The commercial value of untreated wool is determined by its quality, which is assessed by a standard assessment of characteristics including average fiber diameter, coefficient of variation, staple characteristics, coefficient of variation in fineness and fiber yield. The characteristics of the wool are important in determining the price, the quality of the manufactured products and the end use. The development and availability of new technologies and equipment has made it possible to objectively measure many more characteristics of unprocessed wool than was possible in the past. In article the results of researches on studying the influence of mass sample frequency on the results of woolen fiber fineness measurements on the acoustic device are presented