Particle counters display readings in two columns: differential (depicted by ∆ delta) and cumulative (depicted by ∑ sigma).
The differential total shows the counts which are at least that size in diameter and up to, but not including the next size.
The cumulative total shows the amount of particles that were found at that size and greater.
Discover the different classes within the cleanroom ISO standards and their Federal Standard and GMP...Read more
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