Method for determining a gsm substance and/or a chemical composition of a conveyed material sample, and a device for this purpose

A method for determining a weight per unit area and/or a chemical composition of a conveyed material sample. From the analysis of a portion of an incident ionizing radiation, in particular an X-radiation, scattered from a material sample, a detector signal corresponding to the gsm substance and/or the chemical composition of the material sample is generated and used for determining the weight per unit area and/or the chemical composition of the material sample. A device for determining a weight per unit area and/or a chemical composition of a material sample has a compact measurement head arranged unilaterally with respect to the material sample. This measurement head includes an X-radiation source and a detector arrangement integrated into the measurement head of at least one X-ray detector connected to a voltage supply and an evaluation unit.