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Wind, Continued
Using Hand
Held
Anemometers
If anemometers are not installed or not working properly, or for some
reason the readings are in doubt, the hand-held anemometer should be
used. The Wind Measuring Set AN/PMQ-3 (fig. 10-11) is a hand-held
anemometer. It is a combination wind direction and speed indicator. It
indicates direction to 360° and speed from 0 to 60 knots. The speed
indicator has two scales, graduated from 0 to 15 knots and 0 to 60
knots. To use the hand-held anemometer, you choose an observation
point on the windward side of the ship, as far upwind as possible. For
example, if the wind is from the stem, go aft; if it is from the bow, go
forward. If possible, stand facing parallel to the ship’s centerline and
into the wind.
When you use the hand-held anemometer, follow the instructions given
in the table below.
Step
Action
1.
Grasp the instrument by the handle and hold it in an
approximately vertical position at arm’s length with the sight at
eye level.
2.
Aim the instrument at an imaginary point on the horizon. This
is done by aligning the center of the slot in the front of the
sight with the center of the strip between the two slots on the
rear sight. Aim it as you would a gun.
3.
Press and hold the vane locking trigger. Note the reading on
the 0 to 60 (upper) scale on the wind speed indicator. If the
wind speed reading is less than 15 knots, press the range
selecting trigger on the side of the housing, and observe the
reading on the 0 to 15 scale. Care must be taken not to take
the first reading on the 0 to 15 scale because a wind speed in
excess of 15 knots may damage the anemometer.
4.
Note the motion of the wind vane as it moves between the
extremes, and release the vane locking trigger when the vane is
in the position of the predominant (average) wind direction.
Carefully lower and tilt the anemometer and note the wind
direction reading on the direction dial. If the wind is being
observed facing aft, the direction must be converted in relation
to the bow. Add 180° for directions from 0° through 90°.
Subtract 180° for directions from 270° through 360°.
5.
Maintenance of the AN/PMQ-3 should be in accordance with
PMS instructions.
10-21
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