Performance standard for magnetic compass

Performance standard for magnetic compass

Compass Card:
Graduated in 360 degrees.
Numerical indication at every ten degrees.
Cardinal point indication by capitial letters N, E, S and W.
North point indication by suitable emblem.
Directional error should not exceed 0.5° on any heading.
Clearly readable at a distance of 1.4 m.
Magnifying glass is permitted.

Materials:
Corrector magnets for parmanent magnetism should have at least 11.2 coercivity.
Corrector magnets for induced magnetism should have low coercivity.
Binnacle material should be non magnetic.

Performance:
Satisfactory under all environment condition.

Constructional Error:
Compass uniform rotating speed 1.5° per second at a temperature of 20°C ± 3°C.
Card Deflection should not exceed (54/H) degrees.
Friction error should not exceed (3/H) degrees at a temperature of 20°C ± 3°C.

Correcting Device:
Quadrantal spheres.
Flinders bar.
Heeling error magnets.
F&A, athwartship parmanent magnete.

Construction:
Dimmer
No electrical power is needed.
Protection from heavy sea.

Positioning:
Should be sitted on the ship’s centreline.
Lubber mark should indicate heading with an accuracy of ±0.5°.