N. 99 - Microbial Air Sampling Collection Efficiency – The number of Stokes

The efficacy of microbial air sampling collection by impact on agar samplers is characterized by a number without dimensions, called the “number of Stokes”. This number, called (d50), indicates the value that refers to the aerodynamic diameter of particulate that are collected by 50%. Hinds (1982) considers the value (d50) as the diameter of particulates that have a bigger diameter and theoretically are all collected.