The purpose of the recovery test is to determine the amount of time that is necessary for nonunidirectional cleanrooms or clean spaces and their systems to reach a specified steady state cleanliness level after a brief particle generation event within the clean space. It is not recommended for unidirectional airflow clean spaces nor in ISO Class 8 areas.

INSTRUMENTATION AND EQUIPMENT

• An aerosol generator or airflow visualization generator.
• A discrete particle counter. An aerosol photometer may be used as an option.

TEST PROCEDURES

• The number of points and the location of the points is to be determined.
• Ensure that the cleanroom HVAC systems are in operation.
• Set up the particle counter or photometer in accordance with the manufactures instructions.