No direct correlation between the cleanroom class and surface cleanliness

In a cleanroom, the air cleanliness is classified for particles from 0,1 to 5 µm. These particles stay airborne and can be removed with the cleanroom installation. Particles larger than 5 µm tend to deposit depending on their size, mass, shape and momentum. Particles get momentum by air currents and turbulence from people and moving objects. Above the 25 µm field data proves that there is no direct correlation between cleanroom class and surface cleanliness which changes by particle deposition.

Particles > 25 µm will not be removed by the ventilation system

Particle deposition monitoring data in ISO 5 to 8 cleanrooms show a dramatic change in the deposition rate of particles > 25 µm. Tests prove these particles are not removed by the ventilation system. They can only be removed by cleaning.

APMON field results: 24/7, valueble data

In many applications cleanroom users and managers are surprised by the measured particle deposition rate levels. These are in most cases much higher than expected. Often particles ≥ 100 µm determine the particle deposition rate level.

The real-time data show the moments of deposition, often when people and/or goods are entering the cleanroom. But also, when work is prepared or when people come together in the cleanroom.

The particle size distribution helps to decide where improvements should be made: cleaning (cleanroom, work benches, tools and equipment), people (number, garments, changing, working methods) and cleanroom installation.