Method for determining vanishing temperature of petroleum product crystals and device therefor

The invention concerns a method for determining the vanishing temperature of petroleum product crystals, characterized in that it comprises the following steps: introducing the sample to be analyzed in a measuring cell ( 4 ), arranged in a cryostatic chamber ( 1 ); connecting a laser emitter ( 6 ) and an associated optical receiver ( 7 ) to pass an optical beam through the sample to be analyzed and recording the light intensity received by the receiver ( 7 ); gradually lowering the temperature of the cryostatic chamber ( 1 ) then increasing it again gradually while recording the curve representing the variations in the light intensity received by the receiver ( 7 ) based on the temperature; and determining the vanishing temperature of the crystals from said curve.