Abstract: A light detection value determines concentration of a target component, without using a laser emitter of high laser intensity or a large light collector. By changing orientation of the laser emitter about a horizontal axis, or height of the laser emitter, a laser irradiation position on a ground or water surface is switched between first and second irradiation positions. A photodetector detects first scattered light scattering from the first laser beam at the first irradiation position, second scattered light scattering from the second laser beam at the first irradiation position, third scattered light scattering from the first laser beam at the second irradiation position, and fourth scattered light scattering from the second laser beam at the second irradiation position. A concentration calculator calculates concentration of a target component between the first and second irradiation positions, based on detection values of the first, second, third, and fourth scattered light.

Abstract: A calibration apparatus for calibrating a scattered-light measuring device that is embodied to measure a particle concentration in motor vehicle exhaust gases, comprises at least one scattering body that has a number of scattering centers having a defined size and a defined mutual spacing. The scattering centers are disposed in such a way that the scattering body, upon irradiation with light from a light source, delivers scattered light having an intensity and a distribution predetermined by the scattering body.

Abstract: A microparticle analysis apparatus includes at least: a detecting unit having one or a plurality of light sources and a plurality of photodetectors, configured to emit excitation light from the light sources, and to detect light emitted from microparticles on which the excitation light is irradiated, at the photodetectors; a first storage unit configured to store, for each microparticle, data detected at the photodetectors of the detecting unit based on detected time; and a second storage unit configured to store data relating to a particular microparticle of detected data stored in the first storage unit.

Abstract: An apparatus (7) for monitoring particles flowing in a stack (6), comprises: an electrical-interaction monitor (1) operable to provide a signal (300) resulting from electrical interaction of the particles with the monitor (1). a scattered-light monitor (10) operable to provide a signal (310) resulting from detection of light scattered from the particles, and a controller (320) arranged to alter the calibration of the electrical-interaction monitor 1 in response to changes in the relative magnitude of the electrical-interaction (signal 300) and the scattered-light signal (310).

Abstract: This invention is an apparatus and method of real time determination of particle size and optionally chemical composition or both. An aerosol beam generator focuses a beam containing sample particles that passes through a sizing laser beam of approximately constant width to produce light scattering that is detected by a light detection means, allowing generation of electrical pulses that may be used to compute particle velocity. In being formed into a beam, the particles are accelerated to terminal velocities that are functions of their sizes. The duration of time elapsed while a particle passes through the width of the sizing laser beam is a function of its velocity which, in turn, is a function of its size. Chemical composition of the particle is determined by suitable analytical means included in the apparatus, such as mass spectrometry.

Abstract: An optical smoke detector (10) is provided that comprises a light source (154), a light receiver (172), and a control circuit (130) for controlling operation of the detector. The control circuit (130) is configured to apply an unregulated voltage to the to cause it to emit light, to monitor the current through said light source (154) so as to monitor the light emitted by said light source (154); and to monitor the current generated by light received by said light receiver (172) so as to monitor the light received by said light receiver (172). The control circuit (130) generates a ratio signal representative of the ratio of the monitored currents; and compares the ratio signal with a reference value and generate a smoke detection signal in dependence thereon.

Abstract: A system for real-time sizing of fluid-borne particles is disclosed. The system further determines, in real time, whether the detected particles are biological or non-biological. As the fluid is being tested, it is exposed to a microbe collection filter which is cultured to determine the type of microbes present in the fluid being tested.

Abstract: Techniques, devices and systems are disclosed for characterizing particles in a fluid sample by optical space-time coding. In one aspect, a microfluidic device for optical detection of particles includes a substrate, a microfluidic channel formed on the substrate and structured to carry a fluid sample containing particles, in which the microfluidic channel is structured to transmit a probe light, and a mask formed on one side of the microfluidic channel and structured to include a pattern of openings along the microfluidic channel, in which at least two of the openings have varying dimensions across the microfluidic channel, and in which the pattern of openings encodes a waveform on the probe light that transmits through the microfluidic channel to allow optical detection of a position of a particle in the microfluidic channel.

Abstract: One aspect is a light source assembly in a drop detection arrangement. The light source assembly includes a light source and a gradient-index lens array to at least partially collimate light from the light source and to project a collimated light beam into the drop detection arrangement in a direction transverse to a drop direction of droplets in the drop detection arrangement. The light source assembly produces the light beam such that it has a beam width in a direction transverse to the drop direction that is larger than a beam height in the drop direction.

Abstract: A number of fluidic-photonic devices for allowing optical detection, systems employing such devices, and related methods of operation and fabrication of such devices are disclosed herein. In at least some embodiments, the devices can serve as flow cytometry devices and/or employ microfluidic channels. Also, in at least some embodiments, the devices are fluidic-photonic integrated circuit (FPIC) devices that employ both fluidic channels and one or more waveguides capable of receiving and/or delivering light, and that can be fabricated using polymeric materials. The fluidic-photonic devices in at least some embodiments are capable of functionality such as on-chip excitation, time-of-flight measurement, and can experience enhanced fluorescence detection sensitivity. In at least some embodiments, the devices employ detection waveguides that are joined by way of a waveguide demultiplexer.

Abstract: A fluid characterization measuring instrument comprises a sample vessel (14) for a bulk complex sample fluid having a capacity that is substantially larger than a domain size of the complex sample fluid and that is sufficiently large to cause bulk scattering effects to substantially exceed surface effects for the complex fluid sample, a coherent light source (12) positioned to illuminate the bulk complex sample fluid in the sample vessel and a first fibre (16) having a first end positioned to receive backscattered light from the sample after it has interacted with the sample. The first fibre is positioned close enough to an optical axis of the coherent light source and to the sample vessel to substantially decrease a contribution of multiply scattered light in the backscattered light.

Abstract: An optical information analyzing device includes an irradiating unit that irradiates irradiation light to specimens, a transmitted light receiving unit that receives transmitted light and detects the transmitted light as a transmitted light signal, a scattering/fluorescent light receiving unit that receives lateral scattering light and fluorescent light and detects the lateral scattering light and the fluorescent light as a scattering/fluorescent light signal, a nozzle position adjusting mechanism, and an analyzing unit that measures the optical information on the specimen on the basis of the detected transmitted light signal and the detected scattering/fluorescent light signal and analyzes the specimen.

Abstract: A coherent confocal microscope and methods for measuring elements of the non-linear susceptibility of a nanoparticle, including, more particularly, all of the elements of the second-order susceptibility tensor of a single nanoparticle under permutation and Kleinman symmetry. Using a high numerical aperture lens, two-dimensional scanning and a vector beam shaper, the second-order nonlinear susceptibility is derived from a single confocal image. A forward model for the problem is presented and a computationally efficient data processing method robustly solves the inverse problem.

Abstract: One aspect is an aerosol detection arrangement including a light source for projecting a light beam. The arrangement includes a light collector configured to collect light scattered off liquid drops in an aerosol that enter the light beam and processing the scattered light into an output signal. The arrangement includes a controller for receiving the output signal from the light collector and uses the output signal to determine a predicted number of main liquid drops ejected.

Abstract: A microfluidic multiple channel particle analysis system (1) which allows particles (2) from a plurality of particle sources (3) to be independently simultaneously entrained in a corresponding plurality of fluid streams (4) for analysis and sorting into particle subpopulations (5) based upon one or more particle characteristics (6).

Abstract: Provided is a microscope and an observation method which can improve spatial resolution. A microscope according to an aspect of the invention includes a laser light source (10), an objective lens (16) that focuses light from the laser light source on a sample, and a detector (22) that detects the laser light as signal light from a sample (17) when the sample (17) is irradiated with the laser light. The light is applied to the sample with an intensity changed to obtain a nonlinear region where intensities of the light and the signal light have a nonlinear relation due to occurrence of saturation or nonlinear increase of the signal light when the light has a maximum intensity, and the detector (22) detects the signal light according to the intensity of the laser light to perform observation based on a saturation component or a nonlinear increase component of the signal light.

Abstract: An optical detection device is provided for analyzing analytes in a liquid suspension or solution that can detect and process a large number of wavelengths of incident and fluorescent light simultaneously, which is small in size and can be easily adapted to different investigation requirements. The optical detection device may include a light supplying device, an analyte handling device, a light directing device, and a detector integrated on planar substrate devices, respectively. A plurality of optical waveguides are integrated in the substrate devices to direct light emitted by the light supplying device through the different sections of the optical detector to the detector. The analyte handling device may include an analyte channel for the liquid flow of the analyte suspension or solution and an analyte sorting device comprising several sorting channels.

Abstract: An analysis device using scattering light is provided capable of, when a foreign substance such as a bubble is mixed in a measurement target or is attached in a reaction container, reducing the influence by the foreign substance while improving the S/N ratio characteristics. Two or more detectors are disposed on a plane orthogonal to an optical axis of light applied to the measurement target and on a circumference around the optical axis. A change in outputs from the detectors is observed, and a detector influenced by noise due to a foreign substance such as a bubble is specified for rejection, and outputs from the detectors are averaged.

Abstract: Method and device for determining a foam density of foam in beverage containers utilizing the Tyndall effect, and having a focused light bundle emitted into the foam by means of a light source, where the light bundle is refracted in the foam and a scattered ray becomes visible on a surface of the foam. Via a measurement of the contour of such a light spot, conclusions on the foam density can be drawn. For this, one or several lasers can be integrated into existing filling level measuring means which are coupled to the already existing measuring means.

Abstract: Provided is a fire detector in which an element substrate can be easily removed from and mounted into an optical case. The fire detector includes: an optical case (21); an element substrate (31), on which a light-receiving element (12) is mounted, the element substrate (31) being provided in the optical case (21); a signal line (35) passing through an introduction portion of a peripheral wall (21a) of the optical case (21), the signal line (35) being connected to the element substrate (31); and an optical cover (30) for closing an opening of the optical case (21), in which the signal line (35) is inserted into a slit (37) which is open on an upper end surface (21f) of the introduction portion of the peripheral wall (21a).

Abstract: A method of deriving a scattered wave includes the steps of calculating a first scattered wave from a scatterer at a predetermined position by using a predetermined electromagnetic wave entering the scatterer, calculating a second scattered wave from a spherical nanoparticle cluster at the predetermined position by using T-matrix method when the predetermined electromagnetic wave enters the spherical nanoparticle cluster in a state where the spherical nanoparticle cluster containing a plurality of spherical nanoparticles is arranged inside a region that has the same shape and size as those of the scatterer, determining a condition of the plurality of spherical nanoparticles so that the first scattered wave is equal to the second scattered wave, and obtaining the scattered wave from the scatterer at an arbitrary position when an arbitrary electromagnetic wave enters the scatterer, based on the determined condition of the spherical nanoparticle.

Abstract: A low profile optical smoke chamber structure with a top cover incorporating airflow slots, an intermediate annular air channel, a depending light shield wall surrounding an interior detection chamber where the top cover is interengagable with a base member where the light shield wall is spaced from the base member so as to provide minimal deflection of ambient airflow into the detection chamber while preventing impingement of ambient light therein.

Abstract: A method of evaluating a property of a physiological fluid suspension comprises measuring a value of the property of a liquid portion of the physiological fluid suspension via light scattering, and comparing the measured value with a reference value to evaluate the property of the liquid portion of the physiological fluid suspension.

Abstract: A photo-electric smoke detector includes a source of radiant energy and a closed loop control circuit which responds to a radiant energy feedback signal to adjust an output characteristic of the emitted radiant energy and which evaluates a quality characteristic of the emitted radiant energy. The feedback circuit and the source can be intermittently activated. Emitted radiant energy is directed toward a lens. The feedback signal is proportional to radiant energy reflected or scattered off of the lens.

Abstract: A nephelometer for detecting the concentration of particulates in a sample aerosol is provided with a branched flow path with a sample aerosol input, a clean gas input and an output leading to an optical sensor unit. At least one of the inputs has periodic variable flow so that a concentration-modulated gas stream is supplied to the optical sensor unit. The detector output of the sensor unit is processed in synchrony with the concentration modulation to filter out DC components, such as 1/f noise and parasitic instrument noise.

Abstract: The present invention is a device for measuring the intensity of the light scattered by a thin film of a colloidal medium, comprising a monochromatic light source, a convergent optical system focusing the source onto the thin film to be analyzed comprising a dioptric element with one of the faces thereof constituting a first wall defining the thin film, at least one photosensitive detector producing a signal representing light scattered or backscattered by the thin film and means for processing the signal. A second wall of the device has a plane surface at the end of a rod.

Abstract: A fine particle analyzing apparatus includes a light irradiation unit configured to irradiate a fine particle that flows in a flow path with a laser beam, and a detection unit configured to detect light emitted from the fine particle that is irradiated with the laser beam. In the fine particle analyzing apparatus, the light irradiation unit includes at least a light source that is composed of a semiconductor laser, an optical fiber that converts a beam pattern of the laser beam generated from the light source into a top-hat type beam pattern, and a light source driving control unit configured to supply driving current, which is obtained by superimposing high-frequency current on direct current, to the light source.

Abstract: A method is provided for diagnosing the operation of a photometric particle analyzer. The method may determine when the operation is degraded from normal operating conditions, automatically, and the result displayed locally as well as being transmitted to a remote observer. The present invention may be used by optical photometric particle analyzers, or by analyzers that measure other properties of particles collected on filters.

Abstract: [PROBLEMS] A separation unit can confirms a separation state, a detection unit enhances a lighting efficiency and a light reception sensitivity, and a dispensing unit ensures the normal state of a specimen. [MEANS FOR SOLVING PROBLEMS] A specimen separation device characterized by comprising a container for storing a specimen, a nozzle for sucking and ejecting the specimen from the container, a nozzle operating means for moving the nozzle vertically and laterally, and a nozzle controlling means for controlling the suction force and ejection force of the nozzle. A specimen identification device comprising a nozzle for sucking a specimen from a container storing the specimen, a flow path for allowing the specimen to flow therethrough, and a measuring unit having a monitoring light lighting unit and a light receiving unit for observing (monitoring) the specimen that are installed in a flow path, characterized in that the above nozzle, the flow path and the measuring unit are formed in an integrated structure.

Abstract: The invention relates to a system comprising a broadband optical light source and a sorting device and more specifically to laser sorting devices. The object of the present invention is to provide a system comprising a sorting device with a light-source offering all wavelengths for the sorting process. This is solved by using an all fiber supercontinuum light source.

Abstract: The present invention provides a particle counter capable of sensitively determining the contamination level of a light transmission window. The particle counter according to the present invention includes: a light source 281 for emitting light through a light incident window 24 to a measurement area 40 in a vacuum state or in an approximately vacuum state; a scattered light detector 32 for detecting scattered light through a detection window 30, the scattered light being generated when a light is delivered to the measurement area 40; a vacuum gauge 12 for measuring the pressure of the measurement area 40; a signal processor 13 for converting a detection signal of the scattered light into an electrical signal; and a contamination level determiner 19 for determining the contamination level of the transmission window from the time average of the electrical signal and the pressure.

Abstract: A method for increasing the throughput, or the precision, or both the precision and the throughput, of a flow cytometer, or of a hematology analyzer employing a flow cytometer, by utilizing the technique of laser rastering. Laser rastering involves sweeping a laser beam across a flowing sample stream in a hematology analyzer. An apparatus suitable for carrying out the method of this invention comprises an optical module comprising a source of light, a scanning device, a lens or system of lenses, a flow cell, detectors, and filters; and an electronic module comprising preamplifiers, analog signal conditioning elements, analog-to-digital converters, field-programmable gate arrays, digital signal processing elements, and data storage elements.

Abstract: An apparatus for measuring a particle in a liquid, the apparatus having a function that, using a flow channel into which a sample liquid containing a particle is introduced, a pair of flow channels into which a sheath liquid is introduced, the pair of the flow channels being arranged on the opposite sides of the flow channel and joined, and a flow channel in which these flow channels are joined and the sample liquid and the sheath liquid on the opposite sides of the sample liquid flow, applies laser light to a particle flowing in a flow channel in the flow cell, detects scattered light or fluorescence generated from the particle and analyzes the particle.

Abstract: A particle detection system uses a camera to produce a picture based on the scattered light generated by a particle in a liquid medium, when a laser beam is incident on the particle. These pictures are then automatically analyzed through the use of a processing system (e.g., a computer). The processing system is configured to record the forward scattering intensity (e.g., amplitude) and the picture of the scattered light rays to generate a classification of the particle causing the scattering. Count rate and trends of the classified particles are monitored to detect a change that is representative of the overall health safety of the water or by knowing the levels of bacteria in process water, such as Reverse Osmosis (RO) feed water, reject brine, and product water, the operator may better monitor the life and condition of the RO membrane.

Abstract: This invention provides methods and devices to measure particle suspension concentrations through the side wall of a container. Particle back-scatter readings are taken at light wavelengths that do not travel far through the medium. Detected scatter is related to actual particle concentration or standard O.D. values. The methods and devices allow particle concentration readings through containers not normally intended for use in such assays.

Abstract: The inside of an anterior chamber (21) of a human eye containing the protein molecules of albumin and globulin is irradiated with laser light beams having different wavelengths from a variable-wavelength laser light source (10). Scattered light from the protein molecules is received by a detector (8), and an autocorrelation function of the scattered light signal is determined by a correlator (9). A computer (11) computes the concentrations of albumin and globulin or the ratio thereof on the basis of the autocorrelation functions of the scattered light signals of the albumin and globulin irradiated with the laser light beams having different wavelengths. In such a configuration, the concentrations of albumin and globulin, or the ratio thereof can be measured reliably without contact and in a noninvasive manner.

Abstract: A microfluidic device comprises inlets for a sample flow and an out-of-plane focusing sheath flow, and a curved channel section configured to receive the sample flow and out-of-plane focusing sheath and to provide hydrodynamic focusing of the sample flow in an out-of-plane direction, the out-of-plane direction being normal to a plane including the curved channel. Examples of the invention also include improved flow cytometers.

Abstract: An apparatus for detecting a particle is disclosed. The apparatus for detecting a particle in a fluid in accordance with an embodiment of the present invention can include a first light source, which emits a first beam having a wavelength of a particular band toward the fluid, a second light source, which emits a second beam having a wavelength of a band that is different from that of the first beam, a first dichroic mirror, which is placed between the fluid and the first light source and allows the first beam to permeate and reflect the second beam toward the fluid, and a detecting unit, which detects a dispersed beam of the first beam and the second beam in the fluid. An embodiment of the invention can improve the reliability of detection by detecting a particle using a beam that has an optimal permeability according to the type of solution.

Abstract: A fluid submersible sensing device is provided comprising a fluid-tight housing defining an internal chamber and including window structure; sensing structure provided in the internal chamber; light providing apparatus in the internal chamber emitting light capable of passing through the window structure so as to exit the housing; and a sample-providing structure coupled to the housing and located outside of the housing internal chamber comprising a passage through which a fluid flows. The passage may have a longitudinal axis substantially parallel with a flow path through the passage and a cross sectional area substantially transverse to the longitudinal axis. The light from the housing exits the housing, passes through the sample-providing structure including the passage and re-enters the housing toward the sensing structure.

Abstract: A particle monitor system that can detect fine particles in a substrate processing apparatus. The substrate processing apparatus has a chamber in which a substrate is housed and subjected to processing, a dry pump that exhausts gas out of the chamber, and a bypass line that communicates the chamber and the dry pump together. The particle monitor system has a laser light oscillator that irradiates laser light toward a space in which the particles may be present, and a laser power measurement device that is disposed on an optical path of the laser light having passed through the space and measures the energy of the laser light.

Abstract: Measuring and tracking velocity of individual aerosol particles in a bio-threat detection system are accomplished using a single beam laser source in combination with a birefringent crystal that splits the laser beam into two beams having orthogonal polarization. Scattered light is collected with an elliptical reflector and directed into two detection channels, sampling total elastic scatter in the first channel and sampling polarized elastic scatter in the second channel. The difference in intensity of the scattered light in the polarized channel is used to identify the position of the particles. By taking the ratio of signal output from the polarized detector to the total scatter detector, a threshold level can be established to determine the presence of particles traversing the two beams. The particles are time stamped as they traverse the two beams and the time difference between the pulses can be used to measure the velocity of the particles.

Abstract: Method for determining a measured value of a measured variable of a medium, by means of an optical sensor arrangement, which has at least one transmitter and at least one receiver, comprising the steps as follows: supplying the at least one transmitter with an exciter signal for producing an optical transmitter signal with a transmission signal strength, wherein the transmitter signal is converted by interaction with the medium as a function of the measured variable into a changed transmitter signal; producing a receiver signal from the transformed transmitter signal by means of the at least one receiver and registering a receiver signal strength of the receiver signal; conforming an excitation signal strength of the exciter signal based on the registered receiver signal strength for reaching a predetermined receiver signal strength; and registering the excitation signal strength required for reaching the predetermined receiver signal strength and determining the measured value therefrom.

Abstract: A microparticle detection apparatus is provided. The microparticle detection apparatus includes a light emitting optical element, a converging optical system disposed in an advancing direction of light emitted from the optical element to converge the light, a particle path located in an advancing direction of the light having passed through the converging optical system so that the particle path intersects the light, a beam blocking unit to block direct light having passed through the particle path, a condensing lens disposed at the rear of the beam blocking unit, and a detector disposed at the rear of the condensing lens to detect light scattered by particles. A focal point of light formed by the optical element and the converging optical system may be located at the rear of the particle path. A focal point of light irradiated to the particles may be different from the introduction position of the particles.

Abstract: This invention provides a new method for rapidly analyzing single bioparticles to assess their material condition and state of health. The method is enabled by use of a resonant cavity apparatus to measure an optical property related to the bioparticle size and refractive index. Measuring the refractive index is useful for determining material properties of the bioparticle. The material properties depend on the biomolecular composition of the bioparticle. The biomolecular composition is, in turn, dependent on the state of health of the bioparticle. Thus, measured optical properties can be used to differentiate normal (healthy) and abnormal (diseased) states of bioparticles derived from cells or tissues. The method is illustrated with data obtained from a resonator with a gain medium. The invention also provides new methods for making multiple measurements in a single device and detecting, analyzing, and manipulating bioparticles that are much smaller than the wavelength of light.

Abstract: A microchip includes a sample liquid feed channel permitting a sample liquid containing particulates to flow through, at least one pair of sheath liquid feed channels configured to merge to the sample liquid feed channel from both sides thereof for permitting a sheath liquid to flow through surrounding the sample liquid, a merging channel connected to the sample liquid feed channel and the one pair of the sheath liquid feed channels for permitting the sample liquid and the sheath liquid to merge and flow through the merging channel, a vacuum suction unit for drawing into the particulate subject to collection, connected to the merging channel, and at least one pair of discharge channels formed on both sides of the vacuum suction unit for permitting to flow through from the merging channel.

Abstract: A particle detector has a sample area of cross section no in excess of about 2 mm for containing environmental fluid, a light source on one side of the sample area for directing a collimated or nearly collimated beam of light through the sample air or water so that part of the light beam will be scattered by any particles present in the air or water while the remainder remains unscattered, and a beam diverting device on the opposite side of the sample area for diverting or 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 or water sample at a given time from the detector output. The detector may also include a device for discriminating between biological agents and inorganic particles.

Abstract: The invention relates to a method of characterizing a scattering medium. According to the invention, the processing on the electromagnetic radiation scattered by the scattering medium is carried out for an unpolarized signal. In this way, only the anisotrophic incoherent transport of radiation induced by the scattering medium is obtained in the characterization according to the invention. According to the invention, the data representative of the angular variation of the first image representing the unpolarized scattered radiation is representative of the purely isotrophic part of the scattering. Having obtained this purely isotrophic part, it is then possible, according to the invention, to calculate a second image representative of the non-isotrophic part of the scattering. This non-isotrophic part represents the anisotrophic transport of radiation induced by the medium at the moment of scattering.

Abstract: A particle detector comprises a light source, and a metal layer having an incident/reflective surface and a photoelectric surface opposing the incident/reflective surface. Incident light from the light source reaches the incident/reflective surface to excite near-field surface plasmon resonance photons at the photoelectronic surface. A particle deposited on the photoelectronic surface of the metal layer changes the near-field surface plasmon resonance photons to far-field scattered light. The particle detector further comprises a unit, provided above the photoelectric surface of the metal layer, for detecting the far-field scattered light.

Abstract: A measuring system for measuring absorption or scattering of a medium at a plurality of different wavelengths, whereby the measurements for the different wavelengths are performable as simultaneously and as accurately as possible. The measuring system comprises: a measuring chamber; a transmitting unit, which sends light of its respective wavelength into the measuring chamber; a control, which operates each light source with a different time modulation of transmission intensity for each wavelength; a detector for measuring a total radiation intensity. The total radiation intensity corresponds to a superpositioning of each intensity portion striking the detector for each wavelength; and a signal processing system, which determines for each of the wavelengths the associated intensity portion based on the total radiation intensity measured by detector and the modulations.

Abstract: A particle counting method that can count the number of the particles precisely. The method discriminates a wave pattern of the scattered light from a normal particle (subject of the counting) and a wave pattern of the light scattered by the agitation such as a floating particle, a radiation or changes in the intensity of the light. In one embodiment, a method for counting particles is disclosed which irradiates a light to a sample gas, detects a scattered light from a particle included in the sample gas by a photoelectric conversion device, counts the number of the particles of every particle size division by the output voltage wave pattern of the photoelectric conversion device, calculate a time difference (Ta?T1) from a point (T1) being a peak of output voltage wave pattern and a point (Ta) being a falling detection threshold (A), when the time difference (Ta?T1) is beyond counting cancellation time (B), the output voltage wave pattern is not counted as a particle.