US EPA

3012605 

Journal Article 

ADVANCED FILTER TESTER FOR SIZE RESOLVED PENETRATION MEASUREMENTS 

Ondracek, J; Zikova, N; Zdimal, V; TANGER Ltd 

2014 

718-722 

WOS:000352070900128 

Aerosol filtration is the most widely used process to capture aerosol particles. It is used in various applications throughout the different areas of interest (emissions cleaning, occupation safety and health, air-conditioning, etc.). In most of these applications, it is useful to have information about penetration, or filtration efficiency, of the chosen filtration material. Information available from filter manufactures, a background of a decision on which filter to use for the specific purposes, is usually not detailed enough. There are well-known standards describing how to perform the testing of filter efficiency, such as EN 1822 for HEPA and ULPA filters; EN 143 and 149 for respirators. Nevertheless, all these tests give only limited and sometimes even misleading information about penetration of tested filter material (giving information only about total penetration; using polydisperse aerosol with mode at about 300 nm). Therefore, new, fully controlled filter testing instrument was developed and thoroughly tested, providing a size-dependent penetration; proving a very good precision and reproducibility of the results. Using this instrument we have measured several commercial filter materials including standard filters (Whatmann, Milipore, Pall) and personal respirators (e.g. 3M). For personal respirators the maximum penetration was ranging between units and tens of percent, while the pressure drops were usually in hundreds of Pa. In the case of standard filters the maximum penetrations were in orders of tenths to hundredths of percent having pressure drops in orders of kPa units. The most penetrating particle sizes were in vast majority of cases bellow 100 nm. 

filter tester; size resolved penetration; filters; respirators