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

A method of determining the concentration of a gas component, the method comprising the steps of:

• generating a light beam with a light source, the light beam having a wavelength variable in a wavelength range;
• guiding the light beam through a measurement volume in which the gas component to be determined is present, wherein the gas component has an absorption in the wavelength range;
• tuning the wavelength range with a light source controller;
• detecting an intensity of the light beam with a light detector after passage of the light beam through the measurement volume;
• storing measurement points in memory, the measurement points respectively consisting of a point in time and the associated intensity value during the tuning, whereby a direct absorption line is obtained;
• generating an artificial measurement curve from the stored measurement points with an evaluation unit, the evaluation unit shifting the measurement points on the axis of time to generate the artificial measurement curve, wherein the shift takes place such that an artificial modulation of the wavelength results following the shift in the wavelength time extent;
• and
• evaluating the artificial measurement curve, with the evaluation unit, in accordance with the methods of wavelength modulation spectroscopy and determining a first concentration value therefrom.