. Author manuscript; available in PMC: 2023 Sep 18.

Published in final edited form as: J Occup Environ Hyg. 2021 Jan 6;18(2):65–71. doi: 10.1080/15459624.2020.1864152

Table 2.

Arithmetic mean laboratory protection factors calculated over all exercises for each condition n = 3.

		Laboratory Protection Factor
Aerosol	Target Laboratory Protection Factor	PortaCount Mean ± St Dev	DC CPC Mean ± St Dev, p-value^*	DC OPC Mean ± St Dev, p-value^*
Ambient	100	81 ± 11	79 ± 4.1, 0.72	NA
	300	314 ± 27	218 ± 40, 0.02	NA
	1,000	1,920 ± 180	1,944 ± 274, 0.65	NA
Sodium chloride	100	89 ± 7.7	77 ± 3.4, 0.05	156 ± 21, 0.01
	300	370 ± 65	330 ± 52, 0.06	961 ± 54, 0.01
	1,000	1,550 ± 400	1,560 ± 270, 0.75	1,120 ± 100, 0.13
Incense	75	71 ± 8.3	54 ± 3.5, 0.03	68 ± 6.6, 0.20
	500	469 ± 297	351 ± 221, 0.05	1,180 ± 1,010, 0.14

p-value associated with a two-sided paired t-test under the null hypothesis that the mean laboratory protection factor measured with the DC instrument is equal to that of the PortaCount. Balded values represent evidence to reject the null hypothesis that the mean of the PortaCount is equal to the mean of the dual-channel instrument.