Improvements on full-profile fitting pendent drop method used for surface tension measurement

摘要

Surface tension is an important parameter of liquid surface properties. In order to improve the accuracy and stability of the parameter measurement, full-profile fitting pendent drop method is utilized in this article, and algorithm to determine the initial value in two-dimensional optimization is improved. Moreover, the error function is modified via a weighting factor, which reduces the influence of droplet profile deviation point to the surface tension measurement. At 25°C and a standard atmospheric pressure, the improved full-profile fitting method is used to calculate the surface tension of water and ethanol. The final results show that the stability and repeatability of the improved full-profile fitting pendent drop method is much better than the previous method, which effectively verifies the feasibility and superiority of the improved method.