Envirco BSC - Manual (Page 26)

Hard connection is only used in special applications with type A2 Biological Safety Cabinets.
Should your situation require such a configuration, contact Envirco for information.
6.3 Instructions for flow alarm monitor system
Flow alarm monitor system is a pre-programmed, self-contained package that monitors
differential static air pressure. The alarm would note when the air pressure is ±20% beyond
the normal pressure. When the air pressure is 20 % lower than the normal pressure, it hums
three times every five seconds, and when the air pressure is 20 % higher, four times every five
seconds.
FIGURE 11: EXHAUST SYSTEM
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