Abstract: An NDIR sensor includes a cylindrical metallic tube, a printed circuit board platform that fits into one end of the tube, a diffusion filter that fits into the opposite end of the tube, and an optical system. The optical system includes an infrared source on the platform, a mirror on the inner wall of the tube so as to reflect and focus the infrared light from the infrared source, and a detector assembly that receives the infrared light after reflection. The gas sensor may further include a partition between the infrared source and the detector assembly, a removable filter on the diffusion filter, connecting pins attached to the platform, and a sealing layer formed under the platform. The detector assembly includes a signal detector and a reference detector. A first and second bandpass filters are respectively formed on the signal and reference detectors.

Abstract: A method and apparatus for identifying a material type in an article, such as wholly or partly transparent bottle of plastic or glass, including, with the aid of a detector station, irradiating the article with rays from an infrared radiation source, detecting rays which have passed through the article non-absorbed, and then carrying out a correlation analysis of such detected rays. The article is made to pass through the detector station in a continuous or discontinuous movement. The rays from the radiation source are successively filtered by the filters consisting of wholly or partly transparent materials which have different spectral characteristics. The rays filtered by the filters and non-absorbed by the article are intercepted in order to form a sequence of measured values representing characteristic transmission signatures of the article. A correlation analysis of the signatures is carried out in relation to statistical models in order to determine the material type of the article.

Abstract: In a respiratory air flow measuring monitor, a subassembly for analyzing certain respiratory gases through infrared spectroscopy includes an infrared emitter and an infrared detector, the amount of energy detected by the detector corresponding to the concentration of the gas selected for analysis. The subassembly includes a gas sample chamber that utilizes an elliptical reflecting surface for the infrared light source. The light source and detector are both oriented longitudinally along the axis of the ellipse and the light source and detector are each located at the two focal points of the ellipse in order to optimize the light absorption reading. The gas content analyzer subassembly additionally incorporates various compensatory features, allowing for automatic temperature and pressure compensation.

Abstract: A method for measuring trace quantities of OH groups in quartz glass comprises preparing a set of test pieces comprising a reference test piece from a blank of a quartz glass body whose OH group content is known and a sample test piece from a quartz glass body whose OH group content is to be measured, having two planar planes faced to each other, setting the sample test piece and the reference test piece in an infrared spectrophotometer; successively irradiating perpendicular to one of the two planar planes an incident infrared radiation in a wavelength region of approximately 2500 nm to approximately 2950 nm, while simultaneously detecting the outgoing radiation spectrum from the other plane; obtaining the difference of the outgoing radiation spectrum of each of the test pieces; selecting the absorbance peak assigned to OH groups at a wavelength of 2720 nm to obtain the peak height thereof; and calculating the concentration of OH groups from the peak height in the sample test piece.

Abstract: Surface-enhanced spectroscopy for quantitative analysis of analytes in biological liquid samples. A device for testing a biological liquid sample for the presence or concentration of an analyte includes: (a) a substrate defining a surface which has electrically conductive particles disposed thereon, wherein the surface is adapted to accommodate the liquid sample; (b) means for generating radiation and directing the radiation to be incident on said surface of the substrate so that radiation is emitted from the electrically conductive particles; and (c) means for detecting the emitted radiation. In another embodiment a matrix having electrically conductive particles that are incorporated in the matrix or that are disposed on a surface thereof, wherein the matrix is permeable to the liquid biological sample is used in place of the substrate. The device is particularly suited for determining glucose in human whole blood.

Abstract: The present invention provides a liquid concentration detecting method and a liquid concentration detecting apparatus in which light beams of at least two different wavelength bands having a central wavelength within a range of from 1.4 to 2.05 &mgr;m are irradiated on to a solution, and concentrations of at least two constituents contained in the solution are detected by detecting the amount of light transmitting through the solution relative to the light beams of each wavelength band. The present invention permits inline real-time detection at a high accuracy of concentrations of a plurality of constituents contained in a chemical solution used in a semiconductor manufacturing process or a liquid crystal substrate manufacturing process. Further, according to the present invention, it is possible to high-accuracy and high-reliability detection of the liquid concentration with a simple configuration.

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 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.

Abstract: The invention generally relates to optical imaging systems and methods for providing images of two-dimensional or three-dimensional spatial or temporal distribution of properties of chromophores in a physiological medium. More particularly, the following description provides preferred embodiments of optical imaging systems utilizing efficient, real-time image construction algorithms. A typical optical imaging system includes at least one wave source, at least one wave detector, a movable member, an actuator member, and an imaging member. The wave source emits electromagnetic waves into a target area of the medium, and the wave detector detects electromagnetic waves and generates output signal in response thereto. The movable member includes the wave source and/or detector, and the actuator member moves the movable member along with the wave source and detector over different regions of the target area while the wave detector generates the output signal therefrom.

Abstract: In a respiratory air flow measuring monitor, a subassembly for analyzing certain respiratory gases through infrared spectroscopy includes an infrared emitter and an infrared detector, the amount of energy detected by the detector corresponding to the concentration of the gas selected for analysis. The subassembly includes a gas sample chamber that utilizes an elliptical reflecting surface for the infrared light source. The light source and detector are both oriented longitudinally along the axis of the ellipse and the light source and detector are each located at the two focal points of the ellipse in order to optimize the light absorption reading. The gas content analyzer subassembly additionally incorporates various compensatory features, allowing for automatic temperature and pressure compensation.

Abstract: A test piece analyzing apparatus is provided which includes a releasably fixed absorbent member, a horizontally reciprocative pinching mechanism for simultaneously transferring a plurality of test pieces in a transfer direction, and an optical analyzing assembly provided with a primary illuminator and a secondary illuminator. The second illuminator serves to illuminate the bottom surface of the test piece.

Abstract: Device for monitoring the quality of latex in a reactor during emulsion polymerization, including essentially a measuring probe placed in the reactor, an optical coupling of the said probe with a near-infrared spectrophotometer provided with means for emitting light and for capturing the scattered light which is reflected and a computer which has the correlation equations in its memory.

Abstract: The present invention is a photo-acoustic leak detection system that detects whether gas is leaking from a component. The system includes multiple beams wherein one beam is not absorbed by the gas and is used as a baseline measurement, while another beam absorbs the gas and emits an increased signal. Upon contact with the gas, an acoustic sensor senses the reaction or lack thereof between the gas and the beams, thereby allowing a signal processor to receive the respective alternating sensor signals after which the processor calculates the difference between the first and second signals to determine whether a leak exists. The photo-acoustic leak detection system also includes a beam combining means which forces the multiple beams to enter an acousto-optic cell at the same location. The acousto-optic cell, in turn, which is controlled by a signal controlling apparatus, sequentially and alternately diffracts the multiple beams at the same predetermined angle.

Abstract: An apparatus for determining the concentration of a first component in a mixture of at least two components, which have different absorption properties in the IR range, comprises image recording means which are adapted to image the mixture by means of IR radiation to produce at least one image. The apparatus further comprises image processing means which, with the aid of intensity values for pixels in the image which represent the mixture, determine the concentration of the first component in the mixture.

Abstract: An in-line spectrometric method for determining the distillation residue content in an opaque, dark-colored mixture containing an isocyanate and tar-like materials (residue) during the isocyanate production process. A probe capable of directing light at wavelengths of from 1050 to 2150 nm is inserted in a stream of the residue-containing mixture and light is transmitted through the stream. Light absorption data is collected and a near-infrared spectrum is generated. The residue content is then determined using a chemometric model. Knowledge of the residue content makes it possible to control and optimize the distillation process.

Abstract: The present invention relates to an on-line method and a flow system as well as a cuvette for carrying out IR spectrometry for analysis of liquid food products, possibly containing dissolved gases, in a process line in a liquid food product processing plant, especially a dairy processing milk and milk products. A liquid sample is extracted from the process line to a measuring branch, the sample is thermostated and passed to a measurement cuvette. The IR-absorbance spectrum is measured, e.g. in the MID-IR or NIR-range. In order to obtain an on-line monitoring of the process line the liquid food sample is extracted directly from the process line into the measurement branch, in which the pressure is maintaining at least as high as in the adjacent process line. The high pressure ensures that dissolved air will stay dissolved in the liquid food. Before each new sample the measurement branch and cuvette are flushed by high flow rates with a part of the new sample to clean the cuvette.

Abstract: An infrared gauge for, and a method of, measuring a parameter of a sample, e.g.

Abstract: A method and system performs Fourier transform infrared (FT-IR) imaging microspectroscopy on a biological sample fixed on a substrate with a supporting surface that generally reflects infrared light while generally transmitting visible light. Infrared light impinging on the biological sample is reflected by the supporting surface of the substrate. Infrared light from the sample is focused onto a focal-plane array detector with multiple pixels for detecting infrared images of the sample. The detected infrared images are processed to generate spectral images of the sample. The same biological sample is suitable for conventional pathological studies.

Abstract: A method is described for determining the concentration of an organic blood analyte using multi-spectral analysis in the near infrared and mid-infrared ranges. Incident radiation containing a plurality of distinct, nonoverlapping regions of wavelengths in the range of approximately 1100 to 5000 nm is used to scan a sample. Diffusively reflected radiation emerging from the sample is detected, and a value indicative of the concentration of the analyte is obtained using an application of chemometrics techniques. Information obtained from each nonoverlapping region of wavelengths can be cross-correlated in order to remove background interferences.

Abstract: An apparatus for examining a flowable material comprises a tube having an opening for receiving material and an opening for discharging material. Further, the tube comprises a segment adapted for making measurements. Adjacent the tube section there is a measuring device having a light source on one side for transmitting light into the segment and a light receiver on the opposite side to measure the effect upon the light of a material placed in the segment. At the beam path between the light source and the light receiver, the walls of the tube segment are made of a material being translucent or transparent to the range of light wavelengths to be examined. A recording unit connected to the measuring device records individual measurement values or sets of same on material placed in the tube segment.

Abstract: Surface-enhanced spectroscopy for quantitative analysis of analytes in biological liquid samples. A device for testing a biological liquid sample for the presence or concentration of an analyte includes: (a) a substrate defining a surface which has electrically conductive particles disposed thereon, wherein the surface is adapted to accommodate the liquid sample; (b) means for generating radiation and directing the radiation to be incident on said surface of the substrate so that radiation is emitted from the electrically conductive particles; and (c) means for detecting the emitted radiation. In another embodiment a matrix having electrically conductive particles that are incorporated in the matrix or that are disposed on a surface thereof, wherein the matrix is permeable to the liquid biological sample is used in place of the substrate. The device is particularly suited for determining glucose in human whole blood.

Abstract: The present invention is a method for optimizing multivariate calibrations such as those used on FT-IR analyzers. The method involves the selection of an optimum subset of samples to use in the calibration from a larger set of available samples. The subset selection is done so as to minimize the bias of the resulting calibration while simultaneously maintaining acceptable standard errors and ensuring maximal range for the model.

Abstract: A sensor assembly for monitoring process parameters in an adverse environment is disclosed. The sensor is mounted on an exterior side of a chamber for curing polymeric materials using radiation. A shutter on the sensor assembly separates a passageway in which a sensor element is disposed from the adverse environment. A gas source pressurizes the passageway so that the passageway has a positive pressure when the shutter is in an open position as well as a closed position. A mounting device mounts the sensor assembly to an inerting tube of the curing chamber so that the sensor element will sense radiation inside the chamber when the sensor assembly is mounted outside the chamber.

Abstract: A forming method for a calibration curve in an infrared gas analyzer. The forming method minimizes the systematic error that occurs in the infrared gas analyzer improves measuring precision. The forming method modifies a method in which gases having different concentrations are supplied to an infrared gas analyzer. The gas analyzer has the outputs corresponding to the gas concentrations, and samples the gas concentrations as a plurality of points, the number of which is not less than four. A calibration curve is approximated by up to a fourth-order polynomial using a method of least squares based upon the measured values of not less than 4 points thus sampled. In carrying out the above-mentioned polynomial approximation, an inverse number of the square of the divided ratio at each point of the calibration curve is used so as to carry out a weighting operation.