Abstract: A method and system for monitoring the quality of a slurry utilized in a chemical mechanical polishing operation. A slurry is generally delivered through a tubular path during a chemical mechanical polishing operation. A laser light is generally transmitted from a laser light source, such that the laser light comes into contact with the slurry during the chemical mechanical polishing operation. The laser light can then be detected, after the laser light comes into contact with the slurry to thereby monitor the quality of the slurry utilized during the chemical mechanical polishing operation. The laser light that comes into contact with the slurry can be also be utilized to monitor a mixing ratio associated with the slurry.

Abstract: A diffractive optic sheer stress sensor operates by forming diverging fringes over a linear area of measurement. A diode laser focuses light onto a diffractive lens which focuses the light to respective slits. The slits form diverging fringes, and scattered light from the fringes is collected by a window and focused by another diffractive lens to a receiver.

Abstract: The invention relates to a method and a measurement device for measuring a suspension which contains wood fibers, the method comprising directing optical radiation at pulp and measuring optical radiation emitted by the pulp. The solution comprises measuring at least one of the following two properties; kappa number and brightness. The solution comprises changing the pulp consistency in a desired range of consistency extending from a desired initial consistency to a desired final consistency. The pulp consistency and the strength of a desired wavelength from the optical radiation are measured in the desired consistency range. Measurement points are modeled with a function of the desired type by fitting the parameters of the function according to the measurement points. Finally at least one of the following two properties of the pulp is determined by means of the modeling function; kappa number and brightness.

Abstract: A device for measuring the three-dimensional position of a single particle (208) in a solution comprises a pulsed laser (201); a microscope system for irradiating a single particle with a laser beam (203) emitted from a pulsed laser (201); a photodetector (209) for detecting light dispersed by the single particle; a computer (211) for recording the signal detected by the photodetector (209) as displacement data and processing it; and a high-speed A/D board (210) for introducing the signal detected by photodetector (209) into the computer (211). Timing is set for data input so that the signal detected by the photodetector (209) may be input to the computer (211) at the moment of laser irradiation. It is possible to measure the position of a particle of nanometer size in real time with accuracy of nanometer order.

Abstract: According to the present invention, there is provided a light scattering type particle detector, using a semiconductor laser as a light source, for detecting particles contained in sample fluid which defines a flow path, wherein laser light generated from the semiconductor laser is irradiated to irradiate a region of the flow path with a concave mirror and thereby a particle detecting region is defined.

Abstract: A single-particle optical sensor, which has high sensitivity and responds to relatively concentrated suspensions, uses a relatively narrow light beam to illuminate an optical sensing zone nonuniformly. The zone is smaller than the flow channel so that the sensor responds to only a fraction of the total number of particles flowing through the channel, detecting a statistically significant number of particles of any relevant diameter. Because different particle trajectories flow through different parts of the zone illuminated at different intensities, it is necessary to deconvolute the result. Two methods of deconvolution are used: modified matrix inversion or successive subtraction. Both methods use a few basis vectors measured empirically or computed from a theoretical model, and the remaining basis vectors are derived from these few. The sensor is compensated for turbidity. Several embodiments are disclosed employing light-extinction or light-scattering detection, or both.

Abstract: Novel method and apparatus are disclosed for inspecting a wafer surface to detect the presence thereon of exposed conductive material, particularly for determining the integrity of contact holes and vias, in semiconductor wafer manufacturing. The method comprises the steps of irradiating a spot of the wafer surface with a beam having a wavelength sufficiently shorter than the working function of the metal, such as deep UV light beam, collecting the electrons released by the irradiated wafer, generating an electrical signal that is a function of the collected electrons, and inspecting the signal to determine whether the contact holes or vias within the irradiated wafer spot are open. The apparatus comprises a vacuum chamber having therein a stage and chuck for supporting the wafer. An illumination source generates irradiating energy which is formed into a beam using appropriate optics so as to obtain the desired beam spot of the wafer's surface.

Abstract: An optically based liquid level (liquid-vapor) detector for use with a window having a substantially planar side facing the liquid-vapor side and a substantially planar side positioned parallel to the liquid-vapor side facing the outside. The detector comprises a light source positioned on the outside of the window to direct its light through the outside planar side to the inside planar liquid-vapor side and a light detector positioned on the outside of the window to receive light transmitted from the source and returned from the planar liquid-vapor window side. The detector further includes electronic means for detecting the light intensity change affecting the transducer, from the condition of liquid on the liquid-vapor side, to the condition of vapor on the liquid-vapor side of the window, whereby an action or signal is generated in response to such change.

Abstract: Apparatus and method for measuring scatterer size in a dense media with only a single fiber for both light delivery and collection are disclosed. White light is used as a source and oscillations of the detected light intensities are measured as a function of wavelength. The maximum and minimum of the oscillations can be used to determine scatterer size for monodisperse distributions of spheres when the refractive indices are known. In addition several properties of the probe relevant to tissue diagnosis are disclosed including the effects of absorption, a broad distribution of scatterers, and the depth probed.

Abstract: A smoke detector includes a housing defining a dark chamber admitting test atmosphere. A light receiver is disposed within the chamber. A scatter emitter is positioned within the chamber such that light strikes the receiver when reflected off particles suspended in the test atmosphere. An obscuration emitter is positioned within the chamber such that light emitted is directed to the receiver unless obstructed by particles suspended in the test atmosphere. A smoke detect signal is generated responsive to a measurement made responsive to the scatter emitter and/or the obscuration emitter.

Abstract: A new method is presented for measuring the molecular properties of an unfractionated solution of macromolecules. Sharing some similarities with the standard Zimm plot technique, the method begins with the preparation of several sample aliquots spanning a range of concentrations. The aliquots are then injected sequentially into a stream such as provided by a liquid chromatograph. Each aliquot produces, thereby, an effective “peak” whose elements correspond to different concentrations of the diluted aliquot. By analyzing the angular and concentration dependence of the scattering signals throughout the corresponding peaks, the weight averaged molar mass, the mean square radius, and the second virial coefficient may be derived. In contrast to earlier on-line methods, better accuracy is achieved, while using a smaller quantity of sample.

Abstract: A wide range particle counter has sections which separately detect coarse and fine particles in an aerosol. The coarse particles are counted and sized in an optical particle counter. The fine particles are classified with a differential mobility analyzer to determine size and then passed through a vaporizer and condenser and also counted. Using the different sections permits counting and measuring a wide range of particle size in a single instrument with high accuracy and reliability.

Abstract: An ambient air condition sensor housing includes a front portion releasably coupled to a rear portion and defining an interior space therebetween adapted to retain at least one ambient air condition sensor. The rear portion defines apertures for passage of the ambient air therethrough. A labyrinth having a plurality of spaced apart upstanding walls is integrally attached to an inner surface of the rear portion and is positioned so as to cooperate with the air condition sensor. Each wall of the labyrinth includes a slightly arcuate configuration for funneling the ambient air toward the air condition sensor. The rear portion and labyrinth are completely covered with a black coating so as to minimize light reflectivity within the interior space whereby to enhance proper functioning of the air sensor.

Abstract: A method for determining the particle concentration of a continuous medium in a receptacle, in which, a light beam from a light source is first directed through a particle-loaded, continuous medium, to the light-sensitive surface of a position-sensitive sensor, the light beam being so directed at the light-sensitive surface that the light scattered by the particles assuming, on the average, a different position than the unscattered light. The deviation of the midpoint of the scattered light on the light-sensitive surface from the midpoint of the unscattered light is subsequently determined, and this deviation is correlated to a specific particle concentration.

Abstract: An on-line method for detecting particle size of a liquid during a process in which there is not a correlation between low absorbance with small particle size, the method comprises the steps of measuring a plurality of reference particle sizes each associated with a particular near infrared diffuse reflectance spectrum for creating a reference infrared diffuse reflectance spectrum having high absorbance with small particle size; measuring on-line a near infrared diffuse reflectance spectrum of the liquid during the process; and determining the particle size of the on-line liquid based on correlating the on-line-measured particle size with the reference near infrared diffuse reflectance spectrum.

Abstract: The invention relates to a sensor element for optically detecting chemical or biochemical analytes which may be contained in different samples. The object is to minimize the required sample volume and to allow the individual samples to be arranged relatively close together, while nevertheless achieving a high measurement accuracy. At least one interface, at which an evanescent field is formed as a result of total reflection, is formed on the sensor element. The samples are held in mutually separated cavities, and the cavities are formed inside a structured cover layer applied directly to a substrate. In this case, the layer thickness of the cover layer is at least greater than the penetration depth of the evanescent field. The cover layer consists of a fluorinated polymer, and it prevents substance exchange of the individual samples that are held in the various cavities.

Abstract: The present invention provides methods and systems for aligning detection optics with a device by obtaining an optical profile of the system and comparing it with a preprogrammed layout of the various optical features of the device. The invention also provides methods of identifying devices by comparing the optical profile with a library of preprogrammed optical profiles of multiple devices.

Abstract: Systems, and components thereof, for analyzing samples. These systems include apparatus and methods for generating, transmitting, detecting, and/or analyzing light, including without limitation high-throughput optical screening devices for analyzing samples at one or more assay sites. These systems also include apparatus and methods for supporting samples for analysis, including without limitation multiwell sample holders such as microplates.

Abstract: In a method and an apparatus for point-by-point and line-by-line scanning of a master chucked on a scanner drum, for pixel-by-pixel illumination of the master, a light spot is generated in a light conductor and is imaged onto the master as illumination spot. The light conductor is arranged displaceable with an actuating drive for the purpose of modifying the imaging scale of the illumination spot. For setting the illumination, the luminance of the illumination spot is measured with the opto-electronic scanner element. In a computer, control signals for the actuating drive are generated dependent on the measured luminance. For setting the optimum illumination of the master, the imaging scale of the illumination spot is modified such by displacing the light conductor that the measured luminance of the illumination spot is maximum.

Abstract: In an apparatus for point-by-point and line-by-line, opto-electronic scanning of masters chucked on a scanner drum, an illumination unit is provided for generating an illumination spot on the master. A scanner objective, a scanner element and a feed support is provided at which the illumination unit, the scanner objective and the scanner element are arranged. The illumination unit comprises a light conductor that is aligned in the direction of the rotational axis of the scanner drum and has a light exit face for generating a light spot and has optical elements for imaging the light spot onto the master as an illumination spot. At least a sub-section of the light conductor in the region of the light exit face can be inclined by small angles relative to the rotational axis with a Cardanic bearing for fine adjustment of optical beam paths, as a result whereof the illumination spot is displaced on the scanner drum. The slope of the light conductor that has been found to be optimum is then fixed.

Abstract: A method and apparatus for automatically inspecting transparent or translucent materials, especially plastic materials, the apparatus including a light container, at least one camera, a digital processor, and a reject mechanism, the method comprising conveying a particle of the material through the light container, capturing an image of the particle with the camera, identifying defects in the image with the digital processor, and separating out defective material by communication between the digital processor and the reject mechanism. The light container is an illumination device, preferably an integrating sphere, that has two opposing openings through which a particle can pass and one or more other openings or windows through which one or more cameras view the particle.

Abstract: A sensor device is described for detecting wetting of a windshield that has only one transmitter with which two measuring zones of the sensor device can be implemented on a wettable outside of the windshield. A light guidance body injecting transmitter radiation into the windshield has structures with which the transmitter radiation emitted by the transmitter is collected and parallelized in two different directions.

Abstract: A ball detecting apparatus having a simple structure and being capable of surely detecting balls carried in a tube using transparent liquid as a carrier without being affected by bubbles produced in the tube. The ball detecting apparatus has a surface light source 12 for projecting diffused light having a predetermined beam cross section and a predetermined beam spread angle, from a side of a tube 11 in which balls 10 are carried, into the tube 11. A photo detector 13 is arranged opposite to the surface light source 12 with the tube between. The photo detector receives a component of the diffused light that travels directly toward a light receiving area and/or a component of the diffused light that has been deflected by a bubble produced in the transparent liquid to travel toward the receiving area. The light receiving area is adapted to be able to be completely shielded from the diffused light by the balls.

Abstract: An optical sensor includes a sample cell through which a fluid flows, an optical sensor formed by an optical emitter and an optical detector. The sample cell and the optical sensor use light refraction to determine the presence and size of a bubble passing through the sample cell. A housing may also be included to provide better control over light refraction and to protect the optical sensor.

Abstract: A system for quantifying the petroleum content of aqueous media includes a sample cell; a first light source for generating a first light signal that stimulates fluorescent emissions when the first light signal irradiates hydrocarbons present in an aqueous solution in the sample cell; a spectral detector for generating a first electrical signal that represents spectral components of the fluorescent emissions in response to detecting the fluorescent emissions that are emitted from the sample cell; a second light source for generating a coherent light signal that is transformed into scattered light signals when the coherent light irradiates oil droplets in the aqueous solution; a detector for generating a second electrical signal in response to detecting scattered light signals emitted from the tube, where the second electrical signal represents the intensities and scatter angles of the scattered light signals; and a processor for determining a particle size distribution of the oil droplets from the second elec

Abstract: A smoke detector is provided with a light emission section holder having a light-emission element and a light receiving section holder having a light-receiving element. The light emission section holder and the light-receiving element are provided in a smoke detection section constituting a smoke detection space. The light emitted from the light-emission element is scattered by smoke entered the smoke detection space. The thus-scattered light is received by the light-receiving element,thereby detecting occurrence of fire. An insect screen is formed from soft fiber having a mesh pattern and is arranged so as to cover the entirety of the smoke detection section.

Abstract: A particle image analyzer that facilitates display by designating on a distribution an image desired to be displayed from among a large number of recorded images is disclosed. The particle image analyzer is provided with a parameter computation means for computing at least one characterizing parameter for respective particle images obtained by image capture; a storing means for storing correlations between the particle images and the characterizing parameters with regard to the respective particle images; distribution-diagram generation means for generating characteristic-parameter distribution diagram; designation means for designating the area within the distribution diagram; read-out means for reading out from the memory means particle images corresponding to characterizing parameters within the areas designated by the designation means; and display means for displaying the read-out particle images.

Abstract: A low profile, low volume smoke chamber displaces a light source, such as a light emitting diode or laser diode, and a sensor, such as photodiode or phototransistor, to the exterior of the sensing volume. A symmetrical sensing volume results which can be coupled to symmetrical input/output ports via a generally U-shaped flow path. A two part sensing chamber housing is formed with a lower cylindrical base portion and an upper cylindrical cover portion which slideably engage one another. At least the upper cylindrical portion carries a plurality of grooves for suppression of reflections and collection of dust. An exterior end of the upper portion carries a plurality of spaced apart openings which can be filled with a screen. A reduced sensing volume in combination with a selected screen size produces an acceptable signal to noise ratio and response rate while still excluding insects and other non-smoke related particulate matter.

Abstract: A fluid quality sensor system comprising a light source, a first light sensitive element disposed at a distance from the light source, forming a gap having dimensions suitable for permitting a fluid to flow therebetween, and aligned with the light source to receive light transmitted by the light source through the fluid, a second light sensitive element disposed perpendicular to a midpoint of a light path between the light source and the first light sensitive element, and a third light sensitive element disposed so as to form an acute angle at the midpoint with the light source.

Abstract: A scattering light smoke alarm has a light transmitter and a light receiver arranged so that a scattering point of the light transmitter and the light receiver are located outside the scattering light smoke alarm in a free space, a cover for protecting the light receiver and the light transmitter, and an element for distinguishing between smoke and other foreign bodies which are located in an area around the scattering point.

Abstract: A device, by which an unadulterated visibility range can be determined that is independent of the scattering-medium characteristics, determines according to the LIDAR principle the instantaneous visibility range from backscatter light reflected in the scattering medium in front of a vehicle. An evaluation unit is also provided which normalizes a plurality of backscatter measuring curves recorded in succession over time. It forms an average measuring curve from the normalized measuring curves, and derives from at least one measured value of the averaged measuring curve, a visibility range which is independent of the backscattering characteristics of the scattering medium. Using this visibility range thus ascertained, an adaptive compensation of the instantaneously ascertained visibility range is carried out in the evaluation unit.

Abstract: High quality epitaxial layers of monocrystalline materials can be grown overlying monocrystalline substrates such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. An accommodating buffer layer comprises a layer of monocrystalline oxide spaced apart from a silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline material layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer. In addition, formation of a compliant substrate may include utilizing surfactant enhanced epitaxy, epitaxial growth of single crystal silicon onto single crystal oxide, and epitaxial growth of Zintl phase materials.

Abstract: An optical monitoring unit includes a transmitting unit having plural light emitting diodes that are connected together two at a time in respective diode pairs. Each diode of each diode pair is respectively selectively connectable to a current source so as to operate as an active transmitting diode, or to a load resistor across which a voltage may be measured so as to operate as a monitoring diode. When any selected single diode is operated as the transmitting diode, its light output is measured and evaluated by operating the other diode of the pair as the monitoring diode, which receives optical crosstalk from the light output of the transmitting diode and correspondingly generates a photoelectric current through the load resistor.

Abstract: A liquid leakage sensor, paper for detecting liquid leakage, and holder for detecting liquid leakage stably and reliably without being affected by bubbles when a large volume of liquid leaks at once. A liquid leakage sensor also has a tilt detection capability that does not use a test paper and can quickly and reliably detect liquid leakage even before the liquid contacts the case bottom.

Abstract: An improved system and method of analyzing cumulative radiation exposure registered as pits on track etch foils of radiation dosimeters. The light scattering apparatus and method of the present invention increases the speed of analysis while it also provides the ability to analyze exposure levels beyond that which may be properly measured with conventional techniques. Dosimeters often contain small plastic sheets that register accumulated damage when exposed to a radiation source. When the plastic sheet from the dosimeter is chemically etched, a track etch foil is produced wherein pits or holes are created in the plastic. The number of these pits, or holes, per unit of area (pit density) correspond to the amount of cumulative radiation exposure which is being optically measured by the apparatus.

Abstract: Moisture detection permits moisture removal equipment, such as automotive windshield wipers and defogger systems, to be operated automatically. A system for detecting moisture on a surface includes a light emitter directed at the surface. The presence of moisture is based on the intensity of light from the emitter reflected by the surface and received by a light sensor. The light sensor accumulates charge in response to incident light over a variable integration period.

Abstract: A flow cell for obtaining information on particles suspended in sample fluid, wherein an irradiation region M is defined in the flow cell for functioning as a particle detection portion to be irradiated with a laser beam La, and a wall portion of the flow cell is so adapted and arranged that the laser beam La becomes incident upon an outer wall surface of the flow cell 1 at a predetermined angle &thgr;1 (&thgr;1≠0°) and exits from an inner wall surface 5b of the flow cell 1 into the sample fluid 6 at a refraction angle 0°. Further the wall portion 5 of the flow cell 1 is so arranged that the laser beam La becomes incident upon a boundary surface between the sample fluid and the opposite inner wall surface of the flow cell 1 at a predetermined incident angle &agr; (&agr;≠0°) after being incident upon the sample fluid and passing through the irradiation region M.

Abstract: Systems and associated methods are provided for improving detection and measurement of elements in a medium, particularly the measurement of gaseous bubbles in liquid medium, such as blood injected into a patient's body. The systems include a radiation emitter to emit radiation for traversing through a medium, and an analyzer subsystem to receive and to analyze the traversed radiation for presence and/or absence of gaseous elements in the medium. The methods include receiving at least one collection of data corresponding to at least one emitted radiation traversed through a medium, analyzing said collection of data for at least one predetermined condition; and generating a response upon detection of at least one predetermined condition.

Abstract: A sensor device is described for detecting wetting, in particular rainfall and soiling, on a windshield that has at least two, preferably eight, transmitters and at least one receiver for receiving light emitted by the respective transmitters. The at least two transmitters are arranged concentrically around the at least one receiver. A base area is defined by the at least two transmitters and the at least one receiver, with the base area being at least a sector of a circle. This reduces an outer dimension of the sensor device and improves a ratio of sensitive area to base area of the sensor device.

Abstract: A turbidity sensor apparatus and method for measuring very low concentrations of particles in a fluid. The turbidity sensor comprises a laser light source for emitting laser light through a fluid. Such a fluid may be hydraulic fluid, oil, water utilized in water purification systems, or other translucent fluids. The turbidity sensor includes a first light-sensitive detector located 90 degrees to incident laser light emitted from the laser light source, and a second light-sensitive detector located at an angle obtuse to the incident laser light emitted from the laser light source, wherein the first and second light-sensitive detectors respectively measure side scattered light and forward scattered light reflected from particles contained within the fluid that come into contact with laser light emitted from the laser light source, thereby providing an accurate and reliable measurement of very low concentrations of particles within the fluid.

Abstract: The present invention provides a method and an apparatus which eliminate the influences of a scattered light arising due to the pollutants inside and on the surfaces of an optical window, differences in refractive index and light transmittance of a solution to be detected, and the obstruction due to suspending particles and the like to achieve a measurement with high precision and high practicability in the measurement of the scattered light arising. The scattered light propagating within a prescribed angle perpendicularly to the direction of propagation of the light to be propagated through the inside of the solution is measured. Further, the position of the optical axis of the light to be propagated through the inside of the solution and/or the position of the photosensor in the direction of the optical axis are set so that the influence of the scattered light arising at and on the surface of the optical axis is not more than a predetermined value within a practically allowable range.

Abstract: An apparatus for measuring the level of liquid contained in a tank includes a tank, at least one exhaust pipe having a transparent portion, a light source for emitting light to the transparent portion of the at least one exhaust pipe, a photodetector for detecting light reflected by or transmitted through the transparent portion of the at least one exhaust pipe and outputting electric signals corresponding to the detected light, and a liquid level measuring portion for measuring the level of liquid contained in the tank from the electric signals output from the photodetector. The transparent portion of the at least one exhaust pipe has one end thereof installed to be connected to the tank and the other end, horizontally extended a predetermined length from the one end, connected to a set supply path and/or the tank so that liquid can be collected.

Abstract: A method is described to determine the 2nd virial coefficient of an ensemble of molecules dissolved in a selected solvent. Two distinct classes are described: monodisperse and polydisperse molecules. If the molecules are monodisperse, they must be prepared for a chromatographic separation and suitable columns selected. Following standard chromatographic separation procedures such as exemplified by the method of size exclusion chromatography, the sample passes through the separation columns, a multiangle light scattering detector, and a concentration detector. The effect of the columns is to produce a concentration profile of said sample that appears as a peak as it passes through the light scattering and concentration detectors. For each elution interval, &ngr;i, a corresponding concentration value ci and set of excess Rayleigh ratios Ri(&thgr;j) is measured for each scattering angle &thgr;j.

Abstract: An integrating nephelometer is modified to measure 180° backscattering from an aerosol. A laser is mounted outside a housing of the nephelometer and produces a coherent light beam that is directed into a sample volume of the nephelometer, substantially along an optical sensing axis (<4° off the optical axis). Light from the laser beam that is reflected by an aerosol travels back along the optical sensing axis toward a photomultiplier tube (PMT) light detector, which thus produces a signal indicative of the backscattering from the aerosol. A portion of the laser beam is conveyed into the housing of the nephelometer through an optical fiber for use as a reference beam. A motor-driven chopper disk disposed across the optical axis is divided into an open sector, a calibration sector (with a very low transmission), and a flat black light absorbing sector.

Abstract: An improved self-cleaning oven (10) is provided having an assembly (12) to control the cleaning cycle time of the oven (10) depending upon the degree of oven contamination and soil present therein. The assembly (12) includes a measuring chamber (16) as well as a passageway (18) communicating the interior (14) of the oven (10) and the chamber (16). A smoke detector (32) (preferably an infrared smoke detector) is associated with the chamber (16) and is coupled with a controller (20) so as to measure a parameter of smoke passing through the chamber during at least a portion of the cleaning cycle. This parameter is then used to determine the proper duration of the cleaning cycle. In preferred forms, measuring chamber (16a) is equipped with an ambient air inlet (52) and outlet (54) so as to draw an ambient air stream through the chamber (16a) between the smoke detector (32) and the oven gas stream.

Abstract: A self-contained smoke detector system has internal self-diagnostic capabilities and accepts a replacement smoke intake canopy (14) without a need for recalibration. The system includes a microprocessor-based self-diagnostic circuit (200) that periodically checks sensitivity of the optical sensor electronics (24, 28) to smoke obscuration level. By setting tolerance limits on the amount of change in voltage measured in clean air, the system can provide an indication of when it has become either under-sensitive or over-sensitive to the ambient smoke obscuration level. An algorithm implemented in software stored in system memory (204) determines whether and provides an indication that for a time (such as 27 hours) the clean air voltage has strayed outside established sensitivity tolerance limits. The replaceable canopy is specially designed with multiple pegs (80) having multi-faceted surfaces (110, 112, 114).

Abstract: An apparatus for performing scattered radiation measurements in fluids comprising a sender (1)-for example a light source-to directly emit radiation into the fluid (5), a detector (2) to measure scattered radiation in the fluid, at least one separator (4) that is provided between the fluid and the sender and between the fluid and the detector, and that allows radiation to pass through it, wherein, at least one optical deflection element (8, 9) is provided between the sender and the separator and/or between the detector and the separator, in order to deflect the emitted beam/the scattered beam toward the perpendicular onto the separator. This scattered radiation measuring apparatus is characterized by having a very compact design.

Abstract: A system for detecting an underwater object includes an optical signal generator operable to generate and transmit an optical signal into the water. The system also includes an absorption cell operable to receive the optical signal reflected from the water and absorb an unshifted frequency component of the reflected optical signal. The system further includes a detector operable to receive a shifted frequency component of the optical signal from the absorption cell and detect the object using the shifted frequency component of the optical signal. Displacement of the water by the object causes an absence of a portion of the shifted frequency component of the optical signal.

Abstract: The invention relates to an optical sensor for motor vehicles, for detecting ambient parameters that affect vision, having at least one transmitter and at least one receiver for electromagnetic waves (light waves), in which a windshield is disposed in a measurement segment between the at least one transmitter and the at least one receiver and influences a wave propagation between the at least one transmitter and the at least one receiver in such a way that when a film develops on the windshield, and especially when wetting occurs from precipitation, an output signal generated by the receiver varies and serves to trigger a windshield wiper system. It is provided that at least one of the receivers (16, 20, 22) of the optical sensor (4) receives electromagnetic waves (light waves) of an ambient brightness of the motor vehicle and serves to trigger a light system of the motor vehicle.

Abstract: A smoke detector that is insensitive to moisture, such as for use in aircraft cargo bays and the like, is provided. The smoke detector includes a housing defining a chamber that is sealed from outside light sources yet is capable of receiving smoke. The smoke detector also includes a light source that is positioned inside the chamber and a detector for receiving diffusely scattered light within the chamber. Advantageously, the smoke detector also includes a moisture compensating device that reflects a substantially consistent percentage of light incident thereupon regardless of moisture on the surfaces thereof such that the operation of the light source can be reliably tested even in environments where moisture has condensed or otherwise collected on the walls of the housing.