Tightness Test of Adsorption Filters
Adsorption filters are usually tested and certified ahead of delivery to the customer. In practice the installation of the filters can lead to leakages around the filter housing frame. This would cause a breakthrough of unfiltered air.
To measure the tightness of adsorption filters the tracer test is done according to US standard ASME N510-2007 (Testing of Nuclear Air Cleaning Systems). Upstream a Perfluorocarbon Tracer (PFT) is injected into the duct. At the same time the downstream air is analysed for a potential tracer concentration. PFT are used because they will be adsorbed on adsorption filters (e.g. activated charcoal, chemically treated adsorbents) whereas SF6 will go right through.