To measure these properties, the test piece is dried to constant mass, weighed
in air, and then transferred to an airtight dessicator, which is then evacuated until a
minimum pressure is reached. After the vacuumismaintained for a set time period,
the liquid is introduced until the specimens are completely covered and to ensure
open pores are filled. In most cases distilled water is used. However, for materials
that may hydrate or if assessing ex-service materials, which may contain watersoluble
corrosion products, then paraffin is preferable.