DEVICE AND METHOD FOR DETECTING THE FLOCCULATION THRESHOLD OF A COLLOIDAL MEDIUM, IN PARTICULAR A MEDIUM COMPRISING ASPHALTENES, BY ADDITION OF ALIPHATIC SOLVENT

摘要

The invention relates to a device for measuring the flocculation threshold of a colloidal medium, in particular a colloidal medium containing asphaltenes, by addition of aliphatic solvent, comprising: - a measurement cell (10) operating by direct optical transmission and comprising a measurement chamber (101) for receiving the medium, a light emitter (12) for emitting a light beam entering into the measurement chamber in an emission direction and a photoelectric light receiver (14) for directly receiving the light beam exiting the measurement chamber and delivering a current when it receives a light flux; - a control system comprising a system (17) for driving the light emitter, configured to vary the luminous intensity of the emitted light beam between a minimum value and a maximum value, and a measurement system (18) for measuring the current delivered by the light receiver (14), comprising a current-voltage converter (19) configured to receive the current delivered by the light receiver (14) and to deliver a voltage, the converter (19) comprising a controlled switch (190) configured to distribute the current in a circuit chosen from at least two impedance circuits (191, 192) having different impedances, a variable gain amplifier (20) configured to receive the voltage delivered by the current-voltage converter (19) and to deliver a voltage equal or proportional to the incoming voltage and an analogue-to-digital converter (21) configured to receive the voltage delivered by the variable gain amplifier (20) and to deliver a digital signal (S) representative of the quantity of current delivered by the light receiver; and a management system (22) of the control system (16) configured to control the driving system (17), the switch (190) and the variable gain amplifier (20).