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.


Related articles

The Importance of Cleanroom Validation

Cleanroom validation offers ISO compliance and peace of mind.

Read more

7 Steps to a Cleaner Environment

The risk to a finished products sterility increases, as operator activities increase within an asept...

Read more

Cleanroom Classifications

Discover the different classes within the cleanroom ISO standards and their Federal Standard and GMP...

Read more