Since 1 April 2015 our cleanroom has been classified in accordance with ISO 14644-1 Class 6 and laminar flow benches in accordance with ISO 14644-1 Class 5. (The lower the class number, the fewer particles of a certain size per unit of air.)
The installation of a new, separate goods handling unit and personnel sluice has led to a reduction of dust particles in the area by a factor of 10 and enabled a higher cleanliness rating. The cleanliness rating used to be indicated using the US Federal Standard 209 rating. You may still be familiar with this standard, which refers to a Class 10,000 or Class 1000 cleanroom. So a classification in accordance with ISO 14644-1 Class 6 corresponds to the old Fed. Std 209 Class 1000. However, since 2003 the Fed. Std 209 standard has no longer been used in official documentation.
Moreover the upgraded cleanroom has a vacuum cleaning system that enables dust particles on the outside of the instruments to be removed. The surface is illuminated with a UVA lamp, rendering dust particles visible. A special vacuum cleaner is used to remove the dust particles and then the entire unit is packed in the goods handling vacuum.