Probe for measuring light in a liquid, probe for detecting the flocculation threshold of a colloidal medium, related detection method and use for determining the flocculation of asphaltenes

Method for measuring the flocculation threshold of a colloidal medium comprising asphaltenes by the addition in stages of apolar solvent comprising the following stages:

• (i) at least two probes are introduced into the medium, which probes operate by optical transmission at the level of detection zones with distinct dimensions;
• (ii) which of the at least two probes is suited for the measurement is determined by determination of the transmission threshold of the medium before addition of apolar solvent;
• and
• (iii) using the probe suited for measurement determined at step (ii) flocculation is determined after addition of the quantity of the apolar solvent necessary for flocculation at substantially ambient temperature,
• wherein the at least two probes are comprised in a device for measuring light in a medium by inserting the at least two probes into said medium, wherein each of the at least two probes comprises an emitter connected to a first waveguide emitting at the level of a detection zone a light beam directly onto said zone, and a second waveguide receiving perpendicular to its aperture said light beam sent back to a receiver for analysis;
• said second waveguide containing at least one reflecting mirror reflecting the light beam by reflection, situated downstream of said detection zone;
• and wherein each of the at least two probes operates at the level of detection zones of the medium with distinct dimensions.