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making face velocity measurements in a cleanroom
bench or a fume hood.
As you handle the probe, take care not to bump it
against duct walls or other objects. The probe has
been made as rugged as possible, but can be
damaged by careless handling.
Measuring Velocity
For highest accuracy, it is important with the
Model 9880 to properly align the probe to the flow.
Orient the probe so that the air being measured
flows straight through the sensor window in the
direction indicated by the arrow at the tip of the
probe. The arrow at the tip of the probe should
point downstream.
Switching On The Power
Turn on the Model 9880 using the
ON/OFF
switch.
The Model 9880 will display battery life for the
first five seconds. This number represents the
approximate battery life remaining, and will range
from less than 0% for low batteries to something
over 100% for a short time while the “surface
charge” of new batteries burn off.
After five seconds the Model 9880 will display
velocity in the selected units. Units available for
