The large variation that exists within results of e.g. hardness devices (Table 3) is
partly due to the fundamental misunderstanding of breaking behaviour of agglomerates
of biological origin. Analysis of pellet hardness figures with data from five experiments
confirmed this large variation (Table 5). As shown by Fell and Newton (19701,
empirical modification would permit the decrease of the large variation that can be
found in fragmentation-type measurements that employ diametrical compression such as
the Kahl test, Schleuniger test and (partly) the Kramer shear press. Careful application
of the standard conditions under which the device is operated is therefore recommended.
It may be relevant to adjust these standard conditions, in particular for those devices
which show a large variation in pellet quality results.