6Work area lightingThe work area is illuminated by two external fluorescent lamps which provide a minimum of 100 foot-candles of light at the work surface.Drain PanThe drain pan is designed with 7/16” radius in all four bottom corners to facilitate cleaning anddisinfection. The work surface supports have been designed to be removable for easy cleaning and toallow clear unobstructed access to the whole drain pan area during the cleaning procedure. Drainage isprovided by a 3/8” diameter stainless steel ball valve located at the bottom of the drain pan.Air balance adjustmentsAir balancing can be done by either of the following methods. However, it should be done only by atechnician with proper training and equipment (see “The Airflow Balance in Section IV, On-SiteChecks and Maintenance).• A speed controller adjusts for minor voltage differences and filter loading.• An adjustable external damper compensates for supply and intake imbalance due to pressureresistance drop differences of supply and exhaust filters if they are changed at a later date.Easy filter accessFor convenience and ease of service, the downflow and exhaust HEPA filters are installed and removedthrough the front of the cabinet without entry into the work area. This is particularly helpful if thecabinet is connected to an exhaust duct. Filters should be replaced by qualified technicians only.Telescoping stand with adjustable feet. (optional)The optional support stand provides the following range of heights:Stand w/adjustable feetKneeSpaceHeightWorkSurfaceHeightOverallHeightMinimum Setting 28 1/8” 30 1/8” 91 1/4”Maximum Setting 36 5/8 ” 38 5/8 ” 99 3/4”Telescoping stand with casters. (optional)The optional support stand with casters provides the following range of heights:Standw/castorsKneeSpaceHeightWorkSurfaceHeightOverallHeightMinimum Setting 28 ” 30 ” 91 1/8”Maximum Setting 34 ” 36 ” 97 1/8”Stands are shipped disassembled, providing a smaller package for shipping, handling and installation.The stand is easily assembled and attached on site to support the cabinet.