Simrad ST90 - Transducer Description

442703/B
29
Transducerdescription
ThecylindricalST90transducerallowsthesonarbeamtoprovideafull360degrees
coverageofthewatervolume.
ALowerpartofshaftsleeve
BLowerpartoftransducershaft
CTransducerwithitsredprotectivecoating
Thetransducerconvertstheelectricenergygeneratedbythe
TransceiverUnittophysicalvibrations.Thesevibrationsalter
thewaterpressure,andcreateanacousticpulsethatissentinto
thewater.Theacousticsignalistransmittedasabeam.The
durationoftheacousticpulse,aswellasitsfrequencyand
shape,arecontrolledbytheTransceiverUnit.Thedirection
andopeningangleofthebeamiscontrolledbytheTransceiver
Unitandthephysicalpropertiesofthetransducer.After
thetransmission,thetransducerworksasa"microphone".It
convertsthewaterpressurecreatedbytheacousticechoesto
electricenergy.TheseweakechosignalsaresenttotheampliersintheTransceiverUnit.
Thetransducerislargeandheavy.Itcontains384individualelements.
Thetransducerismountedatthebottomendofthehullunit’stransducershaft.This
allowsthetransducertobeloweredintothewaterforoperationaluse,andretractedfor
protectionwhentheST90isturnedoff.Byloweringthetransducerintothewater,you
mayalsobeabletoreducethenoisecreatedbythelaminarowofwateralongthehull.
Note
Theredprotectivecoatingisanvitalpartofthetransducer.Itisveryimportantthat
neitherthiscoatingnortheinternalpartsofthetransduceraredamagedduringthe
handling,installationorcleaning.Anyholesand/orscratchesinthetransducersurface
willallowwatertopenetratethetransducer.Ifaleakoccurs,thetransducermustbe
replaced.
Rulesfortransducerhandling
Atransducermustalwaysbehandledasadelicateinstrument.Incorrectactionsmay
damagethetransducerbeyondrepair.Aphysicalblowtothetransducerfacemayeasily
damageoneormoreelements.Observethesetransducerhandlingrules:
•Donotactivatethetransducerwhenitisoutofthewater.
•Donothandlethetransducerroughlyandavoidimpacts.
•Donotexposethetransducertodirectsunlightorexcessiveheat.
•Donotdamagetheouterprotectiveskinofthetransducer.
•Donotusehigh-pressurewater,sandblasting,metaltoolsorstrongsolventstoclean
thetransducer.
SimradST90