Installation manual

Table Of Contents
Basictheory
Howtocheckforelectricalnoise
Thisprocedureprovidesasimplemethodtochecktheelectrical
noise.
1Switchoffallelectricequipmentthatcancauseelectrical
noise.
Thisincludesmotor,propellers,thrusters,winches,cooling-
andairconditioningsystems,pumps,cranes,hydraulic
systemsetc.
2Switchtheequipmentonagainoneatthetime,andcheck
thesonareverytime.
Withluck,youwillspotwhichofyourelectricalsystems
thatcreatethenoise.Todealwiththeproblem,consultyour
dealerand/oracertiedshipselectrician.
Layersanddeections
Yoursonaroperationsmayalsobedisturbedbyenvironmental
situationsthatyouareunabletocontrol.Twotypicalconditions
aretemperatureandsalinitylayers,anddeectionscausedby
increasingordecreasingwatertemperature.
Temperatureandsalinitylayers
Youmayexperiencethattemperatureand/orsalinitylayersexist
inthewatercolumn.Sincethespeedofsoundinwaterdepends
onitstemperatureandsalinity,suchlayerswillcausethesound
beamtobereected.
Figure44Temperatureandsalinitylayers
B
(CD015005F)
A
Ifyoutransmitasonarbeamdowntowardsatemperature
orsalinitylayer(A),itmaybereectedasindicatedinthe
illustration.Theschoolofsh(B)youthoughtyouwouldsee
willnotbevisibleatall.
323775/B
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