Device for checking the quantity of gasolines, diesel fuels, fuels or liquids in general during introduction in a tank

A device for checking the quantity of gasolines, Diesel fuels, fuels or liquids in general during introduction in a tank, comprising at least one ultrasound emission source and at least one ultrasound receiver, the ultrasound emission source being arranged so as to send a train of sound waves toward the free surface of the liquid that is present in the tank and to receive the sound beam reflected by the free surface of the liquid, the ratio of the speed of the sound waves with respect to the time between the emission of the sound waves by the ultrasound source and the reception of the sound waves providing a distance that constitutes a datum for calculating the quantity of liquid introduced in the tank.