NuAire LabGard NU-581-400, Operation And Maintenance Manual

Page: 65 / 107

OM0302
Rev 2/December 2020 Page 65 of 107
Downflow (CFM) + Exhaust (CFM) Concentration (ug/L)
# Nozzles x 229 CMH x 100 ug/L Challenge
Downflow (CMH) + Exhaust (CMH) Concentration (ug/L)
7.7 Airflow Smoke Pattern Test
The airflow smoke pattern test is performed using a smoke source (i.e. smoke tubes) in and around the cabinet workzone
and access opening to determine a visual representation of the cabinet’s containment performance. To perform the test,
the smoke source should be passed through the following areas:
1. A smoke source shall be passed from one end of the cabinet to the other, along the center line of the work surface,
at a height of 4 inches (102mm) above the top of the access opening.
2. A smoke source shall be passed from one end of the cabinet to the other, 1 inch (25mm) just inside the view
screen, at a height 6 inches (152mm) above the top of the access opening.
3. Pass a smoke source along the edges of the entire perimeter of the work opening approximately 1.5 inches
(38mm) outside the cabinet, with particular attention paid to corners and vertical edges.
4. Pass a smoke source 2 inches (51mm) from the sides up inside of the window at the side channel seals, and along
inside of the cabinet along the top of the work area or immediately below the wiper gasket.
The criteria used to evaluate the smoke patterns is the following:
1. The smoke inside the cabinet shall show smooth downward flow with no dead spots or reflux.
2. No smoke shall escape from inside the cabinet.
3. No smoke refluxes out of the cabinet once drawn in, nor does smoke billow over the worksurface or penetrate
onto it.
4. No smoke shall escape from the cabinet.
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