Brunton ECLIPSE 8099, Instruction Manual

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4. Locate declination scale.
5. Grasp black azimuth ring in one hand, and the vial in the other (figure 6).
6. Hold black azimuth ring stationary, and rotate vial until the arrow on the
blue orienting circle
points to the value of magnetic declination at your current position.
· Adjust orienting circle toward “EAST” for east declination and “WEST” for west declination.
3 – 1 Degree Graduated Dial
The 1° graduated dial has two scales, a green scale and a black scale (figure 7). The green scale
is for forward sighting and the black scale is for reverse sighting. The scale increments from 0° to
359°, where 0° indicates north. In addition, 90° indicates east, 180° is south and 270° is west.
4 – Field Bearing
The following instructions describe two methods of sighting a field bear-
ing – forward mirror sighting and reverse mirror sighting. Since there
are two methods and two scales, please follow instructions carefully for
each method.
4.1 Forward Mirror Sighting
This is the most accurate method of sighting a field bearing.
1. Determing and set the magnetic declination at your position.
· Refer to section 2.1, Magnetic Declination Adjustment, for help.
2. Open sight cover to 45°.
3. At eye-level, look through sight hole, and align object with the
sight hole, cover line and peep sight (figure 8).
0
350
340
330
320
130
230
310
240
120
300
290
110
250
280
260
100
90
270
220
140
150
210
160
200
170
190
180
10
20
30
40
50
60
70
80
4. Rotate azimuth ring until reflection of blue orienting circle,
in the mirror, outlines the red circled "N".
· Make sure base is level and sighting lines and peep
sight are aligned.
5. Position the compass close enough to read field bearing
in magnified index lens.
· Read bearing from green scale at the green index
line – 170° (figure 9).
4.2 Reverse Mirror Sighting
Reverse mirror sighting is another method of sighting a
field bearing.
1. Find and set magnetic declination at your position.
2. Open sight cover to 120°.
3. Hold compass at waist-level, with sight cover pointing
towards you (figure 10).
4. Sight object in the mirror and align mirror line with the
reflection of the cover line.
5. Rotate azimuth ring until blue orienting circle
surrounds the red circled "N".
· Make sure mirror line and reflection of cover line are
aligned with sighted object.
6. Read field bearing from the black scale in the magnified
index lens – 50° (figure 10).
5 – Direction Of Travel
When field bearing to a destination is already known, set
compass to the known field bearing, sight and travel to the
destination. The bearing you travel is known as the direction
of travel. This example uses forward mirror sighting.
1. Set magnetic declination.
2. Open sight cover to 45°.
3. Rotate azimuth ring until compass is set to a known field bearing ( 270° ), using the
green scale
in this example.
Figure 9
Figure 10
Figure 11
Figure 8
350
170
Figure 7
50
230
50
Cover Line
Mirror Line
6 7
Peep Sight
Cover Line
Sight Hole