Methods for Determining Specific Gravity/Density
The Archimedean principle is applied for determining the specific gravity of a solid
with this measuring device:
A solid immersed in a liquid is exposed to the force of buoyancy. The value of
this force is the same as that of the weight of the liquid displaced by the volume
of the solid.
With a hydrostatic balance which enables you to weigh a solid in air as well as
in water, it is possible to:
determine the
specific gravity of a solid
if the density of the liquid causing
buoyancy is known:
W (a) ·
ρ
(fl)
ρ
=
W (a) – W (fl)
or
determine the
density of a liquid
if the volume of the immersed solid is known:
G
ρ
(fl) =
V
where:
ρ
= specific gravity of the solid
ρ
(fl) = density of the liquid
W (a) = weight of the solid in air
W (fl) = weight of the solid in liquid
G
= buoyancy of the immersed solid
V
= volume of the solid
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