Automatic compensation of the VDO Compass
All on-board iron masses of a ship are more or less magnetic and influ-
ence the compass. This effect must be compensated in a fluid compass
as well as in a fluxgate compass.
On conventional fluid compasses this requires the services of a qualified
specialist. On the VDO Compass with its automatic deviation compensa-
tion you can easily and reliably perform this adjustment yourself. As sup-
plied the VDO Compass behaves like a normal, non-compensated fluid
compass.
Perform the automatic compensation during a circular course with calm
sea, at a sufficient distance to port installations and magnetic disturban-
ces (such as steel bridges, sheet piling, other ships). The diameter of
the circle should be five or six times the ship length, the speed adapted
to complete one circle in about 3 minutes.
No valid course is indicated by the instrument during the compensation.
Perform the compensation as follows:
Start the circular course and switch the power supply on while keeping
the button pushed.
The display indicates „
OFFSET
“.
Relase the button when „
OFFSET
“ is displayed. After some seconds the
local compass deviation is indicated (setting see page 32).
After another 5 seconds the display automatically changes to „CAL“.
Push the button during „
CAL
“ until „
CAL1
“ is displayed.
The pointer moves to the „CAL“ position.
(Note: you have about 5 seconds to start the “CAL” function, as this fun-
ction is automatically exited after this time.)
30
COMPENSATION
OFFSET
OS 000
CAL
CAL 1
Push the button
comp_e.qxd 08.04.1998 07:44 Seite 10
