Brunton ECLIPSE 8099, Instruction Manual

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11 – Inclination
Inclination is the angular difference from horizontal (0°). The Eclipse

8099 implements three
clinometer scales, where each is incremented in degrees. The three clinometers are the 5° hinge,
5° card and the 1° graduated dial clinometer.
11.1 5 Degree Hinge Clinometer
This is the quickest method of measuring inclination. The resolution of the scale is 5°, with 2.5°
readable accuracy.
1. Remove rubber shoe to reveal the 5° clinometer scale, located on the end of the hinge.
2. Open the sight cover to at least 120°.
3. Hold the compass at eye level with 5° scale facing you, and extend to arms length.
4. Sight object behind the compass (figure 35).
5. With the base level, open the cover until it reaches the inclination of the object sighted.
6. Read inclination at the white index line, on the hinge – 40° (figure 35).
11.2 5 Degree Card Clinometer
Use the 5° clinometer (reference card 1), for this method. Notice the resolution of the scale on
the card is 5°, so use this method to sight inclination up or down from the horizon, with 2.5°
readable accuracy.
11.2.a -- Edge Sighting
1. Make sure the 5° clinometer, reference card 1, is centered under the vial.
2. With the rubber shoe on the compass, open sight cover to 120°.
10.2.c -- Latitude Determination
1. Use the rectangle that completely
surrounds the ‘X’ .
2. Place scale vertically, until bound by both
horizontal latitude lines, and touches the
‘X’ (figure 33).
3. At the ‘X’ , add the value indicated by the
scale (00’ 50") to the lowest latitude value
(43° 02’ 30").
Add values as you would when adding time on
a clock.
43° 02’ 30"
+ 00’ 50"
43° 02’ 80" = 43° 03’ 20" N. Latitude
10.2.d -- Longitude Determination
1. Slope the scale until bound by both vertical
longitude lines, and touches the ‘X’ (figure 34).
· Make sure scale increases with increasing
longitude lines.
2. At the ‘X’ , add value indicated by the scale
(1’ 15") to the lowest longitude value (108°
22’ 30").
108° 22’ 30"
+ 01’ 15"
108° 23’ 45" = 108° 23’ 45" W. Longitude
Final position of the ‘X’ is:
43° 03’ 20" N. Latitude
108° 23’ 45" W. Longitude
Follow the same procedures when using different scaled maps (1:100,000, for example).
Just make sure to use the correct latitude-longitude template scale.
If you do not have a latitude-longitude template, you may use 10 inches on a ruler. Each
inch represents 15 minutes of latitude or longitude on a 1:24,000 scale map. Ten inches
may not fit, as in section 10.2.c, Latitude Determination, so you must slant the ruler until the
10 inches are completely enclosed by the 2’ 30" lines, and ruler is next to the position.
18 19
00"
20
40
1'
20
40
2'
20
30"
43
o
02' 30"
43
o
05' 00"
N
Latitude
Lines
Figure 33
N
108
o
22' 30" 108
o
25' 00"
00"
20
40
1'
20
40
2'
20
30"
Longitude
Lines
Figure 34
Figure 35