The article substantiates the necessity of using a trier cleaning of barley in the presence of hard-to-separate weed impurities. Research equipment has been developed that provides continuous temporal and spatial control of the technological process of in-line cleaning of grain; developed a device for measuring the angle of natural slope of bulk materials. Studies of the dimensional characteristics of barley seeds and impurity components have been carried out. The interrelations of technological losses of grain of the main crop with the high-speed mode of operation and the angular position of the working edge of the output tray have been established. The dynamics of the release of impurity components from the grain mixture has been established for different values of the initial contamination and operating modes of the trier.