Method and apparatus for testing the operation of an alarm for a ventilated
enclosure, such as a fume hood or bio-safety cabinet. Flow of gas being exhausted
from the enclosure may be adjusted to a known value below or above a threshold
value at which the alarm provides an indication that flow is unacceptably low or
high. Adjustment of flow to the known value may be performed without requiring
a manual measurement of flow, e.g., by performing a traverse in a duct leading
from the enclosure.