Kongsberg EA440 - Transducer Placement Guidelines

392616/B
19
Wheretoinstallthetransducer
Topics
Introductiontotransducerlocation,page19
Mountthetransducerdeep,page19
Avoidprotrudingobjectsnearthetransducer,page20
Keepthetransducerfarawayfromthepropellers,page21
Mountthetransduceratasafedistancefrombowthruster(s),page21
Summaryandgeneralrecommendations,page21
Introductiontotransducerlocation
Asingleanswertothequestion"wheretoinstallthetransducer"cannotbegiven.
Thephysicallocationofthetransducerdependsonthevessel'sdesignandconstruction,
howthehullisshaped,andhowthewaterrunsalongthehull.Therearehowevera
numberofimportantguidelines,andsomeoftheseareevenconicting.
Note
Theinformationheremustbeconsideredasgeneraladvice.EachEA440installation
mustbehandledseparatelydependingonthehulldesignandtheotherelectricaland
mechanicalsystemsinstalledonthevessel.
Mountthetransducerdeep
InordertoachievethebestpossibleEA440performance,mountthetransducerasdeep
aspossibleunderthevessel’shull.
Thereareseveralreasonsforthisrecommendation.
Flownoise
Considerthesituationswhenthevesselisunloaded,andpitchinginheavyseas.The
vesselisridinghigh,andthebowmayevenbeliftedoutofthewater.Thiswillcausea
lotofairtofollowtheshapeofthehull.
Theupperwaterlayersoftheseacontainamyriadofsmallairbubblescreatedbythe
breakingwaves.Inheavyseastheupper5to10metresmaybelledwithair,andthe
highestconcentrationswillbenearthesurface.Airbubblesabsorbandreectthesound
energy,andtheymayinworstcasesblockthesoundtransmissionaltogether.
Preparations