Abrasive water jet cutting (AWJ) uses a high speed water jet to which a mineral abrasive is added. Abrasive grains are greatly accelerated in the nozzle, due to their high speed and hardness they remove material along with the water in contact with the workpiece. With this process, almost all types of materials can be machined, regardless of their composition, structure and hardness. The great advantage of this process is that there is no heat affected zone. There are different ways of dosing the abrasive, the most common are two methods: the first is gravity method, where the mass flow is determined by the diameter of the orifice, for the second, the mass flow is determined by varying the speed of electric motor that drives the conveyor belt or wheel. In this paper we presented the process of AWJ cutting and reviewed the literature on measuring mass flow of granular materials. In the experimental part we designed a dosage system with a rotating wheel, measured mass flow rates on three different dosing systems and evaluated the steadiness of mass flow rate.