Airmar Acoustic Deterrent System—dB Plus II™ - Manual (Page 4)

2
Installation
After the installation of your dB Plus II

system by a trained authorized technician, please familiarize
yourself with the following principles of installation, operation, and maintenance. This system has been
custom engineered and carefully installed at your facility. Should it be necessary to move equipment,
including relocating any of the projectors, it is recommended that the move be done by an authorized
technician for best results.
System Layout
At fish farms with square pens, Airmar recommends placing the batteries, charging devices, and
transmitter in the center of the set of pens thus allowing the projectors to be located close to the outer
corners (see Figure 1). However, if a sheltered location is available for the batteries, charging devices, and
transmitter, it should be used.
The dB Plus II

system is designed to emit high intensity acoustic pulses from each of its four underwater
projectors resulting in significant discomfort to most seals. Sound pressure drops dramatically with
increased distance from the projector, so proper projector layout is
imperative .
Since the placement of the projectors is the key to the success of the dB Plus II

system, they must be
positioned so that the sound patterns overlap. The closer the spacing between the projectors, the higher
the intensity of the sound field, and therefore the greater the protection from predators. Using the 60m
(200') long projector cables provided, will result in the maximum recommended spacing between
projectors at a fish farm with the above pen layout. For protection from seals, the distance between
projectors should never exceed 60m (200').
12m
30m
60m (200')
transmitter
battery bank (can be connected to alternative charging sources
such as: solar panels, wind generator, AC mains or portable generator)
projector
projector
Figure 1. Recommended system layout for typical square pen configuration
(100')
pens
(40')
projector
projector
( Layout will vary with different pen styles)