Class / Patent application number | Description | Number of patent applications / Date published |
073240020 | Produced by radiant energy | 64 |
20080196477 | Photo-Acoustic Spectrometer Apparatus - A photo acoustic detection cell ( | 08-21-2008 |
20080276687 | Thermal Selectivity Multivariate Optical Computing - A method of using photoacoustic spectroscopy to determine chemical information about an analyte includes the steps of emitting a light ray for interaction with a sample of an analyte; transmitting the light ray through a fill fluid disposed in a detection cell, the fill fluid having molecules substantially similar to molecules of the analyte to absorb the light ray; producing a thermal wave and oscillation in the fill fluid proportional to an intensity of the light ray; including a pressure oscillation in the fill fluid by the thermal wave; and detecting the pressure oscillation by a microphone to determine information about the analyte sample | 11-13-2008 |
20090038375 | PHOTOACOUSTIC FREE FIELD DETECTOR - The invention relates to a photoacoustic detector including an acoustically open measuring area which is not completely surrounded by a housing. The detector includes an arrangement for introducing excitation light into the measuring area, such that the excitation light can be absorbed by absorbent materials which are located in the measuring area and which are used to produce acoustic energy. The invention also relates to a detector which includes at least one acoustic sensor and an arrangement is provided in order to concentrate the acoustic energy, in order to reach a local maximum of the acoustic pressure on at least one position. The at least one sensor is arranged in the vicinity of the at least one position, whereon the local maximum of the produced acoustic pressure is present or can be produced. The invention also relates to an associated method. | 02-12-2009 |
20090056415 | METHOD OF MEASURING HYDROGEN CONCENTRATION IN MEMBER AND DEVICE OF MEASURING HYDROGEN CONCENTRATION - An art of hydrogen concentration measurement in which the hydrogen concentration of any given location of an object to be measured can be nondestructively obtained is provided. | 03-05-2009 |
20090183552 | GAS DETECTOR HAVING AN ACOUSTIC MEASURING CELL AND SELECTIVELY ADSORBING SURFACE - A gas detector with a selectively adsorbing surface ( | 07-23-2009 |
20090249861 | STABLE PHOTO ACOUSTIC TRACE GAS DETECTOR WITH OPTICAL POWER ENHANCEMENT CAVITY - A photo acoustic trace gas detector ( | 10-08-2009 |
20090266144 | PHOTOACOUSTIC SENSOR - Various embodiments of the application provide a photoacoustic sensor, which includes: a gas cell having an opening; a light source to generate a radiation to radiate sample gas within the gas cell; a detector to detect the sample gas within the gas cell, and to generate electrical signals in response to acoustic signals generated by pressure fluctuations of the radiated sample gas caused by the radiation; and an active valve having a speaker aligned with the opening of the gas cell. The speaker having a voice coil and a diaphragm attached to the voice coil. A control signal is applicable for the speaker to control access of the gas cell. During sampling, the control signal causes the voice coil of the speaker to repeatedly or constantly lift the diaphragm from contact with the opening of the gas cell to allow sample gas enter the gas cell. While during detecting, the spring force of the voice coil causes the diaphragm in tight contact with the opening of gas cell to seal the gas cell. | 10-29-2009 |
20090288474 | OPTICAL CAVITY-ENHANCED PHOTO ACOUSTIC TRACE GAS DETECTOR WITH VARIABLE LIGHT INTENSITY MODULATOR - A photo acoustic trace gas detector ( | 11-26-2009 |
20090320561 | PHOTOACOUSTIC CELL - Embodiments of the apparatus, systems, and methods relate to a photoacoustic cell including an excitation source, a chamber, and a quantum dot substrate between the excitation source and the chamber. The excitation source generates a light spectrum. The quantum dot substrate, when subjected to the light spectrum, emits a specific wavelength of light to be received by the chamber. The photoacoustic cell apparatus may be part of a portable gas sensing system, and may be used to detect and measure the concentration of one or more gases. Additional apparatus, systems, and methods are disclosed. | 12-31-2009 |
20100011836 | CAVITY-ENHANCED PHOTO ACOUSTIC TRACE GAS DETECTOR WITH IMPROVED FEEDBACK LOOP - A photo acoustic trace gas detector ( | 01-21-2010 |
20100018288 | GAS ANALYZER AND METHOD OF GAS ANALYSIS - The present invention provides a gas analyzer that can be miniaturized and detect a wide variety of gases with high sensitivity, and a method of gas analysis. A separation column | 01-28-2010 |
20100043526 | PHOTO ACOUSTIC DETECTOR WITH IMPROVED SIGNAL PROCESSING - A photo, acoustic detector ( | 02-25-2010 |
20100101305 | PHOTOACOUSTIC DETECTOR WITH TWO BEAM PATHS FOR EXCITATION LIGHT - A photoacoustic detector is presented having the following structure: a first and a second light source ( | 04-29-2010 |
20100107732 | CYLINDRICAL PHOTOACOUSTIC DETECTOR WITH EXCITATION OF THE SECOND AZIMUTHAL RESONANCE - A device is presented for photoacoustic detection, having a cylindrical acoustic resonator ( | 05-06-2010 |
20100107733 | PHOTOACOUSTIC MULTIPASS CELL WITH CONCENTRATING REFLECTION MEANS - The invention relates to a photoacoustic multipass cell with a light source and means ( | 05-06-2010 |
20100107734 | SPECTROPHONE ASSEMBLY FOR IDENTIFYING AND DETECTING MULTIPLE SPECIES - A spectrophone assembly comprises a single detector chamber, a plurality of lasers, a gas inlet for supplying a gas sample to the single detector chamber, and at least one microphone. The detector chamber has an internal geometry arranged to be simultaneously acoustically resonant at a plurality of different resonant frequencies. Each laser operates at a different wavelength and is positioned to emit radiation into the single detector chamber, and is operable to emit radiation that is amplitude modulated at a frequency rate corresponding to a particular resonant frequency different from the resonant frequency of each other laser, simultaneously with each other laser. The microphone(s) are positioned in the single detector chamber so that each microphone is located at or near a maximum of a corresponding acoustic resonance defined by the internal geometry of the detector chamber. | 05-06-2010 |
20100147051 | APPARATUS AND METHOD FOR USING THE SPEED OF SOUND IN PHOTOACOUSTIC GAS SENSOR MEASUREMENTS - A photoacoustic gas sensor includes a photoacoustic cell configured to receive a gas mixture having a first gas component and a second gas component. The photoacoustic gas sensor also includes a light source configured to provide light to the photoacoustic cell. The photoacoustic gas sensor further includes a photoacoustic cell controller configured to measure a concentration of the second gas component using a speed of sound through the gas mixture, where the speed of sound is determined based on an absorption associated with the first gas component. In addition, the photoacoustic gas sensor could include a temperature sensor configured to measure a temperature of the gas mixture, where the photoacoustic cell controller is configured to determine the concentration of the second gas component using the speed of sound and the temperature. | 06-17-2010 |
20100175458 | Photoacoustic Spectroscopy System and Technique for Remote Sensing of Explosives and Toxic Chemicals - A user-friendly photoacoustic spectroscopy (PAS) system and process (technique) provides an open-field PAS instrument, unit and device to remotely sense explosives, chemicals and biological agents. The PAS system and process can include: a pulsed tunable laser, such as a CO | 07-15-2010 |
20100242572 | WAVELENGTH MODULATION SPECTROSCOPY FOR SIMULTANEOUS MEASUREMENT OF TWO OR MORE GAS INGREDIENTS - Methods and systems to measure simultaneously concentrations or concentration ratio(s) of two or more gas ingredients in a sample area comprising: a wavelength modulated light source; an acoustic detector or a photodetector; and means to analyze the signal from the acoustic detector or the photodetector and calculate the concentrations or concentration ratio(s). The light from the light source is transmitted through the sample area. Part of the light will be absorbed in the sample area by the gas ingredients and generates photoacoustic signal. The acoustic detector is used to sample the photoacoustic signal. Alternatively, a photodetector is used to sample the light intensity after the light is transmitted through the sample area. | 09-30-2010 |
20110056272 | SYSTEM FOR ANALYSING PLASMA - A system for analysing plasma. The system comprises at least one sensor which is co-operable with a plasma source for providing an analog signal representative of a characteristic of plasma from the plasma source, and a sound card installed on a computing means in communication with the sensor for converting the analog signal into a digital signal for facilitating digital processing thereof. | 03-10-2011 |
20110072886 | Gas Sensor Based On Photoacoustic Detection - A photoacoustic gas detector and photoacoustic gas detection method are disclosed. The detector includes a laser source, an acoustic resonator, and at least one tuning fork positioned along a longitudinal length of the resonator. The detector is capable of performing fast measurements of the concentration of one or more target gases over a broad temperature range. | 03-31-2011 |
20110088453 | PHOTOACOUSTIC GAS DETECTOR - A photoacoustic detection device including a nanophotonic circuit including a plurality of semiconductor lasers capable of emitting a different frequencies; input couplers connected to optical waveguides; a multiplexer; an output optical waveguide, emerging into a recess; a tuning fork having its free arms arranged at the output of the output optical waveguide; and means for detecting the vibration of the tuning fork, all these elements being assembled in a monolithic component. | 04-21-2011 |
20110094291 | Gas Detection Device - Device for detecting a gas, comprising:
| 04-28-2011 |
20110138878 | CARBON DIOXIDE SENSOR WITH FUNTIONALIZED RESONATING BEAMS - A carbon dioxide sensor comprising a first beam that includes a functionalized surface and a second beam that includes a functionalized surface such that reduced-drift differential sensing of carbon dioxide may be performed by monitoring changes in the resonant frequency of the first beam relative to the resonant frequency of second beam. | 06-16-2011 |
20110154884 | PIPE SYSTEM, A GAS SENSING SYSTEM FOR A PIPE SYSTEM, AND A METHOD OF DETERMINING A GAS COMPONENT IN A CAVITY OF A PIPE - The invention relates to a pipe system comprising a pipe, a gas sensing station and a remote output system. The pipe comprises a pipe gas cavity, such as an annulus, extending lengthwise in part or all of the length of the pipe; the gas sensing station comprises a sensing gas cavity which is in gas communication with the pipe gas cavity: The sensing gas cavity comprises a photoacoustic spectroscope. The pipe system comprises at least one optical feeding fiber for feeding light to the photoacoustic spectroscope and a transmission path for transferring a signal from the photoacoustic spectroscope to the remote output system, the transmission path from the gas sensing station to the remote output system is an optical transmission path. | 06-30-2011 |
20110214479 | Method and apparatus for the photo-acoustic identification and quantification of analyte species in a gaseous or liquid medium - A method and apparatus for the photo-acoustic identification and quantification of one or more analyte species present in a gaseous or liquid medium in low concentration utilizing a laser and a resonant optical cavity containing the medium and having within the cavity at least two partially transparent mirrors, one of which is a cavity coupling mirror and one of which is moveably mounted on an assembly responsive to an input signal. | 09-08-2011 |
20110214480 | METHOD AND APPARATUS FOR THE PHOTO-ACOUSTIC IDENTIFICATION AND QUANTIFICATION OF ANALYTE SPECIES IN A GASEOUS OR LIQUID MEDIUM - A method and apparatus for the photo-acoustic identification and quantification of one or more analyte species present in a gaseous or liquid medium in low concentration utilizing a laser and a resonant optical cavity containing the medium and having within the cavity at least two partially transparent mirrors, one of which is a cavity coupling mirror and one of which is moveably mounted on an assembly responsive to an input signal. | 09-08-2011 |
20110214481 | METHOD AND APPARATUS FOR THE PHOTO-ACOUSTIC IDENTIFICATION AND QUANTIFICATION OF ANALYTE SPECIES IN A GASEOUS OR LIQUID MEDIUM - A method and apparatus for the photo-acoustic identification and quantification of one or more analyte species present in a gaseous or liquid medium in low concentration utilizing a laser and a resonant optical cavity containing the medium and having within the cavity at least two partially transparent mirrors, one of which is a cavity coupling mirror and one of which is moveably mounted on an assembly responsive to an input signal. | 09-08-2011 |
20110290002 | PHOTOACOUSTIC GAS SENSOR AND ITS USE - The invention relates to a gas sensor having a mechanical microresonator, which has an excitation apparatus for optically exciting a mechanical oscillation of the microresonator as well as a reading apparatus for detecting the oscillation of the microresonator, wherein the reading apparatus comprises a waveguide which is implemented together with the microresonator on a dielectric or semiconducting substrate and is intended to optically read the oscillation of the microresonator, and wherein the excitation apparatus has an optical waveguide which is implemented on the same substrate and optically connects an excitation light source to the immediate surroundings of the microresonator. The invention also relates to a use of such a sensor to analyse a gas composition. | 12-01-2011 |
20110296900 | Integrated IR Source and Acoustic Detector for Photoacoustic Gas Sensor - A photoacoustic gas detector includes an integrated source, infrared filter and an acoustic sensor. The source, filter and acoustic sensor can be integrated onto one or more semiconductor substrates, such as silicon. Processing circuitry can also be integrated onto the substrate. Further, the source, filter and acoustic sensor can be integrated into a single component package, such as a metal can transistor package. | 12-08-2011 |
20110314901 | PHOTOELECTRIC GAS SENSOR DEVICE AND MANUFACTURING METHOD THEREOF - The instant disclosure provides a photoelectric gas sensor device and a manufacturing method thereof. The manufacturing method comprising the steps of: (A) providing at least two half-housing modules from at least one corresponding mold; (B) forming a reflecting layer on the ellipsoidal inner surface of the chamber unit; (C) forming a chamber unit having a reflective ellipsoidal inner surface defining a chamber space from the half-housing modules; (D) forming a reflecting layer on each inner surface of the two half-housings; and (E) disposing an emitter assembly having an energy emitter at the first focal point of the ellipsoidal chamber. A fine-adjustment mechanism may be further provided to enable clearance adjustment between the half-housing modules. | 12-29-2011 |
20120000271 | ENHANCED CAVITY FOR A PHOTOACOUSTIC GAS SENSOR - Photoacoustic cells for gas sensors are described. In some instances, the photoacoustic cell may be configured to provide an increased internal path length of the light beam in the photoacoustic cell relative to, for example, a conventional cylindrical photoacoustic cell. The photoacoustic cell may be shaped to provide increased internal reflection of the light within the photoacoustic cell, thereby increasing the absorption of the light by a gas to be detected in the photoacoustic cell. One example photoacoustic cell that can provide such increased internal reflection may be a generally conical-shaped. | 01-05-2012 |
20120055232 | Photoacoustic Gas Detector with Integrated Signal Processing - A flexible gas sensor includes a housing with a predetermined form factor, a photoacoustic gas sensing chamber, and at least one of acoustic, temperature, relative humidity or pressure sensors in combination with processing circuitry which can emulate the characteristic gas response output of a catalytic bead pellistor-type gas sensor in response to a selected gas. The processing circuitry can include a programmable processor and a storage unit. The storage unit can be loaded with data and executable instructions to specify, at least in part, how the signals from the photoacoustic sensor are to be processed by the processing circuitry. | 03-08-2012 |
20120103065 | PHOTOACOUSTIC SENSOR - A photoacoustic gas sensor, system and method is generally described. In some examples, a photoacoustic gas sensor includes a MEMS-based wavelength-selective optical modulator and a ring array of acoustic sensors. The MEMS-based optical modulator can be adapted to provide flexible wavelength selectivity such that a large number of chemical compounds may be detected. The ring array of acoustic sensors can be adapted to measure photoacoustically generated acoustic signals without the need for resonant enhancement of a photoacoustic cell of the gas sensor. In some examples, a unique uncorrelated and deterministic signal may be used to modulate each light wavelength of interest. Signal processing may be used that allows the simultaneous measurement of the absorption spectra of multiple optical wavelengths as well as the rejection of unwanted acoustic noise. | 05-03-2012 |
20120118042 | Photoacoustic Spectrometer with Calculable Cell Constant for Quantitative Absorption Measurements of Pure Gases, Gaseous Mixtures, and Aerosols - A photoacoustic spectrometer that is intensity-modulated, laser-driven and with a calculable cell constant. The axially symmetrical photoacoustic spectrometer combines first-principles models of acoustic wave propagation with high-resolution spectroscopic measurements, and takes into account molecular relaxation. The spectrometer includes a duct and two chambers disposed at the end of the duct. Inlet and exit tubes, which are disposed in substantially the location of acoustic pressure nodes, permit the gas, gaseous mixture or aerosol to enter and exit the spectrometer. The absolute response of the spectrometer may be modeled and measured. A detailed theoretical analysis of the system and its predicted response may be predicted as a function of gas properties, resonance frequency and sample energy transfer relaxation rates. | 05-17-2012 |
20120151994 | ACTIVE DETECTION TECHNIQUES FOR PHOTOACOUSTIC SENSORS - Traditional photoacoustic sensors generally operate in a passive mode, which can degrade the performance. Here, however, a photoacoustic sensor has been disclosed that operates an acoustic resonance chamber and a transducer in an active mode so as to avoid the problems associated with traditional photoacoustic sensors; in particular, because the acoustic resonance chamber operates at near atmospheric pressure such as 100's Torr as opposed to 1 m Torr type of pressure for radio spectroscopy, the sensor is allowed to be scaled to operate on an integrated circuit or IC. | 06-21-2012 |
20120151995 | PHOTOACOUSTIC SENSOR AND METHOD FOR THE PRODUCTION AND USE THEREOF - A photoacoustic sensor, containing a resonance body, which at least partially delimits a space for receiving molecules to be detected, and a device for detecting an oscillation of the resonance body, including a device for optically detecting the location of at least one partial surface of the resonance body. A method for the photoacoustic detection of molecules in the gas phase and to a method for producing an optically integrated photoacoustic sensor. | 06-21-2012 |
20120247183 | Photoacoustic Detector with Acoustic and Vibration Noise Compensation - A photoacoustic detector includes a sensing region for receiving atmospheric samples. One microphone receives acoustic samples from the sensing region. Another microphone receives acoustic samples from a displaced region. Microphone outputs can be subtracted to eliminate common noise and to generate an indicium of gas present in the sensing region. | 10-04-2012 |
20120260719 | PHOTO-ACOUSTIC GAS SENSOR AND METHOD FOR THE PRODUCTION AND USE THEREOF - A photo-acoustic gas sensor and methods for producing same, the gas sensor having a resonance body and a device for detecting a vibration of the resonance body, including a device for optically detecting the location of at least one partial surface of the resonance body, wherein the resonance body and the device for detecting a vibration are disposed on exactly one substrate, the resonance body is formed by at least one first recess of the substrate, and the substrate is a semiconductor material. | 10-18-2012 |
20120266655 | PHOTOACOUSTIC GAS SENSOR WITH A HELMHOLTZ CELL - A photoacoustic detection device including a nanophotonic circuit including a first chip on which is formed at least one optical waveguide and in which is formed a set of cavities defining a Helmholtz resonator; at least one optical source capable of emitting an optical signal in a given wavelength range, capable of being modulated at an acoustic modulation frequency, this source being attached to the first chip; a second chip forming a cap for said cavities and including acoustic sensors; and electronic circuits for processing the output of the acoustic sensors formed in the first or the second chip. | 10-25-2012 |
20120272716 | Photoacoustic Sensor Diffusion Membrane Attachment Structure - A photoacoustic detector includes a sensing region for receiving atmospheric samples of a gas. A permeable membrane overlays a gas input port of the sensing region. The membrane is mechanically clamped to the sensing region by a compression force. | 11-01-2012 |
20120272717 | Photoacoustic Detector with Background Signal Correction - A photoacoustic detector includes a sensing region for receiving atmospheric samples. Radiant energy from a source is directed toward the sensing region. A thermal isolator and a displaced optical filter are positioned between the incoming radiant energy and the sensing region so that the radiant energy passes, at least in part, through both elements. | 11-01-2012 |
20120272718 | Photoacoustic Sensor with Baseline and Span Correction - A photoacoustic detector wherein a detector response transfer function can be measured at various times under predetermined conditions during the life of the detector. One or more of the time related transfer functions each can, when acquired, be compared to the stored initial transfer function established at initial manufacture and calibration of the detector. Span and baseline correction values can be determined. These values can be used to compensate detected output values during normal operation. Time related transfer functions can be compared to each other as well as to the stored initial transfer function. | 11-01-2012 |
20120272719 | PHOTOACOUSTIC SENSOR WITH ADAPTIVE OPERATING FREQUENCY - Some embodiments relate to a photoacoustic sensor that includes a gas cell having an opening and a detector to collect pressure fluctuations within the gas cell to determine a spectral content of the pressure fluctuations within the ambient environment. The photoacoustic sensor further includes a light source to generate radiation to radiate sample gas within the gas cell and a control that receives signals from the detector that represent the spectral content of the pressure fluctuations within the ambient environment. The control adjusts a frequency of the radiation produced by the light source to a frequency that conflicts less with the spectral content of the pressure fluctuations within the ambient environment. The detector generates output electrical signals in response to acoustic signals generated by pressure fluctuations of the radiated sample gas. | 11-01-2012 |
20120279279 | Photoacoustic Detector with Long Term Drift Compensation - A photoacoustic detector wherein control circuits compensate for long term variations of components therein including a light source and sensing microphones. The control circuits intermittently energize the source to evaluate changes in at least source resistance. The control circuits intermittently energize an acoustic generator to evaluate changes in one or more generator responsive microphones. | 11-08-2012 |
20120279280 | Apparatus and Method of Photoacoustic Sensor Signal Acquisition - A photoacoustic detector includes first and second microphones carried by an acoustic sensing chamber. Signals from the microphones are processed using lock-in detection to increase the signal-to-noise ratio. An acoustic pressure generator can be incorporated to calibrate the microphones. | 11-08-2012 |
20120279281 | THERMAL SELECTIVITY MULTIVARIATE OPTICAL COMPUTING - A method of using photoacoustic spectroscopy to determine chemical information about an analyte includes the steps of emitting a light ray for interaction with a sample of an analyte; transmitting the light ray through a fill fluid disposed in a detection cell, the fill fluid having molecules substantially similar to molecules of the analyte to absorb the light ray; producing a thermal wave and oscillation in the fill fluid proportional to an intensity of the light ray; including a pressure oscillation in the fill fluid by the thermal wave; and detecting the pressure oscillation by a microphone to determine information about the analyte sample. | 11-08-2012 |
20120318041 | METHOD AND APPARATUS FOR MEASURING GAS CONCENTRATIONS - Some embodiments are directed to a photoacoustic sensor. The photoacoustic sensor may comprise: a gas cell with an opening; a light source to generate to radiate a sample gas within the gas cell; an optical microphone to detect the sample gas within the gas cell; and a membrane aligned with the opening of the gas cell to permit sample gas to enter the gas cell. The optical microphone includes a semiconducting laser. The semiconducting laser includes a p-n junction within a cavity of the semiconducting laser. The optical microphone further includes a pressure-sensitive membrane that receives coherent light emitted from the semiconducting laser and directs reflected light back toward the semiconducting laser. During operation of the optical microphone, the pressure-sensitive membrane flexes in response to acoustic pressure waves. The phase of the reflected light is dependent upon a distance of the pressure-sensitive membrane from an aperture of the semiconducting laser. | 12-20-2012 |
20130008229 | RESONANT PHOTO ACOUSTIC SYSTEM - A device includes a resonator having an oscillating portion with dimensions chosen to lead to a desired resonant frequency. A light source is positioned to provide light along the length of the oscillating portion at a specific wave length. A detector detects a change in oscillation of the resonator responsive to the wave pressure produced by the light source heating a gas. The light source is modulated with a frequency the same as the resonant frequency of the resonator. | 01-10-2013 |
20130008230 | RESONANT PHOTO ACOUSTIC SYSTEM - A device includes a resonator having an oscillating portion with dimensions chosen to lead to a desired resonant frequency. A light source is positioned to provide light along the length of the oscillating portion at a specific wave length. A detector detects a change in oscillation of the resonator responsive to the wave pressure produced by the light source heating a gas. The light source is modulated with a frequency the same as the resonant frequency of the resonator. | 01-10-2013 |
20130036793 | MICROFABRICATED PARTICULATE MATTER MONITOR - An apparatus for measuring concentrations of airborne particulate matter may include, in one embodiment, a primary channel to receive air samples from the external environment. The air samples include particles of varying sizes. A microfluidic circuit communicates with the primary channel and small particles (having a size less than a threshold size) are diverted around a bend into a secondary channel. Remaining larger particles are unable to make the bend and continue through the primary channel. A mass-sensitive element communicating with the secondary channel includes a collection surface to collect the small particles. A resonant frequency of the mass-sensitive element is reduced in proportion to the mass of the particles collected. | 02-14-2013 |
20130111975 | PHOTO-ACOUSTIC, MULTI-BAND, MULTI-CAVITY GAS DETECTION SYSTEM - A single gas detector combines a dual cavity photo-acoustic gas sensor with a common microphone and common source. Electrical outputs from the microphone can be analyzed to determine an analyte gas concentration in the local region being monitored. Radiant energy from the common source can be directed into both cavities simultaneously. Alternately, the sensor can be used with two microphones to establish a concentration of each of two different gasses, or a gas and water vapor. | 05-09-2013 |
20130205871 | METHOD AND DEVICE FOR DETECTING TRACE AMOUNTS OF MANY GASES - The photoacoustic device for measuring the quantity of at least one gas. The Helmholtz-type esonant container comprises at least two tubes closed at their ends and linked together, close to each of their respective ends, by capillary tubes of diameter lower than the diameter of the parallel tubes. Each of the two radiant laser energy sources is physically separated and adapted to supply an excitation energy to the gas in the container at a different emission wavelength. The modulation means modulates the excitation energy supplied by each laser energy source with a modulation frequency corresponding to the acoustic resonance frequency of the container. At least one acoustoelectric transducer disposed on one of the tubes detects the produced acoustic signals produced and supplies an electric signal representative of the gas concentration in the container. | 08-15-2013 |
20130239658 | PHOTOACOUSTIC SENSOR WITH MIRROR - A photoacoustic sensing device includes a laser tuned to emit light to cause optical absorption by a gas to be detected, a resonant acoustic sensor positioned to receive pressure waves from the gas, wherein the laser is modulated to match a resonant frequency of the resonant acoustic sensor, and a first mirror positioned to receive light from the laser after the light has passed through the gas and to reflect the received light back through the gas to cause additional optical absorption. | 09-19-2013 |
20140026639 | SYSTEM AND METHOD FOR PHOTOACOUSTIC GAS ANALYSIS - A system for analyzing gas concentrations in a gas mixture includes an array of semiconductor light sources which are configured to generate an electromagnetic radiation having a narrow bandwidth. A controller modulates the electromagnetic radiation at a modulating frequency to provide light pulses at an absorption wavelength of at least one target gas. The system also includes an acoustic resonant gas chamber to hold the gas mixture and configured to receive the light pulses and amplify acoustic signals emanating from the gas mixture. A processor determines a concentration of the target gas based on acoustic signals. | 01-30-2014 |
20140047901 | SYSTEM FOR ON-LINE MEASURING AND CONTROLLING OF O2 FRACTION, CO FRACTION AND CO2 FRACTION - A non-destructive resonance (NDR) method of measuring and controlling an O | 02-20-2014 |
20140123729 | CAVITY ENHANCED LASER BASED GAS ANALYZER SYSTEMS AND METHODS - Cavity enhanced absorption spectroscopy systems and methods for detecting trace gases using a resonance optical cavity, which contains a gas mixture to be analyzed, and a laser coupled to the cavity by optical feedback. The cavity has any of a variety of configurations with two or more mirrors, including for example a linear cavity, a v-shaped cavity and a ring optical cavity. The cavity will have multiple cavity resonant modes, or a comb of frequencies spaced apart, as determined by the parameters of the cavity, including the length of the cavity, as is well known. Systems and methods herein also allow for optimization of the cavity modes excited during a scan and/or the repetition rate. | 05-08-2014 |
20140150529 | REMOTE SENSING USING COHERENT SONIC WAVE PHOTOACOUSTIC DETECTION AND METHODS - A method and system for detecting composition of a physical space comprising: a laser beam source; an acoustic sensor; a beam focusing mechanism for focusing the laser beam at predetermined points in the physical space to generate a thermal inhomogeneity which results in the propagation of a pressure wave that propagates outward from the predetermined excitation point at a propagation velocity approximating the speed of sound for the particular composition of the media; at least one processor for controlling the timing for the laser beam focusing to generate thermal inhomogeneities; whereby the laser focal point is moved sequentially along the light-of-sight at various excitation points by the beam focusing mechanism approximately at the phase front velocity to define a series of predetermined excitation points and pressure wave propagations such that the series of pressure wave propagations combine to produce a coherent pressure wave detectable by the acoustic sensor. | 06-05-2014 |
20140245816 | GAS MEASUREMENT DEVICE - A gas measurement device for measuring the concentration of a plurality of gas components by means of absorption measurement comprising a light source for infrared radiation ( | 09-04-2014 |
20140373599 | DETECTION AND LOCKING TO THE ABSORPTION SPECTRA OF GASSES USING QUARTZ ENHANCED PHOTOACOUSTIC SPRECTROSCOPY - A device for generating a frequency reference including a frequency reference generation unit coupled to an integration cell to generate a frequency reference signal based on radio frequency (RF) produced pressure waves detected by an acoustic detector in the integration cell. | 12-25-2014 |
20150101395 | PHOTOACOUSTIC GAS SENSOR DEVICE AND A METHOD FOR ANALYZING GAS - A photoacoustic gas sensor device for analyzing gas includes an emitter module and a pressure-sensitive module. The emitter module is arranged on a carrier substrate and emits light pulses. The pressure-sensitive module is arranged on the carrier substrate within a reference gas volume. The reference gas volume is separated from a volume intended to be filled with a gas to be analyzed. Further, the pressure-sensitive module generates a sensor signal indicating information on an acoustic wave caused by light pulses emitted by the emitter module interacting with a reference gas within the reference gas volume. Additionally, the emitter module is arranged so that light pulses emitted by the emitter module reach the reference gas volume after crossing the volume intended to be filled with the gas to be analyzed. | 04-16-2015 |
20160061784 | OPTICAL GAS SENSOR - A sensor head is described herein. The sensor head can include a first piece, where the first piece can include a body having an outer surface and an inner surface. The first piece can also include a light source cavity disposed in the body at the inner surface. The first piece can further include an optical device cavity disposed in the body at the inner surface. The first piece can also include an ellipsoidal cavity disposed in the body at the inner surface, where the ellipsoidal cavity is disposed adjacent to the optical device cavity. The first piece can further include a receiving device cavity disposed in the body adjacent to the inner surface that forms the ellipsoidal cavity. The first piece can also include at least one channel disposed in the body. | 03-03-2016 |
20160123931 | Apparatus And Method For Non-Intrusive Assessment Of Gas In Packages - A method and apparatus are disclosed for assessment of a sealed package. Light is emitted from a narrow-band laser source towards said package from outside of said package. An absorption signal of said light scattered in said package is measured, wherein said absorption is caused by said at least one gas when said light is scattered and travels in said sealed package. Measuring is made outside of said package, whereby said assessment is non-intrusive with regard to said package. It is determined if a deviation exists from a predetermined, expected gas composition and/or concentration of said at least one gas within said sealed package based on said measured absorption signal. Thus sealing of said package for said gas is detected. | 05-05-2016 |
20190145935 | PHOTOACOUSTIC GAS DETECTION | 05-16-2019 |