The chemical industry requires the
mole to ensure that substances mix
at the ideal ratio for a reaction to be
The PTB supplies elemental solutions
which act as transfer standards for
calibration of industrial applications.
An optical emission spectrometer
compares the content of a specific
element in an unknown solution with
a primary reference solution of known
mass content.

[mol] ‘The MOLE is the amount
of substance of a system which con-
tains as many elementary entities as
there are atoms in 0.012 kilogram
of carbon 12.
When the mole is used, the elemen-
tary entities must be specified and
may be atoms, molecules, ions, elec-
trons, other particles, or specified
groups of such particles.’