Sick Ag

Julian Edler

Thomas Beyer

Rolf Disch

Jürgen Kaufmann

Samson Frank

Torsten Waldmann

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 of a phase of the derivative signal are determined and a correction function is calculated based on the determined measurement values of the phase of the derivative signal in order to correct the derivative signal with the correction function.

Method for measuring a concentration of a gas and associated apparatus

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.

Method of securing a modulation range

The invention relates to a method of determining the concentration of a gas component comprising the steps:

Method of determining the concentration of a gas component and a spectrometer for this purpose

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).

Method of determining the concentration of a gas component and spectrometer therefor

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

Spectrometer and method of operating same

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.

Growing community of inventors

Waldkirch, Germany

Julian Edler