Mask characteristics and mask adapter
®, CM
To compare breathing resistances and filter efficiencies, the three masks were tested on a “Sheffield head” according to the European Standard EN 149 (applied solely to CE certification of FFP masks)In all modules, participants wore in randomized order (1) NM, (2) SM (Typ II, MedicalCare & Serve industry®, Wilfried Rosbach GmbH, Willich, Germany), (3) CM (van Laack® GmbH, Mönchengladbach, Germany) and (4) FFP2 (Dräger X-plore® 1920 NR D, Dräger® Safety AG, Lübeck, Germany). For body plethysmography (Fig. 