Installation manual

Simrad SP90

851-164510 / Rev.E

Important considerations

The Hull Unit trunk must be installed so that it will be vertical

under normal operating conditions. The primary sources of

underwater disturbance (other than a vessel’s main propeller and

bow/sternthruster) that affect transducer reception are:

• Main or bilge keels

• Zinc anodes

• Cooling elements protruding from the hull

• Equipment such as sonar transducers and pitot tubes

• Sea chests

• Overboard discharges

• Dents in the hull

All appendages to the hull, indentations and pipe in/outlets are

potential sources of underwater noise. They may act as resonant

cavities amplifying noise at certain frequencies, create cavitation

or turbulence. Transducers should not be located in the vicinity

of such objects and especially not immediately aft of them.