a sensor slide on the sensor block; (c) a first detector capable of detecting light from the light source which is internally reflected from the sensor surface; and (d) a second detector (e.g. a video camera) capable of detecting light scattered or emitted from an analyte bound thereto. Optionally the apparatus further comprises a second light source for increasing the intensity of the light scattered or emitted from an analyte bound to the sensor surface, preferably, this is sited to such as to minimize the amount of light transmitted therefrom which is detected by the first detector.

Abstract: An improved and lower cost color spectrophotometer, especially suitable for on-line color printer color control systems, incorporating a low cost commercial imaging chip, which normally only forms part of a three row, three color, document imaging bar used for imaging documents in scanners, digital copiers, or multifunction products, having multiple photo-sites with at least three different color filters in three rows. This multiple photo-sites chip may be modified to also provide unfiltered photo-sites. This spectrophotometer may have a substantially reduced number of different LED or other spectral illumination sources, one of which may be for white light, yet provide multiple spectral data outputs from the differently filtered photo-sites being simultaneous illuminated by the light reflected from a color test target area which is being sequentially illuminated by the respective limited number of LEDs, enabling broad spectrum information and color control.

Abstract: A side-entry excitation arrangement is provided with a multi-channel analyte-separation device. In various embodiments, a plurality of channels are disposed in an array, with a laser disposed to direct an excitation beam of light along a beam path that crosses the longitudinal axes of the channels, so as to simultaneously irradiate a region of each of the channels. Devices of the invention can be useful, for example, in the separation and analysis of bio-molecules, such as DNA, RNA, etc.

Abstract: A color spectrophotometer incorporating a low cost commercial imaging chip, which normally forms part of a document imaging bar used for imaging documents in scanners, etc., having multiple photo-sites with three different rows of color filters. Each chip is mounted on the optical axis of an imaging lens system, in the image plane of that lens system, to image the reflected illumination from an illuminated color test target area on the chip. The optical axis of the imaging lens system is oriented at 45° to the illuminated color test patches, and the photodetector chip is physically mounted perpendicular to the plane of the illuminated color test patches. Respective photo-sensor chips and associated 1:1 optics may be mounted on opposing sides of the spectrophotometer physically oriented at 90° to the test target area plane receiving the reflected light from the test target optically oriented at 45° to the illuminated test target.

Abstract: A device determines and subsequently corrects the dispersive influence on a measurement made according to the principles of phase or pulse modulation along a visible range. The device has an element for emission of electro-magnetic radiation with two carrier wavelengths in the border regions of the visible spectrum. After passing through a volume of atmosphere to be probed, and reflection, the radiation is received and the dispersive influence, for instance, on the distance measurements, is calculated and corrected.

Abstract: A spectrometer or multiple wavelength absorbance detection method and apparatus providing improved accuracy for an array of measurements at different wavelengths. The spectrometer utilizes a multiple wavelength illumination system with an array of independent detectors with different pathlength cells, where each cell is illuminated with predominately monochromatic light after separation by a light dispersing element. Each sample cell has an optical pathlength, optics and photodetection device that are optimized for its particular wavelength to accurately measure absorbance through an expected substance.

Abstract: A water monitoring system for a nuclear reactor is provided. In an exemplary embodiment, the water monitoring system includes a fiber optic cable having a first end and a second end, with the first end configured to optically couple to the reactor cooling water distribution system, and at least one laser light source optically coupled to the second end of the fiber optic cable. The water monitoring system also includes a spectrophotometer optically coupled to the second end of the fiber optic cable.

Abstract: Apparatus and method for measuring concentration of a component of target material including a pumping light source for emitting light; a first wavelength conversion unit for converting and outputting the light; a first beam splitting unit for splitting the converted light and directing a first light beam at the target material; a reference light generator for converting a second light beam to be parallel, dividing the parallel light beam by wavelengths, and outputting the result as reference light; a first collimating unit for converting light transmitted through the target material to be parallel and outputting the parallel light; a light intensity measuring unit for measuring the intensity of light from the first collimating unit and the reference light, by wavelengths, using the reference light; and a concentration measuring unit for measuring the concentration of the component based on the intensities measured by the light intensity measuring unit by wavelengths.

Abstract: The present invention provides methods for measuring a photosynthetic parameter. The methods of the invention include the steps of: (a) illuminating a plant leaf until steady-state photosynthesis is achieved; (b) subjecting the illuminated plant leaf to a period of darkness; (c) using a kinetic spectrophotometer or kinetic spectrophotometer/fluorimeter to collect spectral data from the plant leaf treated in accordance with steps (a) and (b); and (d) determining a photosynthetic parameter from the spectral data. In another aspect, the invention provides methods for determining the physiological state of a plant.

Abstract: An improved and lower cost color spectrophotometer, especially suitable for on-line color printer color control systems, incorporating a low cost commercial imaging chip, which normally only forms part of a three row, three color, document imaging bar used for imaging documents in scanners, digital copiers, or multifunction products, having multiple photo-sites with at least three different color filters in three rows. This multiple photo-sites chip may be modified to also provide unfiltered photo-sites. This spectrophotometer may have a substantially reduced number of different LED or other spectral illumination sources, one of which may be for white light, yet provide multiple spectral data outputs from the differently filtered photo-sites being simultaneous illuminated by the light reflected from a color test target area which is being sequentially illuminated by the respective limited number of LEDs, enabling broad spectrum information and color control.

Abstract: An improved and lower cost color spectrophotometer, especially suitable for on-line color printer color control systems, incorporating a low cost commercial imaging chip, which normally only forms part of a three row, three color, document imaging bar used for imaging documents in scanners, digital copiers, or multifunction products, having multiple photo-sites with at least three different color filters in three rows. This multiple photo-sites chip may be modified to also provide unfiltered photo-sites. This spectrophotometer may have a substantially reduced number of different LED or other spectral illumination sources, one of which may be for white light, yet provide multiple spectral data outputs from the differently filtered photo-sites being simultaneous illuminated by the light reflected from a color test target area which is being sequentially illuminated by the respective limited number of LEDs, enabling broad spectrum information and color control.

Abstract: A method for identifying one or a small number of molecules, especially in a dilution of ≦1 &mgr;M, using laser excited FCS with measuring times ≦500 ms and short diffusion paths of the molecules to be analyzed, wherein the measurement is performed in small volume units of preferably ≦10−14 l, by determining material-specific parameters which are determined by luminescence measurements of molecules to be examined.

Abstract: Disclosed herein are methods and apparatuses for sequencing a nucleic acid. These methods permit a very large number of independent sequencing reactions to be arrayed in parallel, permitting simultaneous sequencing of a very large number (>10,000) of different oligonucleotides.

Abstract: A color spectrophotometer incorporating a low cost commercial imaging chip, which normally forms part of a document imaging bar used for imaging documents in scanners, etc., having multiple photo-sites with three different rows of color filters. Each chip is mounted on the optical axis of an imaging lens system, in the image plane of that lens system, to image the reflected illumination from an illuminated color test target area on the chip. The optical axis of the imaging lens system is oriented at 45° to the illuminated color test patches, and the photodetector chip is physically mounted perpendicular to the plane of the illuminated color test patches. Respective photo-sensor chips and associated 1:1 optics may be mounted on opposing sides of the spectrophotometer physically oriented at 90° to the test target area plane receiving the reflected light from the test target optically oriented at 45° to the illuminated test target.

Abstract: Method and apparatus for detecting biomolecular interactions. The use of labels is not required and the methods may be performed in a high-throughput manner. An apparatus for detecting biochemical interactions occurring on the surface of a biosensor includes a light source. A first optical fiber is coupled to the light source and illuminates the biosensor. A second optical fiber detects a wavelength reflected from the biosensor. A spectrometer determines spectra of a reflected signal from the biosensor.

Abstract: Systems and methods for analyzing a sample are disclosed. The system may include a light source operable to transmit light onto the sample, a detector operable to detect intensity of the light emitted from the sample, and a power modulator. The power modulator modulates the light source power such that light is emitted from the light source in more than one mode to reduce changes in the emitted light due to temperature changes in the light source.

Abstract: A color spectrophotometer incorporating a low cost commercial imaging chip, which normally forms part of a document imaging bar used for imaging documents in scanners, etc., having multiple photo-sites with three different rows of color filters. Each chip is mounted on the optical axis of an imaging lens system, in the image plane of that lens system, to image the reflected illumination from an illuminated color test target area on the chip. The optical axis of the imaging lens system is oriented at 45° to the illuminated color test patches, and the photodetector chip is physically mounted perpendicular to the plane of the illuminated color test patches. Respective photo-sensor chips and associated 1:1 optics may be mounted on opposing sides of the spectrophotometer physically oriented at 90° to the test target area plane receiving the reflected light from the test target optically oriented at 45° to the illuminated test target.