Making A Measurement Introduction; Dry Powder Measurement Guidelines - Malvern Scirocco 2000 User Manual

Making
a measurement
Introduction
This chapter describes how to make a measurement using a Scirocco 2000. It cov-
ers:

Dry powder measurement guidelines

To obtain good repeatable dry powder measurements, ensure that the individual
particles are well dispersed in the air flow and that they are transported through the
measurement region at a suitable steady rate and concentration.
The energy used to disperse the particles is mainly controlled by the air pressure.
The concentration is largely determined by the rate at which powder is fed into the
air stream.
The ease of dispersion varies greatly between materials. Cohesive materials such as
magnesium stearate require much more dispersion energy than free flowing sam-
ples such as glass beads. The same material can vary with humidity, temperature
and degree of compaction.
However, do not always simply use the maximum dispersing energy. Many phar-
maceutical and food materials are fragile, as are substances like raw ceramics. Too
much energy will break up the primary particles.
Some cohesive materials may be compacted onto surfaces by high pressure and
flake off as agglomerates.
Scirocco 2000
Dry powder measurement guidelines.
Making a measurement – important differences from the procedure described
in Chapter 4 of the main User Manual.
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