Kongsberg Simrad MF90, Installation Manual

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476671/B
37
Compass deviation requirements
MF90 units that are installed on the bridge may have an effect on the compass.
Once the installation is complete, the vessel must be swung with the MF90 system in both
operative and inoperative modes. The shipowner and captain are responsible for updating
the compass deviation table accordingly with regard to the vessel’s national registry and
corresponding maritime authority.
Related topics
Simrad MF90, page 13
Installation requirements, page 35
Noise sources
The operational performance of the MF90 system depends on the noise conditions. It is
essential that the noise signature is as low as possible.
Vessel noise
The vessel’s hull, rudder(s) and propeller(s) must be thoroughly inspected in dry dock
prior to installation.
Roughness below the water-line deformities in the shell plating and protruding obstacles
can create underwater noise. These sources of turbulence must be smoothed or removed
as best as possible.
Note
It is especially important that the propeller(s) are not pitted or damaged.
Electrical noise
The quality of the vessel’s supply power is crucial to reduce noise. Electrical or electronic
self noise is picked up or generated in any other part of the equipment than the transducer.
The most common source of electrical self noise is hum. The hum is normally generated
by a low quality power supply.It is then picked up by cables and/or sensitive electronic
circuitry. At higher frequencies – where rather wide bandwidths are necessary – the noise
from components, transistors or other analogue electronic may be a limiting factor.
Related topics
Simrad MF90, page 13
Installation requirements, page 35
Simrad MF90