The ALF 114 Filter Test System has been developed especially for air filter testing according to standards ISO 16890, EN 779 and ASHRAE 52.2. Topas can fall back to a long-standing expertise in the field of construction and installing of filter test systems. Since 1995 we have been developing, manufacturing, and installing particle filtration test rigs compliant to standards and user-defined specifications. Test parameters include differential pressure drop, gravimetric efficiency, fractional efficiency and dust holding capacity.