This standard specifies the method for determining the surface tension of liquids using the pull-up liquid film method. It is applicable to measuring the surface tension of surfactant solutions, organic solutions, mixtures containing multiple surfactants, and pure liquids. The core principle of this method involves measuring the maximum force required to slowly and vertically pull a ring of specific material (such as platinum) from the liquid surface until the liquid film formed beneath it ruptures, thereby calculating the surface tension of the liquid under test. The implementation of this method requires the use of a specialized surface tensiometer, which typically automates the processes of liquid film lifting, force measurement, and data calculation. It also includes features such as temperature control to ensure the accuracy and reliability of test results.