| Test | Recommended interval | |------|----------------------| | Airborne particle count | 6–12 months | | Filter leakage | 12 months | | Airflow velocity/volume | 12 months | | Pressurization | Continuous or monthly | | Recovery | On commissioning only (unless process changes) |
If budget is a concern, join a cleanroom user group (like the IEST – Institute of Environmental Sciences and Technology), which sometimes provides standard summaries. Iso 14644-3.pdf
Don’t just test “convenient” spots. Use the statistical grid method from ISO 14644-1 Annex A. For non-unidirectional airflow, include and air returns . For non-unidirectional airflow, include and air returns
While defines cleanliness classes (ISO Class 5, 7, etc.), Part 3 provides the step-by-step test methods to prove your cleanroom meets its class. It covers everything from airborne particle counting to recovery testing. For non-unidirectional airflow