23Warning!Decontaminate the unit before measuring the upstream concentration of aerosol in a contaminatedplenum.3. Perform filter leak test per NSF 49.4. Repair leaks as required.Airflow Smoke Pattern TestWe recommend that qualified technicians verify the direction of airflow within your cabinet before thecabinet is used. The direction of airflow should also be verified at prescribed intervals as specified by anindustrial hygienist, safety officer or other qualified person. NSF International details the steps forperforming the airflow smoke pattern test in their Standard 49.Cabinet Integrity TestThe sealing integrity of your cabinet was tested at our factory before shipment to ensure that the welds,gasketed seams and hardware were free of detectable leaks. Since these items may become damaged intransport, we recommend that they be re-tested, by qualified technicians, before the cabinet is used. Thecabinet integrity test should also be performed at installation, relocation and at prescribed intervals asspecified by an industrial hygienist, safety officer or other qualified person. NSF International details thesteps for performing the cabinet integrity test in their Standard 49.Cabinet Integrity Test Procedure:1. Decontaminate the cabinet if it has been used.2. Disconnect cabinet from electrical source.3. Shut off all gas, air and/or vacuum ports.4. Seal off the exhaust opening by taping around the external damper and the slot, or by taping a piece ofcardboard or plastic over the opening. If the cabinet is connected to an external exhaust, close the gastight damper or remove ductwork to allow sealing.5. Remove the light canopy, the electrical panel and the window tracks.6. Seal the front window opening by taping a piece of heavy gauge plastic around the perimeter of theopening.Warning!Decontaminate the unit before pressurizing, if it has contaminated plenums.7. Perform cabinet integrity test per NSF 49.8. Repair leaks, as necessary.9. Restore the cabinet to operating status. Be sure to remove the sealing material, clean the cabinet andreassemble all components.