Table 1.

Average surface potential (SP) and particle removal efficiency (PRE) of FFP2 and FFP3 FFRs at different irradiation doses [24]. The quoted uncertainties represent the observed standard deviation. There is only one measurement of recharged FFRs presented in the table due to different SP values of each recharged FFRs.

* - filters that were recharged with a negative surface potential, ** - filters that were recharged with a positive surface potential.

	Dose (kGy)	Surface Potential (kV)		Particle removal efficiency (%)
		Gamma	E-beam	Gamma	E-beam
	0	−0.4 ± 0.1		$99.5{}_{-0.9}^{+0.5}$
FFP2	10 20 50 20* 20**	|SP| ˂ 0.1 |SP| ˂ 0.1 −0.2 ± 0.2 −2.3 ± 0.3 2.1 ± 0.2	|SP| ˂ 0.1 |SP| ˂ 0.1 |SP| ˂ 0.1 −2.3 ± 0.3 2.1 ± 0.2	83.4 ± 0.8 87 ± 10 87 ± 1 99.4 98.5	84 ± 2 82 ± 2 86 ± 4 98.7 97.9
	0	−0.6 ± 0.2		${100}_{-0.05}^{+0.0}$
FFP3	10 20 50 20* 20**	|SP| ˂ 0.1 |SP| ˂ 0.1 |SP| ˂ 0.1 −2.8 ± 0.3 1.9 ± 0.2	|SP| ˂ 0.1 |SP| ˂ 0.1 |SP| ˂ 0.1 −2.2 ± 0.3 1.9 ± 0.2	90 ± 2 91 ± 2 91 ± 2 97.1 98.7	92 ± 1 91 ± 1 91 ± 3 99.7 99.7