This work intended to evaluate the technical performance of a gun sprinkler of the type turbine model "Mercury" manufactured by Società Hidromecânica Emiliana (SIME) in Italy and imported by the Brazilian company Metal Lavras Ltda. The study was developed with three nozzles (16, 20 and 22 mm), with service pressures of 250, 300, 350, 400, 450 and 500 kPa by the radial method test, with the purpose of verifying the influence of these parameters on distribution uniformity, application intensity, medium diameter of drops, reach radius and rotation uniformity. Tables with values of average precipitation intensity, recommended spacing and values of uniformity coefficient were created, overcoming a deficiency demonstrated by manufacturer's catalog. It was verified that the medium diameter of drops increased with the decrease of the service pressure, and its behavior did not adapt to the classic model of gradual increase of the medium diameter of drops because several diameters were verified along of the wet radius. The potential equation was adjusted to the data of discharge versus pressure, with the nozzle of 16 mm being the most susceptible to the variations of service pressure. The water distribution profile followed the type "doughnut" and rectangular. The data of rotation uniformity demonstrated the efficiency of the rotation system of the turbine type. It was recommended the use of the tables produced, in substitution to the manufacturer's catalog.
gun sprinkler; turbine; evaluation