The required clean room conditions for the aseptic processes are supplied by the HEPA - high efficient particulate air - filter system of the Isolator. For good manufacturing practices cleanroom Class A (equivalent to ISO 5) a specified maximum number of micro-organisms (colony forming units, cfu) and particles are allowed per m3 of volume. Isolators normally utilise an unidirectional - laminar - air flow filtered by HEPA Filter to comply with these cleanroom conditions.
Calibration of the flow rate of air through the sampler is important to be sure that the collected micro-organisms are associated to the correct volume. Therefore, the air flow has to be measured accurately. The calibration process has to be conducted on a regular basis.