In this paper we present laboratory equipment for illustrating the operation of spraying nozzles. It is also suitable for studying the basic processes of spraying and for measuring and evaluating the methods used in the control of sprayers. The equipment allows the monitoring of the spray film formed by the nozzles, measuring the yield of the nozzle and determining the size of the droplets formed. In the dissertation, we explore the factors influencing the droplet size. We compare the average diameter of droplets formed by the three hydraulic principle nozzles. Based on the average droplet diameters, the operation of the spray nozzles is analyzed and conclusions are drawn.