The monograph summarizes the results of the authors' research related to the creation and development of new aerohydrodynamic principles aimed at the implementation of capillary methods for measuring the viscosity of liquids. The questions of application of aerohydrodynamic principles of realization of capillary methods of viscosity measurement are considered, the influence of a number of uncontrolled quantities on the result of viscosity measurement is analyzed. Descriptions of structures and principle of action of devices of viscosity measurement, as well as units of compensation and correction of influence of uncontrolled quantities on the measurement process are given. For specialists engaged in the development, operation and research of methods and devices of control of substances in various industries