Metrolab Blog

Particle counting – Knowledge Hub

Did you know?* “Vs ; Single Sample Volume”

ISO 14644-1:2015 defines minimum air volume to be sampled as a single sample volume (Vs);


Vs is the minimum single sample volume per location, expressed in liters,

Cn,m is the class limit (number of particles per cubic meter) for the largest considered particle size specified for the relevant class;

20 is the number of particles that could be counted if the particle concentration were at the class limit.
Depending on the cleanroom ISO Class (N; 1 to 9) a single sample volume is changing.

The table shows Single Sample Volume (Vs) for Targeted Class and particles equal to and greater than the considered sizes (Liters) as per ISO 14644-1:2015


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