The particulate cleanliness of the air

Hi
The particulate cleanliness of the air :how to define the number of sampling points?
La propreté particulaire de l’air:comment définir le nombre des points de prélèvement?

Refer to “ISO 14644-1 Classification of air cleanliness by particle concentration” to define the sampling points in classified area.

Refer ISO 14644-1:2015 guideline