Onwa Marine Electronics KAP-833 - Manual (Page 21)

There are two types of compass suitable for this autopilot - a magnetic sensor
unit (fluxgate), which is a complete compass, and the compass-top sensor (CTS),
which is used together with a standard magnetic ships compass.
Installing a Compass-Top Sensor
The sensor unit placed on the glass plate of the ships compass, in the exact centre
of the compass card and secured with an adhesive such as double-sided tape or
silicon sealant. Before fixing the sensor in place, align it carefully so that the
KAP-833 compass displays the same bearing as the ships compass. The compass
top sensor is preferred for steel hull vessels provided a suitably compensated
compass is fitted to the vessel.
Installation of Compass 2 6
Bow
Parallel travel
Bow
Compass sensor
Compass sensor
Compass
Keel line
16