Introduction: It is a crumbly plug of the bottle, the bottle is adjusted to the viscosity of the liquid density measurement, the cork for solid, the glass stopper is flat, a small hole through the opening is about 1.5mm or so, for the excess liquid overflow through a small hole, bottle wall is thin, can accurately determine the volume of the glass or metal container of equipment, simply by weighing of density and the volume of liquid can be measured the volume of the justified.