Abstract: A pair of optical gratings are used to modulate light from an object, and the modulated light from either grating is used to determine the velocity of the object. Each optical grating is offset from a reference focal point by the same distance, one grating being offset in a positive direction, the other in a negative direction. Signals produced in response to the modulated light can be processed to determine a direction in which a primary collection lens should be moved in order to improve a focus of the imaging system on the object. The lens is moved incrementally in the direction so determined, and the process is repeated until an optimal focus is achieved. In a preferred embodiment, the signals are weighted, so that the optical grating disposed closest to the optimal focus position contributes the most to velocity detection.

Abstract: Method for manufacturing of an optical fiber with a decoupling interface for scattered light to monitor the power of light guided through the optical fiber, where the optical fiber has a core having a first refractive index and a cladding surrounding the core, the cladding having a second refractive index smaller than the first refractive index, and where a portion of the optical fiber is substantially straightly aligned in the region of the decoupling interface, in which method the optical fiber is electro-thermally treated at an intermediate position within the substantially straightly aligned portion such that a partial mixture of core material and cladding material and, thereby, formation of scattering centers occurs in an interface region between the core and said the cladding, thereby forming the decoupling interface for scattered light from the modified intermediate position.

Abstract: A pathogen detector has a sample area for containing environmental air, a light source on one side of the sample area for directing a collimated beam of light through the sample air so that part of the light beam will be scattered by any particles present in the air while the remainder remains unscattered, and a beam blocking device on the opposite side of the sample area for blocking at least the unscattered portion of the beam of light and directing at least part of the scattered light onto a detector. The detector produces output pulses in which each pulse has a height proportional to particle size and a pulse height discriminator obtains the size distribution of airborne particles detected in the air sample at a given time from the detector output. An alarm signal is activated if the number of particles within a predetermined pathogen size range of around 1 to 7 ?m exceeds a predetermined normal level.

Abstract: An inexpensive, optical position sensor for measuring a position or length, x, along a one-dimensional curvilinear, coordinate system. The sensor can be used, for example, to determine the position of an interface between a clear and an opaque fluid (such as crude oil and water). In one embodiment, the sensor utilizes the principle of dual-fluorescence, where a primary fiber emits primary fluorescent light and a parallel secondary fiber collects a portion of the primary fluorescent light that is not blocked by the opaque fluid. This, in turn, excites secondary fluorescence in the secondary fiber at a longer wavelength. A light detector measures the intensity of secondary fluorescence emitted from an end of the secondary fiber, which is used to calculate the unknown position or length, x. Side-emitting fibers can be used in place of, or in addition to, fluorescent fibers. The all-optical sensor is attractive for applications involving flammable liquids.

Abstract: A machine tool capable of jetting atomized lubricant (h) forward from the tip of a cutter (17), characterized by comprising a lubricant jetting state detector for detecting the jetting state of the atomized lubricant from the tip of the cutter, the lubricant jetting state detector further comprising a guide member (21) having a straight inner hole (21a), wherein a light detection device for detecting the degree of transmission or reflection of the detection light due to injecting the direction light (c) to a specified position (b) inside the inner hole through a transparent member installed on the peripheral wall portion of the guide member or through the transparent peripheral wall portion of the guide member, and a fluid feed device (23) for feeding clean fluid of rather thin layer flowing in a specified direction along the longitudinal direction of the inner hole is installed near the inner surface of the transparent member or so as to cover the transparent peripheral wall portion, whereby a defective part

Abstract: In a rain sensing device, a sensing device that can estimate the size of raindrops or the like without a large amount of hardware resources, and its sensing method, and a wiper controlling apparatus using the same can be provided. In a sensing device, light emitted from a light-emitting member is introduced to a transparent plate, reflected by a sensing surface of the transparent plate and then received by a photo-detector, thereby detecting a condition of the sensing surface.

Abstract: The present invention provides for measuring a particle size distribution of a population of particles using a light scattering particle sizing instrument having a plurality of selectable imaginary component values of the refractive index. The particles each having a particle size and the process includes the steps of: (i) providing a population of the particles, wherein the particles have a refractive index; (ii) determining a real component of the refractive index of the particles using the Becke Line Method; (iii) determining an imaginary component of the refractive index of the particles; and (iv) determining the particle size distribution of the particles by the light scattering particle sizing instrument wherein the particle size distribution is determined using the real component of the refractive index measured in step (ii) and the imaginary component of the refractive index determined in step (iii).

Abstract: A system for sensing a characteristic of a sample may include a tunable source configured to emit optical radiation that varies over a wavelength range at a sweep frequency and a reference source configured to emit optical radiation at a reference wavelength. A first modulator may be configured to modulate the first optical radiation at a first frequency, and a second modulator may be configured to modulate the second optical radiation at a second frequency that is different from the first frequency and the sweep frequency. A science detector may be configured to detect the optical radiation from the first modulator and the second modulator after interaction with the sample and generate a science signal. A number of lock-in amplifiers may be respectively configured to generate components of the science signal that are present at the first and second frequencies.

Abstract: A deposit detector in which deposit on a detection surface has a surface shape effect, and generation of a flashing phenomenon caused by irregular reflection of the light incident on the deposit from the outside is estimated. In a deposit detection mode, light emitted from a light source (10) for total reflection and total-reflected from the detection surface is received by a light-receiving element unit (50). Each element is disposed at such an angle that the light undergoes total reflection when no deposit is present or the condition of total reflection is not satisfied when deposit is present. Further, in a light-scattering deposit detection mode, light emitted from a scattering light source (20) and scattered by the detection surface is received by the light-receiving element unit (50). In an extraneous light quantity increase detection mode, extraneous light is received by the light-receiving element unit (50).

Abstract: The present invention pertains to a sensor, suitable for use in the detection of an analyte in a fluid, comprising: a tube (4) defining a flow path for the fluid; a generally planar member (3) mounted in the flow path (?) such that the plane is in the direction of flow, wherein the member has, bound thereto, a ligand that interacts with the analyte, wherein interaction causes the member to flex; and means (1, 2) for the detection of the flexing.

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 method is provided for determining an amount of a contaminant on a surface. Base values of infrared energy reflected from the surface without the contaminant at first and second wavelengths is determined. The values of infrared energy reflected from the surface with the contaminant at the first and second wavelengths are also determined. The values of infrared energy absorbed by the contaminant on the surface are determined at the first and second wavelengths. A difference of the absorbance at the first and second wavelengths is determined. The difference is correlated to an amount of the contaminant on the surface.

Abstract: Integrated sensors are described using lasers on substrates. In one embodiment, a first sensor forms a laser beam and uses a quartz substrate to sense particle motion by interference of the particles with a diffraction beam caused by a laser beam. A second sensor uses gradings to produce an interference. In another embodiment, an integrated sensor includes a laser element, producing a diverging beam, and a single substrate which includes a first diffractive optical element placed to receive the diverging beam and produce a fringe based thereon, a scattering element which scatters said fringe beam based on particles being detected, and a second diffractive element receiving scattered light.

Abstract: A non-mechanical fluid level sensor based on light communication channel (LCC) technology. In a preferred embodiment, one end of the LCC is connected to a signal source while another end is connected to a sensor. The LCC is dipped in a fluid container and a signal propagates and undergoes internal reflection through the LCC towards one of its ends which is connected to the sensor. The fluid level is detected preferably by measuring the intensity of the signal reflected with the LCC that reaches a sensor. Different fluid levels preferably correspond to linearly varying detected signal intensities. A main LCC bus may communicate remotely with the sensor without wiring or other electrical connectors.

Abstract: A system for sensing a characteristic of a sample may include a tunable source configured to emit optical radiation that varies over a wavelength range at a first frequency and a reference source configured to emit optical radiation that varies in amplitude at a second frequency. A science detector may be configured to detect the optical radiation from the tunable source and the reference source after interaction with the sample and generate a science signal. A number of lock-in amplifiers may be respectively configured to generate components of the science signal that are present at the first and second frequencies. A processor may be configured to determine a characteristic of the sample based on the components of the science signal that are present at the first and second frequencies.

Abstract: An apparatus for validating the operation of an optical scanning system is provided. The apparatus includes one or more scanning illumination beams (6) for scanning an object, and one or more observing beams that comprise light scattered by the object being scanned, which inversely follow the path of the illumination beams. The apparatus further includes a reflector structure (9) arranged to reflect both the illuminating beams and observing beams scattered by a reference target (10) for a portion of each scan (e.g., a scan may be a 360-degree scan in the case of a circular scanning system). The apparatus still further includes the reference target (10) arranged to be scanned by the illumination beams reflected by the reflector structure during said portion of each scan. Light scattered by the reference target is received as the observing beams, and their optical properties are continuously monitored to validate the proper operation of the optical scanning system.

Abstract: Method allowing control of an evaporative light scattering detector which is coupled to a liquid chromatography column, substantially independently of the elution conditions for the chromatographic separation. A given adjustable constant calibrated volume of the flow which originates from the chromatography column is removed at a given adjustable frequency, this flow being constituted by an eluent which contains compounds to be analysed which have been dissolved therein, and the volume removed in this manner is transferred to a secondary circuit, to which the evaporative light scattering detector is connected, by being conveyed by means of an auxiliary pump with a specific carrier fluid which is independent of the eluent having a predetermined flow, and the successive fractions of the flow which originates from the chromatography column are mixed with the carrier fluid which conveys these fractions upstream of the evaporative light scattering detector.

Abstract: Systems and methods for measuring the flow of a liquid along a conduit are disclosed. A heat source applies thermal energy to a portion of a liquid flowing along a conduit thereby elevating its temperature. An optical sensing means comprising a light source illuminating the liquid in the conduit downstream from the position of application of the thermal energy and an optical detector receiving a portion of this illumination senses the heated portion of liquid by measures a change in an optical property of the illumination caused by a change in the index of refraction of the heated portion of liquid. The time required for the heated portion of the liquid to move from the point of application of thermal energy to the point of optical sensing is measured. This measured time, along with the distance of separation of the heat source and the optical sensing means permits calculation of the velocity of the liquid in the conduit.

Abstract: A device and a method for detecting deposits on surfaces includes a body having a surface on which deposits occur and influence reflection properties of the surface to electromagnetic radiation. A transmitter transmits electromagnetic radiation to the body and a detector detects the presence of the deposits at the surface. The detector measures electromagnetic radiation received from the transmitter after reflection at the surface. Preferably, the device and method are used in a liquid-conveying machine, particularly, a washing machine and/or a dishwasher. Particularly, light is introduced into the light-guiding body to detect the presence of the deposits. The light is internally reflected by the surface and is guided to a sensor. If deposits occur on the surface, the deposits affect the light-reflecting properties of the surface, and the affect is detected by the sensor.

Abstract: The invention relates to a gas cell (2?) that includes a cavity (20) for a chosen gas volume, a light source (30), and one or more light bundle receiving units or detectors (21, 22, 23, 24, 25). The cavity (20) is formed by and delimited by, inter alia, a first partially elliptical mirror surface (20a) and two partially elliptical mirror surfaces, a second (20b) and a third (20c), which are opposed to said first mirror surface (20a) and which are so orientated in relation to each other that a light bundle (130a, 130b) will be reflected by said mirror surfaces (20a, 20b, 20c) so as to form an optical measurement path extremity, and terminate in a light-receiving unit (21, 22, 23, 24, 25) allocated to a chosen measurement path extremity. The light source (30) is disposed in one end region of said cavity (20) and a reflector (30a, 30b) which functions to cause emitted light bundles to converge towards a focusing point (F) is also disposed in said one end region.

Abstract: An object sensor is provided, which has a high object detection rate with respect to an object such as a raindrop adhering to a detection surface, and which is capable of detecting the presence/absence of an object with a high sensitivity. A light source 10, a detection surface 110, a focusing lens 40, and a plurality of photodetecting elements of a photodetecting unit 50 form a focusing system of equal magnification that is capable of catching an image in a size smaller than an object to be detected. Light emitted from the light source 10 is incident on the detection surface 110 via a prism 20 at a predetermined incident angle. Without a raindrop 120, the total internal reflection condition is satisfied as shown by a path 140 of a beam, so that the beam is subjected to the total internal reflection. Then, the beam passes through a prism 30, and is focused on a photodetecting surface of the photodetecting unit 50 by the focusing lens 40.

Abstract: A weather identification system is provided which employs a first photosensitive receiver positioned directly in the path of a beam of light a predetermined distance from a partially coherent light beam source. The first photosensitive receiver is in direct optical communication with the light beam source to produce electronic signals in response to scintillations caused by particle movement between the source and the first receiver. A second photosensitive receiver is positioned out of the path of the beam of light and is oriented at an oblique angle relative thereto to provide an output indicative of forward scattering of light from scintillations that occur in the beam of light. The signals from the second photosensitive receiver are AC coupled to provide an output indicative of rate of fluctuation and having a signal strength characteristic that even distinguishes between light drizzle and fog.

Abstract: A method and apparatus for locating an edge disposed at the junction between two substantially plane surfaces, and in particular to a method and apparatus for locating a platform edge coping relative to a rail vehicle, the method comprising the following stages: a) transmitting waves from at least one transmitter; b) receiving the echoes of the waves transmitted by the transmitter in at least two receivers; c) analyzing the energy of the signal received by each receiver to determine the value of the angle of inclination; d) computing the position of the main points of impact of the waves on the two surfaces by measuring the travel time of the signal transmitted by the transmitter, and received by each receiver; and e) locating the edge by computing the point corresponding to the intersection of the straight lines passing through the two points of impact and forming respective angles with the main transmit axis of the) transmitter.

Abstract: A method and system is disclosed for facilitating the input of information into a computing device by a scanning means. A pocket scanner that has only the minimum components/parts therein and will not operate without being connected to the computing device that subsequently receives scanning signals therefrom. In particular, the disclosed scanner does not have a separate power supply to energize the components/parts to work.

Abstract: A compact particle sensor for fdetecting suspended particles includes a housing, a light source, a light receiver and a plurality of optical elements. The housing provides a test chamber and includes at least one opening for admitting particles into the test chamber, while simultaneously substantially preventing outside light from entering the test chamber. The light source is positioned for supplying a light beam within the test chamber. The plurality of optical elements are positioned to direct the light beam from the light source to the receiver, which is positioned to receive the light beam supplied by the light source.

Abstract: The invention relates to a portable device for carrying out examinations of turbid media using a three-dimensional cross-correlation technique and for suppressing the influence of multiple scattering, as well as to an adjustment method for adjusting the device. The device has a base plate (1) upon which an adjustable laser (2) is positioned in tilting devices or by means of mirrors for directing the laser beam perpendicularly onto the wall of a cuvette (6) filled with a medium to be examined. The device is provided with a translucent plate (7) which in some sections is completely mirror-coated and in other sections is partially mirror-coated and which serves as a beam splitter (4). The plate is firmly secured to the base plate (1) using a positioning fixture (8) whose support surface (16) for the translucent plate (7) is situated at a fixed angle with respect to the base plate (1).

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: A method of determining the Volume Scattering Function of Ocean Waters in the backward direction using a Satellite Ocean Color Sensor the said method made to exploit the geometry of the sun-ocean-satellite detector to function as a backscatter system comprising of the sun [1] as a source of radiation, the ocean as the sampling volume [2], and the satellite ocean color sensor [3] as the detector of the backscattered flux from the ocean emanating from separate ocean pixels arranged on a scan line across the track of the satellite payload and arriving at corresponding pixels on the CCD array detector of the satellite sensor [3]; the output signals from each electronic pixel of the detector is shown to be related to the Volume Scattering Function at a fixed scattering angles (?) which bears a direct relation to the cosines of the solar incident angle (?s) and the angle (?p) of the upwelled flux at the ocean surface, the Remotely Sensed Reflectance (Rrs), and the diffuse attenuation coefficient (Kd) thereby result

Abstract: A fiber optic sensor for monitoring point temperature of in situ reactions in remote, based on the principle of guiding light by means of total internal reflection (TIR) occurring in a right-angled prism, mounted on a glass capillary tube comprises isopropyl alcohol in it and rises due to increase in temperature and touches the prism surface thereby preventing the occurrence of TIR thus reducing the level of output optical signal detected.

Abstract: A device for detecting objects on a windshield of a motor vehicle having a hood includes an imaging unit having a lens and a sensor positioned within the interior of the motor vehicle. The lens images a windshield section associated with a primary field of vision onto the sensor. The sensor generates a sensor signal in response to the windshield section imaged thereon. The imaging unit is positioned in a viewing direction pointing diagonally downwards with respect to the windshield such that the background of the windshield section imaged onto the sensor is the hood of the motor vehicle thereby causing the background of the windshield section imaged onto the sensor to be approximately constant in order to cancel environmental conditions that can impair object detection on the windshield section. An evaluation unit evaluates the sensor signal to detect objects on the windshield section.

Abstract: The present invention relates to a system for monitoring properties of a medium by fiber optics. The present invention particularly relates to a system of fiber optics for monitoring layer thickness of immiscible liquids for industrial applications and a method thereof.

Abstract: For adjusting output voltages of a turbidity sensor which is used for measuring the turbidity of a medium by means of a radiation at least partially propagating through the medium being emitted from a sender and being received by a receiver, ohmic loads for the receiver on its output side are adjusted such that desired output voltages are obtained.

Abstract: The invention relates to a detector for scattered light, especially for detecting particles in a carrier medium. Said detector comprises a housing (1) and an inlet (3) and an outlet (5) in the housing (1). The carrier medium flows through the housing between said inlet and outlet and on a flow path (7). The inventive detector also comprises a light source (9) that directs light to a scattered light centre (11) which lies on the flow path (7). The inventive detector further comprises a receiver (13) for a portion of the light which is scattered onto particles in the scattered light centre (15) and a light trap (15) for light which is not scattered in the scattered light centre (11). The aim of the invention is to improve such a detector for scattered light in such a way that compact construction and high responsiveness are guaranteed. The light trap (15) can be embodied in two ways.

Abstract: The analytical method having both flow cytometery and cytodiagnosis functions comprises the steps of: preparing a sample containing particulate substances such as cells and viruses; injecting the sample into a plate-like sample container; centrifuging the sample container; and using the sample container in which a distribution of the particulate substances has been formed as a preparation for analysis. The preparation is scanned with a laser beam to obtain analytical data. An analytical device for this method is also provided.

Abstract: A dispersion light smoke detector has a structure for providing a definite measuring volume, the structure being formed as two light receivers or an imaging optical system for one light receiver.

Abstract: A method is disclosed wherein engineered particles are used as obscurants and taggants for vehicles. In some embodiments, the engineered particles are nano-crystals or micro-spheres (doped or un-doped). In some embodiments, the particles are engineered to re-radiate the energy that they receive at either the same wavelength or a different wavelength than that of the incident photons. Particles that scatter light at the same wavelength as the interrogating beam are advantageously used as taggants. Particles that scatter light at a different wavelength as the interrogating beam are advantageously used as obscurants. In some embodiments, the method comprises storing a quantity of particles in a first vehicle, and releasing a portion of the particles in an ambient environment of the first vehicle.

Abstract: A method and apparatus for detecting material accretion and peeling in a system such as a plasma process chamber, including multiple optical sensors which are provided in the chamber above a gas distribution plate or other surface inside the chamber. The optical sensors are connected to a central process controller that is capable of terminating operation of the chamber and may be equipped with an alarm. In the event that the optical sensors detect asymmetries in brightness or light reflection among various portions or regions of the gas distribution plate or other surface, which asymmetries may indicate the formation of a material coating on the plate or dislodging of contaminant particles from the plate, a signal is sent to the process controller, which may be adapted to terminate the plasma process, alert operating personnel, or both.

Abstract: A system and method for use with a flow cytometer to improve event reading and data processing capabilities of the flow cytometer, while also providing efficient system configuration assessment capabilities. The system and method enables the flow cytometer to capture and sample an entire waveform representative of an event being read, and provides improved processing and analysis of the sampled data in a real time or near real-time basis. The system and method further enable the flow cytometer to assess its configuration and provide assessment results to an operator in an efficient and effective manner.

Abstract: An interior rearview mirror system suitable for use in a vehicle includes a interior rearview mirror assembly adapted for attachment to an interior portion of the vehicle. The interior rearview mirror assembly includes a housing and a reflective element included within the housing. The mirror system further includes a video device (which includes an imaging sensor) and a control. The imaging sensor is positioned at the interior rearview mirror assembly and has a field of view forward and through the windshield. The imaging sensor is operable to at least sense precipitation at an interior and/or exterior surface of the windshield. The control receives a signal from the imaging sensor and is operable to control at least one of a headlamp of the vehicle, a windshield wiper of the vehicle, a defogging system of the vehicle and a movable window of the vehicle in response to the signal.

Abstract: Optical measuring system for determining the concentration, particularly of turbid liquid samples, comprising a measuring volume for taking up the liquid samples to be measured, a plurality of several photometric channels, each comprising a light source and a light sensor on opposite sides of the sample volume aligned on a common optical axis, the optical axes thereof being disposed under different azimutal angles respective to the sample volume, and an analyzing device which evaluates the concentration of the liquid samples to be measured according to the data provided by the light sensors belonging to a plurality of different photometric channels.

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: A control device and method provides control of at least one operating feature of a cooking device in response to measured smoke and/or gas produced by item(s) being cooked. The device and method may control the temperature and cooking time of the device, and may also shut off the device or provide a fire alarm.

Abstract: An analyzing probe for insertion into numerous different environments to determine at least one characteristic of particulate matter suspended in a fluid stream of a test sample. Preferably, the analyzing probe includes a minimal amount of optical elements such as lenses that are subjected to the conditions of the environment of the fluid stream to be tested. Further, the analyzing probe is preferably designed so that it can be readily manufactured, operated and installed by relatively unskilled laborers.

Abstract: A smoke detecting chamber for use in a light-scattering type smoke detector is provided which includes a chamber cover that forms one side of the smoke detecting chamber. The chamber cover includes a plurality of first baffles that prevent external light from entering the smoke chamber. The smoke detector further includes a chamber base that forms another side of the smoke detecting chamber, the chamber base including a plurality of second baffles that intermesh with the first baffles when the smoke detecting chamber is formed.

Abstract: A smoke detection chamber for use in a photoelectric smoke detector. The smoke detection chamber comprises a side wall with a double row of generally rectangular vanes arranged to provide a labyrinth extending generally around the entire side wall for ingress and egress of smoke particles, a top and a bottom. A mounting arrangement for a photoemitting diode is provided in the side wall of the smoke detection chamber so that a light beam from a photoemitting diode is transmitted across the smoke detection chamber. The mounting arrangement extends from and is spaced from the bottom to provide minimal interference for entry of smoke particles. The bottom of the smoke detection chamber has an opening therein with a shielding arrangement thereabout open to the chamber for a photodiode detector, the opening and shielding arrangement being located between the centerline of the smoke detection chamber and the mounting arrangement in the side wall of the chamber.

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: A mobile gas detector comprising a laser transmitter and signal analyser carried on a vehicle, the vehicle having an exterior, a laser absorption cell carried on the exterior of the vehicle, a light guide connecting light from the laser transmitter into the laser absorption cell, a photo-detector mounted with the laser absorption cell exterior to the vehicle to convert light that has traversed the laser absorption cell into electrical signals, and a cable connecting the photodetector to the signal analyser.

Abstract: A sensor arrangement for detecting a wetting, in particular a precipitation and dirt accumulation, on a window (13) is proposed, with at least one transmitter (14) and at least one receiver (15) for the transmitter light (17) emitted by the transmitters (14), where the transmitters (14) and receivers (15) are disposed on the vertex points of an imaginary trapezoid. As a result, the external dimensions of the sensor are reduced, the ratio of sensitive area (19) and base area (18) of the sensor is improved, and a coherent sensitive area is produced, where there is also space available for a receiving element of an automatic light control.

Abstract: A cleaning end point detecting apparatus detects an end point of a cleaning process in which contamination attached to an inner wall of a reaction chamber is removed by introducing a cleaning gas into the chamber to produce a cluster cloud and detached particles. An irradiating unit irradiates a laser beam onto the cluster cloud and the detached particles within the reaction chamber to produce a scattered laser beam. A monitoring unit monitors the scattered laser beam as a two-dimensional image information. A judging unit judges the end point of the cleaning process on the basis of the two-dimensional image information. Preferably, the judging unit judges, as the end point of the cleaning process, a time instant when neither the detached particles nor the cluster cloud are detected on the basis of the two-dimensional image information.

Abstract: An improved fire detector unit has a plastic base defining a smoke chamber for detection of a smoke density in terms of light scattering due to the smoke particles in the smoke chamber. The base carries a circuit board mounting a light emitting element, a light receiving element, and other components forming a fire detecting circuit responsible for generating a fire warning signal based upon the detected smoke density. A metal-made electromagnetic shield is molded into the base to protect the light receiving element from electromagnetic radiation noises. The electromagnetic shield includes a ground terminal for connection with a ground line of the circuit board. In addition, terminal pins are molded into the base for electrical and physical connection of the circuit board to the base.