Simrad ST90 - Page 357

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neighbouringchannelscauseaninterpolationthatwillrestorealotofthedegraded
presentation.
Whichactionstotakeifsinglechannelsfaildependontheoperationalimpact,the
overallperformanceoftheST90,andacost/benetassessment.Themostimportant
factorinthecost/benetassessmentiswhetheryouneedtoreplacethetransducer,
orjustasingletransceiverboard.Ifmorethan3%ofyourtransducerelementshave
failed,werecommendthatyoucontactyourdealerforadvice.
Note
Forfurtherinvestigationsofthisissue,usethefunctionalityofferedbytheElement
BITE(ElementBuiltInTestEquipment)dialogbox.
10Iftheresultfromthereceptiontestshowsanumberoftransducerelementsthatare
eitherdefectiveorofferreducedperformance,repeatthetest.
Withthevesselinport,theenvironmentalconditionsarenotsatisfactory.Inthe
shallowwatersoftheport,noisefromothervessels,dockyardworkersormachinery
willcauseunreliabletestresults.Ifyoudothistestsinabusyharbour,orwithnoise
sourcespresent,thesensitivereceiverswilldetectallthenoiseinthenearbywaters.
Excessivenoiseorinterferencemaybemisinterpretedasphysicaldefects.
Youmayneedtorepeatthetestseveraltimes,and-ifnecessary-implementa
"silentship"toimprovetheconditions.
11Finishthetest.
aClosetheBITE(BuiltInTestEquipment)dialogbox.
bSetTXPowertoOff.
cSetOperationtoInactive.
dHoistthetransducerbackuptoitsupperposition.
Result
Requirements
Results
Themaximumnumberofunserviceableelementsis3.
Dateandsignature:
Furtherrequirements
Ifthenoiselevelishigherthanspecied,youmustcheckthereason(s)forthis.
•CheckthegroundingoftheTransceiverUnit.
•Verifythatotherelectricequipmentand/ormachineryonboard,suchascooling
systems,hydraulicpumps,electricmotorsetc,donotinuenceonthenoisereading.
Switchoffasmuchmachineryaspossible,especiallyelectricalmotors.
•Checkforinterferencefromotherhydroacousticsystems.
•Checkforenvironmentalnoise,suchasothervesselsinthevicinityoranimallife.
Settingtowork