11); - two measurement photodetectors positioned at two different distances from the light source; - a processing unit programmed to identify a gas species present in the gas on the basis of the detection signals from the two measurement photodetectors.
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01N 21/3518 - Devices using gas filter correlation techniquesDevices using gas pressure modulation techniques
2.
Method for calibrating a gas sensor and method for measuring a gas using the calibration
In a method for calibrating a gas sensor—for determining a gaseous species concentration in a gas, which species absorbs light in an absorption spectral band—the gas sensor includes a chamber for containing the gas; a light source through which a supply electrical current is passable to raise the light source to a temperature; a measurement photodetector for measuring—in a measurement spectral band comprising the absorption spectral band—a measured intensity of a light beam emitted by the light source and transmitted by the gas in the chamber; and a reference photodetector for measuring a reference intensity of a reference light beam emitted by the light source in a reference spectral band. A non-linear calibration function is determined to estimate an intensity, measured in the measurement spectral band by the measurement photodetector in the absence of gaseous species, from a reference intensity measured in the reference spectral band.
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
G01N 33/00 - Investigating or analysing materials by specific methods not covered by groups
3.
Optimized infrared light source for a gas sensor, and manufacturing method thereof
An infrared light source includes an emitting element extending as a radial plane about the emitting element's center and configured to heat up to emit infrared light. The emitting element lies in a cavity bounded by a cover, placed facing the emitting element. The cover has internal and external faces, the internal face facing the emitting element, and the external face defining an interface between the cover and a medium outside the light source. The cover occupies, parallel to a transverse axis perpendicular to the radial plane, a thickness, between the internal and external faces. The external face includes a planar central portion and at least one peripheral portion adjacent and inclined respective to the central portion. The planar central portion extends about the external face's center. In the peripheral portion, the cover's thickness decreases as a function of a distance from the central portion.
G01N 21/25 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
4.
METHOD AND DEVICE FOR ESTIMATING A CONCENTRATION OF A GASEOUS SPECIES BASED ON A SIGNAL EMITTED BY A GAS SENSOR
A method for estimating a concentration of a gaseous species, comprising, at each measuring time: a) the gas sensor forming a detection signal; b) computing the corrected signal at the measuring time, based on a sum of: - a prediction term of the corrected signal at the measuring time, weighted by a first weighting factor based on the corrected variation signal and the corrected signal; - the detection signal, at the measuring time, assigned a second weighting factor; c) computing a variation signal at the measuring time, the variation signal being established based on a weighted sum: - of a difference between the corrected signals respectively at the measuring time and at the previous time, - of the variation signal at the previous time; d) estimating the concentration of the gaseous species, e) reiterating a) to d).
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
A method for measuring an amount of a gas species able to absorb light in an absorption spectral band includes placing a gas between a measurement photodetector and a light source able to emit an incident light wave propagating through the gas to the photodetector. Electrical supply current passes through the light source to bring it to a temperature value. At multiple times: the light source illuminates the gas; the measurement photodetector measures a “measurement” intensity of a light wave transmitted by the gas in a measurement spectral band; and a reference photodetector measures a “reference” intensity of a reference light wave emitted by the light source in a reference spectral band. At each measurement time, a correction function representative of a variation in the incident light wave's intensity in the measurement band relative to in the reference spectral band is taken into account based on the measured reference intensity.
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
G01N 33/00 - Investigating or analysing materials by specific methods not covered by groups
6.
PYROELECTRIC DEVICE COMPRISING A SUBSTRATE HAVING A PYROELECTRIC SURFACE LAYER, AND METHOD FOR PRODUCING SAME
A method for producing a pyroelectric detector (100), involving: producing a first electrode (116) on a first part (118) of a front face (112) of a layer of pyroelectric material (108) of a substrate (102) also having a support layer (104) on which the layer of pyroelectric material is disposed; producing a cavity (132) passing through the support layer such that a bottom wall of the cavity is formed by a part of a rear face (114) of the layer of pyroelectric material, and such that a part of the bottom wall of the cavity is disposed vertically in line with the first electrode; producing a second electrode (142) on the part of the bottom wall of the cavity.
G01J 5/34 - Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors using capacitors, e.g. pyroelectric capacitors
7.
METHOD FOR CALIBRATING A GAS SENSOR AND METHOD FOR MEASURING A GAS USING THE CALIBRATION
xx xx xx refImesmes mesmes xx (Irefref refref ref ); the method comprising determining a calibration function, that is preferably non-linear, allowing the estimation of a measured intensity, in the measurement spectral band, by the measurement photodetector, in the absence of gaseous species, on the basis of a reference intensity, measured in the reference spectral band.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
A device, for emitting and controlling infrared light, comprises a substrate extending between a bottom surface and a top surface. A cavity is provided in the substrate, the cavity opening onto the top surface. A light source extends over the cavity and is able to heat up when passed through by an electric current, so as to emit infrared light. A cover covers the substrate, the cover and the substrate forming a first component enclosing the light source. The light source delineates a first half space comprising the cover, and a second half space comprising the cavity and the bottom surface of the substrate.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01J 3/10 - Arrangements of light sources specially adapted for spectrometry or colorimetry
A gas sensor comprises an enclosure configured to receive a gas. The enclosure comprises a sidewall extending, around a transverse axis, between a first wall and a second wall. The sensor also comprises a light source configured to emit a light wave that propagates in the enclosure and forms, from the light source, a first light cone. A measuring photodetector is configured to detect the light wave emitted by the light source and propagated through the enclosure. The first wall and the second wall each comprise at least one reflective surface, forming a portion of an ellipsoid of revolution. Each reflective surface is associated with a rank n, n being an integer greater than or equal to 1.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
10.
OPTIMISED INFRARED LIGHT SOURCE FOR A GAS SENSOR, AND MANUFACTURING METHOD THEREOF
An infrared light source (10), comprising: • - an emission element (11) extending along a radial plane around a centre of the emission element (11 c), the emission element being configured to heat up and, as a result, emit infrared light; • - a cavity (15) into which the emission element extends, the cavity being defined by a cover (14) arranged opposite the emission element (11), the cover comprising an inner face (17) arranged opposite the emission element (11) and an outer face (16) defining an interface between the cover (14) and a medium external to the light source; • - the cover extending, parallel to a transverse axis (Z) perpendicular to the radial plane, along a thickness (e) between the inner face (17) and the outer face (16); the light source being characterised in that: • - the outer face comprises: • a planar central portion (16 i) extending around a centre (16 c) of the outer face; • at least one peripheral portion (16 2) adjacent to the central part and inclined relative to the central portion at an angle of inclination Θ; • - such that in the peripheral part, the thickness (e) of the cover (14) decreases according to a distance from the central portion.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01J 3/10 - Arrangements of light sources specially adapted for spectrometry or colorimetry
H01K 7/02 - Lamps for purposes other than general lighting for producing a narrow beam of lightLamps for purposes other than general lighting for approximating a point-like source of light, e.g. for searchlight, for cinematographic projector
A method for calibrating a gas sensor includes associating a reference station with the gas sensor, the latter belonging to a network of sensors distributed between various positions in a geographical region and being configured to measure a concentration of an analyte in the air at various measurement times. The geographical regions comprises reference station(s) remote from the gas sensor and configured to measure, at various reference times, a concentration of the analyte in the air. During a calibration time slot, an analyte concentration is measured with the gas sensor, taking into account an analyte concentration measured by the reference station associated with the gas sensor. From the analyte concentration measured by the reference station in the calibration time slot, an analyte concentration in the position of the gas sensor is estimated. The estimated analyte concentration and the analyte concentration measured by the gas sensor are compared.
A method for measuring an amount of a gaseous species present in a gas, the gaseous species absorbing light in an absorption spectral band, comprises placing the gas between a light source and a measuring photodetector. The light source is configured to emit a light wave that propagates through the gas to the measuring photodetector. The light source is activated so as to illuminate the gas, so that the light source emits a light pulse. The method also includes measuring, with the measuring photodetector, a measurement intensity of a light wave transmitted by the gas during the illumination, in a measurement spectral band. The measurement spectral band comprises the absorption spectral band. The light source is activated using a pulsed activation signal, each pulse having a specific form, notably to reduce aging of the source.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
14.
METHOD FOR ESTIMATING THE CONCENTRATION OF ANALYTE IN AIR CLOSE TO A ROUTE TRAVELLED BY MEANS OF TRANSPORT
A method for estimating a concentration of at least one analyte in an urban or peri-urban environment containing roads configured so as to be crossed by road traffic, the method comprising the following steps: a) spatially dividing the environment into meshes so as to obtain mesh points; b) taking into consideration, in each mesh of the environment: - geometric data in relation to each road; - dynamic data that vary depending on the estimation instant, including weather data, data relating to the road traffic, and data about the date and the time of the estimation instant; c) using the data taken into consideration in step b), at an estimation instant, as input data for a first supervised artificial intelligence algorithm so as to estimate a concentration of at least one first analyte in each mesh at the estimation instant.
A gas sensor comprises a chamber configured to receive a gas; a light source configured to emit a light wave propagating through the chamber in an emission cone; a measurement photodetector and a reference photodetector, each configured to detect a light wave emitted by the light source and having passed through the chamber. The chamber extends between two transverse walls, arranged opposite one another and connected to one another by a peripheral wall extending therebetween, about a longitudinal axis (Z), and comprising a first reflective segment configured to receive a first portion of the emission cone to reflect it toward the measurement photodetector, thus forming a measurement cone converging toward the measurement photodetector. A second reflective segment of the peripheral wall is configured to receive a second portion of the emission cone to reflect it toward the reference photodetector, thus forming a reference cone converging toward the reference photodetector.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
G01N 21/27 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands using photo-electric detection
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01N 33/00 - Investigating or analysing materials by specific methods not covered by groups
17.
DEVICE FOR EMITTING AND CONTROLLING INFRARED LIGHT AND GAS SENSOR USING SUCH A DEVICE
G01J 3/10 - Arrangements of light sources specially adapted for spectrometry or colorimetry
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
Gas sensor (1) comprising an enclosure (2) able to accommodate the gas (G), the enclosure comprising a sidewall (3) extending, around a transverse axis (Z), between a first wall (4) and a second wall (5), the sensor also comprising: - a light source (10) configured to emit a light wave (11) that propagates in the enclosure in such a way as to form, from the light source, a first light cone; - a measurement photodetector (20) able to detect the light wave that is emitted by the light source (10) and that is propagated through the enclosure; the sensor being such that the first wall and the second wall each comprise at least one reflective surface, forming an ellipsoid of revolution, each reflective surface being associated with a rank n, n being an integer higher than or equal to 1.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
Infrared light source for gas sensor, including a membrane (30) connected to a substrate by at least two joining arms (21, 22, 23, 24), the light source including a conductive track (200) running between two connection pads (11, 12), which are arranged on the substrate, along at least two joining arms (21, 22), and through the membrane, the conductive track being configured to cause the membrane to heat up when an electric current flows therethrough; the membrane including a support layer formed of at least one dielectric material and a distributing layer, which is thermally conductive and configured to spatially distribute the heating of the membrane; the membrane having a diameter or being inscribed within a diameter smaller than 1 mm; and the conductive track (200) forming, between the connection pads, at least two conductive branches and at most four conductive branches arranged in parallel, each branch forming an electrical resistor.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01J 3/10 - Arrangements of light sources specially adapted for spectrometry or colorimetry
Method for calibrating a gas sensor, the gas sensor belonging to an array of sensors distributed across various positions in a geographical zone, the gas sensor being intended to measure a concentration of an analyte in the air at various measurement instants, the geographical area comprising at least one reference station, distinct from the gas sensor and distant therefrom, the reference station being intended to measure, at various reference instants, a concentration of the analyte in the air, the method comprising the following steps: • a) associating a reference station with the gas sensor; • b) during a calibration timeframe, measuring a concentration of analyte using the gas sensor and taking into consideration an analyte concentration measured by the reference station associated with the gas sensor; • c) on the basis of the analyte-concentration measurement measured by the reference station during the calibration timeframe, estimating an analyte concentration at the position of the gas sensor; • d) comparing the analyte concentration estimated during step c) with the analyte concentration measured by the gas sensor during step b).
Method for measuring an amount of a gaseous species present in a gas, the gaseous species being capable of absorbing light in an absorption spectral band, the method comprising the following steps: a) providing the gas between a light source (11) and a measurement photodetector (20), the light source (11) being capable of emitting a light wave (12) propagating through the gas to the measurement photodetector (20); b) activating the light source (11) in order to illuminate the gas such that the light source emits a light pulse; c) measuring, by means of the measurement photodetector (20), an intensity, referred to as the measurement intensity, of a light wave (14) transmitted by the gas during its illumination, in a measurement spectral band comprising the absorption spectral band. According to the invention, the light source is activated by a pulsed activation signal, each pulse having a specific shape, in particular for reducing the ageing of the source.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01N 21/359 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using near infrared light
22.
Optimization of the spatial distribution of air quality measurement means
G01N 1/22 - Devices for withdrawing samples in the gaseous state
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01N 33/00 - Investigating or analysing materials by specific methods not covered by groups
G06T 17/20 - Wire-frame description, e.g. polygonalisation or tessellation
23.
Device and method for measuring and tracking the quantity or concentration of a compound in a fluid
A device for measuring and tracking over time the quantity or concentration of a component in a fluid comprises: a sensor capable of measuring a quantity or concentration of the component in the fluid and providing a quantitative signal for tracking this quantity or concentration over time; a signal-processing module comprising a low-pass filter of the quantitative tracking signal; and an output interface for providing the filtered quantitative tracking signal. The signal-processing module comprises an estimator of a value of instantaneous trend of variation of the quantitative tracking signal in a predetermined sliding time window. Also provided is means for adjusting over time a high cutoff frequency of the low-pass filter according to the estimated value of instantaneous trend of variation.
G01N 15/14 - Optical investigation techniques, e.g. flow cytometry
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
24.
Method for estimating a quantity of a gaseous species
A method for measuring a quantity of a gaseous species—present in a gas and able to absorb light in an absorption spectral band—comprises: arranging the gas between a light source and a measurement photodetector, the light source being suitable for emitting an incident light wave propagating through the gas to the measurement photodetector, which is suitable for detecting a light wave transmitted by the gas, in the absorption spectral band; illuminating the gas by the light source; measuring, by the measurement photodetector, a measurement intensity of the light wave transmitted by the gas, in the absorption spectral band; measuring, by a reference photodetector, a reference intensity of a reference light wave being emitted by the light source. The method comprises a correction of the reference intensity by consideration of a parametric model, the parameters of the model being determined according to reference intensity measurements performed at various times.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01N 21/27 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands using photo-electric detection
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
The invention is a gas sensor (1) comprising a chamber (10), suitable for receiving the gas (2), the sensor also comprising: a light source (11), capable of emitting a light wave (11') in an emission beam (Ω1); a measurement photodetector (12) and a reference photodetector (13), each being capable of detecting a light wave emitted by the light source (11) and having traversed the chamber, the measurement photodetector (12); the sensor being such that the chamber (10) extends between two transverse walls (21, 22), linked to each other by a peripheral wall (30), the peripheral wall (30) comprising: ‐ a first curved reflective surface (31), capable of receiving a first part of the emission beam (Ω1) in order to reflect it, thus forming a measurement beam (Ω2); ‐ a second curved reflective surface (32), capable of receiving a second part of the emission beam (Ω1) in order to reflect it, thus forming a reference beam (Ω3); the sensor being characterised in that: ‐ the detection plane of the measurement photodetector and the detection plane of the reference photodetector extend parallel or substantially parallel to a transverse wall; ‐ the sensor comprises a measurement reflector, arranged to reflect a part of the measurement beam towards the measurement photodetector, and a reference reflector, arranged to reflect a part of the reference beam towards the reference photodetector.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
A method for estimating a mapping of the concentration of an analyte in an environment uses sensors distributed in the environment. Each sensor generates a measurement of the analyte concentration at various measurement instants, which measurements are carried out by each sensor at each measurement instant, forming an observation vector, each term of which corresponds to a measurement arising from a sensor. The environment is spatially meshed with a plurality of mesh cells. The analyte concentration at each mesh cell, at each measurement instant, forms a “state vector,” each term of which corresponds to an analyte concentration in a mesh cell. A “global bias” is determined and used to correct the state vector to obtain a “debiased state vector.” The state vector is also corrected by a local correction vector as a function of a correction vector.
A method for analyzing a gaseous sample, by comparing an incident light wave and a transmitted light wave, the method comprising: i) illuminating the sample with a light source emitting the incident light wave propagating up to the sample; ii) detecting a light wave transmitted by the sample; iii) detecting a reference light wave emitted by the light source and representing a light wave reaching a reference photodetector without interacting with the sample; iv) repeating i) to iii) at different measurement instants; v) estimating, at each measurement instant, an intensity of the reference light wave; vi) taking into account the estimated intensity of the reference light wave and the detected intensity of the transmitted light wave to perform a comparison, at each measurement instant; and vii) analyzing the gaseous sample as a function of the comparison.
G01N 21/27 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands using photo-electric detection
G01N 21/51 - Scattering, i.e. diffuse reflection within a body or fluid inside a container, e.g. in an ampoule
G01N 21/33 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using ultraviolet light
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
28.
METHOD FOR ESTABLISHING A MAPPING OF AN AMOUNT OF AN ANALYTE IN THE ENVIRONMENT
The invention relates to a method for analyzing gas by an optical method, according to which a gas sample, comprising gaseous species for which it is desired to determine the quantity, is subjected to an illuminating radiation generated by a light source. The method comprises detecting a radiation having crossed the gas, by means of a light sensor. According to the invention, the light source produces different successive illuminations, such that at each illumination, the spectrum of the illuminating radiation varies. During each illumination, the intensity of the radiation detected by the light sensor is recorded. A processor can estimate a quantity of each gaseous species as a function of the respective intensities measured during each illumination. The invention also relates to a gas analysis device implementing the method.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01J 3/10 - Arrangements of light sources specially adapted for spectrometry or colorimetry
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
G01N 21/359 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using near infrared light
The invention relates to a method for measuring a quantity (ex) of a gas species (Gx) present in a gas, the gas species being able to absorb a light in an absorption spectral band (Δχ), said method comprising the following steps: a) arrangement of the gas between a light source (11) and a measuring photodetector (20), the light source (11) being able to emit an incident light wave (12), the incident light wave propagating through the gas towards the measuring photodetector (20); b) illumination of the gas (G) by the light source (11); c) measurement, by the measuring photodetector (20), of an intensity, called a measuring intensity, of a light wave (14) transmitted by the gas in a measuring spectral band, comprising the absorption spectral band (Δχ); and d) measurement, by a reference photodetector (20ref), of an intensity, called a reference intensity, of a reference light wave (12ref ) emitted by the light source (11) in a reference spectral band (Àref); steps b) to d) being implemented at a plurality of measuring moments (1… k... K), and said method comprising, at each measuring moment: e) on the basis of the reference intensity measured by the reference photodetector, and the measuring intensity (l(k)) measured by the measuring photodetector, estimation of an absorption (abs(k)) of the incident light wave (12) by the gas; and f) estimation of a quantity (ex (k)) of the gas species (Gx), on the basis of the absorption estimated during step e). The method is characterised in that step e) comprises taking into account a correction function (S) representing a temporal variation of an intensity of the incident light wave (12) in the measuring spectral band (120) in relation to an intensity of the incident light wave (12) in the reference spectral band (Àref ); and in that the correction function (8) is previously established during a calibration phase comprising the following steps: cal-i) arrangement of a test light source (111) such that it faces a test measuring photodetector (20') and a test reference photodetector (20'ref), the test light source, the test measuring photodetector and the test reference photodetector respectively representing the light source (11), the measuring photodetector (20) and the reference photodetector (20ref); cal-ii) illumination of the test measuring photodetector and the test reference photodetector by the test light source during calibration moments, the duration of which depends on a period of calibration; and cal-iii) comparison of a temporal evolution of the intensity detected by the test measuring photodetector, in the measuring spectral band, with a temporal evolution of the intensity detected by the test reference photodetector (l'ref(k)), in the reference spectral band (Àref ).
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
G01N 21/27 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands using photo-electric detection
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
The invention relates to a gas sensor (1) comprising an enclosure (10) capable of receiving the gas (2), the sensor also comprising: a light source (11), configured to emit a light wave (11') which propagates in the enclosure (10) by forming a transmission cone (Ω1), referred to as first cone; a measurement photodetector (12) which is capable of detecting the light wave emitted by the light source (11) and has passed through the enclosure; the sensor being such that the enclosure (10) extends between two transverse walls (21, 22) arranged one opposite the other, the transverse walls being connected to one another by a peripheral wall (30) extending between the transverse walls, the peripheral wall (30) comprising: a first reflecting surface (SI), of rank 1, curved, with an eccentricity of less than 0.7, and having a first focus (Pl-1) and a second focus (Pl-2), the first reflecting surface being arranged opposite the light source (11); at least one reflecting surface (Sn) of rank n, curved, n being an integer strictly greater than 1, each surface of rank n having: a first focus (Pl-n), coinciding with the second focus of a reflecting surface of previous rank n-1; a second focus (P2-n), distinct from the first focus (Pl-n), coinciding with the first focus of a surface of following rank n+1; a last reflecting surface (SN), of rank N, curved, comprising a first focus (Pl-N), coinciding with the second focus of a reflecting surface of preceding rank N-1, the last reflecting surface also comprising a second focus (P2-N); in such a way that the light wave (11') emitted by the light source (11) is successively reflected by the reflecting surfaces before converging towards the second focus of the last reflecting surface.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
The invention relates to a method for measuring a quantity (c x) of a gaseous species (G x) present in a gas, the gaseous species being able to absorb light in an absorption spectral band (Δ x ), the method comprising the following steps: arranging the gas between a light source (11) and a measurement photodetector (20), the light source (11) being suitable for emitting an incident light wave (12), the incident light wave propagating through the gas to the measurement photodetector (20), the measurement photodetector being suitable for detecting a light wave (14) transmitted by the gas, in the absorption spectral band; illumination of the gas (G) by the light source (11); measurement, by the measurement photodetector, of a measurement intensity (l(k)), of the light wave transmitted by the gas, in the spectral absorption band; measurement, by a reference photodetector (20 ref ), of a reference intensity (l ref (k)), of a reference light wave (12 ref ), the reference light wave being emitted by the light source (11). The method comprises a correction of the reference intensity by consideration of a parametric model, the parameters of the model been determined according to reference intensity measurements performed at various times.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
G01N 21/27 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands using photo-electric detection
34.
DEVICE AND METHOD FOR MEASURING AND TRACKING THE QUANTITY OR CONCENTRATION OF A COMPOUND IN A FLUID
Said device for measuring and tracking, over time, the quantity or concentration of a compound (C) in a fluid (F) comprises: a sensor (10) capable of measuring a quantity or concentration of the compound (C) in the fluid (F) and providing a quantitative signal for tracking said quantity or concentration over time; a signal processing module (12) having a low-pass filter (30) of the quantitative tracking signal; an output interface (36) for providing the filtered quantitative tracking signal. The signal processing module (12) comprises an estimator (32) of an instantaneous trend value of variation of the quantitative tracking signal in a predetermined sliding time window. It further comprises means (34) for adjusting, over time, a high cut-off frequency of the low-pass filter (30) according to the instantaneous trend value of the estimated variation.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
35.
OPTIMIZATION OF THE SPATIAL DISTRIBUTION OF AIR QUALITY MEASUREMENT MEANS
The invention relates to a system for measuring a physical quantity representative of the air quality in an observation area (1), comprising: - a mapping of the observation area (1), comprising a set V of modeled values representative of the physical quantity; - means for measuring the physical quantity, having a number N of positions or a number N of trajectories in the observation area (1), intended to show a spatial distribution Sopt; - means of calculating Sopt, configured to: • produce a grid of the observation area (1), comprising a number G of points; • calculate, for a given spatial distribution, an estimator of V, V, for each of the G points; • calculate a cost function that represents the difference or likelihood between V and the V values taken at the G points; • extract the spatial distribution Sopt that minimizes or maximizes the cost function.
The invention relates to a method for mapping the concentration of an analyte in an environment, from sensors distributed in said environment, each sensor (10p) generating a measurement of the analyte concentration at different measuring intervals, the measurements made by each sensor at each measuring interval (t) forming an observation vector (0(f)), each term of which corresponds to a measurement derived from a sensor; the environment being the subject of spatial meshwork defining a plurality of meshes (20n), the concentration at the level of each mesh, at each measuring interval, forming a vector, called a state vector (M(t)), each term of which corresponds to an analyte concentration in a mesh; the method comprising: a correction, called global correction, of the state vector by a bias determined in positions occupied by measurement vectors, so as to obtain an unbiased vector; a correction, called local correction, of the state vector thus obtained, based on a correction vector.
The invention is a gas sensor (1) comprising a housing (10) capable of receiving gas (2), the sensor also comprising: a light source (11) capable of emitting a light wave (11') propagating inside the housing according to an emission cone (Ω1); a measurement photodetector (12) and a reference photodetector (13), each being capable of detecting a light wave emitted by the light source (11) and having traversed the housing; the sensor being such that the housing (10) extends between two transverse walls (21, 22), arranged opposite one another, the transverse walls being connected to one another by a peripheral wall (30) extending between the transverse walls, about a longitudinal axis (Z), the peripheral wall (30) comprising: a first reflective portion (31) capable of receiving a first part of the emission cone (Ω1) to reflect same toward the measurement photodetector (3), thus forming a cone (Ω2), referred to as a measurement cone, converging toward said measurement photodetector; a second reflective portion (32) capable of receiving a second part of the emission cone (Ω1) to reflect it toward the reference photodetector (4), thus forming a cone (Ω3), referred to as a reference cone, converging toward said reference photodetector.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
A method for analysing a gaseous sample (13) by performing a comparison between a light wave (12) incident on the sample and a light wave (14) transmitted by the sample, the method comprising the following steps: i) illuminating the sample (13) with a light source (11), the light source emitting the incident light wave (12) propagating up to the sample; ii) detecting, using a photodetector, called the measurement photodetector (20), a light wave (14) transmitted by the sample, the transmitted light wave resulting from an attenuation of the incident light wave by the sample; iii) detecting a light wave, called the reference light wave (12ref), using a reference photodetector (20ref), the reference light wave (12ref) being emitted by the light source (11), the reference light wave representing a light wave reaching the reference photodetector without interacting with the sample; iv) repeating steps i) to iii) at different instants (k), called measurement instants; v) estimating, on the basis of each reference light wave (12ref) detected during the various steps iii), at each measurement instant, an intensity (îref, k) of the reference light wave (12ref) at said measurement instants, by implementing the following sub-steps: b) estimating the intensity of the reference light wave (îref, k |k-1) at a measurement instant (k), as a function of an initial intensity (Iref, k=o) or an estimate of the intensity (îref, k) of the reference light wave at a prior measurement instant (k-1); c) measuring the intensity (Iref, k) of the reference light wave (12), detected at the measurement instant; d) updating the estimate of the intensity of the reference light wave (îref, k) at the measurement instant, as a function of the intensity (Iref, k) measured during the sub-step c), and of the intensity (îref, k|k-1) estimated during the sub-step b); e) repeating sub-steps b) to d), on the basis of the estimate of the intensity of the reference light wave (îref, k) obtained during the sub-step d), by incrementing the measurement instant; vi) taking into account the intensity of the estimated reference light wave (îref, k), at each measurement instant, resulting in the step v), and an intensity (Ik) of the transmitted light wave (14) detected during the step ii) in order to perform a comparison (att k), at each measurement instant, on the basis of the reference light wave (12ref), and of the light wave (14) transmitted by the sample (13); and vii) analysing the gaseous sample (13) as a function of the comparison performed in step vi).
G01N 21/27 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands using photo-electric detection
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
G01N 29/00 - Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic wavesVisualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
G01N 23/00 - Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups , or
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01N 21/41 - RefractivityPhase-affecting properties, e.g. optical path length
G01N 21/51 - Scattering, i.e. diffuse reflection within a body or fluid inside a container, e.g. in an ampoule
The invention relates to a method for analysing gas by an optical method, according to which a gas sample, comprising gaseous species for which it is desired to determine the quantity, is subjected to an illuminating radiation generated by a light source. The method comprises detecting a radiation having crossed the gas, by means of a light sensor. According to the invention, the light source produces different successive illuminations, such that at each illumination, the spectrum of the illuminating radiation varies. During each illumination, the intensity of the radiation detected by the light sensor is recorded. A processor can estimate a quantity of each gaseous species as a function of the respective intensities measured during each illumination. The invention also relates to a gas analysis device implementing the method.
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
G01N 21/359 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using near infrared light
40.
Optical frequency filter and a detector including such a filter
G02B 6/12 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
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