Volumetric feeders supply a certain volume of material per unit of time. Known volume units of a particular material are used for the volumetric measurement and the material is transferred to a mass-based discharge using scanned calibration. Feeding is changed by adapting the auger speed.
Unlike gravimetric feeding, volumetric feeding does not determine mass using weight.
Volumetric feeders cannot detect fluctuations in material density. Deviating speeds of discharge are not taken into account.