An apparatus comprising a compact, folded path cell for optical gas detection and/or measurement utilising gas absorption spectroscopy. The apparatus includes a source of electromagnetic radiation, a gas sample cell containing reflective elements, and a detector of electromagnetic radiation. The source and detector are arranged between the reflective elements in an arrangement that reflects the radiation away from the source and detector until the reflected radiation has an adequate optical path length, and then reflects the radiation towards the detector. A spectroscopic analysis can be used to determine the presence and/or to measure at least one parameter of at least one gas species within a gas sample.
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 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
2.
METHOD AND APPARATUS FOR USE IN OPTICAL GAS ABSORPTION MEASUREMENTS
An apparatus for use in absorption spectroscopy, comprising: at least one source of electromagnetic radiation for transmitting electromagnetic radiation along an optical path that passes through a gas measurement volume, towards at least one detector; at least one detector to detect the transmitted electromagnetic radiation after passing through the gas measurement volume and to provide an output signal indicative of the detected electromagnetic radiation; and an analyser connected to the at least one detector to receive the output signal and analyse the effects of absorption by at least one gas species within the gas measurement volume for at least one wavelength range of the transmitted electromagnetic radiation, thereby to detect or measure a parameter of the at least one gas species; wherein at least one source or detector comprises a Chip-on-Board (COB) component comprising a solid-state source and/or detector of electromagnetic radiation mounted onto a substrate in a COB configuration.
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.
APPARATUS FOR COMPACT OPTICAL GAS ABSORPTION MEASUREMENTS
An apparatus comprising a compact, folded path cell for optical gas detection and/or measurement utilising gas absorption spectroscopy. The apparatus includes a source of electromagnetic radiation (1601), a gas sample cell (1606) containing reflective elements (1604, 1605), and a detector of electromagnetic radiation (1602). The source (1601) and detector (1602) are arranged between the reflective elements (1604, 1605) in an arrangement that reflects the radiation away from the source (1601) and detector (1602) until the reflected radiation has an adequate optical path length, and then reflects the radiation towards the detector (1602). A spectroscopic analysis can be used to determine the presence and/or to measure at least one parameter of at least one gas species within a gas sample.
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 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
G01N 21/15 - Preventing contamination of the components of the optical system or obstruction of the light path
4.
METHOD AND APPARATUS FOR USE IN OPTICAL GAS ABSORPTION MEASUREMENTS
An apparatus for use in absorption spectroscopy, comprising: at least one source of electromagnetic radiation (301) for transmitting electromagnetic radiation along an optical path that passes through a gas measurement volume, towards at least one detector (302); the at least one detector (302) to detect the transmitted electromagnetic radiation after passing through the gas measurement volume and to provide an output signal indicative of the detected electromagnetic radiation; and an analyser connected to the at least one detector to receive the output signal and analyse the effects of absorption by at least one gas species within the gas measurement volume for at least one wavelength range of the transmitted electromagnetic radiation, thereby to detect or measure a parameter of the at least one gas species; wherein at least one source or detector comprises a Chip-on-Board (COB) component comprising a solid-state source and/or detector of electromagnetic radiation mounted onto a substrate in a COB configuration.
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
G01J 3/50 - Measurement of colourColour measuring devices, e.g. colorimeters using electric radiation detectors
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
G01N 21/15 - Preventing contamination of the components of the optical system or obstruction of the light path
5.
APPARATUS, SYSTEMS AND METHODS FOR USE IN OPTICAL GAS ABSORPTION MEASUREMENTS
An apparatus for optical gas detection and/or measurement in an absorption spectroscopy system comprising: a gas cell for containing a gas sample or calibration gas with at least one gas exchange port and at least one optical element for allowing transmission of electromagnetic radiation of a desired wavelength range in and out of the gas cell; and at least one source of converging, diverging or collimated electromagnetic radiation for transmitting electromagnetic radiation through a gas sample contained within the gas cell and towards at least one detector; said detector to monitor absorption of electromagnetic radiation for at least one absorption wavelength or wavelength range associated with at least one gas species, by detecting transmitted electromagnetic radiation that is not absorbed; at least one analyser for analysing an output signal from the at least one detector to measure a parameter of at least one gas species within the gas sample, characterised in that at least one dead volume within the spectrometer is filled with a transmissive filler material that reduces or eliminates the presence of at least one undesired gas species.
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 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
6.
APPARATUS, SYSTEMS AND METHODS FOR USE IN OPTICAL GAS ABSORPTION MEASUREMENTS
whereinwherein at least one dead volume within the spectrometer is filled with a transmissive filler material that reduces or eliminates the presence of at least one undesired gas species.
G01N 21/15 - Preventing contamination of the components of the optical system or obstruction of the light path
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
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
7.
MAGNETIC STABILIZATION METHOD AND SYSTEM IN INFRARED, VISIBLE AND ULTRAVIOLET SPECTROSCOPY
In a spectroscopic analysis system, a broadband light source emits infra-red, visible or ultra-violet light which is transmitted through a fluid in a sample cell to a broadband detector. Changes in transmitted intensity are related to measurand in the fluid. A rotatable optical modulator or chopper, driven by an electric motor and located in the optical path, has light-transmissive optical elements, and non-transmissive regions. A non-contact magnetic field generator applies a magnetic field to the modulator or chopper to damp or brake the rotation. In an aspect, the modulator is an electrically conductive, non-ferromagnetic wheel, disc or cylinder in which eddy currents are induced. Optical elements may be apertures, filters, cuvettes, etc. A Hall effect sensor, rotary encoder, optical switch, etc. may determine angular speed or position of the modulator, and a PID controller may be used to maintain rotation speed at a setpoint by modulating an electromagnetic field generator.
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
8.
ELECTROMAGNETIC CONTROL OF ABSORPTION AND SUPPRESSION OF SPECTRAL ARTIFACTS
A method and system for the suppression and/or modulation of absorption spectrum artifacts for the purpose of gas detection and concentration measurements using at least one magnetic, electric or electromagnetic field. A field applied selectively to at least one section of the system modulates absorption by influencing quantum energy state transitions of gas species.
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 21/31 - 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
Methods and apparatus for determination of the gas composition of a sample gas using glow discharge optical emission spectroscopy, in which the method comprises: generating one or more oscillating electromagnetic fields within a plasma cell to excite particles within the cell, to produce a glow discharge plasma in the plasma cell, and controlling the operating conditions for the plasma cell while flowing a gas mixture through the plasma cell to maintain glow discharge optical emissions from the plasma within a desired operating range; and monitoring one or more glow discharge optical emissions from the plasma in the plasma cell by measuring the optical emissions, or measuring a signal that correlates with the optical emissions, at twice the plasma excitation frequency; and processing the signal during each excitation cycle of the electromagnetic excitation, to determine the concentration of a gas within a gas mixture flowing through the plasma cell.
G01N 21/67 - Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light electrically excited, e.g. electroluminescence using electric arcs or discharges
G01N 21/68 - Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light electrically excited, e.g. electroluminescence using high frequency electric fields
Provided are methods, apparatuses and systems for enhanced determination of the gas composition of a sample gas using glow discharge optical emission spectroscopy (GD-OES) for gas analysis. A first method comprises: generating one or more oscillating electromagnetic fields within a plasma cell to excite particles within the cell, to produce a glow discharge plasma in the plasma cell, and controlling the operating conditions for the plasma cell while flowing a gas mixture through the plasma cell to maintain glow discharge optical emissions from the plasma within a desired operating range; and monitoring one or more glow discharge optical emissions from the plasma in the plasma cell; wherein said monitoring of the optical emissions comprises measuring the optical emissions, or measuring a signal that correlates with the optical emissions, at twice the plasma excitation frequency; and processing the signal during each excitation cycle of the electromagnetic excitation, to determine the concentration of a gas within a gas mixture flowing through the plasma cell.
G01N 21/68 - Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light electrically excited, e.g. electroluminescence using high frequency electric fields
Provided are methods, apparatus and systems for stabilization of a glow discharge from a plasma. Also provided are methods, apparatus and systems for processing optical signals from a stabilised glow plasma with enhanced signal to noise recovery. A first method comprises: generating an electric field within a plasma cell using an alternating excitation voltage to excite particles within the cell, to produce a glow discharge from a plasma in the plasma cell in a resonant condition; monitoring, in each excitation cycle of the alternating excitation voltage, one or more signals that correlate with glow discharge optical emissions from the plasma in the plasma cell; and, in response to said monitoring, controlling one or more operating conditions for the plasma cell to maintain the glow discharge emissions from the plasma within a desired operating range in each excitation cycle of the alternating excitation voltage. A relatively stable glow discharge optical emission is maintained via dynamic resonant feedback control of operating conditions such as the electric field that is used to excite particles within the plasma cell. The stabilization of the glow plasma can be used in glow discharge optical emission spectroscopy (GD-OES) for gas analysis and in other applications.
A method and system for reducing the effect of distortions on the baseline signal in an absorption spectroscopy system used for the detection or measurement of chemical species in a medium, whereby one or more correlations or convolutions are performed on the signal using a kernel function. The shape of the kernel function is chosen to reduce the influence of the baseline distortions on the processed measurand determination. The kernel function may also be chosen to enhance the absorption signal.
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 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
An alignment device having two angular degrees of freedom is provided. The alignment device is adjustable such that it is suitable for aligning a first apparatus with respect to a second apparatus. The first apparatus may emit one or more of electromagnetic waves, acoustic waves and matter towards the second apparatus and for detection by the second apparatus. The first and second apparatuses may be disposed in a harsh environment such as is found in the vicinity of an industrial process stack. In some embodiments the first apparatus is a laser, preferably a tunable diode laser, and the second apparatus is a receiver incorporating a detector. In these embodiments the apparatuses may be used to perform laser absorption spectroscopy on a process gas flowing through an industrial process stack.
G01B 11/27 - Measuring arrangements characterised by the use of optical techniques for measuring angles or tapersMeasuring arrangements characterised by the use of optical techniques for testing the alignment of axes for testing the alignment of axes
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
G02B 27/00 - Optical systems or apparatus not provided for by any of the groups ,
G02B 27/62 - Optical apparatus specially adapted for adjusting optical elements during the assembly of optical systems
G02B 7/02 - Mountings, adjusting means, or light-tight connections, for optical elements for lenses
14.
Attachment and alignment device for optical sources, detectors and analysers, and modular analysis system
A device is provided for combining two or more separate components of an optical analysis system, to use common entrance and exit apertures for optical measurements across a measurement space such as a stack, combustion chamber, duct or pipeline, in such way that the optical paths from the respective light sources to detectors are substantially the same, enabling multiple optical measurements over a single optical path or closely aligned optical paths with equivalent ambient conditions such as temperature and pressure distribution and background substance concentrations. The device and a set of interconnectable devices forming a modular system are useful, for example, in absorption spectroscopy, such as for measuring the amount fraction of the chemical constituents of a fluid in a measurement volume.
G01N 21/29 - ColourSpectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands using visual detection
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
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 and system for correcting the effect of intensity fluctuations of the transmitted light in an absorption spectroscopy system used for the detection or measurement of chemical species in a medium, whereby one or more modulation bursts are imposed onto a light beam that passes through the medium. This burst signal may be obtained by modulating the bias current of a tunable diode laser, and the modulation burst signal may be optimally at the second harmonic of the modulation frequency of a wavelength modulated beam to allow usage of the same signal path processing used for the spectroscopic detection of the measurand for a second harmonic detection system. The burst signal can be controlled using a smooth window function to minimise the effects of non-linear perturbations that are inherent in tunable diode laser wavelength modulation spectroscopy systems, of optical interference fringes (etalons) and of the residual light absorption by background chemical species or the measurand at the wavelength coinciding with the modulation burst.
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
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
This present invention relates to a device for the measurement of the amount of oxygen in a gas mixture, or other gas with significantly different magnetic susceptibility than the background gas mixture, by the use of a suspended test body in a magnetic field that experiences force due to the magnetic susceptibility of the measurand gas. In order to enable a fast time response for the system with a change in oxygen concentration, a flow regime is presented which allows a fast sweep of the measurement volume combined with adjustable, balanced pressure drops via a flow balancing element (or elements) within the flow channels to independently minimise flow related uncertainties.
G06G 7/57 - Analogue computers for specific processes, systems, or devices, e.g. simulators for fluid flow
G01N 27/74 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables of fluids
Provided are apparatus and methods for compensation of mechanical imbalance in a measurement apparatus, that provides options for increased accuracy and/or less expensive manufacture of a torsion balance. Orientation measurements are taken and an imbalance torque about the torsion spring's axis of rotation is determined, and used to calculate a compensation. The measurement apparatus of one embodiment includes a test body and a set of magnets for generating a first disturbing force on the test body in response to a paramagnetic gas. A conductor element in the magnetic field receives an electrical current that generates a second opposing force to the test body, under feedback control that varies the current until the test body achieves a balanced null position. The control signal required to achieve the fixed null position is measured. Corrections are then made for an imbalance mass by measuring the orientation of the apparatus relative to an acceleration or gravitational field and determining the imbalance torque resulting from the imbalance mass. Use of the invention can improve accuracy or reduce the cost of manufacture of a torsion balance, by enabling compensation for imbalances.
G01N 27/74 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables of fluids
G01N 27/76 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables of fluids by investigating susceptibility
G01D 3/06 - Measuring arrangements with provision for the special purposes referred to in the subgroups of this group with provision for operation by a null method
G01L 25/00 - Testing or calibrating of apparatus for measuring force, torque, work, mechanical power, or mechanical efficiency
G01P 21/00 - Testing or calibrating of apparatus or devices covered by the other groups of this subclass
An apparatus for the measurement of the magnetic susceptibility of a gas mixture comprises: a gas sample chamber (8) adapted to receive the gas mixture; a test body (1) rotatably suspended within the gas sample chamber; magnets (10) within the gas sample chamber; a compact optical system for detecting rotation of the test body (1) including a light source (12), photodetectors (13) arranged to detect a light signal, and a mirror (5) attached to the test body (1). An actuation system is arranged to keep the test body (1) substantially at a null position. The optical system comprises at least one photodetector positioned on each side of the light source. The light source is arranged to emit a light beam towards the test body. The photo detectors are arranged to each detect an edge of a light beam reflected from the mirror.
G01N 27/76 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables of fluids by investigating susceptibility
G01N 33/00 - Investigating or analysing materials by specific methods not covered by groups
Provided is a compact apparatus for measuring the flow rate of a fluid. The apparatus includes a heated measure element and a heated reference element which are in substantially the same thermal environment within a measure cell, except that the measure element is situated in the path of the cooling fluid flow and the reference element is sheltered from this direct fluid flow. These elements are arranged as parallel and concentric planar elements that are essentially identical to each other with matching thermal characteristics. The elements are electrically connected in a Wheatstone bridge arrangement. Thermal exchange between the reference and measure elements is used to optimise noise rejection due to common mode background thermal effects. Measured parameters from the bridge can be used to derive the fluid flow rate.
G01F 1/68 - Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
An apparatus for the measurement of the magnetic susceptibility of a gas mixture comprises: a gas sample chamber (8) adapted to receive the gas mixture, and a test body (1) rotatably suspended within the gas sample chamber; means (10) for creating an inhomogeneous magnetic field within the gas sample chamber; means for detecting rotational motion of the test (body 1), comprising a compact optical system including a light source (12) and photodetectors (13) arranged to detect a light signal indicative of the rotational motion; and an actuation system (4) arranged to keep the test body (1) substantially at a null position determined by said optical system, wherein the optical system comprises at least one photodetector (13) positioned on either side of the plane which is normal to the mirror and parallel with the rotation axis of the test body, having the light source (12) positioned in the plane. For enhanced performance, an optical element (16) is placed in front of the light source or photodetectors to modify properties of the light emitted by the light source or received by the photodetectors.
G01N 27/76 - Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables of fluids by investigating susceptibility
21.
Chromatographic systems and methods for eliminating interference from interfering agents
The present invention provides a chromatographic method for eliminating interference from interfering agents, coming from the gas sample itself or from the system material used to perform the impurities measurements, on impurities to be quantified in a gas sample. The method advantageously relies on the use of an additional valve and an additional sample loop particularly arranged in a G. C. system, and also on an additional supporting gas inlet operatively connected to the system through the additional sample loop for providing the system with a supporting gas comprising at least a predetermined portion of a predetermined active gas that will react with the unwanted interfering impurities, if any, or with the column material to cancel out unwanted active sites. Thus, the method of the present invention can advantageously be used in gas chromatographic systems to improve sensitivity thereof by acting on column separation material.
B01D 53/02 - Separation of gases or vapoursRecovering vapours of volatile solvents from gasesChemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases or aerosols by adsorption, e.g. preparative gas chromatography
22.
System and method of eliminating interference for impurities measurement in noble gases
The invention provides a system and a method of eliminating interference for impurities measurement in noble gases based on emission spectroscopy which provide very stable, sensitive and interference free results. The method mainly relies on the use of a combination of particularly designed means serially connected for cancelling interferences and proper means for correcting linearity issues. The proposed method is particularly advantageous since it offers long-term stability while providing very accurate and reliable results, even at sub-ppb and up to 10,000 ppm levels, whatever the surrounding conditions and the additional impurities that could be present in the gas under analysis.
The present invention relates to a probe having an elongated main body with a proximal end for attachment to a wall of a duct or volume and a distal end that is disposed on the interior of the duct, such that the main body forms a measurement space through which the fluid is drawn for analysis.
A sensor for determining the thermal conductivity of a fluid comprising a sensing module located within a housing having inlet and outlet ports for a fluid under test, the sensing module comprising a reference base surface and a sensing element spaced therefrom and having measure and reference sections, and there being provided electrical power monitoring means for monitoring the power through the measure and reference sections in order to generate a signal indicative of the power difference due to thermal conductivity through the fluid. The sensing element is a thick film printed disc with measure and reference resistors printed on it. All changes in the fluid are common to both the measure and reference sections except for the thermal conductivity of the fluid itself.
Correlation spectroscopy measure is improved by correcting for cross interference. This is achieved through applying different gains to the output signals whereby the effect of background interferent species can be calculated and an automatic correction factor applied.
An improved chromatographic method for measuring impurities in a gas sample that allows extraction of a peak of impurity masked by the sample background. An impurity peak is extracted from the sample background and put in a second sample loop and the second sample loop volume is injected into a second separation column. A “slice” is taken from the sample background to fill the second sample loop and the “slice”, whose width is preferably substantially equal to the impurities peak width, is injected into the second separation column. Another embodiment allows concentration of a predetermined impurity, thereby providing an improved precision on the results. The chromatographic method provides an improved measure of argon in oxygen, oxygen in argon and oxygen in hydrogen.
patents
