Simrad ST90 - Making a Noise;Speed Curve to Determine Vessel Noise

360
442703/B
Requirements
Results
Weakelements:
Unserviceableelements:
Dateandsignature:
Relatedtopics
Settingtoworksummary,page242
TestingtheST90operationalfunctionality,page345
Makinganoise/speedcurvetodeterminevesselnoise
TheperformanceoftheST90willalwaysbelimitedbydifferentnoisesources.The
weatherandseaconditionsforthenoisemeasurementswillbethoseatthetimeofthe
test.
Prerequisites
TheST90isturnedon,anditisworkingnormally.Thevesselisatsea.Recommended
minimumdepthis100metres.
IftheST90isoperatedfromanyothercompartmentthanthebridge,anopentwo-way
oralcommunicationchannelwiththebridgeisrequired.
Youneedthefollowingequipment:
•Personalcomputer
•Spreadsheetprogram
Forthebestpossibleconditionstocompletethetest,theshipmustbe"silent".
•Theremustbenoothervesselsinthevicinity.
•Asmuchmachineryaspossiblemustbeswitchedoff.Itisparticularlyimportantto
switchoffelectricalmotors,aswellascoolingsystemsandhydraulicpumpsthat
maycauseelectricnoise.
•Topreventinterference,allotherhydroacousticinstrumentsmustbeswitchedoff.
Context
Inordertomeasurethenoise,youmustrecordthenoisevalueusingthefunctionality
intheBITEdialogbox.Sincethenoisewillvarywitheachping,youmustmakeve
measurementsforeachvesselspeed,andthencalculatetheaveragenoise.
Tip
Ifyourecordalltherawdataduringthenoisetest,youcanrepeatthetestlaterusing
thereplayle.Youmaythenusemorethanvenoisesamplesforeachvesselspeed
tomakeamoreaccuratecurve.
SimradST90InstallationManual