Teledyne 9060Z 4.17FILTERPURGING, 4.18CALIBRATIONGASCHECK, 4.19DUSTINTHEFLUEGAS

Model9060ZManual

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25

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highimpedancealarm,‘Probe1(2)HighImpedance’,isnotactive.Theactualimpedancecanbe

displayedonthelowerline.Itshouldbelessthan9KΩat720°C(1320°F).

Onceithasbeenestablishedthattheimpedanceisnormal,theoffsetmaybesetusingthemillivolt

valuemarkedontheoxygenprobe.Seechapter6.3.1,ProbeOffset.Theprobeoffsetcanbetestedon

site.Asmallflowofairmustbeadmittedtoboththe‘REF’and‘CAL’portswhentestingtheprobe

offset.Iftheprobeisintheprocess,theairmustfullypurgetheprobesensorwithoutinterference

fromtheprocessgassample.TeledyneAnalyticalInstrumentsprobescaneasilyachievethiswithor

withoutaprobefilterandagasflowofonly1to5SLPM(2to10SCFH)fora9060Hprobeandupto

20SLPM(40SCFH)foranunheatedprobe.Whenastableoxygenreadinghasbeenachieved,readthe

‘ProbeEMF’.Enterthisvalueintotheset‐upmenu#1fortheprobe1(set‐up#2forthesecondprobe

ifitisinstalled).

4.17FILTERPURGING

Purgingprobefiltersiscontrolledfromthe‘GAS/PURGE’buttonsonthetransmitterwhenin‘RUN’

mode.If‘Automatic’hasbeenselectedineither‘Sol.1Auto/Man’or‘Sol.2Auto/Man’in

CommissioningMenus21or30,pressingtheGAS/PURGEbuttonwillstarttheautomaticcycle.

Pressingthebuttonagainwillcanceltheautopurgecycle.If‘Automatic’wasnotenabled,the

solenoidwillonlystayopenforaslongasthebuttonispressed.Graduallyadjustthepurgeairsupply

regulator,increasingthepressureuntilsufficientflowisobtainedtoclearthefilter.Thisisbest

checkedwithadirtyfilterafteraperiodofoperation,bywithdrawingtheprobefromserviceand

watchinganybuilduponthefilterbeingblownoffatthesetpressure.Normally30kPa(5psi)is

adequatebuttheairpressuremaybesetashighas100kPa(15psi).

4.18CALIBRATIONGASCHECK

Iftheinstallationhasafilterpurgefacility,setthisupfirst.Refertothepreviousparagraph.Pressthe

‘GAS/PURGE1or‘GAS/PURGE2’buttonwhilein‘SETUP’modetoobtainareasonableflowthrough

thecalibrationcheckgasflowmeter.Ifairisbeingusedasacalibrationcheckgas,usetheairfromthe

regulatorforfilterpurge.Then,whensettingupagasforcalibrationchecking,setthepressurefrom

thecalibrationgascylindersothatitisthesameasthepressuresetontheairregulator.Thenthe

settingontherotameter/flowregulatorwillbethesameasthatfortheairflow.Theflowrequiredis

1to5SLPM(2to10SCFH)fora9060Hprobeandupto20SLPM(40SCFH)foranunheatedprobe.

Airisnotthebestgasforcalibrationcheckingonazirconiasensor.Theoutputofazirconiasensor

withaironbothsidesofthesensoriszeromillivolts.Itisbettertochooseagasvaluewhichprovides

areasonableoutputfromthesensorandwhichisneartotheprocessoxygenlevel.Acylinderwith2%

oxygeninnitrogenisacommonlyusedcalibrationgas.Themaximumpressureonthecalibration

checkgascylinderregulatorsis100kPa(15psi).

Note:If‘Dualprobe’wasselectedincommissioningmenu4,‘CalGas2’mustbeconnectedtoprobe2.

4.19DUSTINTHEFLUEGAS

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Forheatedprobesthepreferredmethodofmountingfordust‐ladenapplicationsisfacingvertically

Forunheatedprobeswithnofilter,entrainedsolidsordustinthefluegasdoesnotpresenta

problemunlessthedust,whensettled,isnotporous.Allowthedustintheprocesstobuildupon

theprobe.Itwillformaporouslayerslowingtheresponsetime.Toavoidmechanicalabrasionof

theelectrodematerialininstallationswithunheatedoxygenprobes,pack‘SAFFIL’orequivalent

aluminabasedceramicfiberinthesensingholestoprotecttheelectrode.Donotusesilicabased

ceramicfiberssuchas‘KAOWOOL’,whichcanattacktheelectrodeathightemperatures.Oncethe

dusthasbuiltu

theres

onsetimeofthe

robewill beslower.