The invention discloses a method for measuring liquid
surface tension by using a transparent
glass tube with scale marks, and relates to measurement of physical parameters. According to the technical scheme, the method comprises the following steps: arranging a
millimeter graduated scale on the outer side of the transparent
glass tube, wherein the scale mark 0 of the
millimeter graduated scale is positioned at a tube opening in one end of the transparent
glass tube; mounting a rubber suction
bulb which consists of an
airbag and an
airbag opening, tightly arranging the
airbag opening at one end, at which the scale mark 0 of the
millimeter graduated scale of the transparent glass tube is positioned, in a sleeving manner; compressing the airbag of the rubber suction
bulb, sucking part of liquid into the transparent glass tube to form a
liquid column, and vertically fixing the transparent glass tube on a bracket; removing the rubber suction
bulb at the lower end of the transparent glass tube, so that a
liquid column in the transparent glass tube moves downwards; stretching the open end of a liquid delivery tube into the
liquid column in the transparent glass tube, slowly injecting the liquid into the transparent glass tube till the height of the liquid column does not rise any more, and recording the height h, wherein the
surface tension coefficient sigma of the liquid is equal to d*h*rho*g / 4. The method has the beneficial effect that the change of the
surface tension inside the glass tube and at the tube opening can be clearly observed.