Simrad ES 18 - DATASHEET REV C, Installation Manual

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Using a suitable inclination angle
Ideally, the transducer face should be mounted in parallel with the sea surface when
the vessel is in normal trim, as this will provide the most accurate echo information.
However, it is also very important that the water flow over the transducer face is laminar.
In order to ensure laminar flow, the
transducer face must be tilted slightly
upwards in relation to the water flow. This
allows the flowing water to meet the face
directly, and reduces laminar noise.
The inclination angle must be determined
carefully. The angle must be small on
transducers with a narrow beam angles. As a rule of thumb, mount transducers with
beam angles smaller than seven degrees with 1
°
inclination angle. The smaller beam
angle your transducer has, the smaller the inclination angle can be.
Note
Ensure that you do not mount the transducer with a negative inclination angle. This may
cause turbulence on the transducer face, and reduced ES18 performance.
Related topics
Transducer installation principles, page 47
Using self-locking taps
The mounting rings delivered by Kongsberg Maritime are fitted with self-locking
threads. Normal screws are designed to be loosened. It is however important to avoid
accidental loosening, especially when the installation is subjected to dynamic stress. For
this reason, additional locking devices are required. These are often expensive, they can
only be used once, or react critically to temperature changes.
Introduction to Emuge self-locking threads
Emuge self-lock is a tap design with an integrated locking feature. Standard metric
bolts are used. The internal thread provides a self-locking connection, which can be
used repeatedly. It is not necessary to involve a secondary locking device (for example
chemical, nylon or mechanical). The Emuge self-lock bolts withstand the vibrations
better than standard (metric) threads, because the thread contact stops the sideway
movement. The special design of the internal thread profile also provides a more even
distribution of the tightening stress over the whole thread length. The assembly is just as
easy as with a normal (metric) thread. There is no general applicable standard (e.g. DIN
standard) for the
Emuge self-lock thread.
Transducer installation principles