The LASAIR II series is recommended. They include firmware that automatically generates cleanroom certification reports for ISO, EC GMP, British Standards, and FS-209e.
If your cleanroom meets ISO Class 3 (FS-209e Class 1) or greater, the Lasair II 310/510 may be used. Plus, the Lasair II 310/510 may be used to demonstrate continued compliance.
If your cleanroom meets ISO Class 1-2 (no FS-209e class exists), the LASAIR II - 110 is the only choice (due to the ability to monitor 0.1 µm particle limits. Plus, the Lasair II 110 may be used to re-certify all classes of cleanrooms.
For more information read Selecting Airborne-Particle Counters for ISO Certification of Cleanrooms .