Suunto bearing compasses are designed to combine extreme accuracy with ease and speed of operation. The accuracy is 1/3°, and the graduation interval is 1/2°. The flat, compact, anodized light-alloy housing is water resistant, has no protruding parts and is designed to stand up to heavy-duty wear.
The cards of these compasses are immersed in a special dampening fluid that ensures vibration-free, smooth behavior. The compass card is set on an anti-magnetic pivot with jewel bearing. The sintered special magnet guarantees a long lifetime of accuracy and smooth performance. The liquid remains clear and maintains its viscosity low even in high temperature variations for years.
The compasses have been given permanent anti-static treatment. The lens apertures of the Suunto KB-14 and KB-20 types are restricted horizontally by a column, which automatically centers the eye on the optical axis, thus eliminating parallax.
The vertical intensity and direction of the earth's magnetic field, the inclination, influences the horizontal plane of a compass needle according to the latitude where it is used. Due to inclination, compasses must be balanced for different geographical zones in order to keep the needle in a horizontal position.
The Suunto precision instruments are balanced to five different geographic balancing zones to ensure the best possible performance in each region. The demand for high accuracy and reliability from the professionals using these instruments requires geographic localization of the compass.
The five geographic balancing zones are:
- Northern Hemisphere
- Northern Equatorial zone
- Southern Equatorial zone
- Southern Hemisphere
- Australia, New Zealand and Antarctica