The paper provides an overview of the design features of low-volume RDM rotary-disk mixers, as well as methods for evaluating the quality of mixer operation. It is shown that the most qualitative method is the photometric method. The described method is simple to carry out, quite accurate, allows you to determine many parameters such as the average particle size of the diperse phase, build a graph of the distribution of the number of particles by size, and much more. The dependence of the gap between the rotating and stationary disks on the size of the dispersed phase of the emulsion is determined. It is noted that an increase in the distance between the disks by 0.003 m will lead to an increase in the average particle size of the dispersed phase by approximately 3 times. It is obvious that an increase in the speed of rotation of the rotor, to maintain the quality of the mixture, with an increase in the gap between the disks, leads to an increase in the specific power consumption. In this regard, determining the degree of wear of the apparatus allows you to accurately and timely control the technological mode of processing the emulsion, minimizing operating and energy costs.