GDS Corp GDS-48 User manual

GDSCorp.
1245ButlerRoadLeagueCity,TX77573
409‐927‐2980409‐927‐4180(Fax)www.gdscorp.com
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Operation and Maintenance
Manual
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GDS‐48RemoteBridgeSensorforCombustibleGases,VOCsandCO2
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GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0
GDS Corp Page 2 [email protected]
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CAUTION: FOR SAFETY REASONS THIS EQUIPMENT MUST BE OPERATED AND
SERVICED BY QUALIFIED PERSONNEL ONLY. READ AND UNDERSTAND INSTRUCTION
MANUAL COMPLETELY BEFORE OPERATING OR SERVICING.
ATTENTION: POUR DES RAISONS DE SÉCURITÉ, CET ÉQUIPEMENT DOIT ÊTRE UTILISÉ,
ENTRETENU ET RÉPARÉ UNIQUEMENT PAR UN PERSONNEL QUALIFIÉ. ÉTUDIER LE
MANUE D’INSTRUCTIONS EN ENTIER AVANT D’UTILISER, D’ENTRETENIR OU DE
RÉPARER L’ÉQUIPEMENT.
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REVISIONHISTORY
Revision1.05/1/13 InitialRelease
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Copyright©2013GDSCorp.AllRightsReserved
P/N1200‐0853‐01

GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0
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GDS Corp Page 3 [email protected]
CONTENTS
1SAFETYINFORMATION.............................................................................................................................................4
2GENERALINFORMATION..........................................................................................................................................5
CATALYTICBEADSENSORS................................................................................................................................................5
INFRAREDSENSORS.........................................................................................................................................................5
PIDSENSORS.................................................................................................................................................................5
3SPECIFICATIONS........................................................................................................................................................6
4INSTALLATION..........................................................................................................................................................8
CHOOSINGALOCATION...................................................................................................................................................8
ELECTRICALCONNECTIONS...............................................................................................................................................9
5CALIBRATION..........................................................................................................................................................11
CALIBRATIONOVERVIEW................................................................................................................................................11
GENERALIZEDCALIBRATIONPROCEDURE...........................................................................................................................11
6OPERATIONANDMAINTENANCE............................................................................................................................13
SENSORREPLACEMENT..................................................................................................................................................13
7SPAREPARTS..........................................................................................................................................................15
GRAYENCLOSURE.........................................................................................................................................................15
YELLOWENCLOSURE.....................................................................................................................................................15
SENSORHEADACCESSORIES...........................................................................................................................................15
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TableofFigures
Figure3‐1:RecommendedSensorTemperatureRangesandExcitation*....................................................................7
Figure3‐2:RecommendedSensorWarmupTimes.......................................................................................................7
Figure4‐1:GDS‐48GrayEnclosure................................................................................................................................8
Figure4‐2:GDS‐48WiringConnections(GrayEnclosure).............................................................................................9
Figure5‐1:ApplyingCalibrationGastoGDS‐48..........................................................................................................12
Figure6‐1:SensorReplacement..................................................................................................................................14
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GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0
GDS Corp Page 4 [email protected]
1SAFETYINFORMATION
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Important–ReadBeforeInstallation
UsersshouldhaveadetailedunderstandingofGDS‐48operatingandmaintenanceinstructions.UsetheGDS‐48
onlyasspecifiedinthismanualordetectionofgasesandtheresultingprotectionprovidedmaybeimpaired.Read
thefollowingWARNINGSpriortouse.
WARNINGS
TheGDS‐48sensortransmitterdescribedinthismanualmustbeinstalled,operatedandmaintainedin
accordancewithinformationcontainedherein.Installationinanyhazardousareamustcomplywithall
applicablerestrictions,requirementsandguidelinesforsaidhazardousareas.Itistheendusercustomer’s
finaldecisiontoensurethattheGDS‐48issuitablefortheintendeduse.
TheGDS‐48isdesignedandconstructedtomeasurethelevelofcertaingasesinambientair.Accuracyin
atmospherescontainingsteamorinertgasescannotbeguaranteed.
Alwaysmountthesensorheadverticallywiththesensorheadfacingdown.
Donotpaintsensorassembly.
DonotoperatetheGDS‐48ifitsenclosureisdamagedorcrackedorhasmissingcomponents.Makesure
thecover,internalPCB’sandfieldwiringaresecurelyinplacebeforeapplyingpower.
DonotexposetheGDS‐48toelectricalshockorcontinuousseveremechanicalshock.ProtecttheGDS‐48
andrelatedsensorassembliesfromdrippingliquidsandhighpowersprays.
Calibratewithknowntargetgasatstart‐upandcheckonaregularschedule,atleastevery90days.More
frequentinspectionsareencouragedtospotproblemssuchasdirt,oil,paint,greaseorotherforeign
materialsonthesensorhead.
Periodicallytestforcorrectoperationofthesystem’salarmeventsbyexposingthemonitortoatargeted
gasconcentrationabovetheHighAlarmsetpoint.
Useonlyforapplicationsdescribedwithinthismanual.

GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0
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GDS Corp Page 5 [email protected]
2GENERALINFORMATION
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TheGDS‐48RemoteBridgeSensorisdesignedtosupportremotesensorswithbridge‐styleoutputsignalsthatare
suitablefortransmissionoverlongdistances.TheGDS‐48isideallysuitedforinstallationwherereliabilityandcost
arecriticallyimportantandwherealocaldisplayisnotrequired.
Three‐wirebridge‐styleoutputcompatiblewithGDSCorpcontrollers.
CertifiedforuseinClassIDivision1,GroupsB,C&Dhazardousareas
Easily‐replaceablesensorelement
Faultindicationforsensorfailormissingsensor(atcontroller)
Constructedof316stainlesssteel
Reliablecatalyticbead,infraredorphotoionizationsensortechnology
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CATALYTICBEADSENSORSarethemostcosteffectivesolutionforthedetectionofcombustiblegases.
Catalyticbeadsensorsarecomprisedoftwoindependent‘beads’thatarewrappedwithaspecialwirethatvaries
inresistancebasedonchangesintemperature.Onebeadiscoatedwithamaterial(“catalyst”)thatpromotesthe
burningofanycombustiblegasthatmaybepresent.Duringoperation,anexcitationvoltageappliedtothesensor
raisesthetemperatureofbothbeadstoapre‐specifiedvalue.Whengasispresent,thetemperatureofthebead
withthecatalystcoatingincreases.Thischangestheratioofresistancebetweenthetwobeadsandindicatesthe
presenceofgas.Tooperateproperly,catalyticbeadsensorsmustbeinstalledandbalancedforzerowhennogasis
present.
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INFRAREDSENSORSuseinfraredlightsourcetodetecthydrocarbons.Carbon‐hydrogenbondsinmost
commonhydrocarbonmoleculesabsorbcertainfrequenciesofinfraredlight.Asaresult,whenanyhydrocarbon
gaspassesbetweentheinfraredsourceanddetector,thedetectoroutputdrops,indicatingthepresenceofgas.A
referencebeamthatisnotaffectedbyH‐Cbondsisusedtomonitorchangesinsourceintensityandeliminatefalse
alarms.GDSCorpSmartIRinfraredsensorscontainfullyintegratedsource,receiverandmicroprocessor‐based
circuitrytoperformthisfunctionandgenerateacatalytic‐beadstylebridgeoutput.
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PIDSENSORSareappropriateforvolatileorganiccompoundssuchasbenzeneortoluene.Aphotoionization
detector(PID)sensorusesultravioletlighttobreakdowncomplexmoleculesanddetecttheionizedcomponents.

GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0
GDS Corp Page 6 [email protected]
3SPECIFICATIONS
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Model:GDSCorpRemoteBridgeSensorforCombustibleGasesandCarbonDioxide
PowerInput:Excitationvoltage,dependentonsensor
Display:None
Input:DirectconnectbridgesensorsforcombustibleandCO2gases.
Accuracy:+/‐5%offullscale(typical)
Calibration:Outputisfactoryadjustedbutisnotcalibrated.Receivingdevicemustprovidezero
andspan(two‐point)calibration.TheGDS‐48iscompatiblewithallGDSCorp
controllerswithbridge‐styleinputsthatprovidetwo‐pointcalibrationcapability.
Output:Millivoltbridge‐styleoutputs
ResponseTime:Determinedbysensortype andrange
Temperature:Seeindividualsensortemperaturespecifications
FaultIndication:Providedbycontrollerorreceiver
Housing:Junctionboxepoxy‐coatedaluminum,sensorhead316stainlesssteel.
Approvals: CSAClass1,Division1,GroupsB,CandDExplosionProofwithflamearrestor;
Warranty:Twoyearsonelectronics,oneyearonsensor
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GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0
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GDS Corp Page 7 [email protected]
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SensorRange Temperature ExcitationVoltage*
50Methane0‐100%LEL ‐20°Cto+50
°
C4.5VDC@80mA
51Propane0‐100%LEL ‐20°Cto+50
°
C4.5VDC@80mA
52Methane0‐100%v/v ‐20°Cto+50
°
C4.5VDC@80mA
53CarbonDioxideMultiple ‐20°Cto+50
°
C4.5VDC@80mA
57EthyleneOxide0‐100%LEL ‐20°Cto+50
°
C4.5VDC@80mA
61PID10.6eVLowrange ‐20°Cto+60
°
C3.3VDC@35mA
62PID10.6eVHighrange ‐20°Cto+60
°
C3.3VDC@35mA
63PID9.6eVLowrange ‐20°Cto+60
°
C3.3VDC@35mA
64PID10.0eVLowrange ‐20°Cto+60
°
C3.3VDC@35mA
65PID10.0eVHighrange ‐20°Cto+60
°
C3.3VDC@35mA
70CatalyticBead0‐100%LELCH4 ‐40°Cto+60
°
C2.0VDC@300mA
71CatalyticBead0‐100%LELother ‐40°Cto+60
°
C2.0VDC@300mA
Figure 3-1: Recommended Sensor Temperature Ranges and Excitation*
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*Excitationvoltageisalwaysmeasuredatthesensorjunctionboxbetweenterminals“R”and“A”
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TypeSensorRecommendedWarmupTimeComments
50‐57SmartIRInfrared1hourInternalmicroprocessorprovidesfault
signalandtempcompensation
61‐64PhotoionizationDetector8hourAllowstimeforcontaminantsto
‘burnoff’bulb
70‐71CatalyticBead
4hoursOninitialstartup–mayrequireless
timeifpowerhasbeenturnedofffor
shorttime
Figure 3-2: Recommended Sensor Warmup Times
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GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0
GDS Corp Page 8 [email protected]
4INSTALLATION
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CHOOSINGALOCATION
Factorssuchasairmovement,gasdensity,emissionsourcesandenvironmentalvariablesaffectsensorlocation.
Airmovementbyfans,prevailingwindsandconvectionshouldbecarefullyevaluatedtodetermineifaleakismore
likelytoraisegaslevelsincertainareaswithinthefacility.Vapordensityofagasdeterminesifitwillriseorfallin
airwhentherearenosignificantcurrents.Lighterthanairgasesshouldhavethemonitorsmounted12–18inches
(30–45cm)abovethepotentialgasleakandheavierthanairgasesshouldbethisdistancebelow.Eventhough
theGDS‐48sensortransmitterisdesignedforruggedservice,itshouldbeprotectedfromenvironmentaldamage
fromwater,snow,shock,vibrationanddirt.
TheGDS‐48shouldalwaysbemountedwiththesensorheadopeningfacingdown.Ifnecessary,aSplashGuard
(p/n10‐0205)shouldbeattachedifthereisanychancethatwaterorliquidspraycouldenterthesensoropening
frombelow.Besuretoleavesufficientroom(~12”)belowthesensorheadtoalloweasyaccessforattachmentof
aCalibrationCupand/orremovalofthesensorheadcoverforsensorreplacement.
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Figure 4-1: GDS-48 Remote Bridge Sensor
TB1 
USER‐C‐AforCO MB US TI B L E, CO2orPIDSENSOR
USES‐R‐Cfo r OX YG EN orTOXICGASSENSOR
S—R—C
R—C—A
GrayEnclosureYellowEnclosure

GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0

GDS Corp Page 9 [email protected]
ELECTRICALCONNECTIONS
TheGDS‐48isathree‐wirebridge‐typesensorthatrequiresexcitationvoltageandoutputsamillivolt‐levelsignal
totheremotecontrollerorreceiver.Incorrectwiringcanresultinsensordamageorsensorfailure.
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Figure 4-2: GDS-48 Wiring Connections (Gray Enclosure)
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Figure 4-3: GDS-48 Wiring Connections (Yellow Enclosure)
TB1
USER‐C‐AforCO MB US T I B L E, CO2orPIDSENSOR
USES‐R‐Cfo rOX Y GEN orTOXIC GASSEN ‐SOR
S—R—C
R—C—A
Three‐wireconnection
toremotereceiveror
controller
Three‐wireconnection
toremotereceiveror
controller
“R”
“C”
“A”
“R”
“C”
“A”

GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0
GDS Corp Page 10 [email protected]
Shieldedcableisalwaysrecommended.Wiringshouldbeinstalledinmetalconduitwithnoothercablinginthe
sameconduit.WhenpowerisinitiallyappliedtotheGDS‐48theoutputmaymomentarilyindicateatemporaryoff‐
scalelow(FAULT)oroff‐scalehigh(OVERRANGE)valuebeforesettlingdown.AllGDSCorpcontrollersprovidea
‘warmup’intervalduringwhichthesensorinputisignored.Thiskeepsthecontrollerfromindicatinganalarmdue
tosensorwarm‐upcharacteristics.
Totalwarm‐uptimeisdependentonthetypeofsensorandrangeselected.GDSCorprecommendsafourtoeight
hourintervalbetweeninitialpower‐onandfirstcalibration.Ifthesensorhasbeenpoweredup,andhasonlybeen
offlineforafewhours,thewarm‐uptimewillbeshorter.
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