Abstract: An optical sensor device includes a plurality of light-emitting elements arranged on an arrangement surface to be apart from each other in an x direction perpendicular to a z direction that is a direction connecting an area corresponding to the plurality of light-emitting elements and an area corresponding to a light-receiving element. A light-guide lens portion includes a plurality of incident portions respectively corresponding to the plurality of light-emitting elements and respectively receiving light from the plurality of light-emitting elements. The plurality of incident portions is provided with an equalizing portion configured to equalize intensity of the light incident on the light-guide lens portion along the x direction by reducing the intensity of the light along the z direction out of the light that is emitted from the light-emitting element, while allowing an incident of part of the light emitted from the light-emitting element adjacent to the corresponding light-emitting element.

Abstract: In some embodiments, a LIDAR system may include at least one processor configured to control at least one light source for projecting light toward a field of view and receive from at least one first sensor first signals associated with light projected by the at least one light source and reflected from an object in the field of view, wherein the light impinging on the at least one first sensor is in a form of a light spot having an outer boundary. The processor may further be configured to receive from at least one second sensor second signals associated with light noise, wherein the at least one second sensor is located outside the outer boundary; determine, based on the second signals received from the at least one second sensor, an indicator of a magnitude of the light noise; and determine, based on the indicator the first signals received from the at least one first sensor and, a distance to the object.

Abstract: The invention provides a method and a system for measuring suspended solids in wastewater, including: introducing an aqueous sample into a measurement system, comprising at least one length of tubing; pumping, using a pump, the aqueous sample through the at least one length of tubing; and measuring, using at least one optical sensor, a quantity of suspended solids in the aqueous sample wherein at least one optical sensor is coupled to the length of tubing in a position to measure the quantity of suspended solids while the aqueous sample is located in the at least one length of tubing.

Abstract: An absorption spectroscopy process uses a single radiation beam with two or more pulsed beams (including at least a signal beam and a reference beam) that are passed into a liquid sample to a variable effective depth and then reflected out of the liquid sample where it is detected and processed to obtain a value over a preselected time. As values are determined for multiple effective depths, a sampling dataset is obtained which is used to calculate a concentration level of a targeted particle in the liquid sample by use of calibration dataset obtained from use of known samples.

Abstract: An optical baffle and combination with a laser sensor of especial applicability in attenuating off-axis laser light in the use of a laser sensor for determining the height of a liquid level or distance to a surface detectable through a pipe.

Abstract: Increased precision for liquid absorption spectroscopy, especially for in vivo samples of human analytes, is obtained by varying the signal or signal and interference central wavelengths when the temperature of the sample site varies beyond a selected threshold used for determining standardized signal or signal and interference central wavelengths. The amount of variance for a central wavelength of the signal beam which includes 1,150 nm is approximately 2 nm or less.

Abstract: The present disclosure provides improved optical systems for particle processing (e.g., cytometry including microfluidic based sorters, drop sorters, and/or cell purification) systems and methods. More particularly, the present disclosure provides advantageous micro-lens array optical detection assemblies for particle (e.g., cells, microscopic particles, etc.) processing systems and methods (e.g., for analyzing, sorting, processing, purifying, measuring, isolating, detecting, monitoring and/or enriching particles).

Abstract: The invention relates to a method and an apparatus for measuring particle concentrations in an aerosol. The apparatus comprises means (103) for driving flow (105) into apparatus (101), means (115) for electrically charging particles (109) to become electrically charged particles (123) by ions (113) produced by a charger, means (117) for removing free ions (113) which are not attached to the electrically charged particles (123), and means (119) for measuring electrical current carried by the electrically charged particles (123). The means (115) for charging the particles and the means (119) for measuring electrical current carried by the electrically charged particles (123) are dimensioned such that the means (119) for measuring electrical current carried by the electrically charged particles (123) only measures a part of a total current carried by the particles.

Abstract: Methods, devices, and systems for an unmanned system (US) for smoke detector testing are described herein. In some examples, one or more embodiments include a test kit, a processor, and a memory having instructions stored thereon which, when executed by the processor, cause the processor to perform a test procedure on a projected beam smoke detector in a facility using the test kit and communicate a result of the test procedure to a smoke detector network associated with the facility.

Abstract: Systems for managing abrasive media in cavitated fluid include a set of sensors in communication with cavitated fluid in a processing tank and a processor coupled to the set of sensors. The processor is configured to determine a density of an abrasive media in the cavitated fluid in the processing tank and facilitate maintaining the density of abrasive media in the cavitated fluid in the processing tank at a level that is greater than or equal to a threshold level of abrasive media. The processor is further configured to command the abrasive media addition device to add the recycled abrasive media to the processing tank to increase the density of abrasive media in the cavitated fluid in response to determining that an average density of abrasive media is less than the threshold density of abrasive media.

Abstract: A process quantifies a concentration of a targeted molecule in a liquid sample by pulsing signal and reference beams from their own sources, then spatially combining the pulsed beams into a single radiation beam which passes into the liquid sample and then detecting pulsed output beams after the single radiation beam passes out of the liquid sample. The pulsed outputs of the signal and reference beams are processed to obtain a value over a preselected period of time and, if an interference beam is used, it is processed with the reference beam to obtain a calibration curve adjustment representative of optical interference represented by at least one interfering molecule concentration which is used to calculate the concentration level of the targeted particle in the liquid sample. Two detectors, which may have an optical co-axial configuration, can be used for detection of pulsed beams.

Abstract: An air leak detection system for chest tube collection systems includes a light emitting element, such as an LED, and a photodetector that can detect reflected light emission generated by the light emitting element. The air leak detection system can include a securement component, such as a transparent clip or adhesive, so that the air leak detection system is compatible with any conventional chest tube collection system. In certain embodiments, the light emitting element is positioned closer to the bottom portion of the water seal tube than the photodetector. In certain embodiments, the photodetector is positioned closer to a bottom of the water seal chamber than the light emitting element. In certain embodiments, the air leak detection system is part of a chest tube drainage system. A method of detecting an air leak in a chest tube collection system is also disclosed.

Abstract: A fluid analyzer includes an optical source and detector defining a beam path of an optical beam, and a fluid flow cell on the beam path defining an interrogation region in a fluid channel in which the optical beam interacts with fluids. One or more flow-control devices conduct a particle in a fluid through the fluid channel. A motion system moves the interrogation region relative to the fluid channel in response to a motion signal, and a controller (1) generates the motion signal having a time-varying characteristic, (2) samples an output signal from the optical detector at respective intervals of the motion signal during which the interrogation region contains and does not contain the particle, and (3) determines from output signal samples a measurement value indicative of an optically measured characteristic of the particle.

Abstract: The flow cell of the present application simultaneously monitors and measures light absorbance and fluorescence of particles in a flowing liquid.

Abstract: Methods, devices, and systems for an unmanned system (US) for smoke detector testing are described herein. In some examples, one or more embodiments include a test kit, a processor, and a memory having instructions stored thereon which, when executed by the processor, cause the processor to perform a test procedure on a projected beam smoke detector in a facility using the test kit and communicate a result of the test procedure to a smoke detector network associated with the facility.

Abstract: A telescope system includes a telescope and a selective shielding unit including at least one member including a passage allowable region for an observation target electromagnetic wave and a passage blocking region for the observation target electromagnetic wave. The telescope includes a position detectable detector that detects the observation target electromagnetic wave on a surface different from a focal plane of the telescope. The selective shielding unit is disposed on a front side of the detector. Patterns of the passage allowable region and the passage blocking region of the at least one member and disposition of the at least one member are set to allow for reconstruction of an observation image based on an image detected in the detector.

Abstract: Provided herein are analyzers as well as related methods for measuring both an absorbance and emission of a sample. The analyzer includes light sources for epi-illumination and transillumination of the sample, and detectors for measuring the intensities of excitation, emission, and transillumination light. A dichroic mirror permits a portion of the excitation light to transmit to a detector that monitors changes in excitation light intensity. Temperature sensors allow for signal corrections based on temperature variations of the detectors and sample.

Abstract: A turbidity measurement method includes irradiating a first irradiation light L1 having a first spectrum E1, detecting a first measured light ML1 based on the first irradiation light L1, irradiating a second irradiation light L2 having a second spectrum E2 different from the first spectrum E1, detecting a second measured light ML2 based on the second irradiation light L2, calculating turbidity of a liquid to be measured, and correcting at least one of a first parameter related to turbidity calculation associated with the first irradiation light L1 and a second parameter related to turbidity calculation associated with the second irradiation light L2 so that the calculated turbidity of the liquid to be measured corresponds to the turbidity of the liquid to be measured as measured using another light source serving as a standard of comparison.

Abstract: A temperature sensor 10 according to the present invention includes a coil element (10) connected to a coil of an electric apparatus, an element main body (51) that includes a thermosensitive body (52) detecting heat of the coil element (10) and paired electric wires (55 and 56) connected to the thermosensitive body (52), and a housing (25) that includes an electric insulating resin material and is configured to house the coil element (10) and the element main body (51). The housing (25) according to the present invention includes, at a position corresponding to the thermosensitive body (52), a view window (76) allowing for visual confirmation of the thermosensitive body (52) from outside.

Abstract: A toilet with multiple urinalysis instruments is disclosed. Two or more of the optical instruments are able to take simultaneous measurements. Optical instruments may share a common light source. One or more light source may use amplitude modulation. A cleaning jet may be used to clean and dry a surface tension urine slot. An inductive heater may be used to preheat and control urine temperature while testing the urine.

Abstract: A fluid analyzer includes an optical source and detector defining a beam path of an optical beam, and a fluid flow cell on the beam path defining an interrogation region in a fluid channel in which the optical beam interacts with fluids. One or more flow-control devices conduct a particle in a fluid through the fluid channel. A motion system moves the interrogation region relative to the fluid channel in response to a motion signal, and a controller (1) generates the motion signal having a time-varying characteristic, (2) samples an output signal from the optical detector at respective intervals of the motion signal during which the interrogation region contains and does not contain the particle, and (3) determines from output signal samples a measurement value indicative of an optically measured characteristic of the particle.

Abstract: A system includes a method and apparatus suitable for measuring planar drop sizes in a liquid spray. Measurement may involve illuminating the spray with multiple lasers and measuring the scattered intensities at several view angles using linear arrays. The system may use inverse calculation of the measured scattered intensity to estimate the local drop sizes across the entire plane in a spray. The system includes radiation detectors containing sensing elements, a lens systems, and analog to digital conversion board to convert scattered intensities to drop sizes. In addition, the system may include choppers including at least two unique filters. The filters may be selectively placed in a path between the spray and the sensing elements. By selectively placing a single array may measure both a scattered intensity and an extinction of laser light emitted from the spray.

Abstract: A printing apparatus includes a circulation pathway that circulates an ink between a pressure chamber of a printing head and the outside thereof. The number of eject of the ink to be ejected from an ejection port of the printing head to a unit printing area is set according to a concentration of the ink in the circulation pathway.

Abstract: The present disclosure relates to fire detectors. For example, a fire detector may include: a housing with a smoke inlet; a detection unit for specific fire parameters; an analyzing unit for generating a fire alarm; a light transmitter; and a light receiver connected to the analyzing unit for monitoring the smoke inlet for impermissible pollution. The light transmitter and the light receiver comprise a scattered light arrangement with a scattered light volume near the smoke inlet and susceptible to pollution. A part of a light bundle traverses the region without striking adjacent housing parts, or a part of the light strikes a housing part and the housing part deflects the second part of the light bundle away from the light receiver or absorbs it. The analyzing unit sends a service message if the scattered light detected by the light receiver exceeds a threshold value.

Abstract: Modulation amplitude used for frequency modulation of laser light is set to a1 (<a2) (S1), and laser light is irradiated to a sample state in that state. When moisture concentration is calculated based on secondary harmonic synchronous detection signal that is obtained by synchronous detection of detection signal from transmitted light, the effects of interfering moisture in the optical chamber is ignored, and moisture concentration of the gas to be measured in the sample cell is obtained (S2). If, for example, a high vacuum is created inside the sample cell and the concentration becomes less than the detectable limit (“YES” in S3), the modulation amplitude is switched to a larger amount a2 (S4). By so doing, the detection sensitivity to interfering moisture in atmosphere at atmospheric pressure is increased, and the concentration of interfering moisture is calculated based on the secondary harmonic synchronous detection signal (S5).

Abstract: There is provided a control device including: a determination unit configured to determine a mounted state of a detection device on the basis of a plurality of detection values, the detection unit including a light source and a plurality of light receiving elements and detecting a pulse wave, the plurality of detection values corresponding to signals output in response to light beams received from the plurality of light receiving elements, respectively, distances between the light source and the respective plurality of light receiving elements being different from each other; and an operation control unit configured to control an operation related to detection of the pulse wave performed by the detection device on the basis of a determination result of the mounted state.

Abstract: The invention optically analyzes a component in a sample having a material suspended. An optical analysis system that irradiates a liquid sample with light and analyzes a component of the sample using transmitted light transmitted through the sample includes a container accommodating the sample and an ultrasonic irradiation unit irradiating an ultrasonic wave for exciting the sample. The container includes a pair of light transmission wall portions between which the sample is disposed and which has light transmissivity, and one of the light transmission wall portions and the other of the light transmission wall portions are disposed to be separated from each other at a distance shorter than a wavelength of the ultrasonic wave.

Abstract: An embodiment provides a method for determining a concentration of an analyte in a fluid sample, including: introducing a fluid sample into a measurement chamber; operating a measurement device to introduce light of a first wavelength to the fluid sample; measuring, with a detector, absorbance of the light of the first wavelength with respect to the fluid sample; operating the measurement device to introduce light of a second wavelength to the fluid sample; measuring, with the detector, absorbance of the light of the second wavelength with respect to the fluid sample; determining, using a processor of the measurement device, an absorbance ratio of the fluid sample using both the measured absorbance of the light of the first wavelength and the measured absorbance of the light of the second wavelength; and providing, via an output device, a determined concentration value for the fluid sample that correlates to the absorbance ratio. Other aspects are described and claimed.

Abstract: A method is used to determine an absorption behavior of a medium. The method includes establishing an absorption coefficient of the medium using a first intensity value and at least one second intensity value and a length different between a first measurement distance and a second measurement distance. The first intensity value represents a measured first light intensity after passing over a first measurement distance in the medium. The second intensity value represents a measured second light intensity after passing over a second measurement distance in the medium. The first intensity value and the second intensity value are measured using light with a common initial intensity.

Abstract: Disclosed is a sensing system including an actuator configured to provide a stimulus to a detection-target material, a photo-detector configured to output an electrical signal having a snapback (SB) form corresponding to an optical reaction brought about according to the concentration of the detection-target material to which the stimulus has been provided, an amplifier configured to amplify the electrical signal output from the photo-detector and positively feedback and apply the amplified electrical signal to the actuator, a detector configured to receive the electrical signal and detect the detection-target material, and a voltage clamping device connected in parallel with the photo-detector and configured to clamp a voltage at both ends of the photo-detector so that the voltage does not exceed a predetermined voltage value.

Abstract: An optical device for detecting a first chemical species and a second chemical species contained in a specimen, which includes: a first optical sensor, which may be optically coupled to an optical source through the specimen and is sensitive to radiation having a wavelength comprised in a first range of wavelengths; and a second optical sensor, which may be optically coupled to the optical source through the specimen and is sensitive to radiation having a wavelength comprised in a second range of wavelengths, different from the first range of wavelengths.

Abstract: The present invention discloses a quantitative micro-volume nucleic acids detection device, which includes a light source, a first shielding screen, a second shielding screen, a lower glass plate, an upper glass plate and at least one sensor, wherein a pin-hole on the second shielding screen generates an image of a nucleic acid sample solution fixed between the bottom and upper glasses, the image is then captured by the sensor, concentration of the nucleic acid sample solution is determined accordingly. With the implementation of the present invention, the detection is reproducible and repetitive, the detection optical path is invariant, avoid of interfering from the pollution during detection so that the cost and time are greatly reduced.

Abstract: A fluid analyzer includes an optical source and an optical detector defining an optical beam path through an interrogation region of a fluid flow cell. Flow-control devices conduct analyte and reference fluids through a channel and the interrogation region, and manipulate fluid flow in response to control signals to move a fluid boundary separating the analyte and reference fluids across the interrogation region. A controller generates control signals to (1) cause the fluid boundary to be moved across the interrogation region accordingly, (2) sample an output signal from the optical detector at a first interval during which the interrogation region contains more analyte fluid than reference fluid and at a second interval during which the interrogation region contains more reference fluid than analyte fluid, and (3) determine from samples of the output signal a measurement value indicative of an optically measured characteristic of the analyte fluid.

Abstract: The various embodiments disclosed herein utilize multiple lasers that have different wavelengths and a single detection path. The lasers are mounted orthogonal to one another so that one laser will provide a forward angle light scatter (FALS) signal in the detection path, and one laser will provide a side scatter signal in the detection path (i.e., the single detection optics are approximately in-line with the FALS laser and approximately orthogonal to the side scatter laser). The single detector path spectrally separates the forward and side scatter signals prior to applying them to their respective detectors for measurement.

Abstract: A method is provided for extracting the position of a particle, e.g., a moving or stationary particle that is excited or is emitting light. The method includes, among other steps, detecting and recording a signal based on, for example, the movement of the particle, a correlation step to eliminate noise and to create a transformed signal, a matching or fitting step to match the transformed signal to a fit function and an extracting or determining step to determine the position of the particle from the fit function. In one form, at least two particle positions are detected so that the distance between the subject particles can be determined.

Abstract: The present disclosure is related to a microfluidic flow analyzer for pathological detection. The microfluidic flow analyzer comprises plurality of buffer channels, sample channel, central flow channel, plurality of exciting optical channels and plurality of receiving optical channels. The plurality of exciting optical channels and the plurality of receiving optical channels are placed at predetermined angle to the central flow channel. The plurality of exciting optical channels excite cell in the sample solution flowing through the central flow channel. The cell being excited produces one or more optical signals. The one or more optical signals are received by the plurality of receiving optical channels. The microfluidic flow analyzer comprises plurality of detectors placed on each of the plurality of receiving optical channels for detecting one of the one or more optical signals. The detected optical signal is sent to a computing unit for pathological detection.

Abstract: The present disclosure provides improved optical systems for particle processing (e.g., cytometry including microfluidic based sorters, drop sorters, and/or cell purification) systems and methods. More particularly, the present disclosure provides advantageous micro-lens array optical detection assemblies for particle (e.g., cells, microscopic particles, etc.) processing systems and methods (e.g., for analyzing, sorting, processing, purifying, measuring, isolating, detecting, monitoring and/or enriching particles.

Abstract: A method and an apparatus of measuring a position of a particle in a flow are disclosed. An embodiment of the method comprises temporally modulating and spatially pattering an illumination beam propagating along a first dimension, passing a particle across the modulated illumination beam, detecting a temporal profile of scattered light produced by the particle's passing through the modulated illumination beam, and determining the position of the particle based, in part, on the temporal profile of the detected scattered light.

Abstract: There is disclosed improved apparatus and methods for detection of shape, size and intrinsic fluorescence properties of a fluid borne particle wherein the apparatus comprises a laser, two light sources, two detectors, and optionally a third detector. The apparatus is particularly suitable for detection of airborne biological particles.

Abstract: Systems and methods for determining liquid depth information in a condensate pan of a climate control unit are provided. The systems and methods radiate a light beam into a liquid contained in a condensate pan associated with a climate control unit. The light beam is detected at a point of the condensate pan that is below a surface of the liquid. Information related to the depth of the liquid is determined based at least in part on the detected light beam. The systems and methods disclosed herein can determine if liquid depth in a condensate pan is greater than a threshold depth and can control evacuation of the liquid from the condensate pan.

Abstract: Large area, low f-number optical systems, and microfluidic systems incorporating such optical systems, are disclosed. Large area, low f-number optical systems may be used to collect light from plurality of micro channels associated with a plurality of flow cytometers. The optical systems may be configured to collect light from a source area having an object lateral length or width within a range of 25 mm and 75 mm, configured to have an f-number within a range of 0.9 to 1.2, and configured to have a working distance within a range of 10 mm to 30 mm.

Abstract: Methods, storage mediums, and systems for correlating pulses generated from multiple interrogation regions in a flow cytometer to particular particles flowing through the flow cytometer are provided. Embodiments of the methods, storage mediums, and systems include configurations for calibrating a flow cytometer using a calibration particle having a unique signature to determine a time-of-flight for particles flowing through the flow cytometer. Based on the calculated time-of-flight and relative positions of interrogation regions corresponding to collectors of the flow cytometer, the methods, storage mediums, and systems may further include configurations for associating other signal pulses to particles of one or more different particle sets.

Abstract: An analytical instrument may have multiple distinct channels. Such may include one or more illumination sources and sensors. Illumination may be delivered to specific locations of a specimen holder, and returned illumination may be delivered to specific locations of a sensor array. Illumination may first pass a specimen, and a mirror or reflector may then return the illumination past the specimen. Optical splitters may be employed to couple pairs of fiber optics proximate a specimen holder. Such channels may further include a plurality of illumination sources positioned on one side of a specimen holder and a plurality of sensors on the other side. The plurality of sensor may capture image of a specimen and a spectrophotometer may concurrently scan the specimen. A plurality of specimens may be imaged and scanned in a single pass of a plurality of passes. Spherical or ball lenses may be placed in an optical path of the illumination to achieve a desired illumination pattern.

Abstract: A method of determining a steam quality of a wet steam located in an interior of a steam turbine includes emitting from an optical probe a plurality of wavelengths through the wet steam, measuring with the optical probe a wet steam intensity corresponding to each of the plurality of wavelengths emitted through the wet steam, determining an intensity ratio vector by dividing the wet steam intensity by a corresponding dry steam intensity for each of the plurality of wavelengths, successively applying scaling factors to the intensity ratio vector to obtain a scaled intensity ratio vector, calculating a suitable value for each of the scaling factors to obtain a plurality of residuals, determining a minimum residual of the plurality of residuals, determining a droplet size distribution by calculating the droplet number density corresponding to the minimum residual, and determining the steam quality based on the droplet size distribution.

Abstract: Aerosol and hydrosol particle detection systems without knowledge of a location and velocity of a particle passing through a volume of space, are less efficient than if knowledge of the particle location is known. An embodiment of a particle position detection system capable of determining an exact location of a particle in a fluid stream is discussed. The detection system may employ a patterned illuminating beam, such that once a particle passes through the patterned illuminating beam, a light scattering is produced. The light scattering defines a temporal profile that contains measurement information indicative of an exact particle location. However, knowledge of the exact particle location has several advantages. These advantages include correction of systematic particle measurement errors due to variability of the particle position within the sample volume, targeting of particles based on position, capture of particles based on position, reduced system energy consumption and reduced system complexity.

Abstract: Apparatus (1) for environmental monitoring, allowing to determine the mass concentration of air-dispersed particulate matter by operating or spy filters (F1-F6), comprising a beta radiation emitter (16) and detector (18) for detecting the mass of particulate matter settled on the operating or spy filters (F1-F6), wherein it is further provided the same beta measurement on spy filters (S 12-S1 6) exposed to the same environmental conditions of the operating filters (F1-F6) and the determination of in-air particulate matter concentration by compensation of the two measurements.

Abstract: A system for analyzing smoke has a plurality of units, wherein each unit includes an optical emitter for alternately directing horizontally and vertically polarized light along a beam path, and into a smoke cloud, to generate scattered light. A horizontally polarized detector and a vertically polarized detector are positioned at different locations, but at a same distance and scattering angle relative to the beam path. Each unit has a different wavelength. A computer receives signals from the detectors of all units, in response to each emitter, for analysis of the smoke.

Abstract: The invention provides an optical continuous liquid level sensor used to determine the level of a liquid within a vessel. The sensor includes one or a plurality of light sources located at various height levels, a plurality of light receiving devices located at various height levels, at least one optical lens in front of the light sources and the light receiving devices, and at least one processor connected to the light sources and the light receiving devices, which processor is capable of transmitting outgoing signals to the light sources, receiving reflected signals from the light receiving devices, processing related signal information so as to determine the liquid level continuously. Baseline data can be obtained by placing the entire level sensor in the air.

Abstract: Methods, storage mediums, and systems for correlating pulses generated from multiple interrogation regions in a flow cytometer to particular particles flowing through the flow cytometer are provided. Embodiments of the methods, storage mediums, and systems include configurations for calibrating a flow cytometer using a calibration particle having a unique signature to determine a time-of-flight for particles flowing through the flow cytometer. Based on the calculated time-of-flight and relative positions of interrogation regions corresponding to collectors of the flow cytometer, the methods, storage mediums, and systems may further include configurations for associating other signal pulses to particles of one or more different particle sets.

Abstract: A method for discriminating particle groups comprises generating, by a particle analyzer, a particle characteristic distribution histogram in which the abscissa indicates respective channels for representing the characteristics of the particles, and the ordinate indicates the particle count; setting a valid area selection height in the particle characteristics distribution histogram; and generating an equivalent negative histogram based on the set height and the particle characteristic distribution histogram.