Kongsberg Flexview, Руководство по установке

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Installing the sacrificial anode
Sacrificial anodes are used to protect the Sonar Head from corrosion.
Prerequisites
• To install the Flexview, you must have basic mechanical skills.
• We assume that you are equipped with a standard set of tools. This tool set must comprise
the normal tools for mechanical tasks. This includes different screwdriver types, pliers,
adjustable spanners, etc.
• You must have installed the plastic isolation pad, which ensures the Sonar Head does
not have an electrical connection to the mounting bracket.
• You will need an ohmmeter to verify electrical connections and for continuity testing.
• You will need an underwater lubricant (such as AquaShield) to grease the fasteners.
Caution
If you do not install and properly maintain a sacrificial anode, the Sonar Head housing will
corrode in seawater and over time may sustain significant damage.
Context
When you have two different metals coupled together in close proximity, you have the
potential for galvanic corrosion. Galvanic corrosion is an electrochemical process where
one metal corrodes (anode) at a greater rate than the other (cathode) while in an electrolyte
solution. Seawater is an excellent electrolyte, and will sustain galvanic currents over
significant distances. In seawater, and in combinations with other metals, aluminium is
the most likely metal to become the anode.
The aluminium Sonar Head has a protective anodizing layer added during the production
process, but this thin layer is not enough to protect against a sustained corrosive attack. If
the cathode is large, and the anode is relatively small, the damage to the anode may be very
serious, and may include deep pitting due to the concentration of the corrosive attack.
Properly installed and sized anodes will attract the current flow from other metal parts in
the water, and in doing so will “sacrifice” themselves to the sea, thus protecting the other
metal devices.
Important
You are responsible for protecting your equipment from corrosion during deployment in a
marine environment, even for short periods of immersion. If you are not familiar with the
level of protection required for the mounting method used and the deployment environment,
please consult your local corrosion specialists.
Flexview Installation Manual