This test code is for laboratory use in determining the operating characteristics of air cleaners. It refers specifically to laboratory testing of oil bath@ oil wetted@ dry and multistage air cleaners. Other types should follow this recommended practice wherever applicable. Multistage types should be evaluated as a complete assembly although@ if desired@ a component stage can be tested separately in accordance with its individual type. This code contains alternate procedures and permits prescribing certain specific conditions of a test. Therefore reported results of tests are not complete unless accompanied by statements@ where applicable@ of the specific conditions such as: (1) rated air flow@ (2) prescribed air flow@ (3) steady or variable airflow@ (4) fine or coarse dust@ (5) amount of dust@ and (6) maximum permissible restriction.