Table 3.5.

Penetration of ULPA filter made in China and the USA

Filtration velocity/(cm/s)	Chinese filter media		UK filter media
	Particle size/μm		Particle size/μm
	0.13	0.29	0.13	0.29
7.0	3.27 × 10−9	1.91 × 10−9	2.53 × 10−5	1.32 × 10−5
1.50	5.1 × 10−8	1.25 × 10−8	–	–