Regardes mon premier post pour la filtration des HEPA, il est plus facile d'attraper les particules inférieur à 0,1µm qu'à 0,3µm (je remet le lien aussi : http://www.globalspec.com/learnmore/manufacturing_process_equipment/filtration_separation_products/hepa_filters_ulpa_filters )
Understanding these three methods makes it clear why particles around 0.3 micrometers are most difficult to filter. Particles less than 0.1 micrometers are easily trapped due to diffusion while particles larger than 0.4 micrometers are trapped by inertial impaction. Particles between 0.1 and 0.4 μm are therefore too large for effective diffusion and too small for inertial impaction and efficient interception, so that the filter's efficiency drops within this range. By specifying a HEPA filter's efficiency at 0.3 μm, standards bodies are really describing a variant of the filter's minimum efficiency.
A 0,1µm tu as une filtration quasi à 100% (ça doit être du 99,999%) alors qu'à 0,3 tu descends à 99,95% en gros.