Simrad SC90, Installation Manual

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419050/B
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Transducer description
The cylindrical SC90 transducer allows the sonar beam to provide a full 360 degrees
coverage of the water volume.
A Lower part of transducer shaft
B Transducer with its red protective coating
The transducer converts the electric energy generated by the Transceiver
Unit to physical vibrations. These vibrations alter the water pressure, and
create an acoustic pulse that is sent into the water. The acoustic signal
is transmitted as a beam. The duration of the acoustic pulse, as well
as its frequency and shape, are controlled by the Transceiver Unit. The
direction and opening angle of the beam is controlled by the Transceiver
Unit and the physical properties of the transducer. After the transmission,
the transducer works as a "microphone". It converts the water pressure
created by the acoustic echoes to electric energy. These weak echo
signals are sent to the amplifiers in the Transceiver Unit.
The transducer is rather small with an outer diameter less than 20 cm. It contains 480
individual elements with impedance transformers for each element.
The transducer is mounted at the bottom end of the Hull Unit’s transducer shaft. This
allows the transducer to be lowered into the water for operational use, and retracted for
protection when the SC90 is turned off. By lowering the transducer into the water, you
may also be able to reduce the noise created by the laminar flow of water along the hull.
Note
The red protective coating is an vital part of the transducer. It is very important that
neither this coating nor the internal parts of the transducer are damaged during the
handling, installation or cleaning. Any holes and/or scratches in the transducer surface
will allow water to penetrate the transducer. If a leak occurs, the transducer must be
replaced.
Rules for transducer handling
A transducer must always be handled as a delicate item. Wrongful actions may damage
the transducer beyond repair. A physical blow to the transducer face may easily damage
one or more elements. Observe these transducer handling rules:
•
Do not
activate the transducer when it is out of the water.
• Do not handle the transducer roughly, avoid impacts.
• Do not expose the transducer to direct sunlight or excessive heat.
•
Do not
damage the outer protective skin on the transducer.
• Do not use high pressure water, sand blasting, metal tools or strong solvents to clean
the transducer.
• Do not step on the transducer cables.
Simrad SC90