Labconco 3970202 User Manual - page 39
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Chapter 6: Maintaining Your Filtered PCR Enclosure
6. Over time the HEPA filter will load and eventually slow
the downflow velocity. Once the alarm condition is met,
simply increase the speed control as outlined in Chapter 6
or replace the HEPA filter if the speed control is
maximized.
7. The table below lists typical alarm conditions based on
normal operating conditions. Typical alarm conditions are
set at downflow velocities of 10 to 30 feet per minute
below the normal operating conditions due to supply air
and exhaust air fluctuations, as well as room air cross
drafts. Consult your Safety Officer or Laboratory Manager
for proper operating speeds.
Enclosure Operating
Downflow Speed
Alarm Condition Set Point
Speed
55 ± 10 fpm
25-35 fpm
45 ± 10 fpm
25-35 fpm