Abstract: A calibration assembly employs a thermoelectric cooler to provide a calibration temperature for one calibration flag and a different calibration temperature for a second calibration flag. Either calibration flag is immediately available for insertion into the optical path when calibration of the thermal imaging device is required. Consequently, the time required to calibrate a thermal imaging device within a thermal imaging system is greatly reduced.

Abstract: A method for determining magnitude and direction of spectral channel drift for several consecutive spectral regions over a wide spectral range. According to the method of the present invention, in-field testing of a spectral filter sequentially irradiated by two blackbody sources is performed to generate a response function of the spectral filter. The response function is ensemble averaged to reduce any noise. Background radiance is then removed to produce a smoothed spectral transmittance function of the spectral filter. The first derivative function of the smoothed spectral transmittance function is determined. The first derivative function is separated into spectral band regions having +/− N pixels on either side of the function minima. The value of N is selected to optimize the detection algorithm sensitivity to change while extending the limit of spectral shift magnitude.

Abstract: Systems and methods for infrared sensing a compound's concentration in aqueous solution are provided. In various non-limiting embodiments, the invention provides infrared sensing of methanol's concentration in aqueous solution in connection with a fuel circulation process for a direct methanol fuel cell. In some embodiments, flow-through infrared sensing technique are provided. In other embodiments, window type infrared sensing techniques are provided. As a result of the infrared sensing, an accurate real-time measurement of the concentration of a compound of interest in aqueous solution is affordably obtained.

Abstract: A method for quantitative imaging of gas emissions utilizing optical techniques combining gas correlation techniques with thermal background radiation or gas self-emission radiation is presented. A simultaneous recording of images with and without filtering through a gas-filled cell is utilized for the identification of a selected gas. A new calibration method provides the display of the integrated gas concentration spatially resolved in the generated final image. The procedure includes methods for a correct subtraction of the zero level, consisting of self-radiation from the dual-image camera device including the as correlation cell and electronic offset, and for the calculation of the specific absorption as a function of the difference temperature between the background and the gas emission.

Abstract: A method for identification and partial-pressure determination of two gases in an unknown anesthesia gas mixture comprising n possible gases by measuring the infrared optical radiation, transmitted through the gas mixture, that passes through m filters having different transmission wavelength ranges, in which n is a number greater than 2 and m is a number less than n. The method evaluates the exit intensities, measured after passage through the filters, of the infrared optical radiation transmitted through the unknown gas mixture in such a way that with three filters, for instance, two gases in an unknown gas mixture comprising five possible gases can be identified, and their partial pressures can be determined. By dividing the partial pressures by the total pressure, it is optionally also possible to determine the concentration of the gases.

Abstract: The invention comprises a method of adapting derivative spectrometry for use in a downhole environment and addresses problems that are inherent in this environment. Such problems include, but are not limited to, elevated temperatures and scattering from particles residing within dirty fluid samples. The invention improves the resolution by measuring the first derivative of the spectrum. The derivative spectrometer of this invention operates by vibrating a linear variable interference filter back and forth along the plane of the filter or by oscillating a circular variable filter about some angle.

Abstract: A process for monitoring and/or controlling a nitrating process, having the following steps:

Abstract: The present invention is a dispersive, diffraction grating, NIR spectrometer that automatically calibrates the wavelength scale of the instrument without the need for external wavelength calibration materials. The invention results from the novel combination of: 1) a low power He—Ne laser at right angles to the source beam of the spectrometer; 2) a folding mirror to redirect the collimated laser beam so that it is parallel to the source beam; 3) the tendency of diffraction gratings to produce overlapping spectra of higher orders; 4) a “polka dot” beam splitter to redirect the majority of the laser beam toward the reference detector; 5) PbS detectors and 6) a software routine written in Lab VIEW that automatically corrects the wavelength scale of the instrument from the positions of the 632.8 nm laser line in the spectrum.

Abstract: Methods and apparatus for compensating a radiation sensor for temperature variations of the sensor. In one example, the radiation sensor is a thermal sensor having at least one property that varies as a function of temperature. The thermal sensor outputs signals based on thermal radiation of interest from a particular radiating body in its view. These signals may contain significant undesirable components due in part to changes in temperature of the sensor itself. Methods and apparatus of the invention compensate the sensor for temperature variations of the sensor that are not due to the radiation of interest, so as to significantly reduce undesirable components in the instantaneous signals output by the sensor. In one example, this is accomplished without thermally stabilizing the sensor itself (i.e., dynamic temperature compensation).

Abstract: The invention relates to a method and an apparatus for measuring a coating from paper or board. The measurement is carried out by one detector at different times or by two detectors simultaneously. IR radiation directed at the coating and radiation emerging from the coating are chopped synchronously in blocks. A wavelength band sensitive and insensitive to the absorption are bandpass filtered and measured in both the MIR and NIR region. The absorption strength is measured in a digital signal processing block by comparing the radiation sensitive to absorption to the radiation insensitive to absorption, and the amount of each coating component is determined in the digital signal processing block on the basis of the absorption strength.

Abstract: The invention relates to a method for detecting a test gas that may be present at a measuring location, using an infrared gas analyser (1) that comprises a cuvette (2), an infrared light source (3), an infrared detector (4), and two gas lines (15, 17). Said gas lines supply gases to the infrared gas analyser and one of said lines is adapted to take up a measuring gas at a measuring location that may contain a test gas. The second line (17) is adapted to take up gas from the surroundings of the measuring location (reference gas), which gas may contain a test gas background that is to be taken into consideration when detecting the test gas taken up at the measuring location. In order to improve the sensitivity of the analyser it comprises only one cuvette (2) and the measuring gas taken up at the measuring location and the reference gas are fed to the cuvette of the infrared gas analyser in such a manner that they are alternately present in the cuvette.

Abstract: An apparatus (10) for analyzing lubricant oils and functional fluids includes an optical emission spectrometer (OES) (26) having a substantially continuously valued wavelength versus intensity output (140). The OES (26) analyzes light captured from a spark emission stand (58) through which the fluid sample is flowed. An expert system (160-172) operates according to a set of Rules, and generates diagnostic text (174) for an operator based on the information about the fluid sample provided by the OES (26) and other measurement devices. The apparatus (10) is reduce in size, weight and cost.

Abstract: A method for dynamically calibrating automatic infrared sensing devices in commercial use having an IR detector. Randomly reflected emitted IR radiation is detected by the IR detector which sends as IR detector output to a control module. The control module measures whether the detector output is too high or too low compared to a standard range of output values stored in the control module. An IR emitter input value is then determined to maintain IR detector output within the standard output range of values. This IR emitter input value is stored in the control module as a calibration standard until the next calibration cycle.

Abstract: A method for spectroscopically determining the concentration of alcohols with 1 to 5 carbon atoms, especially ethanol, in liquid probes, especially alcohol-containing food products, healing preparations, cosmetic products and the like. The absorption of light by the probe is measured at at least one wave length in the range of 1100 nm to 1300 nm, and preferably in the range of 1150 nm to 1250 nm. The alcohol concentration is determined from the measured absorption with the help of a calibration. The alcohol content of a liquid probe can be determined in a simple and fast manner and over a large concentration range.

Abstract: In accordance with the present invention, a microbolometer focal plane array is provided with at least one thermally-shorted microbolometer detector that is thermally shorted to the microbolometer focal plane array substrate. A characteristic relationship is empirically derived for determining a corrected resistance value for each detector of the microbolometer focal plane array in response to radiation from a target scene as a function of the corresponding detector resistance value, the thermally-shorted microbolometer detector resistance value, and the empirically derived characteristic relationship.

Abstract: Using a nebulizer gas, sub micron and micron size particulates can be generated from a solution containing salts covering a broad range of elements. The fractional concentration of elements can be determined by bubbling the aerosol through aqueous acid and analyzing the aqueous acid for metals. The nebulizer can be coupled to an ICP (Inductively Coupled Plasma) torch and the ICPMS (Inductively Coupled Plasma Mass Spectrometer) or ICPOES (Inductively Coupled Plasma Optical Emission Spectrometer) response to different elements can be determined. This provides the response factor of the ICPMS or ICPOES for different elements.

Abstract: The invention provides a method for measuring PFC components in a discharged gas with ease and good reproducibility, using an FT-IR. The method for measuring greenhouse gases using an infrared absorption spectrometer in accordance with the present invention includes the steps of selecting a process chemical material, selecting a measurement target chemical material corresponding to the process chemical material, designating expected concentration ranges for the process chemical material and the measurement target chemical material, selecting libraries for the respective expected concentration ranges for the process chemical material and the measurement target chemical material, and analyzing data obtained by a gas infrared absorption spectrometry based on the libraries.

Abstract: A method for controlling the production of formaldehyde resin compositions in which formaldehyde takes part in a reaction with one or a combination of co resin forming material (of the type phenol, urea, melamine) the method includes monitoring at least one of the formation of the reaction mixture and the course of the reaction by near-infrared (NIR) spectroscopy and adjusting the course of the reaction (when necessary) in accordance with the results of the spectroscopy to obtain optimum conditions for the reaction.

Abstract: A method uses spectroscopy to determine an analyte concentration in a sample. The method includes producing an absorbance spectrum of the sample. The method further includes shifting the absorbance spectrum to zero in a wavelength region. The method further includes subtracting a water or other substance contribution from the absorbance spectrum.

Abstract: This invention teaches a method to identify cellular abnormalities which are associated with disease states. The method utilizes infrared (IR) spectra of cell samples which are dried on an infrared-transparent matrix and scanned at the frequency range from 3000-950 cm−1. The identification of samples is based on establishing a reference using a representative set of spectra of normal and/or diseased specimens. During the reference assembly process, multivariate techniques such as Principal Component Analysis (PCA) and/or Partial Least Squares (PLS) are used. PCA and PLS reduce the data based on maximum variations between the spectra, and generate clusters in a multidimensional space representing the different populations. The utilization of Mahalinobis distances, or linear regression (e.g., Principle Component Regression on the reduced data from PCA) form the basis for the discrimination.

Abstract: A photoacoustic spectroscopy method and apparatus for maintaining an acoustic source frequency on a sample cell resonance frequency comprising: providing an acoustic source to the sample cell, the acoustic source having a source frequency; repeatedly and continuously sweeping the source frequency across the resonance frequency at a sweep rate; and employing an odd-harmonic of the source frequency sweep rate to maintain the source frequency sweep centered on the resonance frequency.

Abstract: An apparatus and method for using &agr;-particle energy loss to measure the thickness and stoichiometry of films grown by molecular beam epitaxy and other methods. The apparatus for measuring the thickness of films grown on a substrate in a growth chamber, comprises a protective housing having an aperture opening into the growth chamber, a solid state detector disposed in the protective housing, a shutter for opening and closing the aperture, a shield disposed in the housing between the aperture and the solid state detector for shielding the detector, and a calibration source disposed between the shield and the detector for calibrating the measurements made by the detector. A second calibration source disposed between the shutter and the shield, for measuring deposition on the shield.

Abstract: A qualitative analysis is carried out by first storing reference spectral line data of various elements in different compound forms, exciting a sample and spectroscopically analyzing signal light emitted from the sample to obtain measured spectral line data, determining whether these measured spectral line data include spectral lines of specified compound-forming elements, and comparing the reference spectral line data with the measured spectral line data, if the measured spectral line data are found to include spectral lines of any of the compound-forming elements, to thereby identify elements in the sample.

Abstract: The effects of unwanted components such as H2O and CO2 in spectral data measured by a spectrometer such as an FT-IR spectrometer are suppressed by a technique in which data representing high resolution spectra of the unwanted component is acquired, this data is modified so that its resolution matches that of the instrument, the results data is filtered to allow for perturbing effects of the sample and the resulting data is subtracted from the measured sample sectrum to provide corrected output data.

Abstract: A photoacoustic spectroscopy method and apparatus for maintaining an acoustic source frequency on a sample cell resonance frequency comprising: providing an acoustic source to the sample cell to generate a photoacoustic signal, the acoustic source having a source frequency; continuously measuring detection phase of the photoacoustic signal with respect to source frequency or a harmonic thereof; and employing the measured detection phase to provide magnitude and direction for correcting the source frequency to the resonance frequency.

Abstract: A method for determining the dry mechanical strength for a green wood comprising: illuminating a surface of the wood to be determined with light between 350-2,500 nm, the wood having a green moisture content; analyzing the surface using a spectrometric method, the method generating a first spectral data, and using a multivariate analysis to predict the dry mechanical strength of green wood when dry by comparing the first spectral data with a calibration model, the calibration model comprising a second spectrometric method of spectral data obtained from a reference wood having a green moisture content, the second spectral data correlated with a known mechanical strength analytical result obtained from a reference wood when dried and having a dry moisture content.

Abstract: The invention relates to a process and an apparatus for identifying articles which are at least partly made from at least one polymer, using an optical spectrometer and a transport system, said process comprising the steps of:

Abstract: A procedure is described to calibrate an optical converter, especially for use in the field of reflectrometric interference spectroscopy. The converter has a layer/substrate system with a layer and a substrate. A light beam shines from the substrate side, and parts of it are reflected or transmitted at the interfaces of air/substrate, substrate/layer and layer/air. The converter in particular serves to convert the light beam into a modulated (especially frequency modulated or phase modulated) signal. The light is varied within a wavelength or frequency range from which a corresponding modulated spectrum is determined. In particular, it is assumed that the performance quantities of especially the converter and a radiation source generating the light are subject to temporal fluctuations.

Abstract: The effects of unwanted components such as H20 and CO2 in spectral data measured by a spectrometer such as an FT-IR spectrometer are suppressed by a technique in which data representing high resolution spectra of the unwanted component is acquired, this data is modified so that its resolution matches that of the instrument, the results data is filtered to allow for perturbing effects of the sample and the resulting data is subtracted from the measured sample sectrum to provide corrected output data.

Abstract: A method and apparatus for non-invasively measuring a biological attribute, such as the concentration of an analyte, particularly a blood analyte in tissue such as glucose. The method utilizes spectrographic techniques in conjunction with an improved subject-tailored calibration model. In a calibration phase, calibration model data is modified to reduce or eliminate subject-specific attributes, resulting in a calibration data set modeling within- subject physiological variation, sample location, insertion variations, and instrument variation. In a prediction phase, the prediction process is tailored for each target subject separately using a minimal number of spectral measurements from each subject.

Abstract: A thermal imager system for use in a vehicle utilizes an uncooled microbolometer detector array (19), optics (13) for conducting scene radiation to the array within a sensor module (12) which is separate from an image processing and display unit (39), to provide a small, direct view sensor module (12) that may be oriented for forward viewing. The sensor module (12) is mounted external to the vehicle and the image processing and display unit (39) is mounted internal to the vehicle, and the two are connected by a noise immune bidirectional digital communication path or harness (37). The optics (13) consist exclusively of refractive optical components (14, 16) providing a straight line radiation path from the scene to the array (19).

Abstract: The effects of unwanted components such as H2O and CO2 in spectral data measured by a spectrometer such as an FT-IR spectrometer are suppressed by a technique in which data representing high resolution spectra of the unwanted component is acquired, this data is modified so that its resolution matches that of the instrument, the results data is filtered to allow for perturbing effects of the sample and the resulting data is subtracted from the measured sample sectrum to provide corrected output data.

Abstract: A method for quantitative imaging of gas emissions utilizing optical techniques combining gas correlation techniques with thermal background radiation or as self-emission radiation is presented. A simultaneous recording of images with and without filtering through a gas-filled cell is utilized for the identification of a selected gas A new calibration method provides the display of the integrated gas concentration spatially resolved in the generated final image. The procedure includes methods for a correct subtraction of the zero level, consisting of self-radiation from the dual-image camera device including the as correlation cell,, and electronic offset, and for the calculation of the specific absorption as a function of the difference temperature between the background and the gas emission.

Abstract: In accordance with the present invention, a microbolometer focal plane array is provided with at least one thermally-shorted microbolometer detector that is thermally shorted to the microbolometer focal plane array substrate. A characteristic relationship is empirically derived for determining a corrected resistance value for each detector of the microbolometer focal plane array in response to radiation from a target scene as a function of the corresponding detector resistance value, the thermally-shorted microbolometer detector resistance value, and the empirically derived characteristic relationship.

Abstract: An apparatus (10) for analyzing lubricant oils and functional fluids includes an optical emission spectrometer (OES) (26) having a substantially continuously valued wavelength versus intensity output (140). The OES (26) analyzes light captured from a spark emission stand (58) through which the fluid sample is flowed. An expert system (160-172) operates according to a set of Rules, and generates diagnostic text (174) for an operator based on the information about the fluid sample provided by the OES (26) and other measurement devices. The apparatus (10) is reduce in size, weight and cost.

Abstract: An infrared detector device for a device for detecting properties of a moving web of paper, more specifically for a device for controlling production in the paper making process, the detector device being provided, on the one side, with a polychromator that receives, on its receiving side, light coming from the web of paper and, on the other side, with an infrared detector with a matrix of infrared sensitive photoconductors, an evaluation electronic unit with one memory assigned to a respective one of the photoconductors of the matrix being connected downstream thereof. An additional source of light that can be controllably switched on and off between a first light intensity and a second light intensity which is greater than the first one uniformly illuminates the infrared detector for deriving correction values for correcting the signals from each of the photoconductors during a measurement.

Abstract: The present invention is a dispersive, diffraction grating, NIR spectrometer that automatically calibrates the wavelength scale of the instrument without the need for external wavelength calibration materials. The invention results from the novel combination of: 1) a low power He—Ne laser at right angles to the source beam of the spectrometer; 2) a folding mirror to redirect the collimated laser beam so that it is parallel to the source beam; 3) the tendency of diffraction gratings to produce overlapping spectra of higher orders; 4) a “polka dot” beam splitter to redirect the majority of the laser beam toward the reference detector; 5) PbS detectors and 6) a software routine written in Lab VIEW that automatically corrects the wavelength scale of the instrument from the positions of the 632.8 nm laser line in the spectrum.

Abstract: The invention relates to a method for checking the state of an apparatus for testing sheet material having at least one illumination device, transparent measuring window and detector. For ascertaining the soiling of a measuring window according to the invention the latter is irradiated with UV light by an illumination device, the UV light transmitted through the measuring window being filtered by a UV filter such that only a small fraction passes the filter and reaches a detector. Said fraction of UV light transmitted through the filter is detected and evaluated for determining the degree of soiling of the measuring window.

Abstract: In accordance with the present invention, a microbolometer focal plane array is provided with at least one thermally-shorted microbolometer detector that is thermally shorted to the microbolometer focal plane array substrate. A characteristic relationship is empirically derived for determining a corrected resistance value for each detector of the microbolometer focal plane array in response to radiation from a target scene as a function of the corresponding detector resistance value, the thermally-shorted microbolometer detector resistance value, and the empirically derived characteristic relationship.

Abstract: An apparatus (10) for analyzing lubricant oils and functional fluids includes an optical emission spectrometer (OES) (26) having a substantially continuously valued wavelength versus intensity output (140). The OES (26) analyzes light captured from a spark emission stand (58) through which the fluid sample is flowed. An expert system (160-172) operates according to a set of Rules that corrects background influence from the electrodes, and generates diagnostic text (174) for an operator based on the information about the fluid sample provided by the OES (26) and other measurement devices. The apparatus (10) is reduce in size, weight and cost.

Abstract: The automated selection of the best calibration for measuring selected physical, chemical or atomic properties of continuous moving sheets, or of a coating on the sheets, is provided by the use of an on-line qualitative multi-band infrared measurement of the material. The multi-band qualitative measurement produces a spectral pattern of the material, which is matched to a library of potential materials. Once the best spectral pattern match is selected, then the known calibration constant values are used to make quantitative measurements on selected properties of the sheet of material, or of a coating on the material. Typically, a property of interest is the weight per unit area (i.e., grams per square meter) of a plastic coating on a paper substrate. The automated selection may be done on a periodic basis to adapt to variations in the substrate material that would otherwise cause the quantitative measurements of the coating to become erroneous due to calibration errors.

Abstract: A method and apparatus for measuring a biological attribute, such as the concentration of an analyte, particularly a blood analyte in tissue such as glucose. The method utilizes spectrographic techniques in conjunction with an improved instrument-tailored calibration model. In a calibration phase, calibration model data is modified to reduce or eliminate instrument-specific attributes, resulting in a calibration data set modeling intra-instrument variation. In a prediction phase, the prediction process is tailored for each target instrument separately using a minimal number of spectral measurements from each instrument.

Abstract: In a method for determining the dry mechanical strength for a green wood, the improvement comprising: (a) illuminating a surface of the wood to be determined with a reduced range of wavelengths in the VIS-NIR spectra 400 to 1150 nm, said wood having a green moisture content; (b) analyzing the surface of the wood using a spectrometric method, the method generating a first spectral data of a reduced range of wavelengths in VIS-NIR spectra; and (c) using a multivariate analysis technique to predict the mechanical strength of green wood when dry by comparing the first spectral data with a calibration model, the calibration model comprising a second spectrometric method of spectral data of a reduced range of wavelengths in VIS-NIR spectra obtained from a reference wood having a green moisture content, the second spectral being correlated with a known mechanical strength analytical result obtained from the reference wood when dried and a having a dry moisture content.

Abstract: A method for determining the mechanical properties of decayed wood that has been exposed to wood decay microorganisms, comprising:

Abstract: First, monochromatic near infrared light in a wavelength range of 700 nm-1100 nm from the slit of the near infrared apparatus 1 is applied to a reference ceramic plate through the optical fiber 7 to measure a transmitted light intensity of the ceramic plate which is a reference material for spectrum measurement. Next, in place of the ceramic plate, the test tube 4 containing a liquid sample of which the temperature has been adjusted at a predetermined temperature by a water bath and the like is inserted into the housing portion 5. The transmitted light intensity of the liquid sample is then measured using the same procedure as above. A so-called near infrared absorption spectrum in which absorbance has been plotted against wavelengths is displayed on the screen of the computer 2. Information about each object characteristic is extracted from the spectrum data using a calibration equation.

Abstract: A method for controlling a process for the production of a cellulose fiber containing product, during which at least two substances having a substantial influence on the same property of said product in correspondence to the relation between them are added, whereby a calibration model has been established by linking reference property values and corresponding reference relations, by means of a mathematical function, and in that the method comprises applying the calibration model on the actual relation in order to predict the property value; comparing the predicted property value with a desired target property value; and, if said predicted value is not substantially equal to said target value, adjusting the actual relation in a predetermined way; and repeating these operations until said predicted value is substantially equal to said target value.

Abstract: Instrumentation to detect the presence of, or to measure the concentration of, a gas or pollutant in a gaseous environment. With the use of spectroscopic techniques and energy beams having suitable wavelengths, the presence and concentrations of these can be detected and measured, not only in flowing streams such as in process streams or exhaust stacks, but above a ground area, around its perimeter, or across the road. A calibration means including an internal audit cell and a retrodirective reflector is also shown.

Abstract: The invention provides a method for measuring PFC components in a discharged gas with ease and good reproducibility, using an FT-IR. The method for measuring greenhouse gases using an infrared absorption spectrometer in accordance with the present invention includes the steps of selecting a process chemical material, selecting a measurement target chemical material corresponding to the process chemical material, designating expected concentration ranges for the process chemical material and the measurement target chemical material, selecting libraries for the respective expected concentration ranges for the process chemical material and the measurement target chemical material, and analyzing data obtained by a gas infrared absorption spectrometry based on the libraries.

Abstract: A method for determining the concentration of hydrogen ion, organic anionic species and anionic species selected from the group consisting of OH−, CO3═, HS−, ClO3−, SO4═, S2O3═, polysulfide and peroxide in an aqueous sample solution, said method comprising subjecting said solution to near infrared radiation at a wavelength region of wave numbers selected from about 7,000 to 14,000 cm−1 through a solution path length of at least 3 mm to obtain spectral data for said solution; obtaining comparative spectral data for said anionic species at known concentrations in aqueous solutions; and correlating by multivariate calibration the relationships between said spectral data of said sample solution and said comparative spectral data to determine said concentration of said anionic species in said sample solution.

Abstract: A method for calibration of an IR spectrometry apparatus for providing and evaluating IR spectra in order to determine very low contents of specific components in a fluid, such as milk, and especially low contents of acetone, in a measuring range above 0, such as from 0.5 mM to 2.0 mM acetone in milk, using at least 50, such as from 50-300 known samples including at least 10 samples representing the fluid without any substantial content of the specific component for the calibration. Preferably, a good calibration for acetone shall be based on spectral information including the spectral ranges 1712-1697, 1419-1396, 1378-1353 and 1249-1226 cm−1, or at least a substantial portion/part of said ranges. By use of the new calibration of a FT-IR-spectrometry apparatus it will be possible to determine the acetone content during the sane IR measurement process used for determining other milk parameters such as fat and protein.