Fractional Efficiency Filter Testing

High Efficiency Particulate Air (HEPA) or Ultra Low Penetration Air (ULPA) filters are used in medical facilities, laboratories, clean rooms and other places that require low concentrations of particles, bacteria, etc. These filters must meet high performance requirements that are specified in standards such as EN 1822, IEST RP-CC001/007, and MIL STD. The classification of HEPA and ULPA filters is based on their retention at the most penetrating particle size (MPPS).

The Automated Filter Tester Model 3160 determines the fractional filter efficiency at up to 20 different monodisperse submicrometer particle sizes. From the resulting fit through the data points the MPPS is obtained at the lowest filter efficiency value or highest penetration. The 3160 filter tester contains the state-of-the-art research grade electrostatic classifier and two latest generation condensation particle counters (CPCs) that simultaneously measure the upstream and downstream particle concentration. The measurement is fully automated and data can be exported to Excel or into a data base.

The 3160 can measure filter efficiencies up to 99.999999% (eight 9’s) and is typically used for filter development and optimization and quality control.