Dispensing (often referred to as blending, dosing or tinting) is divided into two main technologies - Volumetric or gravimetric. Formulations or Recipes contain ingredients that are dispensed into a target dispense vessel from storage containers in the required quantities. These quantities are either measured volumetrically or gravimetrically.
Volumetric dispensers dose a volume of product, usually by priming a chamber and discharging like a bicycle pump or syringe. This method delivers an assumed quantity of product into the dispense vessel. There is no feedback in volumetric systems.
Gravimetric dispensers weigh the precise amount of each ingredient using precision dispense valves above a highly accurate weighing platform, thus adding a known quantity into the dispense vessel. Gravimetric systems have feedback control.
Therefore gravimetric dispensing is commonly regarded as the most reliable, accurate, flexible and robust method to produce high quality product batches.