Simrad EC150-3C, Installation Manual

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38
438371/A
Use a suitable toe-in angle
The primary consideration for any transducer installation must be to allow laminar water
flow. In most cases this is achieved by designing the blister in parallel with the keel.
However, if the blister is located close to the bow, the front of the blister should have
a few degrees "toe-in" towards the bow.
A
Keel
B
Blister
C Toe-in angle
The angle must be chosen to allow
for most efficient water flow It
will vary with the location of the
transducer; the depth below the hull,
the distance from the bow, and the
distance to the keel. Typical angles are from 0 to 3° on deplacement hulls. On planing
hulls, the angle is normally close to 0°.
Related topics
Transducer installation principles, page 34
Installation summary, page 30
Transducer installation in a flush mounted steel tank
The transducer can be flush mounted on large vessels, where the size of the hull prevents
air bubbles from reaching down to the transducer face. Flush mounting can also be
used on vessels operating in shallow harbours or waters, where a protruding blister
can not be accepted.
The standard method for flush mounting on a steel vessel is to weld a steel tank inside
the hull, and mount the transducer into this tank.
This can be accomplished by air release through a steel tube. This tube should be
extended either to open air 1.5 m above the water line, or to the water outside the hull at
a point higher than the tank interior.
If the tube is extended to open air, drainage must be provided with a controlled leak
through the transducer flange or by means of a separate hole in the tank bottom.
Note
The drainage hole should be on the opposite side the of the "Forward" arrow on the
transducer body.
Simrad EC150-3C Installation Manual