![background image](http://html.mh-extra.com/html/brunton/ossl/ossl_quick-start-manual_2821332001.webp)
Height On Level Ground -
left
Height = (tanA + tanB) x distance
= (tan30˚ + tan14˚ ) x 60 m
= (.577 + .249) x 60 m
Height = (.826) x 60 m = 49,56 m
Height On Sloping Ground -
right
Height = (tanA + tanB) x distance
= (tan42˚ + tan4˚ ) x 60 m
= (.900 + .070) x 60 m
Height = (.830) x 60 m = 49,8 m
D = 60 m
D = 60 m
Fig. 6
Fig. 1
Fig. 3a
Fig. 5a
Fig. 5b
Brunton OSS Compass—
Align the Circles and Find Your Way
Parts of the Compass:
1. Azimuth ring w/ 2° graduations
2. North-seeking circle/magnetized needle
3. Red Orienteering Circle
4. Rotating Dial
5. Bearing Index line
6. Direction of travel arrow
8. Inch/mm scale
10. Ergonomic Base Plate
11. Declination adjustment scale
12. Declination adjustment index line
13. On the Map meridian lines
(models 30B, 50/60M only)
14. Lanyard lash point
15. Protective mirror cover w/ mono-sight window
(models 50M/60M only)
Magnetic Declination
The difference between True North and Magnetic
North (which attracts your compass needle) varies
depending on your location on the globe. Most maps
will show the degree of declination in the map legend,
or your declination can be found by visiting NOAA’s
online declination calculator here: www.ngdc.noaa.gov/
geomagmodels/Declination.jsp
Your Brunton OSS Compass
features tool-free
declination adjustment. To
adjust, place your thumb
in the center of the liquid
the vial with your
bottom through
opening in the center of
the vial base. Hold the
rotating dial (part no 4
above) still with you other hand, and then twist the
. Adjust to
the appropriate declination setting according to your
location using the red hash mark at the tail of your
magnetized needle. When complete, the compass will
automatically compensate for declination.
For example, if your current declination is 20 degrees
West (or 20°W) the compass should adjust 20 degrees
the factory setting at zero declination, and then com-
pensated according the declination scale (Fig 2a & 2b)
Finding your heading/bearing without a map
1. Select a visible landmark along the route you wish to
travel such as a rock formation or mountain top.
With the compass held level, point the direction of
travel arrow on the compass base plate at the
landmark. (Fig 3a) If you’re
using a mirrored compass,
center the landmark in the
sighting window, and position
the mirror so that a top view
of the compass dial is visible
2. Rotate the dial until the red orienteering circle aligns
with the north-seeking circle of the magnetized
needle. Read your heading/bearing at the index
line. (Fig 3b) When using a
mirrored compass, keep
your landmark centered in
the sighting a window, and
align the circles using the
mirror.
3. Keep the north seeking circle
aligned with the red orienteering circle as you travel
to your landmark. Repeat procedure until your
destination is reached.
If you know your bearing
1. If you have been given a bearing in degrees to
follow, turn the dial so that the index line aligns with
the correct bearing degree number. Hold the
compass level with the direction of travel arrow
pointed straight ahead.
2. Turn your body until
the north-seeking circle is
aligned with the red
orienteering circle. You now
face your correct direction
of travel
3. Pick out a landmark along
your direction of travel and move towards it,
checking periodically that your north-seeking circle
and red orienting circle are aligned. Repeat this
procedure until your destination is reached.
Finding your way using a map
1. Place compass on map
with the straight
edge along your
desired direction
of travel. Make
sure that the
direction of travel
arrow points
toward your
destination.
2. Keeping the
compass in
place along
your desired
direction of travel, reposition
the map until red \ orienting
circle and the north seeking circle
are aligned
.
3. In the landscape,
pick out a landmark
along your direction of
travel and move towards it,
checking periodically that
your north-seeking circle and
red orienting circle are aligned.
Repeat this procedure until your
destination is reached.
Finding your position on a map (triangulation)
1. If your location is unknown, identify (3) three
landmarks that can be seen in the landscape as well
as on the map. These would generally be obvious
rock formations, river bends or mountain tops.
the bearing per instructions above.
3. Place your compass on the map, with one corner
of the straight edge on Landmark #1. Rotate the
base plate of the compass so that the north seeking
circle and the red orienteering circle align.
4. Draw a line along
the straight edge
of the compass
base plate,
extending it as
needed
.
5. Repeat this
process for
landmark #2
and again for #3.
6. The triangle
formed by the
three lines
crossing will
approximate your position on the map.
Use of inclinometer to measure vertical height
(models 50M/60M only)
1. Rotate dial until West (270°) is at the index line.
2. Turn the compass on its side with mirror open out to
the left. Position the mirror until you can see the
3. Sight to the top of the tree or rock formation you
are measuring through the mirror’s sighting window.
needle points at declination scale.
5. Use the sloping ground illustration and tangent table
to calculate vertical height
NOTE: Never expose your compass to extreme tem-
peratures exceeding 140°F or below -30°F. Remember
Prolonged exposure to electronics, stereo speakers,
knives, metals or other magnets (anything with a mag-
polarity. Always check the functionality of the compass
avoiding contact with insect repellents or sunscreens
containing DEET. These can damage clarity of the com-
pass and wear off necessary scales and markings.
Warranty
Brunton has taken every effort to ensure years of use and reliability
from your compass. Brunton warrants this product to be free of defect in
materials and workmanship for life. The warranty is void and a charge for
repair will be assessed if this product has been damaged by negligence,
accident, mishandling or has not been operated according to standard
procedures, or if the product was altered or repaired by anyone other
than Brunton. This product is not subject to guarantees from third
location. Brunton does not assume any responsibility for consequential
damages occasioned by the use of the product. Should your product
prove defective, please contact Brunton and you will be provided with a
Return Authorization (RA) number. Please be prepared to provide proof of
purchase, the RA#, a short description of the problem, and the product
itself. Brunton will repair or replace the product with an equivalent model
per Brunton’s discretion. Brunton recommends insuring the product in
case of loss or damage in shipment.
Brunton Outdoor Group
2255 Brunton Ct.
Riverton WY 82501
+1.307.857.4700
Fig. 3b
Fig. 4
Fig. 2b
Fig. 2a
7
1
13
10
11
12
14
9
4
8
2
3
5
6
Model 30B Pictured
T E C H N O LO G Y
.S.S.
TM
EN
CS
SK
HU
PL
FI
SV
EN