The cotton-wool pad employed in the measurement of integrity
should consist of new, undyed and soft cotton fibres, 20 mm thick
x 100 mm square, and should weigh between 3 g and 4 g. It should be
conditioned prior to use by drying in an oven at 100 ± 5°C
for at least 30 min. After drying, it should be allowed to cool to
ambient temperature within a desiccator, where it may be stored until
needed to be used. For use it should be mounted in a wire frame, as
shown in Figure 10, provided
with a handle.
Figure 10 Cotton pad holder