Operation Guide 3451
E-39
Digital Compass Precautions
Magnetic North and True North
The northerly direction can be expressed either as
magnetic north or true north, which are different from each
other. Also, it is important to keep in mind that magnetic
north moves over time.
•
Magnetic north is the north that is indicated by the
needle of a compass.
•
True north, which is the location of the North Pole of the
Earth’s axis, is the north that is normally indicated on
maps.
•
The difference between magnetic north and true north
is called the “declination”. The closer you get to the
North Pole, the greater the declination angle.
True north
Magnetic north
Earth
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•
You can select a value within the range of
90° W
to
90° E
with these settings.
•
The following explains magnetic declination angle direction settings.
0 OFF:
No magnetic declination correction performed. The magnetic
declination angle with this setting is 0°.
E:
When magnetic north is to the east (east declination)
W:
When magnetic north is to the west (west declination)
•
You can turn off (
0 OFF
) magnetic declination correction (which effectively
makes the magnetic declination angle: 0°) by pressing
D
and
B
at the same
time.
•
The illustration on page E-37, for example, shows the value you should input and the
direction setting you should select when the map shows a magnetic declination
of 1° West.
4. When the setting is the way you want, press
A
to exit the setting screen.
E-37
To perform magnetic declination correction
1. In the Digital Compass/Thermometer Mode, hold down
A
until the
CAL
starts to flash on the display. This is
the calibration screen.
2. Press
C
.
•
The magnetic declination angle and magnetic
declination angle direction will flash on the display.
3. Use
D
(+) and
B
(–) to change the magnetic
declination angle and magnetic declination angle
direction settings.
l
l
l
l
l
l
l
l
ll
llll
ll
ll
Magnetic declination
angle value
Magnetic declination
angle direction
E-36
4. As each dial segment disappears, rotate the watch so the neighboring segment (to
the right) is pointed north.
•
After you complete rotation for one full set of segments, all segments will
re-appear and start disappearing again.
5. Repeat step 4 for the second set of segments.
•
The calibration operation ends automatically after two sets of segment (two full
watch rotations) are complete. Either
OK
(successful) or
ERR
(unsuccessful) will
appear on the display. Press
A
to complete the procedure or
D
to calibrate
again.
•
To stop a bearing sensor correction operation part way through, press
D
and
then
A
.
E-35
To calibrate the bearing sensor
Rotate the watch as
each segment
disappears from
the bearing
indicator dial.
D
▲
▲
1. Remove the watch from your wrist, and position it so its back is parallel with the
ground and the 12 o’clock position of the compass dial is pointed away from you.
2. In the Digital Compass/Thermometer Mode hold down
A
until all the segments are
displayed in the bearing indicator dial.
3. Press
D
.
•
This will cause the segments of the dial to disappear in clockwise sequence one-
by-one.
E-34
•
Magnetic Declination Correction
With magnetic declination correction, you input a magnetic declination angle
(difference between magnetic north and true north), which allows the watch to
indicate true north. You can perform this procedure when the magnetic declination
angle is indicated on the map you are using.
Note that you can input the declination angle in degree units only, so you may need
to round off the value specified on the map. If your map indicates the declination
angle as 7.4°, you should input 7°. In the case of 7.6° input 8°, for 7.5° you can input
7° or 8°.
E-33
Calibrating the Bearing Sensor
If you feel that direction readings being produced by the watch are not correct for
some reason, you can calibrate the bearing sensor to correct them. You can use
either of two methods to calibrate the bearing sensor: bearing sensor correction or
magnetic declination correction.
You also need to calibrate the bearing sensor if 100 days pass without calibration, and
after you have the watch’s battery replaced. The message
CAL
will appear on the
display to remind you to calibrate.
•
Bearing Sensor Correction
With bearing sensor correction, you rotate the watch in accordance with the
movement of an on-screen indicator. Doing this will recalibrate the magnetic sensor
of the watch with magnetic north for the area where you are located.
E-32
3. Rotate the map without moving the watch so the northerly direction indicated on the
map matches north as indicated by the watch.
•
If the watch is configured to indicate magnetic north, align the map’s magnetic
north with the watch indication. If the watch has been configured with a
declination to correct to true north, align the map’s true north with the watch
indication.
•
This will position the map in accordance with your current location.
4. Determine your location as you check the geographic contours around you.
E-31
Example: Determining your current position and your
objective on a map
Having an idea of your current location and the direction
to your destination is important when mountain climbing or
hiking. In this example, we show you how to plot directions
on a map and determine your current location using
direction measurements taken by the watch.
1. With the watch on your wrist, position it so the face is
horizontal.
2. In the Timekeeping Mode, press
D
to take a compass
reading.
•
The reading will appear on the display after about
two seconds.
N
N
North indicated
on the map
North indicated by
north pointer
Current
location
E-30
Direction
Meaning
Direction
Meaning
Direction
Meaning
Direction
Meaning
N
North
NNE
North-
northeast
NE
Northeast
ENE
East-
northeast
E
East
ESE
East-
southeast
SE
Southeast
SSE
South-
southeast
S
South
SSW
South-
southwest
SW
Southwest
WSW
West-
southwest
W
West
WNW
West-
northwest
NW
Northwest
NNW
North-
northwest
•
See “Digital Compass Precautions” on page E-39 for other important information about
taking direction readings.