User manual

EMB-V-BA-e-1321
17
ρ =
A
A-B
o
ρ
ρ =
m
V
8 Density determination
8.1 Principle of Density Determination
Three physical magnitudes are the volume and the mass of bodies as well as the
density of matter. In density mass and volume are related.
Density [ ρ ] is the relation of mass [ m ] to volume [ V ].
SI-unit of density is kilogram divided by cubic meter (kg/m³). 1 kg/m³ equals the
density of a homogenous body that, for a mass of 1 kg, has the volume of 1 m³.
Additional frequently applied units include:
1
g
cm
3
,
1
kg
m
3
,
1
g
l
The determination of the density is based on the "Archimedean Principle", which
states that every object that is dipped into a liquid is as much lighter as the liquid that
it displaces.
Thus, density is calculated according to the formulae below:
 Density determination of solids
Our balances enable weighing of solids in air [ A ] as well as water [ B ]. If the density
of the buoyancy medium is known [ ρ
o
] the density of the solid [ ρ ] is calculated as
follows:
ρ = density of sample
A = weight of the sample in air
B = weight of the sample in the aid liquid
ρ
o
= density of the aid liquid