Measurement of surface tension using a vertical cone

Abstract

The surface tension may be determined from the maximum force, ƒ_maxg exerted on a vertical cone as it is pulled from a liquid interface using σ=gΔρ^⅓(ƒ_max/F_max)^⅔ in which F_max is a unique function of the cone angle when the liquid wets the surface of the cone. Values of F_max are calculated from a force balance on the cone, taking into account the known shape of the liquid interface. The surface tension of several liquids has been obtained using quartz cones having half-angles of 30° and 45° and good agreement obtained with the accepted values.