Simrad ST90 - Page 363

442703/B
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Itisalwaysbesttodomakethenoise/speedcurveunderrealisticconditions.Thismeans
thatallrelevantvesselssystemsshouldbeinuseasundernormaloperations.However,
ifyouexperienceabnormallyhighnoiselevels,youmaywanttorepeatthetestwith
"silentship"settings.Toisolatenoisesources,turnindividualvesselsystemsonoroffto
monitoranychangesinthenoiselevel.
Procedure
1Makesurethatyouhavesufcientwaterdepthbelowthekeelbeforeyoulower
thetransducer.
2Lowerthetransducertoitsbottomposition.
3Ifnecessary,establishaseparatecommunicationlinewiththebridgetoverify
thevesselspeedduringthetest.
4Makethefollowingpreparations.
aAtthebottomoftheST90presentation,selectasuitablepresentationmode,
andactivatetheHorizontalview.
bOpentheOperationmenu.
•SetOperationtoNormal.
•SetTXPowertoOff.
cOpentheActivemenu.
•SelectNoTVG.
•SetPing-PingFiltertoOff.
•SetAGC(AutomaticGainControl)toOff.
•SetRCG(ReverberationControlledGain)to0(zero).
dOpentheSetupmenu.
eSelectBITEtoopentheBITE(Built-InTestEquipment)dialogbox.
fSelectNoisetoopenthepage.
5Repeatthefollowingcycleforeachvesselspeed:
aAskthebridgetosetthespeed.
bOncethebridgereportsthatthespeedhasbeenobtained,selectStartNoise
Measurements.
cIfpossible,verifythevesselspeedonthetopbar.
dRecordthevaluesintheresulttable.
eCalculatetheaveragenoise,andrecorditinthetable.
fAskthebridgetosetthenextspeed.
6Whenallthemeasurementshavebeenmade,typethedata(speedandnoise)intoa
spreadsheettocreatethecurve.
7Hoistthetransducertoitsupperposition.
Settingtowork