Abstract: An apparatus for making isotopic ethane measurements of a gas sample includes a tunable infrared laser configured to emit an infrared laser beam; an infrared sensor configured to receive the infrared laser beam; a gas cell deployed in a path between the tunable infrared laser and the infrared sensor such that the infrared laser beam passes through the gas cell, the gas cell configured to receive the gas sample; and a controller configured to evaluate the received infrared laser beam to estimate a ratio of C13 ethane to C12 ethane in the gas sample.

Abstract: This application discloses a photographing apparatus and method, and relates to the field of image processing. When a high-quality image in a low illumination environment is obtained, costs are reduced, a size is reduced, and product compatibility is improved. The method includes: controlling a light filtering unit to: transparently transmit visible light in incident light and block infrared light in the incident light in a first image exposure interval, transparently transmit the infrared light in the incident light in a first time period of a second image exposure interval, and block the incident light in a second time period of the second image exposure interval; performing, by using an image sensor to obtain a first image, and performing photoelectric imaging on a light ray to obtain a second image; and synthesizing the first image and the second image, to generate a first target image.

Abstract: Systems, devices, and methods for a trace-gas sensor configured to generate a raw detector signal (118) based on a gas sample; an analog processing configured to filter, amplify, lock-in, and/or normalize the generated raw detector signal; analog to digital converters configured to convert the filtered and amplified detector signal to a digital signal; and a drive computer configured to: receive the converted digital signal from the analog to digital converters; and apply a spectroscopic model to the received digital signal to extract one or more properties of the gas sample.

Abstract: Zero power wireless sensors, devices, and systems are used for crop water content monitoring. The sensors consume no power while monitoring for the presence of dry crop conditions. Infrared reflectance from plants is measured and when selected spectral conditions are met, a circuit is closed, activating an alarm, an RFID tag, or a radio transmitter. The deployed sensors consume no power while monitoring, reducing or eliminating the need to change batteries.

Abstract: The invention relates to a modulatable infrared emitter comprising a heating element, a planar base element, a dielectric interlayer, and a planar cover element which is a structured metamaterial, and an actuator, wherein the actuator is configured for a relative movement of the cover element and the base element between a first and a second position in order to modulate the intensity of the emission of the infrared emitter. The invention further relates to production methods for the infrared emitter, methods for the modulated emission of infrared red radiation by means of the infrared emitter, and preferred uses of the infrared emitter. A system comprising the infrared emitter and a control device for regulating the actuator are also preferably the subject matter of the invention.

Abstract: A method for evaluating and controlling roasting and degree (level) of roast in food items including but not limited to: coffee, cocoa, beans, nuts, grains and seeds, involves collecting spectra of the gases (including water vapor) emitted during roasting in the mid-infrared region using either mid-infrared source or visible light to include Raman scattering. The changes in the spectra, due to absorption by molecular vibrations in the gases emitted during roasting are evaluated in real time during roasting. These data may be processed in frequency or time domain. The spectra and change in spectra are correlated with a roasting profile to mark the inception of roasting, progress of roasting and maturity/achievement of degree of a roast. The information can be transmitted to the roaster or controller to monitor the roasting progress and can be used to adjust parameters as desired during roasting.

Abstract: A measuring device for measuring the absorbance of a substance in at least one solution provided in at least two flow cells of the measuring device, wherein said measuring device comprises: —a light source transmitting a first light ray; —said at least two flow cells; —an optical arrangement comprising at least two semi-transparent mirrors with different transmission properties, said optical arrangement being arranged for dividing the first light ray coming from the light source into separate light parts, one for passing each flow cell and one for entering directly after the optical arrangement a reference detector; and —one detector provided after each flow cell for detecting light having passed through the flow cells.

Abstract: Methods and apparatus are disclosed for detecting one or more species in a sample, wherein laser probe light is frequency swept across at least one infra red absorption spectrum feature of each of the species. A path from the probe light source to a single detector element may be switched between at least one sample absorption cell or volume and one or more reference cells or volumes.

Abstract: A method for controlling alkali emissions of a glass element during hot forming is provided. The method includes the steps of: heating the glass element using one or more burner units each providing a burner flame to provide a heated glass element; sensing light emissions of a total light emitting area of the heated glass element and the burner flame of the one or more burner units via one or more sensor units; providing one or more signals of the one or more sensor units of the light emissions; comparing the one or more signals with one or more reference signals; determining, based on the comparing step, determined alkali emissions of the glass element; and controlling the one or more burner units based on the determined alkali emissions to adjust the alkali emissions of the glass element to a pre-given interval.

Abstract: A GaN layer of micro-LEDs is exposed to ion implantation to amorphize one or more regions of the GaN layer. As a result, the GaN layer through which light rays propagate have non-uniform refractive indexes that modify propagation paths of some light rays. Ions are implanted in a region overlapping an active region that emits light to function as a converging GRIN (gradient-index) lens. The ion implanted regions collimate light rays that propagate along predetermined directions. As such, the light extraction from and the focus of the micro-LEDs is increased.

Abstract: Systems and methods disclosed herein, in accordance with one or more embodiments provide for imaging gas in a scene, the scene having a background and a possible occurrence of gas. In one embodiment, a method and a system adapted to perform the method includes: controlling a thermal imaging system to capture a gas IR image representing the temperature of a gas and a background IR image representing the temperature of a background based on a predetermined absorption spectrum of the gas, on an estimated gas temperature and on an estimated background temperature; and generating a gas-absorption-path-length image, representing the length of the path of radiation from the background through the gas, based on the gas image and the background IR image. The system and method may include generating a gas visualization image based on the gas-absorption-path-length image to display an output image visualizing a gas occurrence in the scene.

Abstract: An air filter includes filter media, a sensor, and circuitry coupled to the sensor, the circuitry configured to receive data from the sensor representative of the condition of the filter media and wirelessly transmit such data. The data may be received by a device with a display to use the information to present an indication of the filter media condition to a user.

Abstract: A method is provided for spatially modulating electromagnetic radiation at high frequency where the modulation is phase, polarization or direction of propagation comprises a substrate carrying an ordered array of optical elements in relative motion with respect to an incident beam of electromagnetic radiation to be modulated and measuring the relative motion. The array contains at least three optical elements and at least two different types of optical elements. At least some of the optical elements are formed from and integral to the substrate material. The optical elements may be fabricated on the substrate material by a subtractive process. The electromagnetic radiation to be modulated is incident on a region of the substrate termed the active region. As the substrate moves relative to the incident electromagnetic radiation, the active region also moves and the designation of individual optical elements changes also.

Abstract: A portable unit for metabolic analysis includes a manifold in fluid communication with a mouth of a test subject. A conduit extends from the manifold and defines a flow channel through which the breaths of the test subject travels. A carbon dioxide sensor is attached to the conduit. The carbon dioxide sensor includes an intermediate support housing enclosing a volume disposed along the flow channel to define a first part of the flow channel, an inner support housing attached to a first side of the intermediate support housing, a plurality of IR LEDs mounted to an interior surface of the inner support housing, an outer support housing attached to a second side of the intermediate support housing, and a photodetector attached to the outer support housing. The photodetector faces the flow channel and receives IR radiation emitted by the plurality of LEDs.

Abstract: A multi-core sensor system in taxi roof light is provided. The multi-core sensor system can intelligently determine whether the change is caused by the sub-sensor failure or sudden pollution, when the data detected by the sub-sensor suddenly changes dramatically, so as to increase the reliability of detection data of the sub-sensor. The multi-core sensor system can automatically determine whether the repair is needed when a device fault occurs, thereby ensuring the continuity of the sub-sensor detection data; which has significant value for continuous monitoring required for a haze treatment operation. In addition, human and material resources for device maintenance may be saved, thereby reducing waste.

Abstract: An area monitoring device is placed in a location to monitor volatile organic compounds emissions. The device includes a gas sensor capable of detecting VOCs, a sorbent material capable of absorbing VOC molecules, and a heating element positioned in close relation to, or in direct contact with, the sorbent material. After a period of time during which the sorbent material absorbs VOC molecules, the sorbent material is heated to cause the sorbent material to release a gas containing VOC molecules. The amount of released VOC molecules is sensed and calculated. Data is compiled and analyzed. This is accomplished without removing the device from the location. A pump may be provided to force ambient air through the device.

Abstract: A generalized feed-forward method for accurate tunable laser absorption spectroscopy includes generating a laser beam. The generated laser beam is directed down a reference path and a test/sample path. One or more parameters are extracted from the reference path. The one or more parameters, extracted from the reference path, are used as feed-forward, to adjust spectral analysis of the test/sample path to detect a composition and/or concentration of an analyte gas within the test/sample path. The extraction of the one or more parameters from the reference path and the spectral analysis of the test/sample path are performed substantially concurrently.

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: In order to separately evaluate an influence degree of fuel and an influence degree of lubricating oil with respect to particulate matters contained in exhaust gas, an exhaust gas analysis method includes: analyzing particulate matters contained in the exhaust gas exhausted from an engine, thereby making it possible to analyze the particulate matters derived from the lubricating oil by using isooctane as a fuel.

Abstract: Presented herein are systems and methods directed to a multispectral absorption-based imaging approach that provides for rapid and accurate detection, localization, and quantification of gas emission from within a site to be monitored. The imaging technology described herein utilizes an optical sensor and broadband illumination in combination with specialized reflector installments mounted about the site. The optical sensor detects light (e.g., reflected) from a plurality of sampled locations along the reflector installment, for example by imaging multiple sampled locations at a time and/or scanning an instantaneous field of view (ifov) of the optical sensor. Lines-of-sight from the optical sensor to sampled locations along the reflector installment sweep out an “optical curtain” partially enclosing and/or forming a boundary near various assets to be monitored.

Abstract: Systems and methods are described for calibrating an analytical instrument analyzing a plurality of sample matrices in series. A system embodiment can include, but is not limited to, a sample analysis device configured to receive a plurality of samples from a plurality of remote sampling systems and to determine an intensity of one or more species of interest contained in each of the plurality of samples; and a controller configured to generate a primary calibration curve based on analysis of a first standard solution having a first sample matrix by the sample analysis device and generate at least one secondary calibration curve based on analysis of a second standard solution having a second sample matrix by the sample analysis device, the controller configured to associate the at least one secondary calibration curve with the primary calibration curve according to a matrix correction factor.

Abstract: A particle-measuring system for determining particle mass concentrations in aerosols has a laser diode serving as a radiation source and projecting a beam of laser light through a flowing stream of the aerosol. A receiver for receiving the light from the diode after passing through the stream and converting the received light into a measurement. A frequency radiation output of the laser diode is modulated such that the frequency is substantially greater than a cutoff frequency of the receiver so that a specifiable radiation output of the laser diode is achieved on average over a duration of a measurement signal of the receiver.

Abstract: A system for detecting a gas leak can include: at least one infrared imaging sensor; and an imaging analysis computer operably coupled with the at least one infrared imaging sensor. The imaging analysis computer can be configured to control any infrared imaging sensor and acquire infrared images therefrom at any rate and in any duration. The imaging analysis computer can be configured to analyze the infrared images in order to detect a gas leak. The imaging analysis computer can be configured to detect a gas where gas should not be (or is not present in a baseline) in order to determine that there is a gas leak in the vicinity. The gas can be a hydrocarbon gas or carbon monoxide, or other.

Abstract: The invention relates to a thermopile infrared individual sensor in a housing that is filled with a gaseous medium having optics and one or more sensor chips with individual sensor cells with infrared sensor structures with reticulated membranes, the infrared-sensitive regions of which are spanned by, in each case, at least one beam over a cavity in a carrier body with good thermal conduction. The object of the invention consists of specifying a thermopile infrared sensor using monolithic Si-micromechanics technology for contactless temperature measurements, which, in the case of a sufficiently large receiver surface, outputs a high signal with a high response speed and which can operated in a gaseous medium with normal pressure or reduced pressure and which is producible in mass produced numbers without complicated technology for sealing the housing.

Abstract: An air filter includes filter media, a sensor, and circuitry coupled to the sensor, the circuitry configured to receive data from the sensor representative of the condition of the filter media and wirelessly transmit such data. The data may be received by a device with a display to use the information to present an indication of the filter media condition to a user.

Abstract: A method for determining a multi-dimensional profile of at least one emission parameter corresponding to an exhaust emission of a combustion process is presented. The method includes emitting a laser beam in a plurality of directions through the exhaust emission. The laser beam includes a plurality of wavelengths and the exhaust emission is characterized by the plurality of emission parameters. The method further includes detecting a plurality of absorption spectrum signals for each of the plurality of directions and determining a plurality of single-dimensional profiles corresponding to the at least one emission parameter. Each of the plurality of single-dimensional profiles is determined based on the plurality of absorption spectrum signals corresponding to each respective direction of the plurality of directions. The method also includes generating the multi-dimensional profile corresponding to the at least one emission parameter based on the plurality of single-dimensional profiles.

Abstract: Methods and apparatuses for laser-assisted electron-beam inspection (EBI) are provided. The apparatus includes an EBI device and a laser illumination device. The EBI device includes an e-beam source configured to emit an incident e-beam, a deflector configured to deflect the incident e-beam to be projected onto a surface of a semiconductor device, and an electron detector configured to detect emergent electrons generated by the incident e-beam projected onto the surface. The laser illumination device includes a laser source configured to generate a laser, and a guiding device configured to guide the laser to be projected onto the semiconductor device. The laser changes the emergent electrons to cause, in a positive mode of the EBI apparatus, a PN junction of an NMOS of the semiconductor device to be in a conduction state.

Abstract: A device (1) for determining the concentration of a gas component is configured with a radiation source (30) for emitting (31) a light radiation or heat radiation in an infrared wavelength range. A detector array (40) has at least two detector elements (50, 60), configured to detect the radiation generated by the radiation source (30), in an angular arrangement (52, 62) and with filter elements (51, 61). At least one of the two detector elements (50, 60) is oriented in an angular arrangement (52, 62) in relation to a vertical axis (32), so that a range of overlap (65) is obtained due to the angular arrangements (52, 62). The range of overlap (65) causes attenuations in the propagation of light, which attenuations may be due, for example, to gas molecules or moisture (400), affect both detector elements (50, 60) and are thus compensated concerning the concentration determination.

Abstract: A method for analyzing a gas sample includes the steps of providing a gas sample to a sample canister and heating a sensor to a predetermined resistance. The method further includes the steps of operating a fan at a predetermined speed, and moving a valve to a measurement flow position. When the valve is in the measurement flow position, the fan draws a portion of the gas sample through the valve to expose the sensor to the gas sample.

Abstract: A nail plater apparatus includes a board magazine configured to hold stacked boards, and a pair of spaced apart nail plate magazines, with each nail plate magazine configured to hold stacked nail plates. The nail plater apparatus includes a pair of spaced apart nail plate extractor assemblies, with each nail plate extractor assembly associated with a respective nail plate magazine and configured to position a nail plate therefrom to a respective nail plate pressing area. A board feeder is configured to position a board from the board magazine to a board receiving area, with ends of the board being aligned with the nail plates positioned in the respective nail plate pressing areas. A pair of spaced apart nail plate presser assemblies overlie ends of the board receiving area and is aligned with the respective nail plate pressing areas to press the nail plates into the ends of the board.

Abstract: A method and system for characterizing a chemical reaction in an exhaust after-treatment system that includes providing a first molecule that includes a chemical element that is isotopically labelled. The isotopically labelled first molecule is injected into an exhaust stream of the exhaust after-treatment system to supply the isotopically labelled first molecule to an exhaust treatment component, and second molecules including the chemical element that is isotopically labelled that are produced through a chemical reaction of the first molecule with other constituents of the exhaust stream are quantified.

Abstract: An air filter includes filter media, a sensor, and circuitry coupled to the sensor, the circuitry configured to receive data from the sensor representative of the condition of the filter media and wirelessly transmit such data. The data may be received by a device with a display to use the information to present an indication of the filter media condition to a user.

Abstract: The present invention concerns a flame detector with optical sensors situated within a housing, which is coupled to a signal collector and focuser enclosure. The enclosure includes a reflective surface or reflective surfaces generally oriented outwardly and in optical communication with the sensors through a shield window exposing the sensors; the shield window is situated between the enclosure and the housing of the flame detector. The enclosure may have a conical shape, a parabolic shape, and may include convex or concave surfaces that reflect emission signals from an emission signal source to the sensors in optical communication with the reflective surfaces. The enclosure is thus adapted to collect emission signals and narrow or focus a field of view of the sensors, thereby increasing a detection range between the flame detector and an emission signal source such as a flame source.

Abstract: A sensor (1) for detection of gas, in particular for detection of CO2. The sensor (1) has a contact face (2) which can be directed towards a measuring site. The sensor (1) includes at least one radiation source (3), a measurement volume (4) for receiving the gas to be measured, and at least a first detector (5) for detection of radiation transmitted from the source (3) to the first detector (5) through the measurement volume (4). The sensor has a path (6) of the radiation between radiation source (3) and first detector (5). The radiation propagates along the path in a non-imaging way.

Abstract: The present invention relates to a vehicle control device provided in a vehicle and a control method of the vehicle. A vehicle control device according to an embodiment of the present disclosure may include a windshield provided in a vehicle, and formed to allow changing transparency, a sensing unit configured to sense information associated with the vehicle, and a processor configured to adjust the transparency of the windshield based on that information sensed through the sensing unit satisfies a preset condition.

Abstract: The present invention is one adapted to correct the effect of a second gas component on a first gas component in real time even when the concentration of the second gas component as a coexistent component varies every moment, and includes: a first gas analysis part adapted to measure the concentration of the first gas component contained in sample gas; a second gas analysis part adapted to measure the concentration of the second gas component contained in the sample gas; a correction coefficient storage part adapted to store a correction coefficient for correcting the effect of the second gas component on the first gas component; and a concentration correction part adapted to correct the first gas component concentration on the basis of the correction coefficient, the second gas component concentration of calibration gas used for calibrating the first gas analysis part, and the second gas component concentration.

Abstract: According to embodiments of the invention, a system 200 and method 100 for identifying CO2 concentration in a building area using an imaging device 10 is disclosed. The disclosed method and system includes capturing the number of living beings present in a particular area of the building by the imaging device 10, identifying the active state of the living beings and categorizing the active state as per predefined criteria and identifying the CO2 concentration based on the size of the building area, total number of living beings present in the building area and the active state of the living beings at a given point of time.

Abstract: An optical gas sensor (1), for quantitatively measuring a concentration of one or more gases, includes a radiation source (2) for emitting light waves (L), a cuvette (3) for holding a gas (G) to be measured, and a detector (4) for measuring light intensities. The light source (2) includes at least one emitter (5) of light waves (L) and is configured to emit light waves (L) of at least one first wavelength and of a second wavelength different from the first wavelength simultaneously or separately from each other. The emitter (5) is further configured to emit a spectrum the full half-life width of which is a maximum 50% of the effective wavelength, and to emit light waves (L) having a controlled beam path. The detector (4) is configured to quantitatively detect an intensity of emitted light waves (L) of the first wavelength and of the second wavelength.

Abstract: A gas concentration sensor is includes an integrated die-form electromagnetic radiation source and an integrated die-form infrared detector. In one or more implementations, the gas concentration sensor includes a package substrate defining at least one aperture, a gas permeable mesh coupled to the package substrate and covering at least a portion of the at least one aperture, a die-form electromagnetic radiation source positioned in an interior region of the package substrate, a die-form detector positioned in the interior region of the package substrate, and control circuitry operably coupled to the die-form detector and configured to detect and calibrate one or more signal outputs from the die-form detector to determine a gas concentration within the interior region of the package substrate. The gas concentration sensor can be configured for specific detection of various gases through control of the spectral wavelengths emitted by the electromagnetic radiation source(s) and/or detected by the detector(s).

Abstract: A compact high power laser calibration and testing system includes an active intracavity laser system that amplifies the laser power by recycling photons through a thin disk gain medium that is positioned between two or more highly reflective mirrors. The system is configured for calibration and testing of the high power lasers and optics that can be inserted into or positioned at the end of the intracavity. In another embodiment, the system is configured for characterization of high power laser beam propagation in operation-relevant atmospheres. The intracavity high power laser beam is configured to simulate high power laser beams with orders-of-magnitude reduced size, weight and operation power for calibrating laser powers and testing optical components.

Abstract: A device for non-invasively determining existence of a gas component of interest inside a determination space of a glass unit comprises a laser beam emitting unit comprising a laser source for emitting laser beam towards said measuring space and detecting unit comprising a detector for detecting transmission of said emitted laser beams traveled through said space. The device is configured to measure in a calibration mode locations of at least one reference peak of at least same gas component as to the determined inside the determination space. The emitted laser beam is configured to travel through a calibration space having at least the gas component of interest, and the detecting means is configured essentially to detect or image said beam transmitted through said calibration space.

Abstract: A device for identifying refrigerants includes a gas cell, which has a test gas inlet and a test gas outlet, an infrared source that radiates through the gas cell, and at least one sensor that detects the infrared radiation that passes through the gas cell. At least one wide-band filter is provided between the infrared source and the sensor. The passband of the at least one wide-band filter includes the absorption spectra of the refrigerants to be detected and does not include the absorption spectrum of hydrocarbons. The gas cell is connected to a cartridge, which contains the refrigerant to be detected in pure form as a reference gas.

Abstract: A sealed high intensity illumination device configured to receive a laser beam from a laser light source and method for making the same are disclosed. The device includes a sealed cylindrical chamber configured to contain an ionizable medium. The chamber has a cylindrical wall, with an ingress and an egress window disposed opposite the ingress window. A tube insert is disposed within the chamber formed of an insulating material. The insert is configured to receive the laser beam within the insert inner diameter.

Abstract: An apparatus includes a material having an optical transition profile with a known energy transition; and a detector configured to detect a characteristic associated with the interaction between the material and the testing light beam. The testing light beam is either a primary light beam produced by an optical source or a calibration light beam. The apparatus also includes a spectral analysis module placed in a path of the primary light beam; and a control system connected to the detector and to the spectral detection system. The control system is configured to determine a reference spectral profile of the primary light beam based on the detected characteristic; compare the reference spectral profile of the primary light beam with a sensed spectral profile of the primary light beam output from the spectral detection system; and based on this comparison, adjust a scale of the spectral detection system.

Abstract: A system and method are disclosed for gas sensing over a wide tunable wavelength range provided by one or more quantum cascade lasers. A laser beam is generated within the wide tunable wavelength range, which is given by the sum of the wavelength ranges from the individual lasers. Gas sensing or detection is achieved by obtaining an infrared absorption spectrum for a sample contained in one or more cells having different path lengths for the laser beam.

Abstract: An aeroponic system for supporting efficient low-resource-usage plant growth comprises a housing comprising one or more openings and one or more root chambers; one or more sealing members configured to substantially conform to a stalk of a plant and to substantially isolate a canopy of the plant from the one or more root chambers; one or more root chamber sensors; one or more nutrient storage reservoirs for storage of plant nutrients; one or more air-assisted nozzles configured to introduce atomized nutrient solution into the one or more root chambers; a temperature control system configured to control a temperature of the one or more root chambers; and a control system configured to control the temperature control apparatus and the one or more air-assisted nozzles to maintain environmental parameters associated with the one or more root chambers within desired parameter ranges.

Abstract: A device for recording an absorption spectrum of a fluid has a radiation source (1) that emits a radiation in a spectral range along a beam path (11), a measuring path (5), along which the radiation passes through the fluid and arranged in the beam path, a tunable Fabry-Perot interferometer (7), arranged in the beam path and transmitting radiation in the spectral range as a displaceable bandpass filter, and a detector (9, 35) measuring the intensity of the radiation in the spectral range. An etalon (3) is arranged for spectral modulation of radiation in the beam path and has a plurality of transmission maxima (17) in the spectral range. The bandpass filter, formed by the Fabry-Perot interferometer (7), is displaceable across the spectral range such that spectral modulation of the radiation by the etalon (3) is measured by the detector (9, 35) as a modulation of radiation intensity over time.

Abstract: An infrared detection device can be used to detect coal mine polar gas. The detection device can include a central processor and a gas pool assembly having a moveable optical window. The moveable optical window can include a stationary pool body and a moveable pool body inserted into the stationary pool body.

Abstract: An optical computing device adapted to compensate for the effects of light intensity fluctuation through the use of optical elements that generate a normalization optical channel (or B Channel) having a light intensity that is substantially equal to the light intensity of the characteristic optical channel (or A Channel). As a result, highly accurate normalizations are obtained which give rise to the most accurate results from the optical computing device.

Abstract: A gas concentration measurement device includes a waveguide including an entrance and an exit, a rotating member, first and second band pass filters on the rotating member and on a pair of planes that intersect each other, and a rotational driver. The rotating member is rotated by the rotational driver so that the first and second band pass filters are selectively located at a transmitting position. When a portion of the rotating member, the first band pass filter, or the second band pass filter, the portion having a maximum radius of gyration around a rotating shaft, is defined as a maximum radius portion, and when a rotation locus obtained by imaginarily rotating the maximum radius portion around the rotating shaft in a view along the rotating shaft is defined as a reference circle, the exit is located in the reference circle.