INSIDE-THE-HULL TRANSDUCERS
This type of transducer does not require the drilling of a hole as does the
Through-the-Hull Transducer. However, since the sound waves
transmitted and received by the Inside-the-Hull Transducer must pass
through the hull, transducer performance will be reduced. The success
of Inside-the-Hull installation is greatly dependent upon the purity of the
hull directly below the transducer and the type of hull. Inside-the-Hull
mounting should not be used on aluminum hulls, balsa core hulls,
wooden hulls, or hulls where the deadrise angle is more than 15°.
To reduce sound transmission losses, the adhesive used to bond the
transducer to the hull should conduct sound at speeds close to that of
the plastic or epoxy face of the transducer and the polyester resin of the
hull. Epoxy adhesives, as opposed to silicone, are recommended.
Note:
When performing an Inside-the-Hull installation, you must use
a special Inside-the-Hull Transducer since it contains a
transducer crystal which is wider in diameter, and is designed
to transmit the pulse through the hull. Do not attempt to use
a Transom Mount Transducer, as the crystal is too small to
ensure optimum instrument results.
Selecting an Installation Location
The transducer should be located where the hull laminate is dense and
has no entrapped air. Generally, best operation is obtained by mounting
the Inside-the-Hull Transducer on the centerline of the hull, as it allows a
flat, horizontal mounting area for vertical orientation of the sonic beam.
Do not choose an area above a lifting strake, as air travels underneath
the hull here and could cause erroneous readings.
•
On sailboats, mount the transducer near the centerline and
forward of the leading edge of the keel.
•
On power boats, mount the transducer as far aft as practical.
•
On I/Os, mount in a spot near the engine.
•
On inboards, locate the transducer forward of the prop(s), where it
will not be shaded by prop shafts.
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