System information

74 | Alarm system
The calibration should be done in calm sea conditions and
with minimal wind to obtain good results. Use about 60-
90 seconds to make a full circle.
1. Highlight the Calibrate line in the dialog
2. Begin turning the boat to port or starboard
3. Press the MENU key to start the automatic compass
calibration
a. An information window will be
displayed when the calibration
procedure is running.
b. The digits below the bargraph
will read 0.0 when the turn
rate is correct. Too high or too
low turn rate is indicated as
follows (For RC42 Rate
Compass only!):
Turn rate too high,
turning cw
Turn rate too low,
turning cw
4. The automatic calibration is completed when the
information window disappears from the display
The FC40 and RC42 compasses will store the calibration
and offset data in their own memory.
During the calibration, the compass will measure the
magnitude and direction of the local magnetic field. If the
local magnetic field is stronger than the earth’s magnetic
field (the local field is reading more than 100%), the
compass calibration will fail. If the local field is reading
more than 30%, you should look for any interfering
magnetic objects and remove them, or you should move
the compass to a different location. The (local) field angle
will guide you to the local interfering magnetic object.
See illustration on next page.