Granular particles may be spherical, more or less round but not spherical, elliptical in a general way, flat or flaky, fibrous, rod- like, or irregular without fitting into any particular shape category. A shape analyzer should allow for all these different classes of particle shape.
With generally round or elliptical particles, circularity, aspect ratio and smoothness are important. With straight rods or needles the widths, lengths, and aspect ratios are what we need to know. With fibers, we want the straightened width and length, and the degree of curl. Thin flakes can be analyzed with different shape models, depending on their general shape. With crystals and flakes, where sides are faceted, software can fit irregular polygons to particles and quantize the polygon parameters.
A particle shape analyzer can accumulate histogram-type data on many shape parameters. The Particle Insight allows for six shape categories or models and several measurement parameters within each model. The six shape models are
Ellipse model (6 measures)
Rectangle model (4 measures)
Polygon model (3 measures)
Fiber model (4 measures)
Irregular model (4 measures)
See the list of available measures for all the shape models.
See Measure Definitions for a more complete description of the measures.