Filter performance: The filter is evaluated to measure the reduction in concentrations of specific aerosols in air that passes through the filter.
Test agent: The aerosol that is generated during the filter performance test.
Total inward leakage (TIL): The amount of a specific aerosol that enters the tested respirator face piece via both filter penetration and faceseal leakage, while a wearer performs a series of exercises in a test chamber.
Inward leakage (IL): The amount of a specific aerosol that enters the tested respirator facepiece, while a wearer performs normal breathing for 3 minutes
in a test chamber. The test aerosol size (count median diameter) is about 0.5 micro meter. Pressure drop: The resistance air is subjected to as it moves through a medium, such as a respirator filter.