Patent ID: 7312868

Claim:
Method for measuring a light flux backscattered by a dispersed medium located on a first side of a wall, by interaction with a plurality of light rays emitted from the second side of said wall which is opposite the first wall, said plurality of light rays being able to traverse said wall and being backscattered at least partially by said dispersed medium in the direction of receiving means located on the second side of the wall, wherein said method comprises at least the following steps: emitting said plurality of light rays in the direction of said dispersed medium and through said wall so that said dispersed medium is able to emit in turn, through said wall, a plurality of backscattered light rays with the aim of forming a backscattering spot in which at least one central zone in the form of a disc is defined, the centre of which corresponds to the luminous barycentre of the backscattering spot and the radius of which is equal to four times the maximum free transport length (1* max ) of said dispersed medium, said backscattering spot being able to be imaged at least in part on said receiving means, forming said backscattering spot from backscattered light rays which have traversed said wall and, at least according to a direction extending from the luminous barycentre of said backscattering spot, are free of light rays which have emanated from said central zone and have undergone a total reflection on the surface forming the interface of said wall with said second side, measuring at least one spatial sample of a profile of the light flux in said backscattering spot, extending in said at least one direction, and recording the measurement of the light flux thus measured.