ECD FCA-22 User manual

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FCA‐22InstructionManual
FreeChlorineAnalyzer/Controller
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The information and technical data disclosed in this document may be used and disseminated only for the purposes and to the
extent specifically authorized in writing by Electro-Chemical Devices. Electro-Chemical Devices reserves the right to change
published specifications and designs without prior notice. Part No. 33FCA-22 Revision A A/05-08

FCA‐22InstructionManual
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TableofContents
GeneralDescription
ProductDrawing3
Applications4
Components4
HowitWorks4
InfluencesontheMeasurement
pHValue5
Flowrate6
Temperature6
InstallationandStartUp
GeneralInformation7
Samplerequirements7
MountingandPlumbing7
PoweringtheC‐227
InstallingtheSensors7
StartUp8
Calibration
TemperatureSensor8
pHSensor9
ChlorineSensor10
CommissioningOutputs
4‐20mAoutput12
Assigning&SettingRelays14
Maintenance
FreeChlorineSensor(FCS)18
pHSensor19
ConstantHeadFlowController19
Troubleshooting
TroubleshootingGuide20
Specifications
ProductSpecifications22
SpareParts23
Warranty
Warrantyandservice23

FCA‐22InstructionManual
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GeneralDescription
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FCA‐22Components(fromLefttoRight)
ConstantHeadFlowController
FreeChlorineSensorinFlowCell
pHSensorinFlowCell
C‐22Analyzer/Controller
Part#ModelandProductDescription
1290020‐1FreeChlorineAnalyzer,withautomaticpHcompensation,completeassembly,
panelmountedwithC‐22transmitter/controller
1290020‐2FreeChlorineAnalyzer,withmanualpHcompensation,completeassembly,panel
mountedwithC‐22transmitter/controller

FCA‐22InstructionManual
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GeneralDescription
Application
TheFCA‐22isdesignedforuseindrinkingwater,industrialcoolingandrinsewaterorothersamplesof
freshwaterthatusechlorineintherangeof0‐20ppmasadisinfectant.ChlorineexistsinwaterasapH
dependentmixtureofhypochlorousacidandhypochloriteion.Thesumofthesetwocomponentsis
referredtoasFreeChlorine,sometimesResidualFreeChlorine.
Organicchlorinecompoundsandchloramines,BoundChlorine,arenotdetectedbytheFCA‐22.Other
measurementtechniquesarerequiredforsamplescontainingtheseboundchlorinechemicals.Bound
ChlorineplusFreeChlorineequalsTotalChlorine.TheFCA‐22doesnotmeasureTotalChlorine.
Parts
TheFCA‐22isacompletesystemformeasuringFreeChlorine.Thepanelmountedsystemincludesa
ConstantHeadFlowController(CHFC),FreeChlorinesensor(FCS)andFlowCell,pHsensor(PHS10)and
FlowCellandtheC22Analyzer.SimplysupplypowertotheC22Analyzerandplumbthesamplelinein
andthedrainlineoutandtheFCA‐22isreadytouse.
Howitworks
TheFreeChlorineSensor(FCS)isanamperometricsensorwithaPTFEmembrane,goldcathodeanda
silver/silverchlorideanode.
TheC22analyzerappliesafixedvoltageacrosstheelectrodesandmeasuresthecurrentflow.
Hypochlorousacid(HOCl)diffusesthroughthePTFEmembraneandisreduced(gainselectrons)bythe
goldcathodetochlorideion.Silverontheanodeisoxidized(donateselectrons)tosilverchloride
completingthecurrentloop.Withstabletemperatureandsampleflow,thecurrentflowisproportional
tothefreechlorineconcentration.
Manycompetitivechlorinesensorsrequireserviceonamonthlyorbimonthlybasis.TheFCSusesalarge
surfaceareaanode,combinedwithalargevolumeofelectrolyteandasmallcathodetoprovide
operationalcyclesofuptoayearwithoutrefilling.ThereplaceablePTFEmembraneisalsodesignedfor
longtermstability.Aspecialsupportgridmaintainsaconstanttensionbetweenmembraneandthe
cathodeminimizingeffectscausedbyvaryingpressuresandflow.ReplacingthePTFEmembraneand
rechargingtheelectrolyteiseasilyaccomplishedwithouttheuseoftools.
TheCHFCmaintainsaconstantsampleflowtothepHandChlorineflowcells.Pressureregulatorsand
rotametersarenotneededtomaintainaconstantflowrate,theCHFCprovidestroublefreesample
conditioningbetween10and80gal/hr.
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FCA‐22InstructionManual
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InfluencesontheMeasurement
pHValue
TheFCSonlymeasurestheHOClcomponentofthetotalFreeChlorine.TheHOClproportionvariesfrom
100%atpH5.5to0%atpH10,seeFigure2.1.ThePHS10pHsensorprovidesautomaticcompensation
forthepHdependentratioofHOClandOCl‐presentinthewater.
ThePTFEmembranerejectschargedionsallowingonlyneutralmoleculestopassthrough.Saltsand
otherionicsubstancesareblockedbythemembraneeliminatinganyinfluenceonthemeasurementby
changesintheconductivityofthesample.TheHOClportionofthefreechlorinepassesthroughthe
membranetothecathodeandismeasuredwhilethenegativelychargedhypochloriteion,OCl‐,portion
isrejectedbythemembrane.TheC‐22analyzerusesthepHfromthePHS10sensortocalculatetheOCl‐
value.ThemeasuredvalueandthecalculatedvaluearecombinedanddisplayedasFreeChlorine.
TheDPDcalibrationmethodmeasurestheTotalChlorinebybufferingthesampletopH6.3,thereby
convertingtheentireamountofchlorinetoHOClandthenmeasuringthisHOClcomponent.ThepH
compensationalgorithmintheC‐22isdesignedtomatchthismethod.Thehighestaccuracyisattained
withcalibrationsperformedatneutralpHvaluesandhigherchlorineconcentrations.Theaccuracyof
thecompensationdecreaseswhenthepHisabovepH8sincethereislittlechlorinetomeasureanda
largecompensationtoperform.
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Figure2.1
Flow
TheFCSconsumeschlorinetoproducethesignal.Theareanearthesensingtipwillbecomedepletedof
chlorinewithoutadequateflowtoreplenishthesample.Thesensorrequiresaminimumvelocityof0.5
ft/secpastthemembrane.Belowthisvaluethesensorwillindicatealowerconcentrationthanthe
actualvalue.Higherflowrateshavelittletonoeffectonthemeasurement.SeeFigure2.2.
0
20
40
60
80
100
46810
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pH
pHEffects
%HOCl
%OCl

FCA‐22InstructionManual
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Figure2.2
Temperature
TemperaturevariationinfluencestheFCSbychangingthepermeabilityofthePTFEmembraneandthe
Nernstianresponseofthesensor.Combinedthesechangesaccountforachangeof4%/C°.Thechange
followsthetemperature,asthetemperatureincreasestheoutputofthesensorincreases,asthe
temperaturedropstheoutputdrops.TheFCA‐22automaticallycompensatesforthechanges.The
temperaturesensorislocatedinthepHsensorandithasaresponsetimeofseveralminutes.Rapid
changesoftemperaturewillintroduceanerroruntilthesensorhasequilibratedtothenew
temperature.Calibrationshouldbedoneclosetotheprocesstemperatureforthehighestaccuracy.See
fig.2.3.
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Figure2.3
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%output
Flowrate,gal/hr
FCAFlowdependence
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10
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0204060
mV/ppm
Cl2
TemperatureC°
FCATemperature
Dependence,4%/C°

FCA‐22InstructionManual
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InstallationandStartUp
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GeneralInformation
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MounttheFCA‐22inalocationwherethereiseasyaccesstotheanalyzerandsensors.Installthe
systeminanareawherevibrations,electromagneticandradiofrequencyinterferenceareminimizedor
absent.
Donotmountindirectsunlightorareasofextremeheat.TheFCA‐22issuitableforoutdooruseif
mountedwithaprotectivecoverorsunshield.
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SampleRequirements
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Theconstantheadflowcontrollercanadapttochangingsampleflowsbetween10and80gal/hr
(40‐300L/hr).
Minimumflow:10gal/hr(38L/hr)
SamplePressure:1to30psig(0.1‐2bar)
Temperature:32°to122°F(0°to50°C)
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MountingandConnectingtheInletandDrainfittings
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TheFCA‐22isintendedforwallmountingonly.Thesensorsinsertintotheflowcellsasshowninthe
figures.A¼”barbedfittingisprovidedforthesampleinlet.Ifdesired,a¼”compressionfittingcanbe
used.Thesampleinletis¼”FNPT.Thesampledrainsthroughthe¾”FNPTholeatthebottomofthe
CHFD.Attacha¾”fittingtoalengthofsofttubingandallowthewastetodraintoopenatmosphere.Do
notrestrictthedrainline.Thesamplecanbeintroducedafterthesensorshavebeencalibratedand
installedintheflowcells.
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PoweringtheC‐22
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AttachpowerasdescribedintheC‐22manual.Tightenthecableglandsprovideagoodsealtothe
cable.
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InstallingtheSensors
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TheFCA‐22issuppliedwiththesensorcablespre‐wiredtotheanalyzer.TheFCA‐22instrumentand
sensorswerecalibratedatthefactoryandshouldbereadyforusewhenassembled.However,changes
mayhaveoccurredduringshippingandstoragerequiringrecalibration.(SeeCalibrationsectionbelow)
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ThepHsensormountsintheFlowCellusingthesupplied¾”compressionglandfitting.Removethe
protectivecapandsaveitforfutureuse,thecapcontainsapotassiumchloridesolutionusecarewhen
removingthecapfromthesensor.Loosenthecompressionfittingtoallowthesensortospinfreelyin
thefitting.Insertthesensorintotheflowcellandhandtightentheglandfitting.RetractthepHsensor
approximately½”fromthebottomoftheflowcellandhandtightenthecompressionnuttofixits
position.TheChlorinesensorisheldintheflowcellwithaunionnut.Removetheprotectivecapand
saveitforfutureuse.Slidethesensorintotheflowcellandhandtightentheknurlednut.
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FCA‐22InstructionManual
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Page8
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StartUp
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Supplysampleflowtothesystem.Adjustthesampleflowuntilthewaterisoverflowingintothecentral
overflowtube.Athigherflowratestheexcesswaterwilloverflowdownthedrain.Aminimumflowof
10gal/minisrequiredtomaintaintheoverflowcondition.Verifythesampleflowispassingthrough
bothflowcellsandreturningtothedrain.TheChlorineSensorrequires1‐1½hoursofpolarizationby
theinstrumentbeforeaccuratemeasurementscanbemade.Allowthesystemtorunatleast1hour
beforeproceedingtotheChlorineSensorcalibrationbelow.

Calibration

TemperatureCalibration

TheTemperaturesensorinsidethePHS10sensorwascalibratedatthefactorybeforeshipping.Verify
thedisplayedtemperatureagreeswiththeactualtemperature.Ifthevaluedeviatesbymorethan2°C
thenadjusttheTemperatureTrimintheConfiguration&TrimMenutothecorrectvalue.Foradetailed
descriptionseeTemperatureCalibrationintheC‐22manual.

TemperatureCalibrationScreenShots

#1EntertheConfigure/
TrimMenu
ScrolltotheConfigure
MenuusingtheMENU
SELECTkeyandenterthe
Menubysimultaneously
pressingbothHorizontal
CALIBRATEkeys.
#2Scrollthroughthe
PasswordsScreen
PresstheMENUSELECT
downKeyfourtimesto
thenextscreen.

#3Scrollthroughthe
RelayAssignScreen
PresstheMENUSELECT
downKeyfourtimesto
thenextscreen.

#4Choose°C/°F&temp
cal
SelecttheMenuby
Simultaneouslypressing
bothHorizontal
CALIBRATEkeys.

#5ChoosetheTrim°C
Menu
SelecttheMenuby
Simultaneouslypressing
bothHorizontal
CALIBRATEkeys.

#6AdjusttheTrimto
calibrate
thereading
Usingthevertical
CALIBRATEkeysadjust
thetrimtochangethe
Displayedtemperature
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FCA‐22InstructionManual
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#7Acceptthecalibration
PresstheMENUSELECT
downkeytoacceptthe
newvalue

#8ReturntoHome
Screen
PresstheCALIBRATE
downkeytoreturntothe
HomeScreen.


pHCalibration

ThePHS10pHsensorwascalibratedwithpH7.0andpH10.0buffersatthefactorybeforeshipping.
VerifythedisplayedpHagreeswiththeactualpH.IfthepHvaluedeviatesbymorethan0.2pHthen
adjustthevalueintheBuffer:#1pH:MenubysettingtheexistingpH7valuetotheactualsamplevalue
andthenacceptingthecalibration.ForadetaileddescriptionseeElectrodeStandardizationintheC‐22
manual.

pHCalibrationScreenShots

Calibration2point
(Zeropt.andSlope)
#1HomeScreen
PressMenuSelect
Upbutton


#2SelectionMenu
StatusScreen
PressMenuSelect
Upbutton


#3SelectionMenu
SetUpScreen
PressMenuSelect
Upbutton


#4SelectionMenu
BufferScreen
(calibration)
SelectBUFFERby
simultaneouslypressing
thehorizontalCALIBRATE
keys.

#5ZeroPointCalibration
Initiatethecalibrationby
simultaneouslypressing
thehorizontalCALIBRATE
keyswiththesensorina
7.00pHsolution,or…

#5aStandardizetothe
SamplepHvalue
Adjustthedisplayedvalue
toagreewiththesample
valueusingtheCALIBRATE
keys
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FCA‐22InstructionManual
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#6AccepttheCalibration
Acceptthecalibrationby
pressingtheMenuSelect
downkey.CalmVindicates
thesensorsoutputin7
buffer.


#7MovetoSecondBuffer
PressMenuSelect
Downbuttontwice.


#8SlopeCalibration
Initiatethecalibrationby
simultaneouslypressing
thehorizontalCALIBRATE
keyswiththesensorina
10.00pHsolutionoradjust
toadifferentbuffer.

#9AdjustBufferValue
Usethehorizontal
CALIBRATEkeytoselectthe
digittobeadjusted.


 #10AdjustBufferValue
UsetheverticalCALIBRATE
keytoadjustthevalueand
thenusethehorizontal
CALIBRATEkeytoselect
thenextdigittobe
adjusted.

#11AdjustBufferValue
UsetheverticalCALIBRATE
keytoadjustthevalue

#12Acceptthe
Calibration
AccepttheCalibration
whentheCalValueis
stableforgreaterthan30
seconds.PressMenu
SelectDownbuttonto
accepttheCalibration.

#13ReturntotheHome
Screen
LeavetheCalibration
Screenandreturntothe
HomeScreenbypressing
theCALIBRATEdownkey.



ChlorineCalibration

TheFreeChlorineSensor(FCS)zeropointandtheslope(sensitivity)werecalibratedatthefactory
beforeshipping.AllowtheFCA‐22systemtorunforatleast1hourbeforeproceedingwiththe
calibrationcheck.Thispolarizationtimeisnecessaryforstablereadingsandanaccuratezeropotential.
Verifythedisplayedchlorineconcentrationagreeswiththeactualvalue.Iffurthercalibrationis
necessaryverifythetemperatureandpHreadingsarevalidbeforebeginningthestandardizing
procedure.

Theprimarycalibrationisanadjustmentoftheslopeofthesensor,mV/ppmCl
2
.TheamperometricFCS
generatesanAcurrentproportionaltothechlorineconcentrationwhichissenttothechlorineinput
card.ThechlorineinputcardsendsamillivoltsignaltotheC‐22proportionaltothechlorine
concentration.
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FCA‐22InstructionManual
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PerformaDPDtestonthesampleandenterthemeasuredppmCl
2
valueintheBuffer:#2ppmMenu
andacceptthecalibration.ThedisplayedCalvalue,x.xxmV/ppmCl
2
willchangetothenewslopevalue.
ForadetaileddescriptionseeElectrodeSpanCalibrationintheC‐22manual.

**RecordthedisplayedCl
2
ppmreadingatthesampletime,ifthevaluehaschangedbeforefinishing
theDPDtestthencorrecttheinputvalueappropriately**.

Thezeropointofthesensorisextremelystableandshouldnotneedadjusting.Ifthecalibrationis
neededthenplacethesensorinasampleofchlorinefreeprocesswaterandallowittoequilibratefor½
hour.InitiatethestandardizationintheBuffer:#1ppmMenu.TheStandardizeValuewillbe0.00ppm
Cl
2
andtheCalvaluewilldisplaythenewmVsignalfromthesensor.

ChlorineCalibrationScreenShots

#1HomeScreen
PressMenuSelect
Downbutton

#2GraphicalDisplay
PressMenuSelect
Downbutton

#3SelectionMenu
SelectBUFFERby
simultaneouslypressing
thehorizontalCALIBRATE
keys.

#4ZeroPointCalibration
(optionalstep,setatfactory,
moveto#7)
Initiatethecalibrationby
simultaneouslypressing
thehorizontalCALIBRATE
keyswiththesensorina
0ppmchlorinesolution.
#5Adjustingzeropoint
Ifanon‐zeroppm
solutionisusedthen
adjustthevalueby
selectingthedigitwiththe
horizontalkeysandthe
valuewiththeverticalkey.

#6Acceptingthe
Calibration
Acceptthecalibrationby
pressingtheMenuSelect
downkey.

#7LeaveZeroCalibration
Screen
PressMenuSelect
Downbutton

#8SettingChlorineSlope
Initiatethecalibrationby
simultaneouslypressing
thehorizontalCALIBRATE
keyswiththesensorina
knownchlorinesolution.
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FCA‐22InstructionManual
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#9SettingtheChlorine
ppm
Usethehorizontal
CALIBRATEkeytoselectthe
digittobeadjusted.Setthe
screenvaluetotheDPDtest
reading.
#10AdjustingtheValue
Adjustthenumericvalue
withtheverticalCALIBRATE
keys.Adjustlargestdigit
first.

#11AdjustingtheValue
Movetothenextdigittobe
adjustedwiththehorizontal
Calibratekeys.

#12AdjustingtheValue
Adjustthenumericvalue
withtheverticalCALIBRATE
keys.
Oncethevaluehasbeen
settheanalyzerreading
willstabilize.

#13Acceptingthe
Calibration
Acceptthecalibrationby
pressingtheMenuSelect
downkey.

#14ReturntotheHome
Screen
LeavetheCalibrationScreen
andreturntotheHome
Screenbypressingthe
CALIBRATEdownkey.


CommissioningOutputs
4‐20mARange
TheFCA224‐20mAoutputisconfigured0‐20ppmFreeChlorine.TheRangecanbesettoothervalues
toaccommodatetheuser’srequirementintheSetUpMenu.ToaccesstheSetUpmenuscrolldown
fromtheHomeScreenusingthedownMENUSELECTkey.Enterthemenubysimultaneouslypressing
thehorizontalCALIBRATEkeysandthenscrolldowntothe4mAscreenusingtheMENUSELECTkey.
AdjustthevaluewiththeCALIBRATEkeysandacceptthechangewiththedownMENUSELECTkey.
Repeatforthe20mAscreen.FormoredetailsseetheC‐22Manual.
Settingthe4‐20mARangeScreenShots
#1HomeScreen
PressMenuSelect
Downbutton

#2GraphicalDisplay
PressMenuSelect
Downbutton

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FCA‐22InstructionManual
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#3SelectionMenu
PressMenuSelect
Downbutton

#4 ChooseSetupMenu
ToinitiatetheSetupMenu
Simultaneouslypressboth
HorizontalCALIBRATEkeys


#5DefinePlot
(GraphicalDisplay)
PressMenuSelect
Downbutton

#6SampleRate
(GraphicalDisplay)
PressMenuSelect
Downbutton


#7OutputRange
4mAvalue
Toinitiatethe4mAvalue
Simultaneouslypressboth
HorizontalCALIBRATEkeys

#8Adjusting4mAvalue
Factorysettingis0.00ppm
Anyvaluecanbeentered
usingtheCALIBRATEkeys
PresstheMenuSelect
downkeytoacceptthe
value

#9OutputRange
20mAvalue
PressMenuSelect
Downbutton

#10Adjusting20mA
value
Toinitiatethe20mAvalue
Simultaneouslypressboth
HorizontalCALIBRATEkeys


#11Adjusting20mAvalue
Selectthedigittochange
withthehorizontal
CALIBRATEkey

#12Adjusting20mA
value
Adjustthevaluewiththe
VerticalCALIBRATEkeys


#13AcceptingtheValue
Acceptthe20mAvalueby
PressingtheMenuSelect
Downkey

#14ReturntoHome
Screen
ToreturntotheHome
Screen
PresstheCALIBRATEDown
Key.



FCA‐22InstructionManual
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
Page14



AlarmRelays
TheFCA‐22hastwoassignablerelays.
Bothrelaysaresetto“unused”bythefactoryunlessspecifiedotherwise
bythecustomeratthetimeoforder.TheSPDTrelaysarefullyconfigurable,seeC‐22manualforamoredetailed
description.TheRelaysmustbefirstassignedintheConfigure/TrimMenuandthenconfiguredintheStepUp
Menu.Followtheexamplebelowforguidelinesonassigningandconfiguringtherelays.

ScreenShotsforAssigningtheAlarmRelays

#1HomeScreen
PressMenuSelect
Downbutton

#2GraphicalDisplay
PressMenuSelect
Downbutton

#3SelectionMenu
Buffer
PressMenuSelect
Downbutton

#4SelectionMenu
Setup
PressMenuSelect
Downbutton

#5SelectionMenu
Status
PressMenuSelect
Downbutton

#6Configure/TrimMenu
ToentertheConfigure
MenuSimultaneouslypress
bothHorizontalCALIBRATE
keys
#7PasswordsScreen
PressMenuSelect
Downbutton

#8DefaultDisplayScreen
PressMenuSelect
Downbutton

#94‐20AssignmentScreen
PressMenuSelect
Downbutton

#10ManualModeScreen
PressMenuSelect
Downbutton


FCA‐22InstructionManual

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Page15



#11RelayAssignment/Test
Toassignfunctionstothe
relayssimultaneouslypress
bothhorizontalCALIBRATE
keys

#12AccessRelay1menu
Toaccessthemenu
Simultaneouslypressboth
HorizontalCALIBRATEkeys

#13AssignRelay1to
Chlorine
PresstheUpCALIBRATEkey
toaccessPV1,
PV1=Chlorine

#14AcceptPV1
Toacceptthechange
pressMenuSelect
downbutton

#15SelectRelay2
PressMenuSelect
Downbutton

#16AccessRelay2menu
Toaccessthemenu
Simultaneouslypressboth
HorizontalCALIBRATEkeys

#17AssignRelay2
PressthedownCALIBRATE
keytoaccessPV2,PV2=pH
PresstheupCALIBRATEkey
toaccessPV1,
PV1=Chlorine
#18AssignRelay2
(Missing)
PressthedownCALIBRATE
key

#19AssignRelay2
(ch2temperature)
PressthedownCALIBRATE
key

#20Choose“ch2PV”
PressMenuSelect
Downbutton

#21ReturntoHome
Screen
PressthedownCALIBRATE
key

HomeScreen



FCA‐22InstructionManual
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Page16



SettingtheRelays
#1Ch1SetupMenu
Therelaysarefoundinthe
Setupmenuofthechannel
towhichtheywereassigned
Simultaneouslypressboth
HorizontalCALIBRATEkeys
toaccessthemenu.
#2PlotScreen
PressMenuSelect
Downbutton,twice

#3mARangeScreen
PressMenuSelect
Downbutton,twice

#4Relay1SetupScreen
1On=SetPoint
1Off=Hysteresispoint
Toaccessthemenu
Simultaneouslypressboth
HorizontalCALIBRATEkeys

#5ChooseHigh/LowAlarm
Pressthehorizontal
CALIBRATEkeytomovethe
cursorunderthe>.

#6SetHigh/LowAlarm
PressthedownCALIBRATE
keytochangeto<.Notice
theHysteresissignalso
changed.

#7LowAlarmvalue
Pressthehorizontal
CALIBRATEkeytomovethe
cursorunderthe0.

#8LowAlarmValue
PresstheverticalCALIBRATE
keystoadjustthevalue

#9AccepttheValue
PressMenuSelect
Downbutton

#10MovetoHysteresis
Line
PressMenuSelect
Downbutton

#11SettheHysteresis
Simultaneouslypressboth
HorizontalCALIBRATEkeys

#12Adjustthevalue
Pressthehorizontal
CALIBRATEkeytomovethe
cursorunderthedigittobe
changed.


FCA‐22InstructionManual
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Page17



#13AdjusttheValue
PresstheverticalCALIBRATE
keystoadjustthevalue

#14Adjustthevalue
Pressthehorizontal
CALIBRATEkeytomovethe
cursorunderthedigittobe
changed.

#15Adjustthevalue
PresstheverticalCALIBRATE
keystoadjustthevalue

#16AcceptHysteresis
Value
PressMenuSelect
Downbutton

#17ChooseRelay2
PressMenuSelect
Downbutton

#18SetHighalarm
Simultaneouslypressboth
HorizontalCALIBRATEkeys

#19Adjustthevalues
Pressthehorizontal
CALIBRATEkeytomovethe
cursorunderthedigittobe
changed.

#20AdjustandSavethe
value
SameasSteps8‐9

#21Setandaccept
Thehysteresis
SameasSteps11‐16

#22ReturntoHome
Screen
PressthedownCALIBRATE
key



FCA‐22InstructionManual
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Page18
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
Maintenance

FreeChlorineSensor

Checkthemeasurementatregularintervals,atleastonceamonth.Ifthemembraneisvisiblysoiled
cleanitwithajetofwateroradiluteHClsolutionbetween1‐5%.Donotcleanwithdetergentsor
solventsthatwouldreducethesurfacetensionofthemembrane.

ReplacingtheMembrane(PN1000238)
Replacethemembraneifheavilysoiledortorn.First
unscrewthemeasuringchamberandthenunscrewthe
membranecap.(Seefigure5.1)
Removethemembranefromthecap,replacethe
membraneandreinstallthecaponthemeasuring
chamber.FinallyRefillthemeasuringchamberas
describedbelow.

RefillingtheSensor
Refillthesensorwithelectrolyteonceayearorsooner
dependingonthechlorinelevelmeasured.Refillevery6
monthsforlevelsbetween10–20ppmandatevery
membranechange.
Unscrewthemeasuringchamberfromthesensorand
pouroutthespentsolution.
Fillthechambertoapproximately1cmfromthetop
andtapitgentlytodislodgeanytrappedbubblesinside
thechamber.
Screwthemeasuringchamberverticallybackontothe
sensorensuringallairinsidethechamberisdisplaced
withliquid.
Whentheo‐ringbeginstosealcontinueslowly
tighteninguntilthestop.
Thesensorisreadytouse,re‐polarizethesensorfor60
minutesandrecalibrateasdescribedabove.

Storage
ThemethodforStorageofthesensorisdependenton
time.
Forshorttermstorageofseveralweeksthesensorcanbestoredfilledinsidetheyellowprotectivecap
aslongasthemembraneisnotallowedtodehydrate.Makesurethespongeinsidethecapiswetted.
Forlongertermsrinseouttheelectrolytewithdistilledwaterandallowthesensortodry.Loosely
reassemblethedrysensorsoasnottotensionthemembraneduringstorage.




1. MeasuringChamber
2. Membrane
3. MembraneCap
Figure5.1

FCA‐22InstructionManual
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Page19
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pHSensor

Whenusedincleanwater,pHsensorsrequirelittlemaintenance.pHsensorsdorequireperiodic
calibrationduetodriftinthereferenceelectrodeasitages.ThisagingcausesthedisplayedpHvalueto
behigherthanthetruepHofthesample.
Checkthesensoronamonthlybasis,recalibrateifnecessary.CleanorreplacethepHsensorwhenit
becomesnoisyandslowtorespond.
IfthesensorneedscleaningthenitcanbesoakedinadilutesolutionofHCl,1‐5%,for10‐30minutes.
Thiswillremovescaleorbiofilmsfromthesensor,rinsewellandsoakinpH4bufferfor15minutes
beforereturningthesensortoservice.

ConstantHeadFlowController(CHFC)

TheCHFCisdesignedtoprovideaconstantflowtotheFreeChlorineSensor(FCS)independentof
variationsinthesamplepressure.DecreasingthesampleflowtotheFCSwilllowertheoutputofthe
FCS.InmostcleanwaterapplicationstheCHFCrequiresnomaintenance.Theverticalpositionofthe
centraltubesetstheHeadPressureofthesystem.Itissetforoptimalflowbutlowerflowratescanbe
attainedbyadjustingitsheight.
OnamonthlybasisvisuallyinspecttheCHFC,theinterconnectingtubingandthedraintubingfor
obstructionsorsedimentsthatmayreducetheflow.TheCHFCandtubingcanbeeasilydisassembled
andcleanedwithsoapandwater.SomedirtyapplicationslikeCoolingTowersmayrequireperiodic
cleaningduetosediments.

FCA‐22InstructionManual
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Page20
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
Troubleshooting

TheFCA‐22wasevaluatedandcalibratedatthefactorybeforeshipment.Uponinitialstartupthe
systemshouldrequireminimaltonoadjustments.
Verifythesystemhasadequateflow,greaterthan10gals/hr,thepHelectrodeandthetemperature
sensorarereadingcorrectly.Theseparameterseffectthemeasurementandmustmeetthestandards
listedintheCalibrationSectionabove.Iftheseconditionsaremetandproblemsstillexistusethe
TroubleshootingTabletofindaremedy.
TroubleshootingGuide

SymptomPossibleCauseRemedy

DisplayedvalueisHigher
thanDPDtestvalue.

InsufficientPolarizationtime


DamagedMembraneCap

pHindicationhigherthan
actualvalue

Temperatureindicationlower
thanactualvalue




Electricalshortorwet
connectioninsidethesensor
orcableassembly



PolarizeFCSforfull90
minutesbeforecalibration.

ReplaceMembraneCap

CalibratepHsensororadjust
valueonuncompensatedFCA

CalibratetheTemperature
(seeCalibration)The
temperaturesensorlagsthe
processtemperaturewaitfor
temperatureequilibrium.

Removemeasuringchamber
anddrythecathodesurface,if
theindicationdoesnotgoto
zerothereisleakage.Replace
thesensor.





DisplayedvalueisLowerthan
DPDtestvalue









Chloramineorotheroxidants
presentinsampleyieldinga
highDPDtest.

Coatedordirtymembrane






Replacewaterandchlorinate



Cleanorreplacethe
membrane


