The Density Determination of Small Solid Objects by a Simple Float Method-I

The density determination of a small solid object with a mass of only a few hundred milligrams is always a difficult and often an ellusive measurement. The advent of highly accurate hydrostatic weighing techniques and the density scale based on solid objects are utilized in a two liquid float method presented here that incorporates the advantages of this technology. The resulting measurement is an absolute determination of density with an uncertainty of 500 ppm and has a density range from 2.3 g/cm³ (silicon) to 21.5 g/cm³ (platinum). The instrument was used to measure the variation in the alloy density of nickel with respect to phosphorus content and to determine the density of optical fiber glass.