Simrad Robertson AP9 Mk3, Instruction Manual, Page: 100 / 202

Robertson AP9 Mk3 Autopilot
5-10
20169223D
RFC35NS Fluxgate Compass
For initial installation of the compass, the desired mounting location
should be checked for unseen items which may cause compass error.
This is done easily by a (small) hand held magnetic compass,
provided it has a visible card with markings, to detect magnetic
interference.
Place the compass in the desired
mounting location. Allow the
compass card to come to rest and
note what heading it is reading
(refer to lubber line or other mark on
the compass bowl).
Then slowly proceed to move the
compass in a straight line fore and
aft (without turning it!)
approximately 30 cm out of the
mounting location. Repeat the
movement, but this time athwart
ship.
If at all possible, also move the compass in the vertical plane (up and
down).
As a thumb rule, the compass reading should not vary more than 5
degrees from the initial reading during this test. You can then be
reasonably sure that the compass location is OK.
If more than 5 degrees deflection is observed, it might still be OK, but
if exceeding 10 degrees, chances are that the calibration/
compensation will not be optimal.
If a large deflection is observed, try to find what is causing it or find a
new compass location.
Even though the RFC35 Fluxgate compasses can compensate for up
to 30 degrees of deviation, these general rules should be followed to
ensure the best performance from the compass.
FWD
Fig. 5-13 RFC35 mounting
Up
Down
Stbd.
Port
Fore
Aft