Kurz B Series User Manual

KurzB‐SeriesOperationsGuide 6–7
Flow Meter Configuration
Cleaning A Sensor & The Purge Controller
Thesensorwascalibratedclean,andoperatingitcleanpreservesthebestcalibration.Any
materialthatbuildsuponthethermalsensorcaninsulateit,causingittoloselessheatandread
lowerthanwhenitwascalibrated.RefertotheKurzHardwareGuideforinformationfor
informationonmanually
cleaningadirtysensor.
Operatingadirtysensorthatisfield‐calibratedwithacorrectionfactorfortheproperflowrate
tendstobeunstable.Afteraprocessstopsandcoolsdown,thedirtbuildupfrequentlyflakesoff.
Thiscausesthesensortoreadhigherwhentheprocessrestarts.Theabsence
oftheinsulatingdirt
causesthepre‐andpost‐shutdowndatafrom thesameoperatingpointtomismatch.This
problemcanbelargelyavoidedbyinitiatingan automaticcleaningsystem.
Using the Integrated Purge Controller
TheB‐Seriesisavailableforsingle‐pointormulti‐pointapplicationswithapurgeversion
that incorporatesapurgecontroltimeranddata‐holdfunctionbuiltintotheflowtransmitter.
The cleaningsequencecanbeinitiatedfrom:
• Internalflowmetertimer
• Externalcontactclosurethroughdigitalinput#1
• WriteCoilcommandviaModbus
• HARTcommand
ThePurgeversionoftheflowmeterprovidesanautomatedcleaningmethodtoremoveasmuch
dirtbuildupaspossibleusinghighvelocitygasonthevelocitysensor.Thispurgemethodisvery
effectiveatincreasingtheintervalsbetweenmanualcleaning.Inmanycasesithasaltogether
eliminatedtheneedformanualcleaning ,significantlyreducingthecostofownership.
Thepurgegascanbeatambienttemperatureorheatedtotheprocesstemperature.
The advantageofusingheatedpurgegasisthatitdoesnotcondenseanyoftheprocessgas
onto thesensor,whichcouldcementthedirtontothe
sensorinsteadofblowingitoff.
Implementingtheinternaltimerwiththecleaningcontrolmakesiteasiertobeindependentof
theprocessoperation.VerificationforanactivePurgecycleispossiblebyqueryingastatus
registerthroughModbus(register1XXXX‐coilstatus#8)orusinganalarmconfiguredforpurge.

Themeter’sprocessvariables(flow,velocity,andtemperature)andanalogoutputsareheldat
theirvaluespriortothestartofthePurgecycle.Goingfromadirtysensortoacleansensorwill
showaspikeintheflowrateandvelocityafterthePurgecyclecompletes.Forapplications
that
needtightcontroloftheoperation,theexternalcontactclosureoffersthebestresults.

Kurz B Series Specifications

General

Brand	Kurz
Model	B Series
Category	Measuring Instruments
Language	English