Each composition has its own formula based on the molecular mass of the components. This means that a recipe is fixed in weight units. A weighing controller compares the dosed mass with the desired one. The moment that the masses match, is switched off. However, once the supply is stopped, there is still some material falling. The core of the problem here is, that neither the dosing capacity nor drop height are constant. In addition, there are significant differences in flow properties of powders and differences in viscosity of liquids which influence the flow rate.
A dosing system therefore is a compilation of different dosing devices measuring the setup and discharge system. In order to obtain an optimal result, these individual devices or parts must be coordinated.