ASTM D4948-89 (2022) Standard Test Method for the Determination of Upper Liquids Separated from Tack Liquids specifies a method for the measurement of upper liquids separated from tack liquids. This test is suitable for situations where the upper layer material of the liquid needs to be analyzed after delamination under conditions such as standing or centrifugation, and is generally used in liquid formulation studies in the chemical, food, Coating, and other industries. This method ensures accurate determination of the amount and properties of the separated upper layer liquid without interfering with the Miscellaneous material through standardized steps. Through this test, the rheological performance, dispersion and Stability of liquid components can be effectively evaluated, which provides important data support for product quality control and optimization.