mask fit

In this work we investigate the bidirectional filtration efficiencies of respirators, such as FFP2 masks and medical masks, under cyclic breathing and different fits. We developed a test bench, which consists of a test chamber with an artificial head, and which is connected to a specially developed artificial breathing function. The exhalation filtration performance of masks can be evaluated by exhaling particle-laden air into the test chamber. Similarly, the inhalation filtration performance can be evaluated by inhalation of particle-laden air from the test chamber.