They found that particles with average diameters lower than 25–50 µm were removed at 80% efficiency, whereas particles bigger than 50 µm were only removed at 40% efficiency.
Atopouse que as partículas cun diámetro medio menor que 25-50 µm se eliminaban cunha eficacia do 80%, mentres que con partículas con diámetros maiores que 50 µm soamente se alcanzaban eficacias do 40%.