A method for measuring the concentration of water in a light-scattering material, the method comprising the following steps: - Emission by N light sources (2, 3) SL i of beams of wavelengths Lambda; onto the material - Acquisition by M sensors P j that are sensitive in at least a portion of said wavelengths Lambda; of signals S j emitted by the material - where M+N≥3 the method further comprising the steps of: - calculating a first item of information I dif representative of the scattering and a second item of information l abs representative of the absorption, according to said signals S j and an item of numerical information representative of the scattering material on the one hand and said sources SL i and said sensors P j on the other hand, - calculating said concentration of water using the second item of information I abs, the method being characterized in that the item of numerical information is provided by one or more functions which are determined in a calibration step by acquiring the signals Sj for samples each composed of: at least one of an absorbent, a diluent and a scatterer using scattering particles whose shape, size or size distribution make it possible to reproduce the anisotropy of the medium to be studied, and an intermediate component selected so as to equalize the refractive index of the diluent and the refractive index of the scattering particles before the addition of the absorbent to the sample. - Emission by N light sources (2, 3) SL i of beams of wavelengths Lambda; onto the material - Acquisition by M sensors P j that are sensitive in at least a portion of said wavelengths Lambda; of signals S j emitted by the material - where M+N≥3 the method further comprising the steps of: - calculating a first item of information I dif representative of the scattering and a second item of information l abs representative of the absorption, according to said signals S j and an item of numerical information representative of the scattering material on the one hand and said sources SL i and said sensors P j on the other hand, - calculating said concentration of water using the second item of information I abs, the method being characterized in that the item of numerical information is provided by one or more functions which are determined in a calibration step by acquiring the signals Sj for samples each composed of: at least one of an absorbent, a diluent and a scatterer using scattering particles whose shape, size or size distribution make it possible to reproduce the anisotropy of the medium to be studied, and an intermediate component selected so as to equalize the refractive index of the diluent and the refractive index of the scattering particles before the addition of the absorbent to the sample. the method further comprising the steps of: - calculating a first item of information I dif representative of the scattering and a second item of information l abs representative of the absorption, according to said signals S j and an item of numerical information representative of the scattering material on the one hand and said sources SL i and said sensors P j on the other hand, - calculating said concentration of water using the second item of information I abs, - calculating a first item of information I dif representative of the scattering and a second item of information l abs representative of the absorption, according to said signals S j and an item of numerical information representative of the scattering material on the one hand and said sources SL i and said sensors P j on the other hand, - calculating said concentration of water using the second item of information I abs, the method being characterized in that the item of numerical information is provided by one or more functions which are determined in a calibration step by acquiring the signals Sj for samples each composed of: at least one of an absorbent, a diluent and a scatterer using scattering particles whose shape, size or size distribution make it possible to reproduce the anisotropy of the medium to be studied, and an intermediate component selected so as to equalize the refractive index of the diluent and the refractive index of the scattering particles before the addition of the absorbent to the sample. at least one of an absorbent, a diluent and a scatterer using scattering particles whose shape, size or size distribution make it possible to reproduce the anisotropy of the medium to be studied, and an intermediate component selected so as to equalize the refractive index of the diluent and the refractive index of the scattering particles before the addition of the absorbent to the sample.