Brunton Pocket Transit, Инструкция по эксплуатации

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The isogonic chart shows North America, only. Use an isogonic chart, or current United
States Geological Survey (USGS), Bureau of Land Management (BLM),
or another map to determine magnetic declination at your position.
Declination can be east, west or even 0°, from your current position. At
0° declination, true north and magnetic north are aligned.
Example: If magnetic declination at your position is 15° east, then mag-
netic north is 15° east of true geographic north. Figure 8 displays true
geographic north and magnetic north, as indicated in the legends of
USGS and BLM maps.
Most maps use true north as a reference. When adjustment for magnetic declination is com-
plete, azimuth readings will be with respect to true north, same as the map.
To adjust for magnetic declination, rotate the graduated circle by turning the circle adjusting
screw. Begin with the zero pin at 0°. For
East declination, rotate graduated circle clock-
wise from the zero pin. (Fig 9A) For West declination, rotate graduated circle counter-
clockwise . (Fig 9B) If magnetic declination is 0°, no adjustment is necessary. (Fig 9C)
Azimuth is a term used for direction. Azimuth is normally measured clockwise, in degrees with
true north being 0°. Bearing is a term often used when measuring with a quadrant type instru-
ment. From this point forward, description of pocket transit use will involve the 0° through 360°
graduated circle, and assume the pocket transit is adjusted for magnetic declination. Example
of Azimuth: If a mountain is directly east of your position, the azimuth from your position to the
mountain is 90°. If the mountain is directly south of your position, it would be at 180°.
Caution: The magnetic needle is highly sensitive. When sighting an azimuth, keep the pock-
et transit away from magnetic materials, such as watches, belt buckles, rings, knives, cigarette
lighters, … etc.
4.1 Azimuth Using a Tripod or Unipod
When the greatest accuracy is required, mount the pocket transit on a Brunton non-magnetic
True North
Magnetic North
15 o E
Your Position
Figure 8
Zero Pin Zero Pin Zero Pin
Figure 9A Figure 9B Figure 9C
15
°
East
Declination
15
°
West
Declination
0
°
Declination
4 -- Azimuth Measurement
Figure 7
West Declination
East Declination
6 5