Particle counters display readings in two columns: cumulative (often depicted by ∑ sigma) and differential (often depicted by ∆ delta).
The cumulative total shows the amount of particles that were found at that size and greater.
The differential total shows the counts which are at least that size in diameter and up to, but not including the next size.
ISO 14644-1:2015 Compliant Cleanroom Monitoring
We discuss the changes to sampling procedures and monitoring plans for cleanrooms and clean zones in...Read more
How Big is a Micron?
How often do we actually think about how small a micron actually is?Read more
Discover the different classes within the cleanroom ISO standards and their Federal Standard and GMP...Read more