A gravimetric feeder is a self-calibrating dosing system that doses based on weight in speed.In gravimetric dosing, the weight of the dosed additive is measured using a load cell that is the foundation of the entire system. Weight is calculated using loss-in-weight technology, which measures the reduced weight while dosing. A volumetric feeder is relatively low priced dosing system. Accurate dosing cylinder. Stepper motor speed starting from 0.1 up to 200 rpm. A volumetric feeder, on the other hand, does this based on volume in speed.