Abstract: A measurement device for and a method of measuring a hydrogen concentration included in a gas. The measurement device for performing the method includes: an excitation light generator transmitting excitation light to a sample of the gas; a monochromator providing a portion of Raman scattered light emanating from the illuminated sample to a measurement detector for determining a measured intensity of the portion; and an evaluation unit determining the hydrogen concentration as a linear function of the measured intensity. The portion of Raman scattered light solely includes light having wavelengths in a measurement wavelength range having a range width smaller or equal to several nanometers and including a measurement wavelength given by a wavelength at which a Raman intensity spectrum of pure hydrogen gas exhibits a maximum.

Abstract: A method for spectroscopic determination of at least one measured variable in a medium includes defining an application; providing a spectrometer, providing a raw spectrum; applying a calibration to the raw spectrum to obtain a calibrated spectrum; standardizing the calibrated spectrum to obtain a standardized spectrum. The standardization is performed using spectrometer-type-specific information and a transformation function, wherein the transformation function comprises the calibrated spectrum and additional measurement information as input variables and comprises a spectrometer-specific transformation function and calibration features. The method further comprises selecting, adapting, and/or creating a spectrometer-independent and application-specific model from the standardized spectrum and application-specific data; and determining the at least one measured variable from the raw spectrum using the model.

Abstract: A spectrometric measurement method includes: with multiple calibration light sources, exhibiting known emission spectra performing calibrations of multiple spectrometers; based on calibration data attained by these calibrations, assessing a variability exhibited by measured spectra determined by calibrated spectrometers; determining reference spectra of reference samples exhibiting known reference values of at least one measurand; based on the reference spectra and the previously assessed variability, determining synthetic spectra of reference samples exhibiting the previously assessed variability; and based on the measured reference spectra, the synthetic spectra and the corresponding reference value, determining and providing a model for determining measurement results of the at least one measurand. An analyzer for assessing the variability exhibited by measured spectra determined by calibrated spectrometers is configured to perform simulated calibrations.

Abstract: A measuring system includes: an optical sensor for measuring a variable of a medium in a process vessel; a retractable fitting for mounting the optical sensor, including a hollow cylindrical housing with a housing wall, which includes a service chamber within the housing, and an immersion tube, which is axially movable within the housing between a service position, in which the immersion tube is withdrawn from the medium, and a process position, in which the immersion tube is in the medium, wherein the optical sensor is disposed in the immersion tube, and wherein the housing wall includes an opening adjacent the service chamber; and a calibration unit movably mounted in the opening between a rest position and a calibration position, wherein the calibration unit is outside the service chamber in the rest position, and wherein the calibration unit is in optical contact with the optical sensor in the calibration position.

Abstract: An electro-optical adapter module includes a housing; at least one input interface with a connector on the housing, wherein the input interface is designed to be connected to a probe via a cable; an output interface with a connector on the housing, wherein the output interface is designed to be connected to a spectrometric base module; with an, for example, bidirectional, electrical connection from the input interface to the output interface; a first optical connection from the input interface to the output interface for optical input signals, for example, measurement signals; and a second optical connection from the output interface to the input interface for optical output signals, for example excitation signals.

Abstract: A method of performing an optical analysis on multiple vessels using a single optical analysis device includes placing on and in each vessel a protective sheath that will accept a probe head of the optical analysis device. The probe head may be easily inserted into and removed from the protective sheath. A Cartesian robot may move the probe head from vessel to vessel to perform the analyses. The system for the optical analysis include at least two vessels, an optical analyzer, and a Cartesian robot.

Abstract: A measuring system includes: an optical sensor for measuring a variable of a medium in a process vessel; a retractable fitting for mounting the optical sensor, including a hollow cylindrical housing with a housing wall, which includes a service chamber within the housing, and an immersion tube, which is axially movable within the housing between a service position, in which the immersion tube is withdrawn from the medium, and a process position, in which the immersion tube is in the medium, wherein the optical sensor is disposed in the immersion tube, and wherein the housing wall includes an opening adjacent the service chamber; and a calibration unit movably mounted in the opening between a rest position and a calibration position, wherein the calibration unit is outside the service chamber in the rest position, and wherein the calibration unit is in optical contact with the optical sensor in the calibration position.

Abstract: A waveguide for conveying light with an input end and an output end to supply for an electromagnetic spectrometer includes: an input end having a convex envelope of a cross-section of the waveguide at the input end, which envelope defines a circular shape or a shape of a regular polygon with n1 corners, wherein n1 is a natural number bigger than 3; an output end having a cross-section that defines a slit shape; and a plurality of filaments, wherein an arrangement of the plurality of filaments defines the cross-sections at the input and output ends, wherein each filament includes a core and a reflective coating covering a lateral area of the core, wherein the core includes an optically transparent material.

Abstract: A spectrometer including: a laser light source, including a tunable diode laser with a coherent laser output, wherein the laser light source is configured to modulate the frequency of the coherent laser output; a photodetector arranged to receive the coherent laser output; at least one optical element arranged between the laser output and the photodetector; and an evaluation unit electrically connected to the photodetector. The laser light source and/or the first optical element is mounted on a movable carrier, wherein the movement of the carrier is oscillatory and changes the path length of the radiation such that interference signals are suppressed, wherein the suppression occurs due to interference between the radiation emitted from the light source and the change in the path length of the beam path due to the movement on the movable carrier.

Abstract: A photonic crystal waveguide for conveying light with an input end and an output end to supply for an electromagnetic spectrometer includes: an input end having a convex envelope of a cross-section of the waveguide at the input end, which envelope defines a circular shape or a shape of a regular polygon with n1 corners, wherein n1 is a natural number bigger than 3; an output end having a cross-section that defines a slit shape; and a plurality of photonic crystal fibers, wherein an arrangement of the plurality of photonic crystal fibers defines the cross-sections at the input and output ends.

Abstract: A waveguide for conveying light with an input end and an output end to supply for an electromagnetic spectrometer includes: an input end having a convex envelope of a cross-section of the waveguide at the input end, which envelope defines a circular shape or a shape of a regular polygon with n1 corners, wherein n1 is a natural number bigger than 3; an output end having a cross-section that defines a slit shape; and a plurality of filaments, wherein an arrangement of the plurality of filaments defines the cross-sections at the input and output ends, wherein each filament includes a core and a reflective coating covering a lateral area of the core, wherein the core includes an optically transparent material.

Abstract: A gas sensor for determining a concentration of at least one gas in a gas mixture includes: at least one intensity modulatable light source; a measuring section, into which the gas mixture to be investigated can be allowed to flow; and an essentially gas-sealed detection cell, wherein the gas sensor is embodied such that light emitted from the light source is radiated into a measuring section, wherein the intensity of the emitted light is modulated with a modulation frequency, which differs from the resonant frequency of a mode of the acoustic resonance of the detection cell by less than 0.5 times, especially less than 0.25 times, the half-width of the mode. Further, a method for determining the concentration of the at least one gas in the gas mixture uses the gas sensor.

Abstract: The present disclosure relates to a device for measuring a first analyte concentration and a second analyte concentration in a measuring medium, the device including: a sample cell; a first light source unit; a first detector unit; a functional element; a second light source unit; a second detector unit; and a control unit adapted to analyze a detected first light for determining a first value representing the concentration of the first analyte in the measuring medium and adapted to analyze a detected third light for determining a second value representing the concentration of the second analyte in the measuring medium. A method of using the device is also disclosed.

Abstract: A method for determining an amount of a Raman-invisible gas in a multi-component gas stream includes performing a first and second absolute Raman analysis on the gas stream. A decrease in the absolute Raman bands from the first analysis to the second analysis is attributed to an increase of the Raman-invisible gas in the gas stream. The amount of the Raman-invisible gas is calculated from the difference between the first and second sets of Raman bands. The calculation of the Raman-invisible gas is verified via a measurement and a calculation of a secondary property of the gas stream such as the thermal conductivity of the gas stream or the density of the gas stream.

Abstract: A method for determining an amount of a Raman-invisible gas in a multi-component gas stream includes performing a first and second absolute Raman analysis on the gas stream. A decrease in the absolute Raman bands from the first analysis to the second analysis is attributed to an increase of the Raman-invisible gas in the gas stream. The amount of the Raman-invisible gas is calculated from the difference between the first and second sets of Raman bands. The calculation of the Raman-invisible gas is verified via a measurement and a calculation of a secondary property of the gas stream such as the thermal conductivity of the gas stream or the density of the gas stream.

Abstract: The present disclosure relates to a computer-implemented method for forecasting calibration spectra including a step of providing a machine learning model trained using historical calibration data corresponding to different gas species at different pressures. The computer-implemented method also includes steps of performing a calibration scan of one gas species at one pressure using an analyzer and generating calibration curves for the analyzer corresponding to one or multiple gas species at multiple pressures using the machine learning model and the calibration scan. Thereafter, a spectrum is obtained using the analyzer, and a concentration measurement is generated using the spectrum and at least one of the calibration curves.

Abstract: The present disclosure relates to a device for measuring a first analyte concentration and a second analyte concentration in a measuring medium, the device including: a sample cell; a first light source unit; a first detector unit; a functional element; a second light source unit; a second detector unit; and a control unit adapted to analyze a detected first light for determining a first value representing the concentration of the first analyte in the measuring medium and adapted to analyze a detected third light for determining a second value representing the concentration of the second analyte in the measuring medium. A method of using the device is also disclosed.

Abstract: The present disclosure relates to a computer-implemented method for forecasting calibration spectra including a step of providing a machine learning model trained using historical calibration data corresponding to different gas species at different pressures. The computer-implemented method also includes steps of performing a calibration scan of one gas species at one pressure using an analyzer and generating calibration curves for the analyzer corresponding to one or multiple gas species at multiple pressures using the machine learning model and the calibration scan. Thereafter, a spectrum is obtained using the analyzer, and a concentration measurement is generated using the spectrum and at least one of the calibration curves.

Abstract: A spectrometer includes a light source that emits a beam into a sample volume comprising an absorbing medium. Thereafter, at least one detector detects at least a portion of the beam emitted by the light source. It is later determined, based on the detected at least a portion of the beam and by a controller, that a position and/or an angle of the beam should be changed. The beam emitted by the light source is then actively steered by an actuation element under control of the controller. In addition, a concentration of the absorbing media can be quantified or otherwise calculated (using the controller or optionally a different processor that can be local or remote). The actuation element(s) can be coupled to one or more of the light source, a detector or detectors, and a reflector or reflectors intermediate the light source and the detector(s).

Abstract: A spectrometer includes a light source that emits a beam into a sample volume comprising an absorbing medium. Thereafter, at least one detector detects at least a portion of the beam emitted by the light source. It is later determined, based on the detected at least a portion of the beam and by a controller, that a position and/or an angle of the beam should be changed. The beam emitted by the light source is then actively steered by an actuation element under control of the controller. In addition, a concentration of the absorbing media can be quantified or otherwise calculated (using the controller or optionally a different processor that can be local or remote). The actuation element(s) can be coupled to one or more of the light source, a detector or detectors, and a reflector or reflectors intermediate the light source and the detector(s).