Installation manual
SimradES70
Externalmountingofstreamlinedtransducer
Certaintransducershaveastreamlinedhousing,andthesearedesignedforinstallation
outsidethehull.Thesetransducersaremainlyusedonsmallervessels.Alocation
approximately0.5masidefromthekeelmaybeadequateforthepassageofwater
betweenthekeelandthetransducer.Theguresillustrateexternalmountingof
transducersonsteelhullsandonwoodorpolyesterhullsrespectively.
Smoothsurfaceisimportant
Mountingscrewsorboltsmustnotbeextrudingfromthetransducerorthearea
immediatelyaroundit.Makesurethatthesurfaceofthetransducerface,theinstallation
hardwareusedtomountit,thehullplatingandtheputtyaroundthetransducerisas
evenandsmoothaspossible.Obstructionsonthesesurfaceswillcreateproblemswith
turbulentow.
Toe-in
Theprimaryconsiderationmustbetoallowlaminarwaterow.Inmostcasesthisis
achievedbydesigningtheblisterinparallelwiththekeel.However,iftheblisteris
locatedclosetothebow,thefrontoftheblistermayhaveafewdegreestoe-intowards
thebow.
Figure24Toe-inprinciple
AKeel
BBlister
CToe-inangle
(CD17010C)
A
B
C
Theanglemustbechosentoallowformostefcientwaterow.Itwillvarywiththe
locationofthetransducer;thedepthbelowthehull,thedistancefromthebow,andthe
distancetothekeel.Typicalanglesarefrom0to3°ondeplacementhulls.Onplaning
hulls,theangleisnormallycloseto0°.
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