Installation manual

Basic theory
2 Switch the equipment on again one at the time, and check
the sonar every time.
With luck, you will spot which of your electrical systems that
create the noise. To deal with the problem, consult your dealer
and/or a certified ships electrician.
Layers and deflections
Your sonar operations may also be disturbed by environmental
situations that you are unable to c ontrol. Two typical conditions
are temperature and salinity layers, and deflections caused by
increasing or decreasing water temperature.
Temperature and salinity layers
Yo u may experience that temperature and/or salinity layers exist
in the water column. Since the speed of sound in water d epends
on its temperature and salinity, such layers will cause the sound
beam to be re flected.
Figure 33 Temperature and salinity layers
B
(CD015005F)
A
If you transmit a sonar beam down towards a temperature
or salinity layer (A), it will be reflected as indicated in the
illustration. The school of fish (B) you thought you would see
will not be visible at all.
Deflections
On warm days — especially during summer — the sea surface
will be heated by the sun, and the water temperature will
gradually decrease with increasing depth.
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