Dry powders are often stored where they may be subjected to vibrations, such
as in buildings where there is heavy machinery, and on vehicles or ships. It is
possible that certain amplitudes and frequencies of vibration can cause consolidation
or "packing" of the powder which in turn will have an adverse effect on the
discharge of the extinguisher when it comes to be used.
A review of the levels of vibrations likely to be encountered in various
locations has been made, in order to provide information for use when designing
experiments to investigate the "packing" of powders by vibrations.