This bin has been designed to solve metering problems for facilities with small or average capacities. Its storage system and ample volume are two features which contribute to keeping the volumetric weight of the material to be extracted constant, irrespective of the bin’s filling level, resulting in a perfectly even extraction. The material is distributed and leveled inside the bin by means of a set of screws or rakeback conveyor system, while a set of doffing roll disks at the outlet ensures that the material is evenly distributed over the whole weighing belt. The method adopted for particle metering is that of conveyor belt speed variation. A weighing belt is located at the end of the conveyor belt, which, thanks to a special mechanical-electronic system, is able to determine the instantaneous throughput of the material.