Kuchirka Y. Improved methods for improving the accuracy of the research results of the surface tension of liquids and device for its implementation

The thesis is devoted to development of improved methods for improving the accuracy of research results of the surface tension of liquids and apparatus to implement them using the three fixed capillaries with different inner radii and the distance between their lower ends. Known methods and instruments for measuring surface tension of liquids and surfactants solutions by method of maximum pressure in the bubble are analyzed. Presented improved methods for improving the accuracy of research results of the surface tension of liquids and surfactants solutions by using of maximum pressure in the bubble, taking into account nonsphericity of meniscus, the effect of air resistance of circuit elements on the obtained results, allow to strictly determine moment of maximum pressure in the process of measurement and does not require prior determination of the density of liquid and precision system for capillary immersion at a certain depth of fluid. Structural, functional, electrical, pneumatic circuit design and software of three-capillary device for the automated study of equilibrium and dynamic surface tension of liquids and surfactants solutions are presented. Conducted a metrological analysis and testing of three-capillary device that confirmed the efficiency of the developed methods and procedures, and have shown that the maximum error of the surface tension of liquids and surfactants solutions is within the calculated margin of error and not exceeding 0,5 mN/m.