Kongsberg EM 712, Maintenance Manual

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451106/B
System units
Topics
Transducer description, page 14
Processing Unit description, page 14
Transmitter Unit description, page 15
Receiver Unit description, page 16
Hydrographic Work Station description, page 16
Transducer description
A transducer is a device that converts one form of energy to another. In an echo sounder
system the transducer converts between electric energy and sound.
The EM 712 uses separate transducer arrays for
transmitting and receiving sound pulses. Both
transducer arrays can have one or more modules which
are assembled in mounting frames.
The EM 712 transducer modules are available in an
ice reinforced version. For more information, contact
Kongsberg Maritime.
The two transducer arrays are normally mounted as “T” or “L” configurations under the
vessel’s hull (Mills Cross configuration). The transmit transducer array should be aligned
parallel to the vessel’s keel. The receiver transducer array should be aligned 90 ° on the
keel. Both transducer arrays should be horizontal on a plane on the keel.
Processing Unit description
The EM 712 Processing Unit is provided to process the signals to and from the
Transmitter and Receiver Units.
The EM 712 Processing Unit is an industrial
computer using both COTS (commercial off-the-shelf)
components and custom made components. The unit is
designed and tested for rugged use.
The Processing Unit performs the receiver beamforming, bottom detection, and motion
and sound speed corrections. It contains all interfaces for time-critical external sensors
such as vessel attitude (roll, pitch, heading and heave), vessel position and external
clock. More than one sensor of each type may be connected simultaneously, with one in
use and all of them logged.
Kongsberg EM 712 Maintenance Manual