6.3 ClearingaBlockage
IfusingaDigitalSensorwithDiffusionSupervision,andiftheDiffusionSupervisionfeaturehasbeenenabledintheSensor
Settings,thesensorwillnotifytheuserifitdetectsforeignmaterialobstructingthesinteredmetalfritwheregaswould
normallyenterthesensor(seeFigure43).Whenthisconditionisdetected,thetransmitterwillgointofaultandshow
“DiffusionSupervisionFault”onthedisplay.Followtheserecommendedstepstoattempttoclearthisfault:
1. Inspectandclearthesensorinletandfrit.
2. Inspectandclearanyaccessoriesattachedtothesensor.
3. EnsureSensorisfullymatedtotheSensorBodyAssembly.
4. AttempttorecalibratetheSensor.
5. DisableDiffusionSupervisionorreplacetheSensor.
First,withthesensorstillinstalled,visuallyinspectthesensortoseeifanyobjectsarecoveringthegasinletandremove
them.ExampleobjectsmayincludetapeorthegreenCalibrationCap.Next,checktomakesurethatthereisnoforeign
materialstucktothefrit.Ifanymaterialisfound,gentlyremoveitwhileconsideringanyhazardsthatmayarisefromsuchan
action,liketheaccumulationofastaticcharge,andtakingthenecessarystepstoavoidthem.Takecaretoensurethatthe
fritisnotdamagedduringthecleaningprocess.DONOTusewaterorliquidstotrytocleanthefrit.Thefritactslikea
spongeandwillretainliquids,whichwillkeepthegaspathblocked.
Figure 44 Frit Location
WARNING!
ThesensorreliesonthefritasapartofitsFlameproof/Explosionproofapproval.Ifthefritisdamagedwhileattemptingto
cleanit,immediatelyremovepowerfromthedevice.Ensuretheareaisfreeofahazardousatmosphere,thenfollowall
stepsasoutlinedinthismanualtoproperlyreplacethesensor.
Failuretofollowthiswarningcanresultinseriouspersonalinjuryordeath.
Ifnomaterialisvisible,thefritmaystillbeblockedbyaliquidwhichhasabsorbedintothefrit.Onceabsorbed,liquidsare
verydifficulttoremove.Forthesesituations,relyingonnaturalevaporationisrecommended.Duetothetimeitcantakefor
liquidstoevaporatesufficientlyfromthefrit,usersmaywanttoconsiderswappingouttheaffectedsensorwithonethatis
knowntobeclear.Placingabsorbentmaterialagainsttheoutersurfaceofthefritcanhelpacceleratethisprocess.
IfasensorisinDiffusionSupervisionFault,thedevicewillstillallowtheusertoattempttocalibratethesensor.Intherare
eventthatasensorcalibrationissuccessful,buttheDiffusionSupervisionsystemcontinuestodetectablockageinthegas
path,theDiffusionSupervisionFaultwillreturninapproximately24hours.Inthisscenario,thereislikelyanenvironmental
factoraffectingtheDiffusionSupervisiondetection.Providedthesensorcansuccessfullycalibrate,thesensorisstill
US Ultima X5000 Gas Monitor 71
6 Maintenance