Figure 2
From: Filtration efficiency of medical and community face masks using viral and bacterial bioaerosols
(Left) Schematic of a six-stage viable ACI (yellow). Airborne particles (red) are aspirated inside the cascad e impactor with a 28.3 L/min flow rate (blue arrow). Each stage of the ACI contains a Petri dish (green) filled with nutrient agar (brown). (Right) Images of a BFE test for each impaction stage for the three mask types (MFM, CFM1 and CFM2; MFM refers to medical face mask, CFM refers to community face mask). d50 refers to the cut-off size of the cascade impactor stage. The colonies on the Petri dishes were observed using an HD colony counter.
