Three tanks (diam. D = 200-400 mm) equipped with agitators with diams. related to D in 1:3 ratio were used sep. to measure the torque values of each agitator rotating at various frequencies during emptying tank when level of liq. was lowering close to upper surface of the rotating blades. On the basis, the quantitative increases of power consumption for the frequencies of the rotating agitator were detd. The highest values of mixing power were obsd. for low frequencies of rotating agitators.