59
Note: When scanning the edges of the exhaust HEPA filter, photometer operation may
become erratic due to the aspiration of room air into the exhaust air stream. This
problem can be minimized or eliminated by placing the edge of a sheet of rigid plastic or
metal just outside the edge of the HEPA filter when scanning the filter edges. See
Figure 10-8 as reference.
Acceptance Criteria
Aerosol penetration shall not exceed 0.01%.
Replace and secure the exhaust cover and its screws.