This is the most established method used to determine surface tension, in this method the presence of surface tension of the liquid/gas interface involves catching the fluid in a thin tube, usually a capillary formed from glass, and this occurrence was used to determine the surface tension of the liquid. For this reason, a thin round capillary is inserted deep into the liquid already tested. If the liquid molecules have a strong interaction between the capillary walls, the capillary end is deeply in solution. The height reached by the liquid in a capillary is associated with the surface tension.