GEONAUTE COMPASS C400, Руководство пользователя

Страница: 6 / 20

21
Restrictions on use/precautions for use
¥
Compasses must always be used HORIZONTALLY. It is very important to
avoid friction against the dial’s pivot point by holding the instrument with a
maximum of 5¡ from a horizontal position.
¥
This compass detects the Earth’s magnetic field. It is very important to keep
this instrument away from any sources of electromagnetic disturbance (high
voltage, emission of waves, e.g. telephone, cell phone, radio, or television; and
objects containing ferrous metals).
¥
This compass detects MAGNETIC North, which is not in exactly the same
place as geographic north. The difference (the declination) depends on the
user’s position on the globe. It is given in the following table.
¥
Declination values for some large cities of the world. For your city, enter the
average of the values of 2 nearby cities.
If the declination is West (W), subtract the indicated value from the value you
have just read. If the declination is East (E), add the variation to the value you
have just read. The position of magnetic north also changes with time, but these
variations are negligible over a time span of a few years.
¥
A compass is a precision instrument. Do not drop it
¥
The operation of the compass varies with the temperature. The oil that slows
the needle may congeal or liquefy depending on the ambient temperature. In
order to preserve its performance capabilities, protect the compass from
extreme temperatures (e.g. by keeping it under a garment).
¥
The compass requires a few seconds to stabilize. Do not take the reading into
account until the needle has stabilized completely.
¥
To use this compass, you need to have a map. Opt for a map with a scale
available on the compass. For optimal use, also bring along a wooden pencil
and an eraser.
USING THE COMPASS
3 operating modes are available for different orienteering needs :
1 -
You know where you are and you have located your destination on the map
(the angular direction in relation to the north)?
2 -
You know where you are and you have taken the bearing (angular direction) to
follow,
3 -
You do not know where you are How do you determine your position on the map ?
How do you find your way ?
How do you take a bearing ?
City Declination
Anchorage 22¡E
Atlanta 4¡W
Bombay 1¡W
Boston 16¡W
Calgary 18¡W
Chicago 3¡E
Denver 4¡W
Jerusalem 3¡E
London 4¡W
Munich 14¡W
City Declination
New York 1¡E
Oslo 14¡W
Paris 2¡W
Rio de Janeiro 21¡W
San Francisco 15¡E
Seattle 19¡E
Shanghai 5¡W
Toronto 11¡W
Vancouver 20¡W
Washington 10¡W