- ISO Rating: ISO 5, ISO 6, ISO 7, ISO 8
• Marks & Listings: UL, ULC
The Recirculating HEPA-Filtration version of the General-Use Pass-through adds another layer of protection against contamination for materials being transferred. A blower/filter module emits a continuous, laminar flow of HEPA-filtered air from the ceiling that prevents airborne contamination from reaching senstive materials.
When run continuously, this micro-filtration system sweeps away any particles that may enter the transfer chamber when the doors are opened and maintains an extremely clean pass-through environment. The blower also slightly pressurizes the chamber, similar to the ISO-classified positive pressure utilized in a cleanroom. Because the pressurization is minimal, the pressure gauge on the unit measures the backpressure at the filter, which can be used to monitor its efficiency and remaining filter life.
The status indicator lights confirm that the pass-through is operational. The installed Minihelic gauge measures backpressure at the HEPA filter in order to determine when a replacement filter is needed.