Simrad NSS12 Installation Manual page 46

46 |
Autopilot | NSS Installation Manual
Compass calibration
Before the compass calibration is started, make sure that there is enough open water around
the vessel to make a full turn.
The calibration should be done in calm sea conditions and with minimal wind to obtain good
results. Follow the on-screen instruction, and use about 60-90 seconds to make a full circle.
During the calibration, the compass will measure the magnitude and direction of the local
magnetic fi eld.
• If the local magnetic fi eld is stronger than the earth's magnetic fi eld (the local fi eld is reading
more than 100%), the compass calibration will fail
• If the local fi eld is reading more than 30%, you should look for any interfering magnetic
objects and remove them, or you should move the compass to a diff erent location. The
(local) fi eld angle will guide you to the local interfering magnetic object.
 Calibration
must be made on the compass that is active for the autopilot. If another model
compass from Simrad or another manufacturer is installed, refer to the instruction for that
compass regarding calibration.
 Note:
In certain areas and at high latitudes the local magnetic interference becomes more
signifi cant and heading errors exceeding ±3° may have to be accepted.
Compass mounting off set
After compass calibration, the diff erence between the compass lubber line and the boat's
center line should be compensated for.
h h
LUBBER LINE
h fi ld
Magnitude of local fi eld in
% of earth's magnetic fi eld.
Direction of local fi eld with
respect to lubber line. It can
also be on the reciprocal.