Abrasive water jet (AVC) cutting is one of the contour cutting proceses. Cutting is performed by a high speed water jet to which abrasive grains are added. For abrasive dosing two main approaches are used. The first is called passive or gravitational, in which the mass flow is predetermined by the aperture diameter. In the second dosing system, the mass flow is determined by the travel speed of the wheel or conveyor belt. In this paper, we reviewed the literature on the properties and types of abrasives and reviewed various methods of measuring particle flow. In the experimental part of the thesis, we redesigned the dosing system with rotating wheel and installed an optical measuring system which we made during the thesis. In order to find the connection between the mass flow of abrasive and the intensity of the transmitted light, we measured both quantities at different rotational speeds of the wheel. The results of both quantities were presented with graphs which show the corellation between them. At the end an empirical equation was written with which we described the relation between the intensity of transmitted light and the mass flow of the abrasive.