These portable systems provide user protection by keeping powders and particulates contained during weighing procedures

The deep interior easily accommodates large micro and analytical balances. The Clean-Sweep™ airfoil allows air to sweep the work surface for maximum containment. The perforated rear baffle promotes horizontal laminar airflow to maximize containment. The upper containment sash foil bleeds air into the enclosure to direct concentrations of contaminants away from the operator’s breathing zone. The upper dilution air supply introduces room air at the top of the sash to dilute contaminants in the upper chamber and bathe the back of the sash with clean air. Additional side-entry airfoils allow air to sweep across the interior glass surfaces to enhance containment. The airfoil’s ergonomic design provides a comfortable position for the operator’s forearms. Systems feature a true bag-in/bag-out filter disposal system for safely removing and replacing the HEPA filter. The HEPA filter cell is 99.99% efficient on particulates 0.3µm in size. An upper diffuser screen, located above the work area, provides protection for the HEPA filter. The system also features a front-mounted Minihelic® pressure gauge that monitors pressure differential across the HEPA filter to help determine filter loading. The built-in, positive pressure impeller is surrounded by a negative pressure plenum so that if a leak should develop, the unfiltered air is captured and refiltered. The blower also has vibration isolation supports to minimize disturbance to sensitive balances.

Sturdy glacier white and gray, dry powder epoxy-coated aluminum frame and steel rear plenum and baffle dissipate static charge. Tempered safety glass front sash, sides, and top offer excellent visibility, ambient light, and protection. Ergonomic angled sash allows a closer view, reduces glare, and provides a more comfortable operating position than vertical sashes. Hinged sash pivots upward and locks to a loading height of 48.7cm (19"). The 1.5m (5') and 1.8m (6') models incorporate a gas-assist lift and have a loading height of 70.4cm (27¹¹/₁₆"). The operating sash height is 23.9cm (9¹³/₃₂") on the 0.6m (2'), 0.9m (3'), and 1.2m (4') models. The 1.5m (5') and 1.8m (6') models have a 30.5cm (12") operating sash height. A wiping seal helps keep contaminants contained. Systems also include front-mounted light and blower switches, two utility ports, and glare-free fluorescent lighting.

Enclosures also feature an optional built-in airflow monitor. If the hood’s face velocity falls below the setpoint for more than six seconds, an audible alarm sounds and a red light glows. The alarm can be muted. On the Guardian™ monitor, an LED glows green when the airflow is within setpoint range. The Guardian™ 1000 digital monitor features an LCD display of actual face velocity and an RS-232 port. Optional trace odor carbon filters can be easily installed atop the system to trap nuisance vapors from organic solvents, formaldehyde, ammonia, or amines. Stainless steel work surfaces feature a spill trough. The utility shelf kit has three epoxy-coated steel shelves that can hold a printer, utensils, and other miscellaneous supplies. Shelves attach to the rear baffle perforations of the enclosure.

All systems conform to modified ASHRAE 110-1995 standards, SEFA 1-2002 standards, and ANSI Z9.5-1-993 standards. The 115V systems are ETL and ETL-C listed; the 230V systems are CE marked.

The built-in blower and HEPA filter are mounted in the upper plenum to save space, and the enclosures have low installation costs and require no outside ducting. Systems also provide quiet operation as low as 45dBA, depending on face velocity.