Abstract: The invention relates to a method for measuring a concentration of a gas in a gas mixture, said method comprising that: a light beam modulated in a ramp shape and/or in a step shape in its wavelength and additionally periodically modulated, in particular in its wavelength, is transmitted from a light source, in particular a laser, into a measurement zone; the modulated light beam passes through a gas mixture in the measurement zone and is detected as reception light by a detector, wherein the reception light is converted by the detector into a detector signal; a derivative signal is determined based on the detector signal by performing a transformation of the detector signal into the frequency range, in particular by a Fourier transform of the detector signal, wherein an evaluation of the detector signal transformed into the frequency range is performed, in particular only, for an n-fold of the frequency of the modulated light beam in order to obtain the derivative signal; and at least two measurement values

Abstract: A method of securing a modulation range of a wavelength-variable radiation source as part of the measurement of an absorption line of a substance comprises: the radiation source being controlled to transmit radiation such that the wavelength of the radiation runs through the modulation range in accordance with a time pattern; the radiation being filtered by means of a filter in whose pass band the absorption line is disposed and which has at least one filter flank whose actual wavelength is within the modulation range; a spectrum of the filtered radiation being determined in that the intensity of the filtered radiation is detected with respect to the time pattern; and a determination being made whether the spectrum has the at least one filter flank.

Abstract: The invention relates to a method of determining the concentration of a gas component comprising the steps: generating and guiding a light beam having a wavelength variable in a wavelength range through a measurement volume in which the gas component having an absorption in the wavelength range is present; tuning the wavelength range; detecting the intensity of the light beam after passage through the measurement volume; storage of measurement points during the tuning that respectively consist of a point in time and an associated intensity value, to obtain a direct absorption line; generating an artificial measurement curve from the stored measurement points by shifting the measurement points on the time axis; wherein the shift takes place so that an artificial modulation results in the wavelength time extent; and evaluating the artificial measurement curve in accordance with the method of the wavelength modulation spectroscopy and determining a first concentration value therefrom.

Abstract: A method of securing a modulation range of a wavelength-variable radiation source as part of the measurement of an absorption line of a substance comprises: the radiation source being controlled to transmit radiation such that the wavelength of the radiation runs through the modulation range in accordance with a time pattern; the radiation being filtered by means of a filter in whose pass band the absorption line is disposed and which has at least one filter flank whose actual wavelength is within the modulation range; a spectrum of the filtered radiation being determined in that the intensity of the filtered radiation is detected with respect to the time pattern; and a determination being made whether the spectrum has the at least one filter flank.

Abstract: The invention relates to a method and to a spectrometer for determining the concentration of a gas component, wherein a light source of the spectrometer is operated as in wavelength modulation spectroscopy (WMS). Thus a determination of the concentration can also take place in accordance with WMS and the measured data can, however, additionally be processed, namely a sorting takes place on the time axis, such that the concentration can be determined using the methods of direct absorption spectroscopy (DAS).

Abstract: The invention relates to a method and to a spectrometer for determining the concentration of a gas component, wherein a light source of the spectrometer is operated as in WMS and thus a determination of the concentration can also take place in accordance with WMS and the measured data can, however, additionally be processed, namely a sorting takes place on the time axis, such that the concentration can be determined using the methods of DAS.

Abstract: The invention relates to a method of determining the concentration of a gas component comprising the steps: generating and guiding a light beam having a wavelength variable in a wavelength range through a measurement volume in which the gas component having an absorption in the wavelength range is present; tuning the wavelength range; detecting the intensity of the light beam after passage through the measurement volume; storage of measurement points during the tuning that respectively consist of a point in time and an associated intensity value, to obtain a direct absorption line; generating an artificial measurement curve from the stored measurement points by shifting the measurement points on the time axis; wherein the shift takes place so that an artificial modulation results in the wavelength time extent; and evaluating the artificial measurement curve in accordance with the method of the wavelength modulation spectroscopy and determining a first concentration value therefrom.

Abstract: The invention relates to a spectrometer having a plurality of dispersive optical elements arranged such that electromagnetic radiation entering into the spectrometer is incident on the dispersive optical elements to be split spectrally there; the dispersive optical elements differ from one another with respect to their spatial positions and/or their spectral splitting capabilities; the dispersive optical elements are arranged such that the spectra generated by the respective dispersive optical elements by the splitting of the electromagnetic radiation extend in the same direction and are adjacent to one another transversely to this direction of the spectral splitting; and a detector resolving spatially in two dimensions and being located in the optical path of the split electromagnetic radiation for the detection of at least some respective part sections of the spectra.

Abstract: A spectrometer has a first and second light sources (12, 14) which generate light radiation (24) in a first and second wavelength ranges, and a mirror unit (16) for deflecting the light radiation (24, 26) into a measurement path (18), arranged so that the radiation of both wavelength ranges (24, 26) runs through on the same optical path. A detector (20) detects radiation (24, 26) running through the measurement path (18) and an evaluation unit (22) evaluates the radiation (24, 26) incident at the detector (20) and for determining a concentration of a measurement gas component present in the measurement path (18). The mirror unit (16) is configured as a micromirror array (32) and that a single micromirror (34) only deflects a portion of the radiation (24, 26).

Abstract: A method of determining a concentration of a gas in a sample and/or the composition of a gas using a spectrometer comprises transmitting of radiation whose wavelength substantially continuously runs through a wavelength range, wherein the continuous running through of the wavelength range is overlaid by a wavelength modulation; measuring of an absorption signal as a function of the wavelength of the radiation; converting of the absorption signal into first and second derivative signals; deriving of a first and a second measured gas concentration value from the first and the second derivative signals, respectively; and determining of the concentration and/or the composition of the gas from at least the first measured gas concentration value, wherein the wavelength modulation is adapted in response to a change of a state variable of the gas such that a ratio between the first and the second measured gas concentration values is kept substantially constant.

Abstract: A method of determining a concentration of a gas in a sample and/or the composition of a gas using a spectrometer comprises the transmitting of radiation whose wavelength substantially continuously runs through a wavelength range, wherein the continuous running through of the wavelength range is overlaid by a wavelength modulation; the measuring of an absorption signal from the absorption of the radiation by the gas as a function of the wavelength of the radiation; the converting of the absorption signal into a first and a second derivative signal; the deriving of a first measured gas concentration value from the first derivative signal and of a second measured gas concentration value from the second derivative signal; and the determining of the concentration and/or the composition of the gas from at least the first measured gas concentration value, wherein the wavelength modulation is adapted in response to a change of a state variable of the gas such that a ratio between the first measured gas concentration

Abstract: A spectrometer has a first and second light sources (12, 14) which generate light radiation (24) in a first and second wavelength ranges, and a mirror unit (16) for deflecting the light radiation (24, 26) into a measurement path (18), arranged so that the radiation of both wavelength ranges (24, 26) runs through on the same optical path. A detector (20) detects radiation (24, 26) running through the measurement path (18) and an evaluation unit (22) evaluates the radiation (24, 26) incident at the detector (20) and for determining a concentration of a measurement gas component present in the measurement path (18). The mirror unit (16) is configured as a micromirror array (32) and that a single micromirror (34) only deflects a portion of the radiation (24, 26).

Abstract: A method of determining a concentration of a gas in a sample and/or of the composition of a gas by means of a spectrometer includes measuring an absorption signal of the gas as a function of the wavelength. The wavelength substantially continuously runs through a wavelength range and is superimposed by a harmonic wavelength modulation, wherein the influence of the wavelength modulation on the absorption signal via the light source modulation properties and the detection properties of the spectrometer is dependent on the device properties of the respective spectrometer. The method includes converting the absorption signal into at least one first derivative signal; deriving a gas concentration measurement parameter from the first derivative signal; determining the concentration and/or composition of the gas from at least the gas concentration measurement parameter and from a calibration function compensating for influences of state variables of the gas and of the spectrometer properties.