Simrad ST90 - Measuring the B-Scan Noise with the Transducer Disconnected from the Transceiver Unit

442703/B
285
Requirements
Results
Maximumnoiselevel(indB)shownontheNoisepagewhenthetransducerisdisconnectedis≤25dB.
MaximumnoiselevelmeasuredontheNoisepage:
Dateandsignature:
Relatedtopics
Settingtoworksummary,page242
TurningontheST90forthersttime,page276
MeasuringtheB-Scannoisewiththetransducer
disconnectedfromtheTransceiverUnit
Lownoiseisakeyfactorforhighqualityandreliablemeasurements.Theperformance
oftheST90willalwaysbelimitedbydifferentnoisesources.Ahighnoiselevelwill
masktheechoesandmakethemdifculttoreadandinterpret.Thenoiseismeasured
whiletheST90operatesinPassivemodewiththetransmitpulsesdisabled.
Prerequisites
TheST90isinstalledasspeciedinthismanual.Allcables-exceptthetransducer-are
properlyconnected.Neithertoolsnorinstrumentsarerequired.
Context
Thistaskallowsyoutocheckthenoiseconditions.Tomeasurethenoiselevel,observe
thevaluepresentedontheB-ScanpageintheElementBITE(ElementBuiltInTest
Equipment)dialogbox.
Note
ThistaskmustbedonewiththetransducercabledisconnectedfromtheTransceiverUnit.
Procedure
1OpentheOperationmenu.
2SetTXPowertoOff.
3Makethefollowingpreparations.
aAtthebottomoftheST90presentation,selectasuitablepresentationmode,
andactivatetheHorizontalview.
bSetFrequencyto14kHz.
cSetRangeto1500m.
Settingtowork