Abstract: An arrangement for in-situ optical interrogation of plasma emission to quantitatively measure normalized optical emission spectra in a plasma chamber is provided. The arrangement includes a flash lamp and a set of quartz windows. The arrangement also includes a plurality of collimated optical assemblies, which is optically coupled to the set of quartz windows. The arrangement further includes a plurality of fiber optic bundles, which comprises at least an illumination fiber optic bundle, a collection fiber optic bundle, and a reference fiber optic bundle. The arrangement more over includes a multi-channel spectrometer, which is configured with at least a signal channel and a reference channel. The signal channel is optically coupled to at least the flash lamp, the set of quartz windows, the set of collimated optical assemblies, the illuminated fiber optic bundle, and the collection fiber optic bundle to measure a first signal.

Abstract: The present invention is directed to systems and methods which utilize a cavity ring-down spectroscopy (CRDS) technique implemented for the measurements of vapor transmission rate. In one embodiment, the vapor content to be measured is contained within an optical cavity. Light is then injected into the cavity up to a threshold level and the delay time of the injected light is measured. When the wavelength of the injected light is resonant with an absorption feature of the vapor the decay time increases linearly as a function of vapor content. In this manner, vapor content causes a longer delay time and thus the amount of vapor passing through the film (film permeation rate) can be determined in real-time.

Abstract: An apparatus and method are used to enhance the sensitivity of a spectrometer (sensor) for trace gas species detection by employing an external cavity continuously tunable CW quantum cascade laser and integrating the absorption spectra across multiple lines of the species. With this method the absorption spectra of NO2 is continuously recorded across the R-branch from 1628.8 cm?1 to 1634.5 cm?1. By integrating the resulting spectra, the detection sensitivity for NO2 is improved by a factor of 15 compared to the sensitivity achieved using single line laser absorption spectroscopy with the same apparatus. This procedure offers much shorter data acquisition times for the real-time monitoring of trace gas species compared with adding repeated scans of the spectra to improve the signal-to-noise ratio.

Abstract: A gas or particulate sensor is provided for the detection of at least two target gases and/or particulates. The sensor comprises: a chamber for containing a gas sample under test; a first optical measurement channel configured for the detection of a first target gas or particulate within the gas sample, and a second optical measurement channel configured for the detection of a second target gas or particulate within the gas sample, each optical measurement channel comprising a respective optopair which comprises a radiation source adapted to emit radiation and a radiation detector adapted to output a signal in response to detected radiation; and focusing optics able to form an image of an object.

Abstract: Gas analyzer systems and methods for determining gas flux in a short intake tube configuration without using any Webb-Pearman-Leuning density correction. Gas analyzer systems and methods for measuring concentrations of gasses and in particular dry mole fraction of components of a gas. The systems and method allow for rapid measurement of the gas density and/or dry mole fraction of gases for a number of environmental monitoring applications, including high speed flux measurements. A novel coupling design allows for tool-free removal of a cell enclosing a flow path to enable in field cleaning of optical components.

Abstract: Gas analyzer systems and methods for determining gas flux in a short intake tube configuration without using any Webb-Pearman-Leuning density correction. Gas analyzer systems and methods for measuring concentrations of gasses and in particular dry mole fraction of components of a gas. The systems and method allow for rapid measurement of the gas density and/or dry mole fraction of gases for a number of environmental monitoring applications, including high speed flux measurements. A novel coupling design allows for tool-free removal of a cell enclosing a flow path to enable in field cleaning of optical components.

Abstract: A method to measure the concentration of a constituent element in a gas sample contained in an analyzer. A sample cell of a detector has an inlet and an outlet. The outlet of the sample cell is sealed. A predetermined mass of a gas sample is received through the inlet into the sample cell over a predetermined pressurization period until substantially the entire mass of the gas sample contained in the analyzer is contained within the sample cell. The gas sample is pressurized to a predetermined pressure over the pressurization period. A concentration of a constituent element in the pressurized gas sample is determined.

Abstract: A highly sensitive fluid composition analyzer where a fluid may be placed in contact with a very small area on a material sensitized to change color in the presence of a specific type of compound, to be impinged with light. The light reflected, transmitted and/or scattered by the material may serve as input for the analyzer electronics. The fluid may be pre-concentrated prior to being brought in contact with the material. The area on the material may be a spot having an outside dimension of less than one millimeter.

Abstract: An absorption spectroscopy apparatus provides an apparatus for analyzing gaseous sample. A measuring section irradiates the gaseous sample with terahertz radiation. An analysis section calculates a concentration of a specific constituent based on a level of absorbance by the gaseous sample. Terahertz radiation at least contains frequency components where the specific constituent shows an absorbance larger than an absorbance by a background constituent. Terahertz radiation at least contains frequency components where a spectrum of absorbance by the background constituent shows relatively flat profile.

Abstract: Gas analyzer systems and methods for measuring concentrations of gasses and in particular dry mole fraction of components of a gas. The systems and method allow for rapid measurement of the gas density and/or dry mole fraction of gases for a number of environmental monitoring applications, including high speed flux measurements. A novel coupling design allows for tool-free removal of a cell enclosing a flow path to enable in field cleaning of optical components and to enable re-configuration between open- and closed-path analyzer configurations.

Abstract: A system for obtaining emission flux of a gas plume, emanating from a source, includes an airborne differential absorption lidar (DIAL) system for determining multiple concentration path length (CPL) values along a flight path; and an airborne wind measuring system (WMS) for determining a wind vector at the aircraft altitude. Also included is a processor for receiving the multiple CPL values determined by the DIAL system and the wind vector determined by the WMS. The processor uses the CPL values to compute either (a) an area-integrated concentration (AIC) value or (b) an average concentration value over a cross-plume extent, defined along the length dimension of the flight path. The processor also scales the wind vector to the near ground altitude level of the gas plume to obtain a scaled wind vector. The emission flux is obtained by multiplying either the AIC value or the average concentration value with a component of the scaled wind vector.

Abstract: A sensor device for determining a physical value using a laser, whose emission behavior can be affected by the physical value is described. The laser is arranged to emit at least two concurrent modes lying above a laser threshold and the physical value is determined using a comparison of changes of the at least two modes occurring under the influence of the physical value.

Abstract: The attenuation and other optical properties of a medium are exploited to measure a thickness of the medium between a sensor and a target surface. Disclosed herein are various mediums, arrangements of hardware, and processing techniques that can be used to capture these thickness measurements and obtain three-dimensional images of the target surface in a variety of imaging contexts. This includes general techniques for imaging interior/concave surfaces as well as exterior/convex surfaces, as well as specific adaptations of these techniques to imaging ear canals, human dentition, and so forth.

Abstract: Micro-cavity gas or vapor sensors and gas or vapor detection methods. Optical energy is introduced into a resonant micro-cavity having a deformable coating such as a polymer. The coating swells or expands when it is exposed to or absorbs a gas or vapor, thereby changing the resonant wavelength of optical energy circulating within the micro-cavity/coating. Expansion or swelling of the coating may be reversible such that it contracts when gas or vapor diffuses from the coating. The coating deformation and/or a change of one or more optical properties of the optical energy circulating within the micro-cavity are used to detect the presence of the gas or vapor or molecules or particulates thereof.

Abstract: According to example configurations herein, a system includes an inertial filter, a temperature controller, and analyzer. The inertial filter has multiple ports including a first port, a second port, and a third port. A sample gas flows between the first port and the third port of the inertial filter. The second port of the inertial filter outputs a portion of the gas flowing between the first port and the second port. The temperature controller controls a temperature of the inertial filter and/or the gas flowing through the inertial filter. The analyzer receives the portion of the gas flow outputted by the second port of the inertial filter and produces a value indicative of a concentration of sulfur trioxide in the portion of the gas flow.

Abstract: Provided are sensors and methods of measuring the oxygen concentration of a fluid. An excitation light source is in optical communication with a transducer for transmitting an excitation light that is at least partially absorbed by the transducer. The transducer has a property of photoluminescence, and enters a higher energy state by at least partially absorbing the excitation light and enters a lower energy state through radiation of emitted light, thus producing spectral indicia. A light detection system, which is also in optical communication with the transducer, processes the spectral indicia to determine the concentration of oxygen in the fluid.

Abstract: A device comprising an acoustic detector, one or more thermal sensing elements coupled to the acoustic detector, and a light source. A method comprising directing a beam of light at a wavelength at or near one or more thermal sensing elements, wherein the thermal sensing elements are coupled to an acoustic detector, determining a resonance frequency of the acoustic detector, wherein the acoustic detector is coupled to one or more of the thermal sensing elements, and measuring the response of the acoustic detector to detect optical radiation absorption proximate to or at the surface of one or more thermal sensing elements.

Abstract: A method of monitoring a coal supply includes receiving a sampled level of at least one combustible gas in the coal supply from a combustible gas sensor device embedded in the coal supply, analyzing the sampled level to identify an accumulated combustible gas condition, and indicating a combustible gas alert in response to the accumulated combustible gas condition.

Abstract: Energy-efficient operating method for a gas sensor. In a method for determining a gas concentration with the aid of a gas sensor having a radiation source, the radiation source is operated using a first electric power in a first operating mode, and is operated at a second electric power in a second operating mode, the second electric power being greater than the first electric power.

Abstract: A cavity ring down system is optimized to precisely measure trace gases or particles in an air sample by using time sampling detection and multiple-sample averaging resulting in a high signal-to-noise ratio. In one embodiment, a cavity ring down system is programmed to measure the rise time and the fall time of the light level in an optical cavity. The cavity ring down system is programmed to integrate a plurality of sample portions during a rise time and a plurality of sample portions during a fall time (in alternate intervals) to obtain a time constant with no sample present and a time constant with sample present. The measurements are used to calculate trace gases in the air sample.

Abstract: An apparatus and method for monitoring precursor flux is disclosed herein. The apparatus comprises an optical cell configured for electromagnetic radiation spectroscopy and has a precursor reservoir or deposition chamber configured to provide a flow of a vapor deposition precursor therethrough, a first inner window sealing a first optical opening in the precursor reservoir or deposition chamber, a first outer window in optical communication with the first inner window, a first vacuum chamber disposed between the first inner window and the first outer window, a second inner window sealing a second optical opening in the precursor reservoir or deposition chamber, a second outer window in optical communication with the second inner window, a second vacuum chamber disposed between the second inner window and the second outer window. Each window being disposed to be in optical communication with one another, a electromagnetic radiation or light source, and an optical detector.

Abstract: A calibration tool for use in combination with a photoluminescent oxygen-sensitive working probe and an analytical instrument capable of reading the working probe. The calibration tool is effective for achieving two-point calibration of the analytical instrument, and includes at least first and second solid state compositions having different sensitivities to oxygen. The first composition is an oxygen-sensitive photoluminescent dye that is the same as that in the working probe, embedded within an oxygen-permeable carrier matrix that is the same as that in the working probe. The second composition is an oxygen-sensitive photoluminescent dye that is the same as that in the first composition, embedded within a carrier matrix that is different from that in the first composition. The oxygen sensitivity of the second composition is less than the oxygen sensitivity of the first composition.

Abstract: A method and system for measuring the concentration of a gas component in a measuring gas a provided. The wavelength of a light source is modulated with a modulation signal at a modulation frequency, while the wavelength is swept over an interaction feature of a sample. The intensity of the light source is further modulated at a wavelength outside the interaction feature with a burst signal, where an N-th harmonic of the burst frequency coincides with an M-th harmonic of the modulation frequency. The light is passed to the sample and thereafter to a detector. The detector output is demodulated at the M-th harmonic, and the demodulated detector output is normalized by calculating the ratio between a demodulated detector output portion derived from the light modulated with the modulation signal and another demodulated detector output portion derived from the light modulated with the burst signal.

Abstract: The invention relates to an improved optoelectronic apparatus for optical gas analysis by means of which the interfering influence of the particles contained in the gas is reduced with regard to the intended measurement. For this purpose the optoelectronic apparatus in accordance with the invention has a light transmitter and a light receiver which define an optical measurement path including a measurement volume between one another. The received signals of the light receiver can be evaluated in an evaluation unit, to ultimately obtain the desired information therefrom, for example, the concentration of a specific gas content. In accordance with the invention an ionizer is further provided which is arranged upstream of the optical measurement path. The ionizer causes an ionization of the undesirable particles, i.e. e.g. the dust particles, smoke particles or such like aerosols so that the ionized particles can be deflected by electric fields or also magnetic fields by means of an ion acceleration apparatus.

Abstract: A cavity ring down gas sensor is disclosed. In one illustrative embodiment, the cavity ring down gas sensor includes an electromagnetic radiation source (e.g. laser) configured to emit an input beam of light having a wavelength corresponding to an absorption line of a gas to be detected. The input beam of light may be coupled into an optical cavity to amplify an internal beam of light that is reflected about the optical cavity. An optical element may be disposed in the optical cavity at an angled close to, but not at, the Brewster's angle to reflect a relatively small portion of the internal beam of light in the optical cavity to a detector for determining the intensity of the internal beam of light in the optical cavity. When a specified light intensity is reached in the optical cavity, the input beam of light may be shut off or otherwise prevented from entering the optical cavity, and a cavity ring down time decay may be measured.

Abstract: A detector for optically detecting biological aerosols in a sample volume using non-imaging optical components (NIOCs) includes a light source configured to stimulate bio-fluorescence of tryptophan or nicotinamide adenine dinucleotide. In at least one embodiment, a sample volume and each non-imaging optical component are defined by surface features in each of a first monolithic structure and a second monolithic structure, when the first monolithic structure and the second monolithic structure are disposed in a facing relationship. In at least one embodiment, each NIOC comprises a compound parabolic collector. To facilitate volume production, the monolithic structures can be molded. Preferably, the sample is a volume of a gaseous fluid, such as air.

Abstract: An illustrative cavity ring down gas sensor includes an optical cavity for receiving a gas to be detected and at least two electromagnetic radiation sources. The first electromagnetic radiation source may emit a first beam of light having a wavelength corresponding to an absorption wavelength of the gas to be detected, and the second electromagnetic radiation source may emit a second beam of light having a second wavelength that is off of an absorption wavelength of the gas to be detected. The first beam of light may detect a cavity ring down time decay, which is related to the concentration of the gas to be detected. The second beam of light may be used to detect a baseline cavity ring down time decay, which may be used to help increase the accuracy of the sensor by, for example, helping to compensate the concentration of the gas detected by the first beam of light for sensor variations caused by, for example, sensor age, temperature or pressure changes, and/or other conditions.

Abstract: Embodiments of the apparatus, systems, and methods relate to a photoacoustic sensor includes an excitation source, a modulator, a quantum dot filter, an interferometer, a gas chamber, and a microphone. The excitation source generates a monochromatic light. The modulator intensity modulates the monochromatic light at a first modulation frequency. The quantum dot filter down converts the modulated monochromatic light into a broadband spectrum of infrared light. The interferometer further intensity modulates the broadband spectrum such that the at least one wavelength component of the broadband spectrum is further intensity modulated at a second modulation frequency. The gas chamber stores a sample gas and receives the plurality of modulated wavelength components. The microphone detects pressure changes within the gas chamber to produce an acoustic signal, which can be used to analyze properties of the sample gas.

Abstract: A multi-frequency photoelectric smoke detector includes a multi-frequency, source and an multi-frequency sensing array. The array can be part of a solid state camera which can be used to sense scattered multi-frequency light. Multiple wavelength signals, red, blue green for example, emitted by the camera can be analyzed to determine a degree of airborne particulate matter in a sensing region between the source and the array.

Abstract: A gas analyzer capable of measuring a concentration of a gas component in gas at sensor units provided at a plurality of positions in real time by decreasing the number of signals input from the sensor units to an analyzer so as to reduce a data amount input to the analyzer and a gas analyzing method. The gas analyzing method includes the steps of: demultiplexing laser light by a demultiplexer into measurement laser light and reference laser light; letting the measurement laser light pass through gas to be received by a photoreceiver; finding an absorption spectrum absorbed by a gas component in the gas based on a light intensity of the received measurement laser light and of the reference laser light; and analyzing the absorption spectrum to measure a concentration of the gas component.

Abstract: A system for detecting engine fluid constituents includes an engine having a sample channel having a conduit for a working engine fluid. The system includes an electromagnetic (EM) source that emits EM radiation through a first metal tube, where the EM radiation is EM energy at a wavelength of interest. The system further includes an EM detector that receives a remainder radiation through a second metal tube, the remainder radiation including the remaining EM radiation after passing through the sample channel. The system includes a controller that determines a composition indicator signal representative of an amount of a constituent in the working engine fluid in response to a strength of the remainder radiation, and determines a concentration of a component of interest according to the composition indicator signal.

Abstract: An TDLS gas sensor with a measuring pick-up to be arranged outside of the interior chamber of an incubator or a climate chamber of similar design, and with an absorption pick-up to be arranged inside the interior chamber, and also with a window separating the measuring area and absorption area for the atmospheric separation of the laser diode from the interior chamber of the incubator, with the window being arranged at an angle to the axis of the laser beam emitted by a laser diode, and with the optronic components being arranged in a block of material in the measuring pick-up, said block being made of thermally well-conducting material and serving as heat sink, and with a heating system for the window in the measuring pick-up. The TDLS gas sensor is easy to install and remove and permits the measurement of moisture and of the carbon dioxide concentration in one measuring cycle. However, it does not need to be removed for the sterilization.

Abstract: Techniques are generally described related to a method and system for monitoring gas concentrations. One example gas monitoring apparatus includes a light source, a MEMS micro-mirror arranged to be in an optical path of a light from the light source that has passed through a sample and configured to direct selected wavelengths of the light to a single detection point, a detector arranged at the single detection point and configured to convert incident light into electrical signals, and a processor programmed to determine a gas concentration of one or more gases in the sample based on the electrical signals.

Abstract: A chemical sensor is disclosed. The sensor has a test chamber for receiving chemicals in a gaseous state, the test chamber having two substantially transparent windows at first and second ends of the test chamber. The sensor uses a pulse operated ultraviolet light emitting diode at the first end of the test chamber emitting at a wavelength close to a maximum in the absorption band of a test chemical, and an electromagnetic sensor at a second end of the test chamber, the sensor being sensitive to the light emitted by the light emitting diode.

Abstract: A sensor head for a dry powder agent according to an exemplary aspect of the present disclosure includes a housing defined along an axis along which light is communicated, the housing defines a multiple of apertures transverse to the axis and in communication with a measurement volume along the axis. Each of the multiple of apertures defines a longitudinal length along the axis which is less than a lateral length defined around the axis. A minor is within the housing to reflect the light through the measurement volume.

Abstract: This invention makes it possible to measure a concentration of a gas component having the adsorption even thought the concentration is low, and to improve a response speed of the measurement of the concentration, and comprises a body that has an introduction port to introduce a sample gas into a measurement cell, a laser light irradiation part that irradiates the laser light on the measurement cell, a heating pipe that applies heat to the sample gas introduced into the introduction port, a flow rate limit part that makes the sample gas at a negative pressure and that introduces the negative-pressurized heated sample gas into the body, and a negative pressure pump that keeps inside of the measurement cell and a flow channel from a downstream side of the flow rate limit part to the measurement cell at the negative pressure.

Abstract: A method and device for measuring trace levels of particles in an air sample is described. A device operating in a gradiometer configuration with two cavities built from a monolithic structure and utilizing a single probe laser, provides common mode subtraction of acoustic, vibrational, laser intensity and other noise sources, which allows sensitivity more closely approaching the quantum limit. Differential measurements between the two cavities occur simultaneously, which reduces errors due to cavity drift. Absorptive gradiometry can therefore provide noise immune detection for trace gasses, including broad linewidth absorbers where frequency-noise immune schemes are not practical. Differential measurements can be used for background subtraction, sensing vapor plum gradients and determining vapor plume propagation direction.

Abstract: [Object] To provide a gas monitoring device etc. with which gas monitoring can be preformed at high sensitivity by using an InP-based photodiode in which a dark current is reduced without a cooling mechanism and the sensitivity is extended to a wavelength of 1.8 ?m or more. [Solution] An absorption layer 3 has a multiquantum well structure composed of group III-V semiconductors, a pn-junction 15 is formed by selectively diffusion of an impurity element in the absorption layer, and the concentration of the impurity element in the absorption layer is 5×1016/cm3 or less. The gas monitoring device detects a gas component and the like contained in a gas by receiving light having at least one wavelength of 3 ?m or less.

Abstract: An oscillator element is provided, e.g., for use in a photo acoustic detector for detecting a concentration of a sample in a sample mixture using a light beam for excitation of molecules of the sample in proximity of an excitation area of the oscillator element. The oscillator element includes piezoelectric material for generating a voltage when mechanically distorted. Electrodes at least partially cover a surface of the oscillator element for detecting the generated voltage. The excitation area is arranged in such a way that heating of the electrodes in the excitation area by the light beam is avoided.

Abstract: This invention comprises an arrangement adapted for spectral analysis having a transmitting means adapted for electromagnetic radiation, a delimited space, in the form of a cavity, serving as a measuring cell and intended to be capable of defining an optical measuring distance, a sensing means of said electromagnetic radiation passing said optical measuring distance from said transmitting means, and a unit at any rate connected to said sensing means performing the spectral analysis. Said sensing means for the electromagnetic radiation is opto-electrically adapted sensitive to the electromagnetic radiation, which is intended to fall within the spectral range whose chosen wavelength components or spectral elements are to become objects of an analysis in the unit performing the spectral analysis for determining in this unit, over calculations, the relative intensity of radiation of the spectral element. Said electromagnetic radiation is adapted to pass the space in which a sample of gas exists.

Abstract: A wireless sensor system is provided that utilizes reliable, small, inexpensive and low power-consuming sensor nodes for monitoring environmental parameters that can communicate through wireless transmitters to a base station. The sensor nodes preferably incorporate anti-biofouling protection, so as to withstand continuous field deployment in streams and/or riparian areas.

Abstract: A hydrogen purity sensing system includes a light source which provides an optical signal through a fiber optic cable. A hydrogen purity sensor is provided in the system which comprises a multilayered nanostructural film of high refractive index and low refractive index materials for receiving the optical signal. The system further includes a photodetector for receiving a reflected optical signal from the hydrogen purity sensor and a processing circuitry coupled to the photodetector for analyzing the reflected optical signal.

Abstract: The nitrogen oxide sensing element of the present invention is such that a sensing film (11) is formed on the surface of a substrate (12a), the sensing film including a polymer containing as dispersed therein a porphyrin containing cobalt as a central metal, or a single derivative having a porphyrin skeleton containing cobalt as a central metal or a mixture of derivatives each having a porphyrin skeleton containing cobalt as a central metal; thus, this sensing element is capable of determining the concentration of NO with high sensitivity and satisfactory accuracy under the condition that the cobalt porphyrin is not affected by reaction inhibitors such as O2 and CO even in the atmosphere.

Abstract: In one embodiment, a VCSEL includes a plurality of semiconductor layers, an insulative region, a resistive region, and a remainder region. The semiconductor layers include a lower mirror, an active region, and an upper mirror. The active region is disposed over the lower mirror and includes a first lasing region. The upper mirror is disposed over the active region. The insulative region and the resistive region are integrally formed in the semiconductor layers. The remainder region includes the semiconductor layers except for the insulative region and the resistive region integrally formed in the semiconductor layers. The insulative region is disposed between the resistive region and the remainder region.

Abstract: A sensor that generates an output signal in response to a stimulus, where the output signal is generated with a predetermined relationship to one or more properties of the stimulus such that the one or more properties of the stimulus can be determined as a function of the output signal. In one embodiment, the sensor includes a component, a sensor processor, and a transmitter. The component deteriorates, thereby causing predictable fluctuations in the predetermined relationship between the output signal and the one or more properties of the stimulus. The sensor processor provides information related to the deterioration of the component. The transmitter wirelessly transmits the information provided by the processor.

Abstract: A gaseous component concentration determination apparatus that can obtain a sufficiently large light detection value and determine a concentration of a target component in a desired section without using a laser emitter of a high laser intensity or a large light collector is provided.

Abstract: A process and to an apparatus for isotope ratio analysis having the steps of: performing an LC process and thus providing a first eluate which comprises at least one first liquid carrier fluid and one or more analytes, collecting a portion of interest from the eluate, processing the eluate portion of interest by combining with a second liquid carrier fluid and removing the first carrier fluid to form a processed eluate portion, processing the processed eluate portion to form one or more gaseous conversion products of the analytes, and supplying the gaseous conversion products with gaseous carrier fluid to an isotope analyzer and determining the isotope ratios.

Abstract: A method and system for measuring a physical property of a fluid in which light having wavelengths in the near-infrared is directed into a test cell containing the fluid and portions of the light not absorbed by the fluid and passing out of the cell are spatially dispersed by wavelength, forming a light spectrum that is projected onto a detector. The light spectrum is digitized and inputted into a data processing unit in which it is compared to the actual spectrum of the light source stored in the system to determine the absorbance spectrum of the fluid. The system is spectrally calibrated by identifying known spectral features of the fluid absorbance spectrum. To correct for deviations in the original light source spectrum, a calibration method in which the pressure of the fluid in the test cell is alternated between a first positive pressure and a second positive pressure is employed.

Abstract: A system is provided for determining emission rate of a gas from a source. The system includes a selector for designating an in-plume area extending across a plume of gas. The in-plume area includes a length dimension greater than a width dimension. The system also includes a processor for determining an area-integrated concentration value for the in-plume area. The system further includes a wind vector received by the processor. The processor determines the emission rate of the gas based on the area-integrated concentration value and a vector component of the wind vector.

Abstract: Provided is a detecting element that detects a parameter for a predetermined gas or liquid in a surrounding atmosphere by being excited by excitation light and generating light corresponding to the surrounding atmosphere, the detecting element including: a substrate; and nanoscale crystal structures formed on the substrate and constituted by a compound semiconductor light emitting element having a heterostructure well layer, wherein when the nanoscale crystal structures adsorb atoms or molecules of the predetermined gas or liquid, there is distortion of a band of a structure with a smaller bandgap width in the well layer, this distortion brings about a change in transition energy, and this change brings about a change in at least one of an intensity and a wavelength of light generated by the well layer, thereby indicating the parameter for the gas or the liquid.