Fig 1.
Picture of the practical mask test system with an aerosol applicator, a particle-tight, closed Plexiglas chamber with standardized test head, and a connected particle counter.
Fig 2.
A: Distribution of the mean pressure drop across filter fabrics for the mask types tested; B: Distribution of the mean filtration efficacies against aerosol particles sized 0.5 μm for the different tested mask types; C: Distribution of the as-worn filtration efficacies against aerosol particles sized 0.5 μm for the different mask types tested on the dummy head.
Fig 3.
As-worn Filtration efficacy in dependence of material filtration efficacy and pressure drop over filter material: A: As-worn filtration efficacies of the mask variants according to the material filtration efficacies; B: As-worn filtration efficacy according to the pressure drops over the filter material of each mask variant. The vertical and horizontal lines represent the mean values of the respective parameters of all masks tested in our study.
Fig 4.
Interaction between the filter effect of the material and the pressure drop across the material to the total filter performance on the dummy head.