What does the air purifier test video show? At the start of the video, the air purifier is turned on and a particle counter displays two sets of numbers. The number to the left is for particles between 0.3 to 0.5 microns range. These are the smallest and hardest to remove. The number to the right is a measurement of particles larger than 1 micron (most allergens).

The particle counter takes 30 to 40 seconds to calibrate. So the numbers you see at the end of the videos reflect the air that is coming out.

Ideally, the numbers should decrease with this test. The closer you get to zero (ie 100% particles removed)the cleaner the air is coming out of the air purifier.

Results with a laser particle counter showing 100% of particles removed.