Installation manual

Wheretomountthetransducer

Mountthetransducerfarawayfromthepropellers

Thepropulsionpropelleristhedominantnoisesourceonmostshingvessels,research

vessels,merchantvesselsandpleasurecrafts.Thenoiseistransmittedthroughthesea

water.Forthisreason,thetransducershouldbeplacedfarawayfromthepropeller,

whichmeansontheforepartofthehull.Positionsoutsidethedirectlineofsightfrom

thepropellerarefavourable.Onsmallvesselswithshortdistancesitisadvisedtomount

thetransduceronthatsideofthekeelwherethepropellerbladesmoveupwards,because

thepropellercavitationisstrongestontheotherside.Thecavitationstartsmosteasily

whenthewaterowsinthesamedirectionasthepropellerblade,andthatistosome

degreethecaseatthatsideofthekeelwherethepropellerbladesmovedownwards.

Mountthetransducerfarawayfromthebowthrusters

Bowthrusterpropellersareextremelynoisy.Wheninoperation,thenoiseandcavitation

bubblescreatedbythethrustermaketheechosounderuseless,almostnomatterwhere

thetransducerisinstalled.Andwhennotinoperation,thetunnelcreatesturbulence,

andifthevesselispitching,thetunnelmaybelledwithairoraeratedwaterinthe

upperpositionandreleasethisinthelowerposition.Ingeneral,alltransducersmust

bethereforeplacedwellawayfromthebowthruster.However,thisisnotaninvariable

rule.Certainthrusterdesignscombinedwithitsphysicallocationonthehullmaystill

offersuitabletransducerlocationsnearthethruster.Ifyouareindoubt,consultanaval

architect.

Mountthetransducerwithaslightlyinclinedtransducerface

Ideally,thetransducerfaceshouldbemountedinparallelwiththeseasurfacewhen

thevesselisinnormaltrim,asthiswillprovidethemostaccurateechoinformation.

However,itisalsoveryimportantthatthew

a t e r  o w overthetransducerfaceislaminar.

Inordertoensurelaminarow,thetransducerfacemaybetiltedslightlyupwardsin

relationtothewaterow.Thisallowstheowingwatertomeetthefacedirectly,and

assureslaminarow.Theinclinationanglemusthoweverbedeterminedcarefully.The

anglemustbesmallontransducerswithnarrowbeamangles.Asaruleofthumb,mount

transducerswithbeamanglessmallerthansevendegreeswithminimuminclination

angle.Thesmallerbeamangleyourtransducerhas,thesmallertheinclinationanglecan

be.Ensurethatyoudonotmountthetransducerwithanegativeinclinationangle.This

maycauseturbulenceunderthetransducerface,andreducedechosounderperformance.

Summaryandgeneralrecommendations

Someoftheaboveguidelinesareconicting,andeachcasehastobetreatedindividually

inordertondthebestcompromise.Generallythepropellernoiseisthedominantfactor,

andarecommendedtransducerlocationisintheforepartofthehull,withmaximum

distancefromthebowequaltoonethirdofthetotallengthofthehullatthewaterline.

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