GDS Corp GDS-48 Operation and Maintenance Manual

Brand: GDS Corp

Model: GDS-48

Type: Operation and Maintenance 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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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]

1 SAFETY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]

2 GENERAL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]

3 SPECIFICATIONS

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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”



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]

4 INSTALLATION

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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.



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

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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.



Figure 4-2: GDS-48 Wiring Connections (Gray Enclosure)



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.



GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0

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GDS Corp Page 11 [email protected]

5 CALIBRATION



CALIBRATIONOVERVIEW

TheGDS‐48doesnothavethecapabilitytoperformzeroandspancalibration.Finalzeroandspancalibrationmust

beperformedbythecontrollerorreceivingdevice.

FollowtheseGDS‐48calibrationguidelines:

 Calibrationaccuracyisonlyasgoodasthecalibrationgasaccuracy.GDSCorpcalibrationgasesare

traceabletoNIST(NationalInstituteofStandardsandTechnology).

 Neverusecalibrationgasthathaspasseditsexpirationdate.

 AlwaysuseaGDSCorpcalibrationcupthatcompletelysurroundsthesensorhead.

 BesuretouseZEROAIR,amixtureof21%oxygenand79%nitrogen,asazeroreferenceunlessyouare

certainthatnotargetgasexistsinthearea.Ambientgasmayresultinan‘elevatedzero’conditionthat

willcauseaFAULTtooccuroncetheambientgasisnolongerpresent.

 GDSCorprecommendsusingaspangasthatisbetween25%and75%offullscale.GDSCorpdoesnot

recommendusingfullscaleasthespansetpoint.

 Alwayscalibrateanewsensorbeforedependingonthedeviceforpersonnelorequipmentsafety

 Calibrateonaregularschedule.GDSCorprecommendsafullcalibrationevery3months,withperiodic

‘bumptests’onamorefrequentbasistoensurethatthesensorhasnotbeenaffectedbytemperature

extremesorthepresenceofincompatiblegases.



Ingeneral,calibrationinvolvesapplyingazeroreferencegasandtellingthereceivingdevicetoacceptthatoutput

as‘zero’,followedbytheapplicationofaspanreferencegasandthentellingthereceivingdevicetoacceptthe

newoutputas‘span’oncetheoutputhasstabilized.Thisisgenerallyperformedbytwopersons,oneatthesensor

transmitterandoneatthereceivingdevice.Actualprocedures,timeintervalsandtechniquesforindicatingzero

andspanvaluesdependonthespecificreceivingdevice.AllGDSCorpdisplayandalarmcontrollersprovidethe

necessarylocalcalibrationcapability.



GENERALIZEDCALIBRATIONPROCEDURE

Beforebeginningcalibration,makesureyouhavethefollowingitems:Acylinderofcalibrationgas,fixedflow

regulatorandanappropriatecalibrationcupconnectedtotheregulatorviaalengthofflexibletubing.Ifnecessary,

acylinderof‘zeroair’maybenecessaryiftheabsenceoftargetgascannotbeconfirmed.GDSCorprecommends

aflowrateof0.5liters/minute.

InthecaseofPIDsensors,itmaybedesiredtosubstituteasurrogategasforthetargetgas,especiallyifthetarget

gasisdangerousorunavailableinacalibrationgascylinder.Formoreinformationonsurrogategasesandrelative

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responsefactorsforcommonvolatileorganiccompounds,contactGDSCorpforalistofavailablegasesand

responsefactors.

Theactualstepsinvolvedincalibrationvarydependingonthereceivingdevice,butcanbegeneralizedasfollows:

1. SelecttheappropriatechannelonthecontrollerorreceiverandenableCalibrationMode.Thisshould

disablealarmsduringthecalibrationprocess.Makesurethatthecontroller’sCalSpanvaluematchesthe

cylinderofcalibrationgas.

2. ApplyzeroairtothesensorasshowninFig.6‐1orconfirmtheabsenceofanytargetgas.

3. Atthecontrollerorreceiver,pressthe“SetZero”buttontoconfirmthatthecurrentreadingis‘zero’.

4. ApplyspangastothesensorasshowninFig6‐1.

5. Atthecontrollerorreceiver,monitortheoutputuntilitstabilizes.Whenstable,pressthe“SetSpan”

buttontoconfirmthatthecurrentreadingcorrespondstotheSpanvalue.

6. Turnofftheregulatorandremotethecalibrationcupfromthesensorhead.

7. Atthecontrollerorreceiver,exitCalModeandresumenormaloperation.



Figure 5-1: Applying Calibration Gas to GDS-48

CylinderofCalibrationGas

FixedFlowRegulator

CalibrationCup

GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0

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GDS Corp Page 13 [email protected]

6 OPERATIONANDMAINTENANCE



Inthenormaloperatingmode,themillivolt‐leveloutputcorrespondstothedetectedgasconcentration.Inthe

eventofasignificantgasrelease,theGDS‐48willindicateanoverrangeconditionifthesensor’soutputcontinues

toincreasebeyondthefullscalevalue.Intheeventthatthesensoroutputdropsbelowzeroduetointerference

gasesorsensorfailure,theoutputwilldroptozero,indicatingaFAULTconditiontotheremotereceiveror

controller.Ifthesensorisremoved,theoutputwillalsodroptozero.



TheGDS‐48shouldbecheckedregularlyfordamage,wateringressorflamearrestorcloggingduetoexcessivedust

ordirt.Iftheflamearrestorhasbecomecontaminatedbydust,dirtormoisture,removethesensorheadcover

(afterfirstmakingsuretodeclassifythearea)andcarefullycleanwithcompressedair.Useofsolventis

discouragedasremnantsofthesolventmaterialmayaffectthesensor.Therearenouser‐serviceablecomponents

andmaintenanceislimitedtocleaningand/orsensorreplacement.



SomeGDSCorpcontrollersandgasdetectorsmonitor‘sensorlife’bycalculatingavaluebetween0and100%

basedonthecurrentresponsetocalibrationgasascomparedtotheinitialresponsewhenthesensorwasfirst

installed.Toensurethatthecalculationsareaccurate,pleasemakecertaintofollowthe‘newsensor’installation

instructionsintheappropriatedevicemanual.



SENSORREPLACEMENT

IfasensorshowsFAULT,doesnotrespondtogasorcannolongerbecalibrated,itshouldbereplaced.GDS‐48

sensortransmittersuseGDSCorptype10‐95XXsensors,wheretheXXisthegastypeshowninSection3.The

rangevalueshouldalsobespecifiedwhenorderingreplacementsensors.Forexample,areplacementSmartIR

infraredforcombustiblegas,0‐100%LELwouldbe“10‐9550‐R0100”.



Toreplaceasensor,reviewFig.6‐1andfollowthesesteps:

1. DeclassifytheareaorremovepowertotheGDS‐48.

2. Unscrewthesensorheadcover.Ifunabletoopenthecoverbyhand,useaSensorHeadReplacement

Tool(p/n10‐0187).

3. Removetheoldsensorbypullingstraightdown.

NOTE:PULLSTRAIGHTDOWN.DONOTTRYTOUNSCREWTHESENSOR.

4. Carefullyinstallthereplacementsensorbyaligningthearrowonthesensorwiththearrowengravedon

thesensorhead.Pushstraightupuntilthesensorconnectorseatsfirmlyintothesensorconnector.

5. ReinstallthesensorheadcoverbyCAREFULLYscrewingthecoverontothesensorhead.

NOTE:IFTHESENSORFALLSOUTOFTHESENSORHEADDURINGTHISSTEP,ITCANBEDAMAGED.USE

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CAUTIONWHENREINSTALLINGTHESENSORHEADCOVER.



Figure 6-1: Sensor Replacement

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GDS Corp Page 15 [email protected]

7 SPAREPARTS



GRAYENCLOSURE



YELLOWENCLOSURE



SENSORHEADACCESSORIES



3.5”

8.0”

5.5”

Enclosure+SensorHead(Nosensor):

20‐0126Fullassemblylesssensor(gray)

Enclosure/JunctionBoxOnly:

20‐0099Grayjunctionboxenclosurew/PCB

SensorHead Only:

10‐0247Remotebridge‐stylesensor(Type1‐4)

Note:Doesnotincludesensor

Enclosure+SensorHead(Nosensor):

20‐0153Fullassemblylesssensor(yellow)

SensorHead:

10‐0247Toxic(Type1‐4)

Note:Doesnotincludesensor

Sensor:

10‐95xxGDSCorpbridgesensor

Sensor:

10‐95xxGDSCorpbridgesensor

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



SplashGuardFlowCell

SensorHeadSplashGuard

10‐0198SplashGuard(Fitsallsensorheads)

SensorHeadFlowCell

10‐0205FlowCell(1/8”NPTcompressionfittings)

20‐0205SOther(specify)

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8 DRAWINGSANDDIMENSIONS



Figure 8-1: GDS-48 Yellow Enclosure



5.0”

7.75”

GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0

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

Figure 8-2: GDS-48 (Gray Enclosure)



3.5”

3.5”

5.5”

8.0”

GDS Corp GDS-48 Operation and Maintenance Manual

Brand: GDS Corp

Model: GDS-48

Type: Operation and Maintenance Manual

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GDS Corp GDS-48 Operation and Maintenance Manual

GDS Corp GDS-48 Operation and Maintenance Manual

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