Abstract: Aspects of the present disclosure include methods for determining baseline noise of a photodetector (e.g., in a light detection system of a particle analyzer). Methods according to certain embodiments include irradiating a sample having particles in a flow stream, detecting light with the photodetector from the irradiated flow stream, generating data signals from the detected light and calculating a moving average mean squared error of the generated data signals to determine the baseline of the photodetector. Systems (e.g., particle analyzers) having a light source and a light detection system that includes a photodetector for practicing the subject methods are also described. Integrated circuits and non-transitory computer readable storage medium are also provided.

Abstract: A method for training a pattern recognizer to identify regions of interest in unstained images of tissue samples is provided. Pairs of images of tissue samples are obtained, each pair including an unstained image of a given tissue sample and a stained image of the given tissue sample. An annotation (e.g., drawing operation) is then performed on the stained image to indicate a region of interest. The annotation information, in the form of a mask surrounding the region of interest, is then applied to the corresponding unstained image. The unstained image and mask are then supplied to train a pattern recognizer. The trained pattern recognizer can then be used to identify regions of interest within novel unstained images.

Abstract: A structure includes an array of nonvolatile memory cells, wordlines and bitlines connected to the nonvolatile memory cells, sense amplifiers connected to the nonvolatile memory cells, and reference cells connected to the sense amplifiers. Each of the reference cells has a transistor connected to a variable resistor, one of the wordlines, a reference bitline separate from the bitlines, and the sense amplifiers.

Abstract: Provided are systems and methods for analyte detection and analysis. A system can comprise an open substrate configured to rotate. The open substrate can comprise an array of immobilized analytes. A solution comprising a plurality of probes may be directed, via centrifugal force, across the array during rotation of the substrate, to couple at least one of the plurality of probes with at least one of the analytes to form a bound probe. A detector can be configured to detect a signal from the bound probe via continuous rotational area scanning of the substrate.

Abstract: The invention relates to a method for feeding a sample into an analysis branch of a liquid chromatography system, in particular a high-performance liquid chromatography system. A solvent or a solvent mixture from at least one solvent branch is supplied as volume flow {dot over (A)} into the analysis branch. At least one sample from at least one sample branch is fed as volume flow ? into the analysis branch within a predetermined time interval. The volume flow {dot over (A)} is reduced to an extent during the predetermined time interval, and a volume flow ? resulting from the sum of the volume flows {dot over (A)} and ? remains substantially constant in the analysis branch. The invention further relates to a sampler for carrying out a method of this kind.

Abstract: A gas detector including: an assembly of two coaxial parabolic reflective caps having opposite concavities, and a wafer arranged in the focal plane of the two caps, at the center of this focal plane, comprising, back-to-back: a diverging light emitter directed towards the first cap and a light receiver directed towards the second cap, wherein the two caps are distant substantially by the sum of their focal distances plus the thickness of the wafer.

Abstract: This invention provides a novel methods and devices for measurement of particle concentration or changes in particle concentration over a wide linear range. The invention comprises one or more radiation sources and one or more detectors contained in a housing which is interfaced to a medium containing particulate matter. The one or more radiation sources are directed into the medium, scattered or transmitted by the particulate matter, and then some portion of the radiation is detected by the one or more detectors. Methods for confining the measurement to a specific volume within the medium are described. Algorithms are provided for combining the signals generated by multiple source-detector pairs in a manner that results in a wide linear range of response to changes in particle concentration. In one embodiment the sensor provides non-invasive measurements of biomass in a bioreactor. In another embodiment an immersible probe design is described, which may be suited for one-time use.

Abstract: A system (10) for multispectral imaging includes a first optical filter (24, 20) having at least two passbands disposed in different spatial positions on the first optical filter, a second optical filter (20, 24) having another at least two passbands, and processor (32) adapted to identify an intensity of light in the at least two passband of the second optical filter.

Abstract: A method of using a sensor array that measures the long-term change in the organic content of the near-surface seawater by simultaneously comparing downwelling sunlight attenuation in the blue and green wavelengths over a significant vertical distance.

Abstract: An apparatus and method provide measurement of a constituent of a fluid, such as ozone in ozonated water. The apparatus includes a vessel to contain the fluid, a light source configured to direct a first band of light and a second band of light along a substantially shared path though the fluid, and a photosensor that senses the first band of light and the second band of light. The constituent has a greater absorption associated with the first band of light than with the second band of light. The method includes modification of a measured attribute of the component in response to the sensed second band of light to improve the accuracy of the measured attribute.

Abstract: A radiation detector is disclosed with a detector arrangement, which has a plurality of detector elements, by means of which a detector signal is obtained during operation of the radiation detector, and with a control device, wherein the detector elements each have a spectral sensitivity distribution, and are suited for generating signals, at least one detector element comprises a compound semiconductor material, and this detector element is designed for detecting radiation in the visible spectral region, the radiation detector is designed such that the sensitivity distributions of the detector elements are used to form different spectral sensitivity channels of the radiation detector, a channel signal assigned to the respective sensitivity channel can be generated in these sensitivity channels using the detector elements, and the control device is designed such that the contributions of different channel signals to the detector signal of the radiation detector are differently controlled.

Abstract: A computer implemented method for utilizing a plurality of self-activating display shaping devices to provide shape adjustment information for a digital image projected on a display is disclosed. In one embodiment, the plurality of display shaping devices are automatically activated, the plurality of display shaping devices defining a desired digital image shape for a display. In addition, the plurality of display shaping devices is utilized to identify an actual projected digital image shape. The actual projected digital image shape is then compared with the desired digital image shape for the display. Correction information is then provided for adjusting the actual projected digital image shape to approximate the desired digital image shape for the display.

Abstract: A fluid content monitor including a cuvette, a colorimeter adapted to generate a signal indicative of contents of a fluid sample contained in the cuvette, a container for holding a reagent, and a pump assembly for delivering reagent from the container to the cuvette. The pump assembly includes a tube extending from the container to the cuvette, check valves preventing reverse flow in the tube, and a hammer driven by a solenoid for repetitively compressing the tube to pump reagent to the cuvette. The cuvette can be removed for cleaning and replacement.

Abstract: An apparatus and method provide measurement of a constituent of a fluid, such as ozone in ozonated water. The apparatus includes a vessel to contain the fluid, a light source configured to direct a first band of light and a second band of light along a substantially shared path though the fluid, and a photosensor that senses the first band of light and the second band of light. The constituent has a greater absorption associated with the first band of light than with the second band of light. The method includes modification of a measured attribute of the component in response to the sensed second band of light to improve the accuracy of the measured attribute.

Abstract: A system (10) for multispectral imaging includes a first optical filter (24) having at least two passbands disposed in different spatial positions on the first optical filter, a second optical filter (20) having another at least two passbands, and processor (32) adapted to identify an intensity of light in the at least two passband of the second optical filter (20).

Abstract: A microfluidic analysis system for optically analyzing a substance includes a light source having a plurality of selectable single-wavelength light sources, a substance presentation member optically coupled to the light source, and an optical detection system associated with the substance presentation member.

Abstract: A wavelength meter, an associated method, and system are generally described. In one example, an apparatus includes a photodiode to receive an optical signal and to generate a photocurrent upon receiving the optical signal, the photodiode having an absorption edge that is substantially aligned with a band of wavelengths, wherein the absorption edge shifts toward longer wavelengths when a reverse bias is applied to the photodiode, and control electronics coupled with the photodiode to apply at least a first reverse bias and a second reverse bias to the photodiode, wherein a ratio of a first measurement of the photocurrent at the first reverse bias and a second measurement of the photocurrent at the second reverse bias provides information about the wavelength of the optical signal.

Abstract: A low cost calorimeter wherein a linear taper potentiometer proportions the current through sample and reference solid state light sources in a near logarithmic fashion. The position of the potentiometer slider is proportional to the absorbance of the solution in the sample path when the light intensity of the two paths is balanced. The light intensity may be balanced visually or with a simple electronic comparator.

Abstract: A fluidic structure includes a channel and along the channel is a series of sensing components to obtain information about objects traveling within the channel, such as droplets or other objects carried by fluid. At least one sensing component includes a set of cells of a photosensor array. The set of cells photosense a range of photon energies that emanate from objects, and include a subset of cells that photosense within subranges. A processor can receive information about objects from the sensing components and use it to obtain spectral information. The processor can perform an initial analysis using information from one set of sensing components and, based on the results, control a fluidic device in the channel, such as a gate, to retain objects, such as for concentration and more detailed analysis by other sensing components, or to purge objects from the channel.

Abstract: An absorption detection system is provided. The system includes a plurality of monochromatic light sources and a separator for separating the light from the plurality of monochromatic light sources into a plurality of wavelengths. A plurality of detectors, receives light of a single wavelength to measure absorption of light in a biological sample.

Abstract: An apparatus for photometrically testing several specimens each irradiated by a light source, the light altered by the specimens being detected by an optical device and analyzed, the apparatus including a light source, a plurality of sample holders configured adjacent to one another on a support, a detector that receives altered light from sample within the sample holders, the detector including a filter for eliminating interfering light, a sensor having a sensor face and a diffusing optical member located between the filter and the sensor, wherein light is diffused and shines on a greater portion of the sensor surface, and with a more homogeneous brightness as compared to when the light is not diffused.

Abstract: A fluidic structure includes a channel and along the channel is a series of sensing components to obtain information about objects traveling within the channel, such as droplets or other objects carried by fluid. At least one sensing component includes a set of cells of a photosensor array. The set of cells photosense a range of photon energies that emanate from objects, and include a subset of cells that photosense within subranges. A processor can receive information about objects from the sensing components and use it to obtain spectral information. The processor can perform an initial analysis using information from one set of sensing components and, based on the results, control a fluidic device in the channel, such as a gate, to retain objects, such as for concentration and more detailed analysis by other sensing components, or to purge objects from the channel.

Abstract: An integrated circuit (IC) includes a photosensor array, some cells of which are reference cells that photosense throughout an application's energy range, while other cells of which are subrange cells that photosense within respective subranges. For example, the subrange cells can receive photons in their respective subranges from a transmission structure that has laterally varying properties, such as due to varying optical thickness. The reference cells may be uncoated or may also receive photons through a transmission structure such as a gray filter. Subrange cells and reference cells may be paired in adjacent lines across the array, such as rows. Where photon emanation can vary along a path, quantities of incident photons photosensed by subrange cells along the path can be adjusted based on quantities photosensed by their paired reference cells, such as with normalization.

Abstract: In one exemplary embodiment, apparatus is provided with a plurality of laser diodes, sensing means and control means. During normal operation, the laser diodes produce a mixed light. The sensing means measures light that is output by the laser diodes; and the control means 1) compares the measured light to a spectral reference, and 2) sets drive signals of the laser diodes in response to the comparison. In a related and exemplary method, 1) a mixed light is produced using a plurality of laser diodes of different colors, 2) a measurement of light produced by the laser diodes is compared to a spectral reference, and 3) drive signals of the laser diodes are automatically set in response to the comparison.

Abstract: A liquid measuring cell for measuring optical properties of liquids, with a measuring chamber (16), which is adjoined on one side by a transparent window (11), and with a reflector (30) disposed on the opposite side of the measuring chamber (16), which reflects the light striking it toward the outside through the measuring chamber (16) and the window (11), is particularly easy to clean and permits favorably reproducible measurements if another transparent window (33) is disposed between the reflector (30) and the measuring chamber (16) and this window (33) adjoins the measuring chamber (16) on the other side.

Abstract: An optical sensor device for determining the presence or concentration of an analyte, contains a waveguide disposed over a light source and a light detector mounted on a surface of a substrate and separated by an internal baffle, wherein the waveguide has a thickness corresponding to a far field emission point of the light source as determined by a light shielding baffle between the light source and light detector. An analyte indicator matrix is disposed on the outer surface of the waveguide. The sensor device geometry takes advantage of only direct illumination of the indicator matrix, and direct collection of indicator matrix illumination, without any significant reflection by said waveguide. Undesirable light noise generated by the light source passes directly out of the device through the waveguide.

Abstract: A multichannel fluorosensor includes an optical module and an electronic module combined in a watertight housing with an underwater connector. The fluorosensor has an integral calibrator for periodical sensitivity validation of the fluorosensor. The optical module has one or several excitation channels and one or several emission channels that use a mutual focusing system. To increase efficiency, the excitation and emission channels each have a micro-collimator made with one or more ball lenses. Each excitation channel has a light emitting diode and an optical filter. Each emission channel has a photodiode with a preamplifier and an optical filter. The electronic module connects directly to the optical module and includes a lock-in amplifier, a power supply and a controller with an A/D converter and a connector. The calibrator provides a response proportional to the excitation intensity, and matches with spectral parameter of fluorescence for the analyzed fluorescent substance.

Abstract: An instrument for processing light information to assay chemical or biological molecules is made more flexible by the use of a replaceable filter module. Several light filters, or in one embodiment dichroic mirrors, are mounted in a common module in fixed position relative to each other. The whole filter module can then be removed, and a different one inserted in its place, to change the wavelength bands of light detected by the instrument, as needed, for different applications.

Abstract: In the production of de-inked pulp, measuring devices are used to register spectral and/or physical characteristic values of a starting material. These values are then fed to a neural network, by means of which correction variables are obtained for a regulating or controlling device which in provided. According to the invention, the measuring device is used to evaluate at least the starting materials of the production of pulp and/or paper. The evaluation of the characteristics of the raw material used in the production of pulp and paper is thereby possible.

Abstract: A device is described for measuring changes in parameters in transparent objects, in particular for medical applications. For universal use in various applications, the device includes a light source, an optical line sensor which detects the intensity of the light of the light source passing through the object as a function of location in at least one extension direction of the object, and a computer unit which compares the distribution of the light intensities detected by the optical line sensor as a function of location with at least one predetermined reference distribution. According to another embodiment, the light source supplies approximately parallel light, and the computer unit shapes the first derivation according to location of the distribution of the light intensities detected by the optical line sensor. The device is designed so that the different light sources can be easily replaced or combined.

Abstract: A method of detecting the presence of a predetermined vapor of a predetermined concentration in a monitored area, the method including the steps of (a) exposing gas in or from the monitored area to radiation at wavelengths at least covering and surrounding from both sides a main absorption peak of the vapor; (b) simultaneously sensing the radiation after passing through the gas by a signal sensor and a reference sensor, each of the sensors including a radiation sensing element, wherein the signal sensor further includes a first optical filter passing wavelengths covering the main absorption peak, yet substantially blocking wavelengths from both sides of the main absorption peak of the vapor, whereas the reference sensor further includes a second optical filter passing wavelengths surrounding from both sides the main absorption peak, yet substantially blocking wavelengths covering the main absorption peak of the vapor; and (c) comparing signals obtained from the signal and reference sensors for determining a p

Abstract: A method to compensate for lamp spectrum shift, comprises exposing a first detector to a first light from a lamp, thereby generating a first signal indicative of intensity of said first light; exposing a second detector to a wavelength (.lambda.) of a second light from said lamp, thereby generating a second signal indicative of intensity of said wavelength of said second light, after said second light has interacted with a sample; determining a new color temperature (T.sub.1) of said first light using the following equationT.sub.1 =(F.sub.1 /A).sup.1/xwhere A=F.sub.i /(T.sub.i).sup.x,x=a color temperature exponent of said lamp, F.sub.1 =said first signal, F.sub.i =an initial reference signal, and T.sub.i =an initial color temperature corresponding to said initial reference signal; and determining a first compensated signal (I.sub.1) using the following equationI.sub.1 32 S.sub.1 /B.sub.1where ##EQU1## S1=said second signal, h=Planck's constant, c=speed of light in vacuum, and k=Boltzman constant.

Abstract: A photometer for measuring electromagnetic radiation absorption of a sample utilizing a source of the electromagnetic radiation. Electromagnetic radiation is conducted from the source, to a sample sensor or sensors, and is passed through or scattered from, the sample utilizing a sample cell. The electromagnetic radiation is then directed to a detection system which determines absorbance of electromagnetic radiation by the sample at the sample cell. The detection system includes a beam splitter which receives the electromagnetic radiation and outputs first and second beams. A first detector having a first wavelength filter and a second detector having a second wavelength filter receives the two beams from the splitters. One detector may be employed to produce a reference signal. The remaining detector or detectors produce an output signal which is a representation of a characteristic, such as absorbance of the sample.

Abstract: A spectrophotometer employs an array of optical elements to focus light from at least one, but preferably two light sources onto a fiber optic beam splitter that provides a pickup for a selected bandwidth of wavelengths of light in the spectral pattern. The spectral pattern can include wavelengths in the visible, near infrared and ultraviolet spectrum. To create the spectral pattern, two reflecting prisms having spherical surfaces are used, and the optical elements are arranged so that the two spectral bands from each prism are longitudinally aligned to create the spectral pattern. The prisms are on a motor driven pivot mount so that the spectral pattern may be swept across the pickup. The optical elements and the pickup are sized so that the selected bandwidth is less than twenty nanometers over the spectral pattern. The pickup is formed by a single row of the ends of fiber optic strands which are then collimated into two bundles to transmit a test component and a reference component of light.

Abstract: A flow cytometry system includes a flow tube through which particles marked with different fluorochromes pass from a first location, illuminated by a red laser, to a second location, illuminated by a blue laser. A "red" photodetector is optically coupled to detect red fluorescence from both locations. "Yellow" and "green" photodetectors respectively detect yellow and green fluorescence from the second location, while a "scattered light" detector detects scattered light from the second location. During a sample run, the red photodetector can output pulses that correspond primarily to APC fluorochrome at the first location and to PerCP at the second location respectively. A delay device delays the APC pulse relative to the PerCP pulse so that the peaks can be scaled and subtracted in the analog electrical domain to remove APC/PerCP crosstalk. The delay is calibrated using a set of APC tagged cells.

Abstract: An optical detector for flowing sample comprises a light condenser for condensing a diverging monochrome light, a flow cell arranged in the course of convergence of the converged light beam, and a sample-side detector for receiving a sample-side light. Such a construction makes it possible to correct delicate changes of the light axis due to intensity, position, temperature changes of the light source, density change of the flowing liquid, and any change of other causes effectively for stable sample analysis without difficult optical adjustment.

Abstract: In the method, the totality of the gases is conducted through an absorption cell. A reference cell contains a reference gas. The cells are optically transirradiated and a signal representing a quantity for the mass flow to be identified is generated in a detector which picks up the optical radiation emerging from the cells.

Abstract: Apparatus for measuring the color of glass, particularly pieces of broken glass relies upon simultaneously measuring the glass transmission in different spectral regions. The glass pieces travel along a conveying path between a light source and a light sensor containing a plural number of optical filters and groups of photoelectric detectors. The groups of photoelectric detectors are disposed at an end face of respective substantially cylindrical tubes. Tube axes enclose an angle and intersect in a conveying plane defined by the conveying path. The optical filters have different spectral transmission regions. Optical lens systems are retained intermediate the respective groups of photoelectric detectors and an opposite end face of the respective tubes. Each optical lens system images the conveying plane at the associated group of photoelectric detectors.

Abstract: The present invention relates to a system for generating the same instantaneous pressure between two tanks filled each with a given medium, the first tank including at least one inlet channel and at least one outlet channel for the given medium, the second tank including at least one outlet channel, and means for opening and for closing said channels. The system according to the invention further includes at least one linking capillary between each tank, intended notably for transmitting instantaneously a pressure variation from the first tank towards the second tank.

Abstract: A method of analyzing fluid samples using a bent capillary flow cell, in which method an external UV/visible light ray beam is directed into an elongated section of the flow cell from a bend thereof, this incident light ray beam is limited to a solid acceptance angle .OMEGA.. This solid acceptance angle .OMEGA. is determined such that light rays which enter the elongated section traverse predominantly the longitudinal axis thereof, i.e. propagate through the fluid sample, providing an improved S/N ratio. Lens means, such as ball lenses, may be used at the entrance and exit side of the elongated section. A bent capillary flow cell is provided, in which the elongated section deviates by an angle .psi. from a line N perpendicular to a flat side face of a holding template.

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

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

Abstract: A detector cell, having a capillary entrance elbow through which a beam of exposing light can be directed into the bore of a central leg of the detector cell capillary. Ray traces, to determine the effect of the entrance elbow on the beam of exposing light are used to optimize performance of this detector cell. Back ray tracing is implemented to illustrate an optimized embodiment. Forward ray tracing is also illustrated and can be used to determine system performance for a range or choices of a single parameter or for concurrent ranges of choices of a subset of the parameters of the beam of exposing light.

Abstract: A method and apparatus are described for an accurate determination of the concentration of a gas, vapor or a gas dissolved in a sample which compensate for variations in temperature and light - source intensity. The apparatus comprises a sensor containing a fluorescent reagent connected to a transfer optic, such as fiber optics prism or glas pipes, and to a reference sensor containing the same fluorescent reagent. The reference sensor is encapsulated in an environment containing air. The light emitted from the first sensor and the reference sensor is determined and recorded automatically, the concentration of the gas being calculated based on the output from said light detectors using calibration data of the fluorescent reagent present in the sensors. The reagent is immobilized in the sensor by a glue, such as a silicon glue.

Abstract: Method for making a probe with a plurality (one or more) of optical fiber sensors containing colorimetric chemical indicators in gaps in the fibers, the fibers bent to provide good light transmission qualities. Apparatus for making a probe with a plurality of such optical fiber sensors. A probe with a plurality of such optical fiber sensors. A vacuum chuck for holding the ends of such fibers.

Abstract: A method for maintaining a preselected concentrations of first and second charge directors in a toner composition, where such composition is being subjected to a use in which initial concentrations of the first and second charge directors are being depleted.

Abstract: A light absorption detector includes a light source substantially adjacent a window of a chromatogrpahic flow cell. The flow cell is defined by a housing member which also includes a photo-sensitive detector.

Abstract: A Method and Apparatus for identifying and distinguishing fluids and for recognizing contamination of a fluid, which method and apparatus utilizes spectrographic analysis of control samples of known fluids and then spectrographic analysis of unknown fluids to generate optical signatures, finger prints and/or profiles of data and processed data relating to the relative intensities of light at selected wavelengths; and then, through comparison of the various signatures, fingerprints and/or profiles, provides determinative information as to contamination or non-contamination of the unknown fluids; after which appropriate operation control is effected and/or exercised.

Abstract: A method and apparatus for identifying and distinguishing fluids and for recognizing contamination of a fluid, which method and apparatus utilizes spectrographic analysis of control samples of known fluids and then spectrographic analysis of unknown fluids to generate optical signatures, finger prints and/or profiles of data and processed data relating to the relative intensities of light at selected wavelengths; and then, through comparison of the various signatures, fingerprints and/or profiles, provides determinative information as to contamination or non-contamination of the unknown fluids; after which appropriate operation control is effected and/or exercised.

Abstract: In an apparatus for determining the concentration of foreign matter in a water stream, a stream of liquid is bypassed through conduits both before and after the pipeline block for the process and each stream is pumped into a cell, a beam source being associated with each of the cells whose beams penetrate the cells and are led by a beam splitter both to a first detector and to a second detector, the electrical signals of the detectors being compared by an electrical circuit and processed to a recognition signal. To make a bubble-free sample stream possible, magnetically actuated valves are inserted into the return lines which are connected to the cells, and the signals for opening and closing the valves are produced by a frequency generator.