HEPA filter challenge test particles solve both the contamination and health risk problems associated with traditional DOP or oil-based filter test materials. The solid polystyrene microspheres are non-toxic and do not leave behind the oily residue that has traditionally been a serious contamination problem when testing filters already in place. As such, the particles are ideal for leak testing of filters already installed, where the highest degree of cleanliness is required. The 25mL aqueous concentrate of HEPA-Check is designed to be diluted into one gallon of clean water and then nebulized upstream from the filter to be tested. Nebulizing can be accomplished by using commercially available ultrasonic humidifiers. The single-use bottles ensure reproducible test conditions from site to site. The bottles are small and easy to transport. This product is available in the particle sizes traditionally associated with leak testing.
Microspheres are used to validate separation processes and ensure that filters are effectively removing unwanted particles. Polymer (non)-fluorescent microspheres are available from Thermo in sizes ranging from 0.02-1000µm and in distinctive fluorescent