Abstract: A biological safety cabinet with several air flow directional control enhancements. A perforated air intake grille within the work chamber inwardly adjacent the user access opening has a forwardly facing make-up air intake surface and a rearwardly facing internal air intake surface angled in converging relation to promote a physical division between intake of ambient air and internal air into the cabinet's air recirculation system. An aerodynamic user arm rest is affixed to a support stand to extend alongside the access opening at a spacing outwardly from the housing to assist in directing make-up air to the ambient air intake opening without cross-contamination between the arm rest and the work chamber. An air transmission grille above the work chamber has a horizontal main extent terminating at a spacing from the sash and an upwardly angled extent adjacent the sash to direct increased laminar air flow downwardly along the sash.

Abstract: A system for displaying information related to an operational parameter of a biological safety cabinet that may change during ongoing operation thereof, comprises a sensor for detecting a prevailing value of the operational parameter at least periodically during operation, a display comprising a pictorial graphic having a series of adjacent arcuate segments graphically representing a range of possible values for the operational parameter between a minimum value represented by a first segment, a maximum value represented by a last segment, and incremental intermediate values represented by a plurality of segments intervening between the first and last segments, and a processor associated with the sensor and with the display for comparing the prevailing value of the operational parameter to the range of possible values and selectively actuate illumination of all, none or another number of the segments to visually signify the prevailing value in relation to the range of values.

Abstract: An improved system and method for monitoring contamination loading of a filter in a biological safety cabinet comprising a housing defining a work chamber and a filtration chamber, a system for circulating air between the work chamber and the filtration chamber via a fan which draws air under negative pressure from the work chamber and delivers the air under positive pressure through the filter and into the filtration chamber. The filter monitoring system determines a pressure differential between the negative and positive air pressure at opposite sides of the fan, and evaluates the degree of contamination loading of the filter on the basis of the pressure differential. An air flow baffle is disposed within the filtration chamber adjacent the fan for dividing the pressurized air delivered by the fan and partially redirecting a portion thereof for more uniformly delivering the air to the filter.