Table 1.

Average RP (ratio of particle number concentration while PIPER moving to concentration during reference period; Equations 1 and 2) over all 26 samples. The standard deviation of RP was computed for each minute, size channel, sampler, and floor type across all homes.

Sampler	Floor type	0.3 to 0.5 μm	0.5 to 1.0 μm	1.0 to 2.5 μm	2.5 to 5.0 μm	5.0 to 10.0 μm	>10.0 μm
Stationary	Bare floor	0.936 ± 0.238	0.948 ± 0.340	0.985 ± 0.391	1.03 ± 0.495	1.12 ± 0.551	1.25 ± 0.651
	Carpet	0.856 ± 0.230	0.924 ± 0.283	0.947 ± 0.226	1.02 ± 0.301	1.20 ± 0.482	1.52 ± 0.783
PIPER	Bare floor	0.985 ± 0.231	1.02 ± 0.367	1.05 ± 0.422	1.13 ± 0.629	1.22 ± 0.814	1.38 ± 1.26
	Carpet	0.970 ± 0.404	1.05 ± 0.659	1.05 ± 0.463	1.37 ± 1.06	1.88 ± 1.93	2.22 ± 1.78