A method for detecting a plurality of substances of a gas mixture by means of a temporally successive determination of individual concentrations of the substances

The invention relates to a method and an apparatus for detecting a plurality of substances of a gas mixture by means of a temporally successive determination of individual concentrations of the substances by using a single measuring arrangement with the aid of the photoacoustic spectroscopy. Here, at least two selectively activatable radiation sources and / or radiation generated by filtering a signal outputted from at least one radiation source radiation spectrum used in the invention.