A method for determining the composition of a gas mixture

A method for determining the composition of a gas mixture, wherein said plurality of mutually independent physical quantities of the gas mixture are measured and the composition of the gas mixture is determined from the measured quantities about correlation calculations, characterized in that the sound absorption coefficient of the gas mixture is additionally determined by the gas mixture with sound waves applied for the generation of multiple reflections and the sound absorption coefficient is determined by detecting the decrease in the amplitude of the multiple reflections, and that the sound absorption coefficient determined is used as a further variable for correlation calculations.