Greyline Instruments SLT32 - Appendix B - Applications Background

APPENDIXB-APPLICATIONSBACKGROUND
Conditionsinthetankorchannelwheretheultrasonicsensorisinstalledcanaffecttheperformance,
rangeandaccuracyofthesystem.Thefollowingnotesareforgeneralreference.ContactGreyline
Instrumentsoryourlocalrepresentativeforspecificinformationonyourapplication.
FOAM -Solidordensesurfacessuchasasmoothliquidsurfacewillgivethebestechosinan
ultrasoniclevelmeasuringsystem.Foamactsasasoundinsulatorandmayeliminate,orreducethe
strengthofanecho.Measurementrangemaybereducedinasystemwherefoamispresent.Ultrasonics
arenotrecommendedwherethickdensefoamiscontinuallypresent.Intermittentorthinlayersoflight
foam(1/8in.orless)cangenerallybedisregarded.Useastillingwellinopenchannelapplications.
LIQUIDS -TheSLT32isidealtomonitortankliquidlevelorinventory.Caustic,corrosiveorvery
viscousliquidscanbemonitoredwithoutcontactingtheliquid.
SOLIDS -TheSLT32willmeasuremostgranularmaterialandpowdersaswellasliquids.Powders
willnotgenerallyprovidethesameechostrengthasliquids.Thereforemaximumexpectedrangeshould
bereducedtoapproximately20feet(6m)forpowders.Therearemanyexceptionstothisruleand
installationofatestsystemisrecommendedwhenindoubt.
DUST -Anyobstructionstothesoundwillaffectperformanceofthesystem.Insilo’swhereheavy
concentrationsofdustareexpectedultrasonicsmaynotwork.Wheremoderatedustisencountered
careshouldbetakentomountthesensorinapositionwheredustaccumulationwillbeminimizedand
wherethesensorcanbecleanedifnecessary.
SENSORTEMPERATURE -ThestandardsensormodelPZ32TsuppliedwitheachLevel&Flow
Monitorincludesabuilt-intemperaturesensor.TheSLT32automaticallycompensatesfortemperature
fluctuationstoretainhighaccuracy.Notetheoperatingtemperaturerangeslistedintheproduct
specificationssection.Donotexceedthesensortemperatureratingsordamagemayoccur.
ELECTRONICSTEMPERATURE -Noteoperatingtemperaturerangeslistedintheproduct
specifications.Temperatureshigherthanthemaximumshowncanreducetheoperatinglifeofthe
electronics.Moisturecondensationfromthosetemperaturesbelowtherangeshowncanalsodamage
electronicscomponents.Incoldoroutdoorenvironmentstheoptionalfactory-installedenclosureheater
andthermostatisrecommended.
NOISE -BecausetheSLT32’ssensoroperatesathighsoundfrequency,regularprocessnoiseor
vibrationwillnotaffectthesystem.Sensorsinstalledincloseproximitytooneanotherinthesametank
may“cross-talk”andshouldbesynchronized.
VAPOUR -Mayaffectbutitcanbecompensatedforbycalibrationin-situ.Severevapourstratification
cancausefalseechoes.Variablevapourcannotbecompensated.
CHEMICALCOMPATIBILITY
-TheSLT32isconstructedofverydurablematerialswithbroad
compatibilities.TankcontentsshouldbecheckedfortheircompatibilitywithPVC.Anall-teflonsensor
isavailableforcorrosiveapplications.
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SLT32Level&FlowMonitor
ManualSeriesB.11