Stadler Form Roger Operating Instructions Manual page 43

during control runs. Statistical fluctuations are unavoidable, especially for a test like the one
described in this report. Several factors affect the outcome of the result. The sampling process and
the assay bring their own variability, and one must not forget that the virus, adapted to the ideal
'survival' environment of the human body, is aerosolized into an indoor space with certain physical
characteristics, where physical forces such as inertia and diffusion are applied on the viral particles
throughout the test duration (Hind 1999, U.S. EPA 2010, Lee et al. 2011). The aerosolised virus
may also adhere to the chamber surfaces after a certain period or move to areas of the chamber
with a lower or null concentration of virus, with a consequent variation in the number of particles
collected by the SKC BioSamplers over an extended period. In contrast, a 99.9% decrease in Inf A
levels is observed in the test runs 60 minutes after the air purifier is turned on.
100
50
0
0
Figure 5.3. The average percent reduction of Influenza A during test
and control runs (n=3)
ASCR092437
Percentage Reduction of Influenza A
Control
10 20 30
Time (minutes)
Page 8 of 10
Test
40 50 60
FM1201