Operation Manual

80 | Setup at installation
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 next page.
1 Calibration is made on the compass that is active for
the autopilot.
2 If another model compass from Simrad or another
manufacturer is installed, refer to the instruction for
that compass regarding calibration.
Lubber line Lubber line
Magnitude of
local field in % of
earth’s magnetic
field.
Direction of local
field with respect
to lubber line. It
can also be on
the reciprocal.
In certain areas and at high latitudes the local magnetic
interference becomes more significant and heading errors
exceeding ±3° may have to be accepted.