Debimetre Fluid diphasic gas / liquid cryogenic

The invention relates to a flow meter for fluids cryogenic two-phase gas / liquid comprising: - a separator for liquid / gas phase, preferably consisting of a tank (1), in the upper part of which is admitted the cryogenic liquid; - a fluid flow sensor (21), located on a fluid conduit in fluid communication with the lower part of the vessel, the vessel being placed in the high position (H) in space relative to the liquid flow sensor (21 ); - a gas pipe, in fluid communication with the upper part of the tank, provided with a gas valve (12); and - a device for measuring the liquid level in the vessel, preferably comprising two level sensors: a sensor (3) and a low level sensor (2) high level.