Abstract: A probe for a spectrometer has a slot for receiving a sample, an illuminating fiber optic bundle directing light to the sample in the slot, and first and second collecting fiber optic bundles transmitting light from the sample to the spectrometer, wherein the first collection fiber optic bundle is positioned to optimize the collection of transmitted light without scattering through the sample, and the second collection fiber optic bundle is positioned to optimize the collection of light diffusely reflected from the sample. In one embodiment, the first collection bundle is arranged in an annulus around the illuminating bundle, and the second collection bundle is arranged in an annulus around the first collection bundle. In a second embodiment, the second collection bundle is arranged in an annulus around the illuminating bundle, and the first collection bundle terminates in an interface with the sample located across the slot from the illuminating bundle and the second collection bundle.

Abstract: A method and process for the determination of presence and distribution of clouds is presented. The method involves the use of a sensor, such as laser ranger, for the collection of echo location measurement data from a three dimensional volume of the sky. The process involved in this invention utilizes the measurement data to evaluate and test for the presence of cloud banks. The process also utilizes the measurement data to quantitatively and qualitatively determine the cloud coverage amount and distribution. The preferred embodiment includes a laser ranger that samples the three dimensional volume at several azimuth-elevation angles through the application of a device capable of selecting azimuth-elevation angle values.

Abstract: There is described a fiber optic probe and associated system for measuring light extinction due to forward scattering by steam droplets. A system is also described for analyzing the light transmissibility to produce a measure of steam wetness.

Abstract: The Laser Induced Fluorescence Attenuation Spectroscopy (LIFAS) method and apparatus preferably include a source adapted to emit radiation that is directed at a sample volume in a sample to produce return light from the sample, such return light including modulated return light resulting from modulation by the sample, a first sensor, displaced by a first distance from the sample volume for monitoring the return light and generating a first signal indicative of the intensity of return light, a second sensor, displaced by a second distance from the sample volume, for monitoring the return light and generating a second signal indicative of the intensity of return light, and a processor associated with the first sensor and the second sensor and adapted to process the first and second signals so as to determine the modulation of the sample.

Abstract: A sensor is described which simultaneously allows visual range and rain-covered area detection. To this end, light is coupled into the windshield in such a way, that a portion is reflected in the windshield and a portion leaves the windshield and is scattered outside the windshield. The rain-covered area is determined from the reflected portion, and the usual range is determined from the scattered portion which returns to the windshield, wherein both portions are detected by means of a decoupling mechanism and a light receiver.

Abstract: A multiple pathlength sensor is disclosed that is installed substantially within a process stream containing particles at high concentrations. The sensor includes a transparent surface for receiving the first and the second light energy emissions projected by first and second light delivery arrangements. The first and second light energy emissions penetrate the transparent surface and enter the sensor in a first directional path. A first light deflecting surface modifies the first and second light energy emissions to travel into a second directional path through the sensor. A first passage exposed to the process stream is sized to receive particles of a first predetermined size range. The first light energy emission in the second directional path is projected through the first passage to irradiate the particle ensemble therein. A second passage exposed to the process stream is sized to receive particles of a second predetermined size range.

Abstract: A detector used in a measurement system that determines the size distribution of particles contained in a dispersant medium is disclosed that includes means for exciting the dispersant medium at an ultrasonic frequency to cause particles contained in the dispersant medium to oscillate at the applied ultrasonic frequency. The detector of the present invention further includes a light source for producing light energy in a specific frequency range, a first light guide for conveying the light energy from the light source to the dispersant medium, a second light guide for capturing and conveying the light energy scattered by the particles in oscillation and a third light guide for conveying light energy from said light source to the second light guide to produce heterodyned light energy. A light energy detection device optically connected to the second light guide receives the heterodyned light energy and produces signals representative of the heterodyned light energy detected.

Abstract: The intelligent alarm system of the present invention provides a reliable, low cost system for alerting a user to the presence of snow outside of a building. The system includes a sensor and an intelligent alarm clock for use inside a building or dwelling. The system can be set by a user to signal an alarm a programmable amount of time earlier or later than the user's normal waking time if an accumulation of snow is detected. The system is capable of processing preprogrammed data, user entered data and data accumulated from the sensor to determine whether a true snow condition exists and to generate an appropriate alarm signal.

Abstract: A submersible light scattering probe for the absolute characterization of polymer and colloid solutions includes a ring member made of a preferably dark, opaque material, having embedded therein a plurality of optical fibers which can be connected to optical detectors remote from the probe. The ends of the optical fibers are preferably in direct contact with the fluid being tested. Instead of submersing the probe in a fluid, fluid can be caused to flow through the probe, placed in the probe, or placed in a transparent vessel placed in the probe. Individual large scattering particles can also be detected, counted, and characterized at the same time absolutes characterization of the polymer or colloid solution is performed.

Abstract: Method and apparatus for detecting conditions in the atmosphere which are hazardous to flying aircraft and providing early warning to pilots or ground personnel. The method includes using a laser beam and a coherent optical receiver to optically sense sound waves produced by those hazardous conditions and measuring the effect of those sound waves on the transmitted and received optical beams.

Abstract: The present invention relates to a fiber optic detector for detection of scattered light or fluorescent light from a liquid suspension, comprising: a lighting optical fiber for transmitting light to a lighting optical fiber outlet; a first gradient index lens disposed at the lighting optical fiber outlet to parallelize light; a detecting optical fiber for transmitting back-scattered light from a detecting optical fiber inlet; a second gradient index lens disposed at the detecting optical fiber inlet to parallelize back-scattered light; and at least one means for focusing parallelized light transmitted from the lighting optical fiber on a point and for focusing light back-scattered from the point to the second gradient index lens of the detecting optical fiber for transmission by the detecting optical fiber.

Abstract: A fiber-optic imaging probe is disclosed for use in dynamic light scattering applications. The probe includes two monomode optical fibers and two GRIN lenses to form a pair of identical fiber-lens combinations. Each fiber is positioned off the optical axis of its associated lens. Further, the optical fibers are placed at an image plane of the lenses. The fiber-lens combinations are parallel to and mirror images of each other. The first fiber-lens combination projects a tightly focused spot of light into a scattering volume containing suspended or dispersed microscopic particles, or biological or live tissues. The second fiber-lens combination collects the light which is scattered from the particles in the scattering volume and conveys it to a photo detector and autocorrelator for analysis. The probe minimizes the scattering volume by advantageously using imaging principles of lenses. Further, the probe optimizes sensitivity and spatial coherence.

Abstract: A particle sensor for a semiconductor device fabrication tool scans a laser beam through a measurement volume immediately adjacent a wafer during processing and detects light scattered by particles adjacent the wafer. Scanning provides a real-time count of particles without interfering with processing. Detected light can be forward-scattered, side-scattered, or back-scattered depending on available optical access for a detector portion of the sensor. A pulse in the intensity of scattered light results each time a particle is scanned. Because the scanning velocity is high relative to the particle velocity, each particle may be scanned several times while the particle is in the measurement volume. Analysis fits a series of pulses observed for a single particle to a Gaussian distribution to determine a size, position, and velocity for each particle and a time-resolved particle count of the particles.

Abstract: For automated visual range measurement by a LIDAR system, a distance measuring range is first determined through repeated evaluation of a voltage level U(R) which indicates the intensity of a threshold value. After random initialization of a start value, the start value is then replaced each time with a new mean visual range, resulting in iterative improvements, and the mean visual range in the determined range is then displayed automatically as soon as the visual range lies within the measuring range of the LIDAR system. Using the Klett method, the accuracy can be determined with the aid of a breaking-off criterion in the form of a threshold value with respect to a deviation percentage between a new and a previous calculation. With this method the deviation can be identified to an order of magnitude of about 10%.

Abstract: An optical inspection module detects defects on an active surface of a substrate in an integrated process tool system. The optical inspection module includes an enclosure, a substrate holder, a light source, a light beam path, a lens and a photodetector array. The light source has a light beam port. The light beam path extends from the light beam port to the substrate holder and has a grazing angle of incidence with respect to the active surface of the substrate. The light beam path illuminates substantially the entire active surface. The lens is oriented to collect non-secularly reflected light scattered from the light beam path by any defects on the active surface. The photodetector array has a plurality of pixels which are positioned within a focal plane of the lens. Each pixel corresponds to an area on the active surface, and the plurality of pixels together form a field of view that covers substantially the entire active surface.

Abstract: Apparatus for analysing particle dimensions of particles contained in a fluid with an illuminating device for illuminating the particles to be analysed, incorporates a source for generating light. An optical system is disposed between the source and the fluid with a fluid-side window transparent to the light, which focusses the light on the opposite side of the window in the fluid and displaces the focal point along a path running around a center line of the apparatus. A detector device detects the light scattered by the particles and generates an electric signal dependent on the scattered light. A housing is provided between the fluid and the illuminating device and/or the detector device, with an analysis unit for determining the size and/or the size distribution of the particles.

Abstract: The invention relates to an apparatus and method for measuring visibility and present weather. The apparatus includes a light source (1) for directing a light ray toward the object (9) to be measured, a detector (3) for measurement of light which is forward scattered from the object (9), and computing elements (12-15) adapted to differentiate the signal representing the forward scattered light from signals representing stray or ambient light. The apparatus may include a pulsed light source, a receiver (19) for receiving directly backward reflected/scattered light pulses, and computing elements (11) for computing the propagation delays of the different backward reflected components in the received pulse-shaped optical signal.

Abstract: A device is disclosed for measuring light scatter by particles (3) suspended in a carrier medium with a view to ascertaining the density, size or size distribution of the particles. The device comprises: at least one light source (8) which directs light onto a light-scattering center (2) in the carrier medium with the suspended particles (3); a receiver (4) to pick up a portion of the scattered light from the light-scattering center; and an evaluating device connected downstream of the receiver (4). The invention provides for an elongated detection chamber bounded radially around its central axis by the wall of a housing (1) which also acts as a duct for the through-flowing carrier medium with the suspended particles (3). Each light source (8) is mounted on the wall of the housing (1) and points toward the central axis of the detection chamber.

Abstract: Methods and apparatus utilizing back scattered laser light measurement techniques for the measurement of particle size distribution in a fluid are disclosed. Such methods and apparatus are particularly suited for but not limited to the measurement of sub-micron particle size distribution in fluids such as petroleum fluids which are colored or opaque and strongly absorptive of incident light. Utilizing an optical transceiver partly immersed in the fluid, the methods and apparatus include provision for the measurement of particle size distribution while the fluid is subjected to conditions of high pressure and/or high temperature.

Abstract: A motion picture signal, as it is obtained from a camera, is processed by a spatiotemporal filter so that an optical flow of a concerned object is measured, and a velocity of the object is measured from the optical flow, identifying the object.

Abstract: A method and an apparatus for determining analytical data concerning the inside of a scattering matrix, in particular of a biological sample. In a detection step detection measurements are carried out in which light is irradiated into the matrix as primary light at an irradiation site (12) through an interface bounding the scattering matrix (6) and light emerging out of the scattering matrix through the interface is detected as secondary light at a detection site (13) at a predetermined measuring distance from the irradiation site, in order to determine as a measurement variable a measurable physical property of the light which varies due to the interaction of the light with the scattering matrix, which measurement variable is a measure of the analytical data to be determined. In an evaluation step the analytical data are determined on the basis of the measurement variable measured in the detection step.

Abstract: A system and method are disclosed for the self-calibrating, on-line determination of size distribution and volume fraction of a number of particles dispersed in a medium by detecting multiply scattered light from the particles. The multiply scattered light is re-emitted in response to exposure to a light source configured to provide light of time varying intensity at selected wavelengths. The determination includes calculating the isotropic scattering coefficient for the particles at each of a number of wavelengths from the multiply scattered light as a function of an intensity modulation phase shift, and iteratively estimating the size distribution and volume fraction as a function of the isotropic scattering coefficient for each of the wavelengths. An estimation approach based on an expected form of the distribution and the mass of the particles is also disclosed.

Abstract: An in-situ imaging system suitable for analyzing particles or droplets contained in process reactor vessels or pipelines at full process concentrations is disclosed. The system includes a light source capable of high peak power output operated in a pulsed mode that is located inside of a probe. The light from the light source is coupled into an optical fiber. The light is carried by the optical fiber to a lens system near the end of the probe which focuses the light through a window to the area which coincides with the field of view in the focal plane of the imaging optics. The imaging optics collect the light which is back-scattered from particles or droplets, magnifying the image and projecting it onto an image detector such as a CCD array.

Abstract: A suspended particle concentration monitor includes near and far detector circuits with near and far elements sensing scattered visible or near infrared radiation projected into a fluid volume in which particle concentration is determined. The spacing and characteristics of the light sensitive elements and the gains of the near and far detector circuits are selected to produce generally equal peak signals at separate particle concentrations. A computer contains three tables each containing particle concentrations in respective portions of the particle concentration range being monitored. Based upon analysis of the near and far detector signals, one of the tables is selected and used to find the particle concentration corresponding to one of the near and far detector signals.

Abstract: An apparatus for determining particle properties from detected light scattered by the particles. The apparatus uses a light beam with novel intensity characteristics to discriminate between particles that pass through the beam and those that pass through an edge of the beam. The apparatus can also discriminate between light scattered by one particle and light scattered by multiple particles. The particle's size can be determined from the intensity of the light scattered. The particle's velocity can be determined from the elapsed time between various intensities of the light scattered.

Abstract: A non-contact optical backscatter insertion probe includes an outer chamber, an electromagnetic energy source positioned within the outer chamber for emitting photons towards a medium to be analyzed, and an inner chamber positioned within the outer chamber. The inner chamber has a reflective outer surface to prevent photons emitted by the electromagnetic energy source in the outer chamber from entering the inner chamber. The probe also includes a sensor positioned within the inner chamber for receiving backscattered photons from the medium. The inner chamber provides the backscattered photons emitted from the medium to the sensor. A processor receives and processes signals output by the sensor.

Abstract: The invention provides a method and a system for measuring geometric properties, such as diameter, shape and surface roughness of single rough particles by an optical method. The particle may be immersed in a gaseous or liquid fluid. A volume of the fluid, containing the particles to be measured, is illuminated by a beam of coherent electromagnetic radiation, resulting in a distribution of scattered radiation with a speckle structure. This distribution is detected with a one-dimensional or two-dimensional image detector. An autocorrelation function RI(r) of the detected intensity distribution is calculated, and from the position .delta.r of its first zero the diameter d.sub.P of the scattering particle is evaluated based on I, the wavelength of the electromagnetic radiation, and Z.sub.0, the distance from the particle to the detector.

Abstract: A method for the direct reconstruction of an object from measurements of the transmitted intensity of the scattered radiation effected by irradiating the object. The transmitted intensity is related to the image by an integral operator. The image is directly reconstructed by executing a prescribed mathematical algorithm, as determined with reference to the integral operator, on the transmitted intensity.

Abstract: An optical probe for sensing presence of small moving particles passing through a defined sensing region comprises:i) an emitter optic fiber for transmitting from its tip radiant energy outwardly of the probe;ii) a receptor optic fiber for receiving radiant energy reflected by such particles moving through said sensing region;iii) a lens for focusing radiant energy emitted from the emitter tip into a focal region, spaced outwardly of the probe and which diverges outwardly into a defined high density radiant energy region;iv) the receptor optic fiber defining a diverging viewing region projecting outwardly towards the high density radiant energy region, the receptor optic fiber being positioned relative to the lens to project the viewing region to overlap a useful portion of the high density radiant energy region to define thereby the sensing region. This sensor is particularly useful in monitoring the flow characteristics of catalytic particles in a catalytic reactor for cracking of gasoline constituents.

Abstract: A laser observation space instrument for the quantitative characterization by DOPPLER effect of movements within a fluid mass carried by a planet having a reference axis locally parallel to its trajectory and including a laser generator, a frequency measuring unit, first and second sighting elements aligned on the reference axis and having first and second lines of sight of non-null inclinations with respect to the reference axis and intended for emitting and receiving laser beams, a single telescope with its axis merged with the reference axis in order to send beams emitted by the laser generator to the sighting elements and to apply laser beams received by these sighting elements to the measuring unit, and rotating means for rotating the sighting elements with respect to the panel about the reference axis.

Abstract: A method and apparatus are provided that indicate the amount of gas such as air in a clear liquid such as water. The apparatus includes a transparent pipe (60), an input coupling (16) at a first end of the transparent pipe, and a shutoff valve (20) at the second end of the pipe. The first end of the pipe is connected to a source of water (12) under pressure, whose air content is to be determined. With the valve (20) open, water is allowed to pass through the pipe and valve to purge the pipe of air and any previous water. The shutoff valve is then closed, to contain the water under pressure. The dissolved air in the static, pressurized water, immediately forms microscopic air bubbles, which result in the water having a "milky" appearance. The presence of the milky appearance indicates the presence of a considerable amount of dissolved water (when the water is not under high pressure). The reflectivity of the water indicates the amount of dissolved air per unit volume of water (when not under high pressure).

Abstract: A distance measuring system for an automotive vehicle is provided. The distance measuring system outputs laser pulse signals at given angular intervals over an object detectable zone, and receives a signal produced by reflection of one of the outputted signals from a reflective object to determine the distance to the object. The distance measuring system also includes an object type determining function of determining a type of the object present in the object detectable zone. When there are a plurality of signals produced by dispersion of a single shot of the laser pulse signals, and when distances derived by signals reflected from most of the object detectable zone show given shorter distance values, the object present in the object detectable zone is identified as a particle such as snow or fog floating in the air.

Abstract: The present invention describes an optical technique for analyzing undiluted, multi-phase fluid flows as typically encountered inside reactor vessels or flow lines in the chemical industries. In particular the technique uses a pulsed, coherent light source and measures the back-scattered light collected over a wide scattering angle. A light beam is relayed via a set of lenses down a long probe tube, through a window at a probe tip to illuminate the material that is passing past the window. The light beam is pulsed to "freeze" the motion of the particles streaming past the window. The backscattered light is collected by the same set of optics and is focused on the front surface of a CCD chip.

Abstract: The present invention is directed to an optical range measurement device which is able to compensate for lens contamination. The optical range measurement device includes one or more windows having at least two sections positioned at an angle to one another, a transmitter for producing a main beam and transmitting the main beam into the atmosphere, and a receiver for receiving the main beam back scattered by the atmosphere. The device also includes a transmitter producing a reference beam which illuminates the at least two sections and a receiver for receiving the reference beam.

Abstract: A nephelometer instrument capable of measuring from zero to 10,000 NTUs. The instrument includes four light detectors, three of which are positioned such that they measure light scattered at specific directions by a liquid sample. The fourth detector measures light transmitted through the sample. A removable light filter is also included. The light beam is focused on the front surface of the sample cell.

Abstract: A detection system for use in an aircraft which is able to monitor atmospheric conditions ahead of the aircraft, generate an alarm signal if adverse atmospheric conditions exist ahead of the aircraft and generate information which indicates the position of the adverse conditions so the adverse conditions can be avoided. The system is able to detect the presence of volcanic ash cloud ahead of the aircraft and, if desired, can also be used to detect a high density of sulphur dioxide gas and/or clear air turbulence ahead of the aircraft. The system monitors infrared radiation received by the aircraft, generates intensity signals representative of at least one predetermined wavelength of the radiation and compares intensity signals with reference signals or intensity signals of another infrared wavelength.

Abstract: The device can be used on an aircraft or spacecraft. It comprises a laser for emitting short light pulses, a channel for receiving the backscattered light flux and an optical conical scanner means making it possible to orient a direction common to laser emission and to reception via the channel along successive generatrices of a cone. The scanner has a mirror rotated about a scanning axis for deflecting an optical path common to a receiving detector and to the laser along successive directions distributed at regular angular intervals around the scanning axis and several stationary reflectors distributed at the regular intervals. The reflectors are successively inserted on the common optical path by the rotating mirror. The stationary reflectors correspond to different probing orientations along the cone. The rotating mirror has a size very much less than that of the beam entering and exiting the device.

Abstract: The invention relates to an optical sorting system for a color sorting machine. Product is irradiated with visible, infra-red or ultra-violet light by a transmitter. If there is no product in the ray path of the transmission source, all of the light falls onto a residual light receiver. If product is present, on the other hand, the light is partly or wholly scattered back to one or more product signal receivers.

Abstract: This invention relates to a method for biodetection and identification of antibiotic susceptibility tested in bacteria by cerating spectrum against target cells and comparing them.

Abstract: An aerodynamic particle size measuring device includes a laser energy source and beam splitting, shaping and polarizing optics for forming two parallel, peripherally overlapping beams. The beams are caused to intersect a gas stream perpendicular to the direction of gas flow, thus to form a measuring volume at the intersection of the beams and flow. Single particles are carried through the measuring volume with the gas flow, each particle scattering and extinguishing light according to the beam profile, as predetermined by the degree of beam overlap and the Gaussian intensity distribution of each beam. A photodetector, responsive either to scattered light or light extinction, generates a time-dependent voltage profile that tends to replicate the intensity profile. The resulting electrical signal is processed to determine an amplitude, set a threshold for minimally acceptable amplitudes, and to derive two negative-going zero crossings for an unambiguous time/velocity determination.

Abstract: A lidar system which utilizes optical backscatter and extinction to determine the size of particles inside the exhaust plume of an aircraft at a distance of several hundred meters behind the aircraft. The system transmits a laser beam through the exhaust plume of the aircraft, where it is reflected by the particles contained in the exhaust plume. The reflected light is detected by a receiver, where it is processed by a computer to calculate the size of the particles in the exhaust plume.

Abstract: A nephelometer instrument capable of measuring from zero to 10,000 NTUs. The instrument includes four light detectors, three of which are positioned such that they measure light scattered at specific directions by a liquid sample. The fourth detector measures light transmitted through the sample. A removable light filter is also included. The light beam is focused on the front surface of the sample cell.

Abstract: The invention concerns a method and device for measuring the meteorological visibility and the scattering of light. A light pulse is emitted into the atmosphere via an optical transmit system, the backscattered light returns via the optical transmit system after which its intensity and delay are measured. The waveform of the optical transmit pulse generated at the instant of its launching from within the apparatus is sensed in a manner that excludes any backscattered light originating from outside the measurement system, this signal is scaled for both its magnitude and phase so as to achieve a suitable feedback signal relative to the actual measurement signal and said feedback signal is subtracted from said measurement signal to avoid overloading of the receiver.

Abstract: A dynamic light scattering analyzer which comprises: a sample cell which comprises a cell housing and a cell chamber, the cell chamber being formed within the cell housing such that the cell chamber is exposed to a membrane which is capable of retaining within the cell chamber the particles of a sample introduced into the cell chamber while allowing a liquid carrier to diffuse across the membrane in and out of the cell chamber; a light source; an optical waveguide which is capable of exposing the particles to a light source and which is capable of receiving the light scattered from the particles within the cell chamber and the light reflected from the waveguide-solution interface; a photodetector which is capable of detecting the light scattered from the particles within the cell chamber and the light reflected from the waveguide-solution interface; and a pump for controlling the flow rate and concentration of the carrier liquid which contacts the membrane.

Abstract: Light-transmitting plastic and/or glass bottles are tested at a station where selected portions of their internal surfaces scatter radiation issuing from a beam of monochromatic radiation. The scattered radiation is intercepted and monitored for the generation of signals which denote the presence or absence of impurities on the selected portions of the internal surfaces and/or certain substances in the walls adjacent the selected portions of the internal surfaces of tested bottles. Such signals are processed, and the processed signals are utilized to classify the bottles according to their defects and/or to segregate unsatisfactory bottles from acceptable bottles and/or to segregate glass bottles from plastic bottles and/or to classify satisfactory plastic bottles in accordance with the nature of their plastic materials. The scattered radiation can constitute Raman, Rayleigh and/or fluorescence radiation.

Abstract: In measuring the turbidity of a liquid, especially for determining water clarity in a water purification process in which after the addition of flocculant the water is centrifuged, light is emitted as a diffuse beam from a light source and the intensity of light reflected from gas bubbles in the liquid is detected by a photosensor. The light source and photosensor are incorporated in a probe having transparent cylindrical wall. The probe is sealed within a housing confining a liquid receiving chamber. A plurality of seals are provided forming a space containing a cleaning solution. An actuator is coupled to the probe for reciprocating the probe relative to the housing and seals for cleaning deposits from the wall.

Abstract: Optical smoke detectors such as extinction smoke detectors and scattered-light smoke detectors include a radiation source, a radiation detector or receiver, and a measurement volume which is in communication with ambient atmosphere and which is traversed by a light path from the radiation source to the radiation receiver. For compactness and simplicity, such an optical smoke detector is provided with a planar-optical element in the optical path. Suitable as planar-optical elements are diffractive elements, e.g., holographic-optical elements (HOE), and micro-Fresnel elements (MFE), e.g., micro-Fresnel reflectors (MFR).

Abstract: A device for analyzing fine particles in a sample gas includes a light source for emitting light, a convergent device for converting the light emitted by the light source into a convergent light beam having a light focus point and an energy density sufficient to dissociate the fine particles to be analyzed. The device also includes a transparent analyzer tube having a window for admitting the convergent light beam and a throat located at the light focus point of the convergent light beam, the analyzer tube receiving the sample gas and passing the sample gas through the throat. The device includes a light collecting device for collecting, through the analyzer tube, light emitted from dissociated fine particles, dissociated by the convergent light beam in the throat of the analyzer tube, and an analyzing device for analyzing the light from the dissociated fine particles collected by the collecting device.

Abstract: Methods and apparatus for detecting biological activities in a specimen such as blood are disclosed. The present invention provides a system whereby the intensity of light with a wavelength within the range of about 600 nm to 800 nm introduced into a sample at a first location is measured as it reemerges at a second location. A significant change in the intensity of the reemerging light indicates the presence of biological activity. Preferably, the intensity is also measured at a fourth location, or alternatively, a second light source is disposed at a third location to permit comparative intensity data to be collected. These data are useful in partially identifying the types of microorganisms present in the sample. In preferred embodiments, light emitting diodes are used as the light sources and multiplexed to a plurality of samples.

Abstract: Optical measurements of turbid media, that is media characterized by multiple light scattering, is provided through an apparatus and method for exposing a sample to a modulated laser beam. The light beam is modulated at a fundamental frequency and at a plurality of integer harmonics thereof. Modulated light is returned from the sample and preferentially detected at cross frequencies at frequencies slightly higher than the fundamental frequency and at integer harmonics of the same. The received radiance at the beat or cross frequencies is compared against a reference signal to provide a measure of the phase lag of the radiance and modulation ratio relative to a reference beam. The phase and modulation amplitude are then provided as a frequency spectrum by an array processor to which a computer applies a complete curve fit in the case of highly scattering samples or a linear curve fit below a predetermined frequency in the case of highly absorptive samples.