What is Difference Between Specific Gravity and Density and detail of their units?
Specific gravity is a dimensionless quantity (see below). Specific gravity is an expression of the weight of a substance relative to the weight of an equal volume of water. Water has a specific gravity of one. Substances with a specific gravity greater than one are denser than water, and so (ignoring surface tension effects) will sink in it, and those with a specific gravity of less than one are less dense than water, and so will float in it. Specific gravity is a special case of, or in some usages synonymous with, relative density, with the latter term often preferred in modern scientific writing. The use of specific gravity is discouraged in applications requiring high precision. Actual density, in dimensions of mass per unit volume, is preferred in such cases. Specific gravity, SG, is expressed mathematically as: \mbox{SG} = \frac{\rho_\mathrm{substance}}{\rho_{\ma… where \rho_\mathrm{substance}\, is the density of the substance, and \rho_{\mathrm{H}_2\mathrm{O}} is the density of w
