The paper presents the results of research conducted within regular inspections of the testing station 001-RH at the Faculty of Agrobiotechnical Sciences in Osijek. The examination was performed as a pre-test to determine the correctness of technical systems for the application of plant protection products. The significance of the correctness of such systems lies in their economy and efficiency of application, as well as in the aspect of environmental care. Furthermore, this examination provided manufacturers with insights into potential errors or malfunctions that need to be rectified. The focus was primarily on testing the performance of nozzles, specifically measuring their flow rates at a pressure of 3 bars. The examination revealed that out of the total of 293 nozzles considered in this pre-test, deviations of more than 10% were measured in 37 nozzles, which is approximately 12.5%, while deviations greater than 15% were observed in only 2 nozzles, approximately 0.7%. Out of the 17 sprayers, 7 were equipped with a set of fully functional nozzles, all of which provided acceptable flow rates. Nozzles that displayed significant deviations from the desired values were replaced with functional ones. Since the obtained values are specific to each technical system and depend primarily on the age and operation of the machine, as well as the number and flow rates of the nozzles, it was not possible to compare the obtained values. Subsequently, the sprayers were brought to a state of proper functioning, meeting the minimum flow rate criteria at a pressure of 3 bars during operation. Ultimately, manufacturers were issued a certification, in the form of a label, confirming the correctness of their equipment for the next 3 years along with the acquired knowledge.