An examination of sentis' method and extensions for the determination of the surface tension of liquids

Sentis' method for the determination of the surface tension of liquids is examined. The method involves the measurement of the maximum diameter of a pendent drop and a height which corresponds to the hydrostatic pressure difference across the interface at the base of the drop. Using a table derived from computed pendent drop meridian curves rather than Sentis' original equations, the surface tension of liquids can be obtained with an accuracy comparable to, or even greater than, that obtainable by conventional capillary rise and pendent drop methods. It is shown that simplifying assumptions used by Sentis result in errors which are negligible if the drop size is sufficiently small. Modifications of the original method are outlined. These suggested alternatives involve easily made measurements from which surface tensions can be calculated using a table. Various aspects of pendent drop stability are discussed in the course of the description of these new methods.