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




Operation and Maintenance
Manual



GDS‐48RemoteBridgeSensorforCombustibleGases,VOCsandCO2




GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0
GDS Corp Page 2 [email protected]



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.








REVISIONHISTORY
Revision1.05/1/13 InitialRelease








Copyright©2013GDSCorp.AllRightsReserved
P/N1200‐0853‐01

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

GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0
GDS Corp Page 4 [email protected]
1SAFETYINFORMATION

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

GDS Corp Page 5 [email protected]
2GENERALINFORMATION

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

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.

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.

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

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



GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0

GDS Corp Page 7 [email protected]

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*

*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


GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0
GDS Corp Page 8 [email protected]
4INSTALLATION

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

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

GDS Corp Page 11 [email protected]
5CALIBRATION

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

GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0
GDS Corp Page 12 [email protected]
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

GDS Corp Page 13 [email protected]
6OPERATION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

GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0
GDS Corp Page 14 [email protected]
CAUTIONWHENREINSTALLINGTHESENSORHEADCOVER.


Figure 6-1: Sensor Replacement

GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0

GDS Corp Page 15 [email protected]
7SPAREPARTS

GRAYENCLOSURE


YELLOWENCLOSURE




SENSORHEADACCESSORIES

3.5”
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

GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0
GDS Corp Page 16 [email protected]



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)

GDS-48 Remote Bridge Sensor Operation and Maintenance Manual, Revision 1.0

GDS Corp Page 17 [email protected]
8DRAWINGS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
GDS Corp Page 18 [email protected]





Figure 8-2: GDS-48 (Gray Enclosure)



3.5”
3.5”
5.5”
8.0”