Testing Filters with Precision Means

A testing method for air filters closely mirrors the HEPA certification standard by using smoke from matches to create millions of fine particles around the 0.3 micron size. This size is crucial because it presents the greatest challenge for filtration. If a filter effectively captures this smoke, it is likely to trap larger particles, such as pollen and bacteria, as well as smaller particles including viruses, although viruses typically do not exist in the air individually.