Home-made vacuum system for calculating the apparent density of solid materials

Abstract

Home-made vacuum system was set up for measuring the apparent density of solid materials or more accurately the volume of solid materials. The volume of samples was calculated based on the method of gas displacement and the inversely proportional relationship between the absolute pressure and volume of a gas known as Boyle's Law, pV=k. Nitrogen gas was used as a probe and the measurement was done at room temperature and at low pressure in order to minimize the effect of the compressibility factor of the gas. The system was calibrated by stainless steel ball with the error was less than 5%. The apparent density of hollow stainless steel (non-porous), rice (irregularly shaped) and Clorets sweet (regularly shaped) were 7.61, 1.60 and 1.23 g/mL, respectively. Whereas the apparent density of porous powdered materials were 1.34, 1.26 and 1.67 g/mL for Pt/SO4 2--Al2O3, WO3-ZrO2 and Portland Cement, respectively. The experimental error for measuring the solid volume was less than 5%.