11 – WHICH IS THE CORRECT VOLUME OF AIR TO BE ASPIRATED BY AN ACTIVE AIR SAMPLER?

The volume depends from the expected number of micro-organisms present in the environment under control.

The number of cfu /plate should easy to count (not more than about 150 cfu) and therefore it is necessary to establish the volume to be aspirated (e.g.: 300 – 500 – 1000 litres).

The obtained result should be then related to 1000 litres of air (1 cubic metre of air).