A method for detecting dispersed elements flowing through a capillary tube, and associated apparatus

This method comprises the steps of: - placing a light source (32) on one side of a measuring passage (38) with respect to a central axis (A-A '); - providing a detector (70) on the other side of the measuring passage (38) relative to the central axis (A-A '); the light source (32) generating an incident light beam (50), the detector (70) detects for each dispersed component passing through the measurement passage (38), a light intensity variation resulting from an output light beam (54) emerging from the measurement passage (38), the output light beam (54) being derived from the incident light beam (50), and forming a non-zero angle with the incident light beam (50).