High Span Adjustment
Set instrument in the wind tunnel with the
probe positioned so that the air flow is in the
direction of the arrow on the probe. Set
instrument to the HI position. Set the wind
tunnel to 2000 FPM (10 m/s) and turn the
HSPAN adjustment screw on the left hand
side of the instrument until the meter needle
lines up with the full-scale mark.
Final Check and Adjustment
Again cover the probe window to prevent any
air flow past the sensors, and check that the
meter reads zero when the switch is set to
either the LO or HI position. If it does not,
repeat the zero and span adjustments as
required, until all three meter readings are
correct without additional movement of the
screws.
MAINTENANCE
The Model 9850 Thermo-Anemometer is
manufactured with solid state components.
Thus no maintenance is required, other than
periodic checking that the instrument and
probe are clean and not damaged.
Cleaning
Meter Window: Clean with liquid eyeglass
cleaner. Do not use abrasives or solvents.
Case: Use mild soap (dishwashing detergent)
and water solution on a damp cloth to remove
finger marks, oils, or fats. Do not use
abrasives or solvents. Do
not
immerse
instrument or allow liquids to enter case. Dry
instrument thoroughly after cleaning.
Probe: Periodically check to be sure that the
sensing area of the probe is clean, and the
sensors are free of foreign particles. If
cleaning is required use denatured or iso-
propyl alcohol; extreme care must be used to
avoid damaging the sensors. Allow the probe
to dry completely before using. Always keep
the probe in its retracted position between
uses.
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