Simrad ST90 - Measuring the BITE Noise in Passive Mode with the Transducer Connected to the Transceiver Unit

350
442703/B
Result
Requirements
Results
Theloweringandhoistingfunctionality-asseenfromthesonarroom-is
operational.
Thetransducerisloweredandhoistedwithoutcomplicationsorobstacles.
Dateandsignature:
Relatedtopics
Settingtoworksummary,page242
TestingtheST90operationalfunctionality,page345
MeasuringtheBITEnoiseinPassivemodewiththe
transducerconnectedtotheTransceiverUnit
Lownoiseisakeyfactorforhighqualityandreliablemeasurements.Theperformance
oftheST90willalwaysbelimitedbydifferentnoisesources.Ahighnoiselevelwill
masktheechoesandmakethemdifculttoreadandinterpret.Thenoiseismeasured
whiletheST90operatesinPassivemodewiththetransmitpulsesdisabled.
Prerequisites
TheST90isinstalledasspeciedinthismanual.Thevesselisatsea.TheST90isturned
on,anditisworkingnormally.Neithertoolsnorinstrumentsarerequired.Inorder
todothistest,theshipmustbe"silent".
•Thewatermustbeasdeepaspossible.Recommendedminimumdepthis100metres.
•Theremustbenoothervesselsinthevicinity.
•Thevesselmustliestillinthewater.
•Asmuchmachineryaspossiblemustbeswitchedoff.Itisparticularlyimportantto
switchoffelectricalmotors,aswellascoolingsystemsandhydraulicpumpsthat
maycauseelectricnoise.
•Topreventinterference,allotherhydroacousticinstrumentsmustbeswitchedoff.
Thistestmustbeconsideredasindicative.Withthevesselinport,theenvironmental
conditionsarenotsatisfactory.Intheshallowwatersoftheport,noisefromother
vessels,dockyardworkersormachinerywillcauseunreliabletestresults.Ifyoudo
thistestsinabusyharbour,orwithnoisesourcespresent,thesensitivereceiverswill
detectallthenoiseinthenearbywaters.
Context
Thistaskallowsyoutocheckthenoiseconditions.Tomeasurethenoiselevel,observe
thevaluepresentedontheNoisepageintheBITEdialogbox.
SimradST90InstallationManual