Accuracy of hard particles concentration measurement is affected by different influence quantities. Main of them are discussed, analyzed and introduced in the theses. The aim of the investigation was to measure particles concentration with different instruments in real conditions, to compare and analyze the results, to determine coefficients showing difference of different instruments, to compare simulated and experimental researches results, to estimate measuring errors. Final master work contents of five chapters. In first review chapter measuring methods of hard particles concentration, demand of these measurings, implements and their characteristics were considered. Also maesuring standards and normatives were considered. In second chapter measuring methodology and equipements are described. The widely used mass method was compared with optical and vibro methods in this work. Possibilities of different measuring methods practice were evaluated, when sampling air flow velocity was 1 l/min, 2 l/min, 3 l/min, 5 l/min ir 10 l/min. In third chapter air flow in arcuated duct was simulated on real experimental data. Reliance of hard particles concentration on position of measuring point in duct cross-section was rated. In fourth chapter experimental measuring and simulation results were compared. In fifth chapter statistical analysis of measuring data was done. Random and systematic errors of particles concentration measuring were estimated. It could be staded that optical and... [to full text]