NORTHROP GRUMMAN NAVIGAT X MK 1, Operation, Installation And Service Manual

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056343/C NAVIGAT X MK 1
6-6 Alignment Error Correction
6.5 Alignment Error Correction
In order to obtain correct heading data, the existing alignment error (i.e.
the angular difference between the compass orientation and the vessel's
fore-and-aft axis) must be determined and the required correction
applied. Alignment error is 0° if the sides of the compass housing run
exactly parallel to the vessel‘s longitudinal axis and the back of the
housing points dead ahead. The alignment error correction is carried out
electronically by setting the correction value in the Service Setup 1.
To carry out the alignment error correction:
1. Determine the existing alignment error by comparing the compass
heading with the vessel's true heading. The true heading must be
known to an accuracy of at least 0.5°.
2. In the Service Setup 1, select the align error correction sub-menu.
c omp a ss or i ent a t i on
vessel's f ore- a nd- af t a x i s
a l i gnment error
CAUTION
The compass must have been in continuous operation for at least 4 hours
before the alignment error can be determined accurately.
If bearing repeaters are used to determine the true heading, these must
be properly aligned to the vessel's fore-and-aft axis.
3. Enter the required correction
value. The correction value
equals the alignment error with
the sign reversed.
Example:
The vessel’s true heading is
123.0°, the compass displays
123.4°, the alignment error is
therefore 0.4°, thus, the required
correction range is –179.9 to
180.0°.
)####"
Note After correction of the alignment error, the compass is to display the ves-
sel's true heading to an accuracy of at least 0.5°.