Measurement techniques for characterization of
particle shape have through time been developed
within many areas of application, in basic research
and for industrial purposes. For example, sedimentologists are interested in grain shape and
grain-size distributions for characterization of
different deposits as the shape and size distribu-
tions are functions of the genesis. There is also a
wide range of industrial applications where mineral
fillers are added to different products, which should
fulfil certain consistency requirements, e.g. paint,
cosmetics, asphalt, and concrete.
The classical method for measuring grain-size
distributions is by sieving (proposed European
standard EN 933-1, 1992). However, the method
is not very suitable for the fine fractions. The
reasons for this are the difficulties for fine material
to pass the masks in the sieves and the amount of
particles in relation to the sieve area. Further,
normal sieve analysis only gives a rough measure
of the width of the particles. This does not give
all data needed for a good characterization. There
are many more geometrical parameters that can
be named and measurement that can be made.
Geometry of grains is traditionally expressed as
flakiness (the ratio width–thickness) and elongation (the ratio length–thickness). There are
different analysis methods to measure these form
attributes, such as methods DIN 52 114, BS 812 (1975) and European standard EN 933-4 (1993), which measure the properties of separate grains
and methods BS 812:105.1 (1989) and European
standard EN 933-3 (1996) which measure the
properties of grain amounts. However these methods are not suited to analyse fine materials.