The Alpaga 500 utilizes an
advanced image analysis program to determine the particle size distribution
based on up to 16 different measurement parameters. The most commonly employed
parameters are;
Size
The size distribution is
determined by computing the diameter of the largest inscribed disc that will fit
within a particle outline (see image below). This Algorithm was developed by the
researchers at Occhio and is exclusive to our instruments. It is extremely
robust and allows the software within the Alpaga 500 NANO to compute the real
size distribution curves with unrivaled accuracy.
Elongation
The size distribution is determined by computing the elongation parameter, which is one minus the ratio
of the rotational axis of a circumscribed ellipse.
Roundness
It is based on a very
accurate measurement of the local curvature of the particle. It takes into
account the fact that local asperities are more significant than very acute
ones. The Roundness Index is directly related to the amount of grinding in an
abrasion process.
Roughness
It is defined as a ratio
between the blunted surfaces and the entire surface of the grain. This
parameter measures the acute asperities for each particle.
Convexity
It is defined as one minus the ratio between the convex area and the real area
of the particle. It is based by calculating the convex shape of the particle as
defined by a virtual rubber band that is stretched around the perimeter of the
particle.
