Metal Samples MS2700E User manual





MS2700E
High Resolution ER RS-485 Transmitter
Operator’s Manual








































Metal Samples Company
ADivision of Alabama Specialty Products, Inc.
152 Metal Samples Rd., Munford, AL 36268 Phone: [phone] Fax: [phone]
E-mail:[email protected] Internet: www.metalsamples.com

Table of Contents



I.Introduction..............................................................................................................................................1
A.GeneralDescription...................................................................................................................1
B.PrinciplesofOperation..............................................................................................................1
C.TechnicalSpecifications.............................................................................................................3

II.InstallationandOperation.......................................................................................................................4
A.ReceivingtheMS2700Etransmitter..........................................................................................4
B.Installation.................................................................................................................................4
1.PhysicalMountingandProbeConnection...................................................................4
a.Direct‐ProbeMounting
......................................................................................4
b.RemoteMounting..............................................................................................5
2.PowerandDataConnections.......................................................................................5
a.MakingConnections........................................................................................5
b.Grounding.........................................................................................................6
c.SafeAreaInstallation........................................................................................7
d.HazardousAreaInstallation...............................................................................7
3.SetupandOperation.......................................................................................................9
a.ProbeSettings.................................................................................................9
b.RS‐485CommunicationSettings...................................................................10
i.BaudRateandDefaultCommunicationParameters.............................11
ii.DeviceAddress......................................................................................11
iii.CommunicationProtocols.....................................................................11
iv.TerminationResistor.............................................................................11
v.DataRegisters.......................................................................................11
c.CalibrationandTesting.................................................................................12
i.Calibration...............................................................................................12
ii.Testingoutputzeroandspan.................................................................12
iii.TestingtheMS2700EtransmitterwiththeMeterProver.......................12
d.InterpretingData...........................................................................................13
i.MetalLoss................................................................................................13
ii.CalculatingCorrosionRate.......................................................................14
e.Commissioning..............................................................................................15
C.Maintenance............................................................................................................................15
D.Troubleshooting.......................................................................................................................16

III.ServiceandWarrantyInformation.......................................................................................................17
A.Warranty...................................................................................................................................17
B.ObtainingServiceandReturningtheInstrumentforRepair....................................................17
C.InstrumentRepairForm...........................................................................................................18

AppendixA‐Drawings...............................................................................................................................19
ControlDrawing(HazardousAreaWiringDiagram).....................................................................20
SafeAreaWiringDiagram.............................................................................................................21

AppendixB–RevisionHistory...................................................................................................................22

1

I.Introduction

A.GeneralDescription

ThemodelMS2700E transmitterisahighresolutioninstrumentdesignedtomeasureandtransmit
corrosion(metalloss)datafromanElectricalResistance(ER)probetoaplantcontrolsystemorother
recordingdevice.TheMS2700E transmitterutilizesRS‐485communicationwhichallowsmultiple
unitstobedaisy‐chained,simplifyinginstallationandreducingassociatedcosts.TheuseoftheRS‐485
protocolalsoallowsthetransmittertobeplacedgreatdistancesfromthecontrolsystemorrecorder
whilemaintaininggoodnoiserejection.Practicaldistancescanbeupto4000feet.Additionally,the
MS2700E transmitteroffersuser‐selectableRTUorASCIIcommunicationprotocolsmakingithighly
versatile.
TheMS2700E transmitteriscompatiblewithalltypesofMetalSamplesERprobes,aswellasany
standardERprobefromothermanufacturers.Unlikecompetitors’products,theMS2700E
transmitterdoesnotrequirefactorymodificationtoaccommodatedifferentprobetypes.Theprobe
typecanbeeasilychangedatanytimeusingtheon‐boardprobeselectionswitches(seepage9.)
TheMS2700E transmitterisavailableasdirect‐mount(standard)orremote‐mount.Thedirect‐mount
versionismounteddirectlytotheERprobe.Thisoptionoffersthesimplestinstallationandminimizes
noiseproblems.Theremote‐mountoptionallowstheMS2700E transmittertobemounted
independentlyfrom(butincloseproximityto)theERprobe.Itisthenconnectedtotheprobeviaa
shortprobecable.(Seepages5and6formountingdiagramsandspecifications.)
B.PrinciplesofOperation

TheMS2700E transmitteroperatesontheElectricalResistance(ER)techniqueandisusedin
conjunctionwithanERprobe.TheERprobeutilizesaresistivesensingelementmanufacturedfrom
thematerialofinterest(oracloseapproximation)whichisexposedtoacorrodingenvironment.This
iscalledtheExposedorCorrodingElement.TheresistanceoftheExposedElementisdirectlyrelated
toitsthickness,soastheelementcorrodestheresultinglossofmetalcausesaproportionalincrease
intheelement’sresistance.TheprobealsocontainsaninternalReferenceElementwhichisusedto
compensatefortheinfluencesoftemperatureontheExposedElement.
TheMS2700E transmitterisdesignedtoworkwithanystandardERprobe,butitisrecommendedthat
CylindricalandLargeFlushtypeprobesbeusedtoensureoptimumperformance.Theirphysical
designplacestheReferenceElementincloserproximitytotheExposedElementcomparedtoother
probetypes,providingmoreeffectivetemperaturecompensationandthusreducingtheeffectsof
thermalnoise.
Becausetheyaredesignedtocorrode,ERprobesaresacrificialinnature.EachERprobewillhavea
finitelifethatisbasedontheelementthickness.ERprobesareavailableinanumberofgeometries
andthicknessesdesignedtosuitawidevarietyofapplications.Table1liststhecommonERelement
optionsavailablefromMetalSamplesandtheeffectivelifeofeach.

2

ElementTypeCompatibilityThicknessProbeLife
(Span)
TubularLoopCompatible
42
84
WireLoopCompatible
4010
8020
Flush(Small)Compatible
4 2
8 4
20 10
CylindricalPreferred
10 5
20 10
50 25
Flush(Large)Preferred
52.5
10 5
20 10
40 20

Table1.StandardERProbeElements
TheMS2700E transmittermeasuresanERprobeutilizingahigh‐resolution,16‐bitmeasurement.
Thisallowstheunittodetectmuchsmalleramountsofmetalloss,thusrespondingfasterto
corrosioneventsandupsets.At16‐bitresolutiontheMS2700E transmittercanmeasuremetalloss
amountsassmallas0.0015%oftheprobelife.

MetallossreadingstakenbytheMS2700E transmitterareoutputasadigitalRS‐485signalwhich
canbefedintoaplantcontrolsystemorotherrecordingdevices.TheMetalLossisrepresentedby
a16‐bitdigitalvaluebetween0and65535,where:

0=0mils(0%MetalLoss)
65535=ProbeLife*inmils(or100%MetalLoss)

*TheProbeLife(orSpan)oftheprobebeingused(seetable1above.)

TheMetalLossdatacanbeusedtocalculatethecorrosionratebetweenanyperiodsofinterest.
Thisiscoveredinmoredetailonpages13and14.MoreinformationonERprobes,theirtheory,
selection,andusecanbefoundonourwebsiteat http://www.alspi.com/erintro.htm.




3
C.TechnicalSpecifications
ModelMS2700EHighResolutionERRS‐485ModbusTransmitter
PhysicalData
InstrumentWeight: 3.70lb.(1.68Kg)
TotalWeightw/Accessories:5.76lb.(2.61Kg)
InstrumentDimensions:6.0"Hx4.0"Dia
(15.25cmHx10.16cmDia)
OperatingTemperature: ‐4°to158°F(‐20°to70°C)
StorageTemperature: ‐40°to176°F(‐40°to80°C)
EnvironmentalRating: IP66
EnclosureMaterial:316StainlessSteel
MountingSpecifications:Directprobemount(standard)
Maybepolemountedusingoptionalhardware
(Uptoa2.5”(6.35cm)Dia.pole)
PerformanceData
MeasurementType: ERmeasurementusinganystandardERprobetype
(WireLoop,TubeLoop,Cylindrical,Flush,Strip,etc.)
Range:0‐100%ofprobelife
Resolution:0.0015%ofProbeLife(16‐bit)
CycleTime:75Seconds
ElectricalData
PowerRequirements:10to28VDC
MaximumProbeCableDistance:30ft(9.1m)
OutputSpecifications:RS‐485Modbus,RTUorASCIIProtocol(SwitchSelectable)
2400/4800/9600/19.2KSelectableBaud
32MaximumUnits(Addresses1to32)
HazardousLocationCertifications–IntrinsicSafety
USA/CanadaConformstoANSI/ULStd.60079‐0,60079‐11,61010‐1
CAN/CSAStd.E66079‐0,E60079‐11&CAN/CSAC22.2No.61010‐1
ForStand‐AloneUseForMulti‐DropUse
ClassI,Zone0,AExiaIICT4GaClassI,Zone0,AExiaIIBT4Ga
Zone20,AExiaIIICT130°CDaZone20,AExiaIIIBT130°CDa
‐20°C≤Ta≤+70°C‐20°C≤Ta≤+70°C
EuropeandWorldwideForStand‐AloneUseForMulti‐DropUse
(ATEXandIECEx)II1GExiaIICT4GaII1GExiaIIBT4Ga
II1DExiaIIICT130°CDaII1DExiaIIIBT130°CDa
‐20°C≤Ta≤+70°C ‐20°C≤Ta≤+70°C
ATEXCertificateNo:ITS14ATEX28092X
IECExCertificateNo:IECExITS14.0052X
X‐seeSpecialConditions(page7)
IncludedAccessories
33’(10M)WiringHarness,MeterProver,OperationsManual
OptionalAccessories
ProbeExtensionCable,RemoteMountingHardware
4.0”Dia
(10.16cm)
6.0”H
(15.25cm)
Figure1.OverallDimensions

4

II.InstallationandOperation

A.ReceivingtheMS2700ETransmitter

ChecktheMS2700E Transmitterforanyshippingdamagewhenitisfirstreceived.Whentheunitis
unpacked,verifythatthefollowingitemsareincluded:

Transmitter
WiringHarness
MeterProver
User’sManual
ProbeCable(optional,forremote‐mountonly)
MountingHardware(optional,forremote‐mountonly)

Intheeventofshippingdamage,quantityshortage,ormissingitems,itisrecommendedthatthe
eventisdocumentedimmediatelyandthatdigitalphotographsaretaken.Anyshortagesormissing
itemsshouldbereportedtoMetalSamplesimmediately.Intheeventofshippingdamage,aclaim
shouldbeopenedwiththeresponsiblecarrier.
B.Installation

CAUTION:Usingthisproductinanywayotherthanthatspecifiedwithinthismanualmayimpairthe
intrinsicsafetyprotection.


InstallationoftheMS2700E transmitterinvolvesthefollowingsteps:

1. PhysicalMounting
2. ElectricalConnection
3. SetupandProgramming

1.PhysicalMountingandProbeConnection

WhenselectingalocationtomounttheMS2700E transmitteritisimportanttoconsiderthe
surroundingenvironment.Toensureproperoperation:

Donotmountthetransmitterinalocationthatexceedsitsoperatingtemperature.
Avoidmountingthetransmitternearsourcesofstrongelectricalnoise.
Ensurethatthereissufficientclearanceforinstallationandtoopenthetransmittercover
afterwards.

a.Direct‐ProbeMounting
TheMS2700E transmitterisdesignedfordirect‐probemountingwhicheliminatestheneedfor
additionalhardwareandtransmitter‐to‐probecabling.Thisgreatlysimplifiesinstallation,reduces
costs,andminimizeselectricalnoisethatcanbecoupledontoprobecablingfromnearbyelectrical
equipment.

BeforemountingtheMS2700E transmitter,firstensurethattheprobeisinstalledproperlyand
securely.Duringinstallationitisimportantthatyoudonotapplyexcessiveforceontheprobeor
seals,asdoingsocouldbreakthesealandresultinsystemleakage.

5

TomounttheMS2700E transmitter:

1. Alignthekeywaysofthetransmitterandprobeconnectors.
2. Insertthetransmitterconnectorplugfullyintotheprobeconnectorreceptacle.
3. Securethetransmittertothetopoftheprobebytighteningthecouplingnut.
NOTE:Hand‐tightissufficient.Donotover‐tightenthecouplingnut.
NOTE:Neverforcetheconnectorstomate.Ifthereisresistance,stopandcheckforbentpinson
theprobeandforforeignmaterialinthefemalesocketsofthetransmitterconnector.Gently
straightenanybentpinsandclearanyforeignmaterialthatmaybefound.



Figure2.DirectMountInstallation
b.RemoteMounting
Whenitisnotpracticaltodirect‐probemounttheMS2700E transmitter,theunitcanberemote
mountedinstead.Inthiscasetheinstrumentismountedtoaseparatemountingpoleusingthe
optionalRemoteMountingHardwareKit.ThetransmitteristhenconnectedtotheERprobeviathe
optionalprobeextensioncable.Whenpossible,thetransmittershouldbemountedwithin10’(3m)of
theprobetokeeptheprobecablingshortandminimizesignaldegradation.

2.PowerandDataConnections

a.MakingConnections
TheRS‐485connectionsaremadeviatheexternal6‐pincircularconnectorCN1asshowninFigure3.
Thishermeticallysealedconnectorpreventsmoistureingressandeliminatestheneedforinternal
wiringbyanoperator,thusreducingtheriskofphysicaldamagetothecircuitboard.

AlignKey
Insert
Connector Tighten
CouplingNut
12 3

6



Figure3.RS‐485Connector
Tofacilitatewiring,athreefoot(1meter)wiringharnessisprovided.Thiswiringharnessconnects
directlytothe6‐pinconnector,andextendstoanearbyjunctionbox(notincluded)tomakethe
necessarypoweranddatawiringconnectionsfromthecontrol(DCS/PLC)system.



Figure4.MS2700ETransmitterWiringHarness
NOTE:DonotconnectcableshieldingtotheTransmitter.Theshieldmustremainfloatingatthe
Transmitter.

ThemaximumpermissiblelengthofthefieldwiringbetweentheMS2700E transmitterandthe
controlsystemisdeterminedbythecontrolsystemsupplyvoltage,theelectricalresistanceofthe
cableandtheloadofthecontrolsysteminput.IftheTransmitteristobeinstalledinasafearea,refer
tosectionc.SafeAreaInstallationfordetails.IftheTransmitteristobeinstalledinahazardousarea,
refertosectiond.HazardousAreaInstallation.

b.Grounding

TheMS2700E transmitterenclosureisgroundedinternallythroughthewiringharness,butan
additional,externalgroundingterminalisprovidedaswell.Theenclosureshouldbegrounded
properlyusingtheexternalgroundingterminaltoensuresafeoperation.

ConnectorCN1
(PowerandData)
JunctionBox
(NotIncluded)
Wiring Harness

7

c.SafeAreaInstallation

TheMS2700E transmitterisapprovedforuseinhazardousareas,butcanbeusedinnon‐hazardous
areasaswell.Forbasicsafeareawiringinformationrefertothecircuitdiagramshownonpage21.


CAUTION:Whenusedinnon‐hazardousareas,equipmentmustbesuppliedwithapre‐approvedpower
supplyunitorapprovedequipmentwhichmeetstheentityparametersshownbelow.

Thepre‐approvedequipmentmustbecertifiedtotheelectricalsafetystandardsforequipmentin
ordinarylocations(forexample,EN/IEC/CSAUL61010‐1orEN/IEC/CSAUL60950‐1).Failuretomeet
theserequirementswillvoidtheintrinsicsafetycertificationoftheequipmentandprohibititsfuture
useinhazardousareas.


d.HazardousAreaInstallation


CAUTION:Thissectionprovidesgeneralguidelinesforhazardousareawiring.However,regardlessof
anythingstatedhere,theMS2700E transmittermustbeinstalledinfullcompliancewiththecontrol
drawinglocatedonpage20andallofthelocalarearequirements.


CAUTION:WhenusedinHazardousareas,equipmentmustbesuppliedwithapre‐approvedpower
supplyunitorapprovedequipmentviaacertifiedintrinsicallysafebarrieroragalvanicallyisolated
barrier)withthefollowingentityparameters.
Input supply terminal, RS-485 channel
and connector CN2 (Combined) Connector CN1 pins A & B (J2 on PCB):
Ci = 68uF Ui = 23 Vdc
Li = 0 Ii = 88.2 mA
Co = 32uF Pi = 0.52 W
Lo = 0.14 mH Ci = 0
Li = 0
RS-485 channel at each line
Connector CN1 pins D & E (J9 on PCB):
Ui = 3.7 Vdc
Ii = 225 mA
Pi = 0.206 W
Uo =5V
Io =51mA
Po = 0.064W
Probe connector CN2 (J1 on PCB):
Uo = 5 V
Io = 503 mA
Po = 0.7 W


SpecialConditions

1.Probedielectricrating<500Vr.m.s.Donotexceed.
2.Probecannotbeinstalledintheexplosiondustatmosphere(GroupIII).
3.Networked(“daisy‐chained”)arrangementnotforuseinGroupIIC/IIICenvironment.
4.Maximum32transmittersareallowedinthedaisy‐chainarrangement.


8

Wheneveranelectricallydrivensensorormeasuringdeviceisusedinapotentiallyexplosive
environmentthemeasuringsystemmustbeinstalledinsuchawaythatelectricalenergyiseither
effectivelyisolatedfromtheexplosiveenvironment(viaexplosive‐proofcontainers,cableconduits,
etc.)ortheamountofelectricalenergyproducedinthehazardousareamustbelimitedtoan
intrinsicallysafelevel.

LimitingelectricalenergyisthemostpracticalmethodofprotectingtheMS2700E transmitterwhenit
isinstalledinahazardousarea.IntheMS2700E transmitter,electricalenergylimitsaremaintainedby
theuseofappropriatesafetybarriersinstalledinthepoweranddatawiring.Thesafetybarriersmust
belocatedinthesafeareaneartheboundarybetweenthesafeandhazardousareas.Thesafety
barrierwillrepeatthesignalcurrentgeneratedbytheTransmitterandwillrelaythesignaltothedata
receivingstation.

Caution:WhenasafetybarrierisusedwiththeMS2700E transmitter,thetransmitterwiring
connectionsmustbeconnectedtothesafetybarrier’shazardousareaterminals.Allotherconnections
mustbemadetothebarrier’ssafeareaterminals.

ThetypeofrepeatersafetybarriersusedwiththeMS2700E transmitterdependsonthespecific
classificationofthehazardousenvironmentinquestion.However,theentityparametersmustmatch
thoseoftheMS2700E transmitter.



CAUTION:Forhazardousareainstallations,themaximuminductanceandcapacitanceofthefield
wiringbetweenthesafetybarrierandthetransmittercannotexceedtheentityparametersofthe
selectedbarrier.





9

3.SetupandOperation

a.ProbeSettings

Theprobeselectionswitchesarelocatedonthetopleftcornerofthemainboardasillustratedin
Figure5below.TheseswitchesareusedtosettheERprobetype.Theyalsoallowtheinstrumentto
beplacedintoseveraltestmodeswhichoutputfixedvalues,allowingverificationoftheoutputsignal.
Table2givestheswitchsettingsforeachprobetypeandthevarioustestmodes.



Figure5.ConnectorandSwitchDetails

Switch1

Setting
Position
1 2 3 4
Operating
Positions
Wire Loop Off (↓)On (↑) On (↑) Off (↓)
Tube Loop/Flush On (↑) Off (↓)On (↑) Off (↓)
Cylindrical*Off (↓)Off (↓)On (↑) Off (↓)
Test
Positions
Zero Output (0) On (↑) On (↑) Off (↓)Off (↓)
Maximum Output
(65535) Off (↓)On (↑) Off (↓)Off (↓)
Full Scale Sweep On (↑) Off (↓)Off (↓)Off (↓)

Table2.ProbeSwitchSettings
*Cylindricalprobesettingisillustrated.
Switch1‐Probe
SelectionSwitch
(SeeTable2below)
PowerConnector
(J2)
ProbeCableConnector
DataConnector
(J9)
Switch2‐ RS‐485
ConfigurationSwitches
(SeeTable3below)

10
b. RS‐485CommunicationSettings
TheRS‐485configurationswitchesarelocatedonthetoprightcornerofthemainboardasillustrated
inFigure5.Theseareusedtosettheinstrumentaddress,baudrate,communicationprotocol,andto
enabletheterminationresistor.Table3givestheswitchsettingsforeachoftheseparameters,and
theyareexplainedinmoredetailbelow.
Switch2
Device
Address
Position
34567
1Off (↓)Off (↓)Off (↓)Off (↓)Off (↓)
2On (↑)Off (↓)Off (↓)Off (↓)Off (↓)
3Off (↓)On (↑)Off (↓)Off (↓)Off (↓)
4On (↑)On (↑)Off (↓)Off (↓)Off (↓)
5Off (↓)Off (↓)On (↑)Off (↓)Off (↓)
BaudRatePosition6On (↑)Off (↓)On (↑)Off (↓)Off (↓)
12 7Off (↓)On (↑)On (↑)Off (↓)Off (↓)
2400
On (↑)On (↑)
8On (↑)On (↑)On (↑)Off (↓)Off (↓)
4800Off (↓)On (↑)9Off (↓)Off (↓)Off (↓)On (↑)Off (↓)
9600On (↑)Off (↓)10On (↑)Off (↓)Off (↓)On (↑)Off (↓)
19200
Off (↓)Off (↓)
11Off (↓)On (↑)Off (↓)On (↑)Off (↓)
12On (↑)On (↑)Off (↓)On (↑)Off (↓)
Communication
Protocol
Position 13Off (↓)Off (↓)On (↑)On (↑)Off (↓)
814On (↑)Off (↓)On (↑)On (↑)Off (↓)
ASCIIOn (↑)15Off (↓)On (↑)On (↑)On (↑)Off (↓)
RTUOff (↓)16On (↑)On (↑)On (↑)On (↑)Off (↓)
17Off (↓)Off (↓)Off (↓)Off (↓)On (↑)
Termination
Resistor
Position 18On (↑)Off (↓)Off (↓)Off (↓)On (↑)
10 19Off (↓)On (↑)Off (↓)Off (↓)On (↑)
ActiveOn (↑)20On (↑)On (↑)Off (↓)Off (↓)On (↑)
InactiveOff (↓)21Off (↓)Off (↓)On (↑)Off (↓)On (↑)
22On (↑)Off (↓)On (↑)Off (↓)On (↑)
ReservedPosition23Off (↓)On (↑)On (↑)Off (↓)On (↑)
924On (↑)On (↑)On (↑)Off (↓)On (↑)
NotUsedN/A 25Off (↓)Off (↓)Off (↓)On (↑)On (↑)
26On (↑)Off (↓)Off (↓)On (↑)On (↑)
27Off (↓)On (↑)Off (↓)On (↑)On (↑)
28On (↑)On (↑)Off (↓)On (↑)On (↑)
29Off (↓)Off (↓)On (↑)On (↑)On (↑)
30On (↑)Off (↓)On (↑)On (↑)On (↑)
31Off (↓)On (↑)On (↑)On (↑)On (↑)
32On (↑)On (↑)On (↑)On (↑)On (↑)
Table3.RS‐485ConfigurationSwitchSettings

11

i.BaudRateandDefaultCommunicationParameters

ThedefaultcommunicationparametersfortheMS2700E transmitterareprovidedinTable4below.If
necessary,thebaudratecanbechangedusingPositions1and2ofSwitch2,asillustratedinTable3.

ParameterValue
BaudRate19200
DataBits8
ParityEven
StopBits1
Table4.DefaultCommunicationParameters

ii.DeviceAddress

Upto32MS2700E transmittersmaybeconnectedinamulti‐dropnetwork(“daisy‐chained”)usinga
singlecablerun.However,eachtransmittermustbesettoauniquedeviceaddresstoavoidconflicts.
ThisisdoneusingPositions3through7ofSwitch2,asillustratedinTable3.

CAUTION:Besuretoobservetheappropriategasgroupratinglistedonpage3forstand‐aloneor
multi‐dropoperation.


iii.CommunicationProtocols

TheMS2700E transmitteroffersuser‐selectableRTUorASCIIcommunicationprotocols,givingtheunit
abroaderrangeofcompatibility.ThecommunicationprotocolissetusingPosition8ofSwitch2,as
illustratedinTable3.

iv.TerminationResistor

Toensureproperoperation,theRS‐485networkmustbeterminatedproperlywithatermination
resistor.Tofacilitatethis,eachMS2700E transmitterhasabuilt‐in120terminationresistorthatcan
beswitchedonoroffusingPosition10ofSwitch2.Onceallunitshavebeeninstalled,besureto
enabletheterminationresistorofthelastunitinthenetwork.Theterminationresistorsofallother
transmittersshouldbeturnedoff.
v.DataRegisters

Table5liststhedataregistersoftheMS2700E transmitter.

NoRegisterAddressDescription
140001DeviceStatus
240002DeviceAddress
340003BaudRate
440024DACValue
540026ProbeSwitchSetting
Table5.ModbusDataRegisters


12

c.CalibrationandTesting

i.Calibration

TheMS2700E transmitterisfullycalibratedwhenshippedfromthefactory.Thecalibrationsettings
arefixedtoavoidaccidentalchangewhichcouldresultinerroneousdata.Nofieldcalibrationis
required.However,itisimportanttotesttheunituponinstallation,andduringperiodicmaintenance
inspections,toensuretheunitisoperatingproperly.

ii.Testingoutputzeroandspan

TheMS2700E transmitterProbeSelectionSwitches(page9)offerthreetestsettingsthatallowthe
unittobeplacedintovariousdiagnosticmodesasfollows:

1) ZeroOutput–Forcesadigitaloutputof0.
2) MaximumOutput–Forcesadigitaloutputof65535.
3) FullScaleSweep–Causestheoutputtocontinuallycyclefrom0upto65535.

Thesetestmodescanbeusefulwhentroubleshootingcommunicationproblemsbetweenthe
transmitterandtheDCS/PLCsystem.

iii.TestingtheMS2700EtransmitterwiththeMeterProver

AMeterProverisprovidedtoallowroutinechecksoftheMS2700E transmitter.TheMeterProver
simulatesaWireLooptypeprobeatafixedvalue.TotesttheunitwiththeMeterProver:

1) Disconnectpower.
2) DisconnecttheMS2700E transmitterfromtheprobe(oriftheunitisremote‐mounted,
disconnecttheprobeextensioncablefromtheprobe.)
3) ConnecttheMeterProvertotheprobeconnectorstem(ortotheprobeextensioncableifthe
MS2700E transmitterisremote‐mounted.)
4) LoosentheEnclosureLockScrew.
5) Unthreadandremovethetransmittercover.
6) ChangetheProbeSelectionSwitchestotheWireLoopposition(seepage9.)
7) Reconnectpowerandallowtheinstrumenttomeasureforseveralminutestostabilize.
8) Afterseveralminutesobservethetransmitteroutput.Theoutputshouldcloselymatchthe
valueprintedontheMeterProverlabel.

IfthetransmitteroutputmatchestheMeterProvervalue,youmayreturntheProbeSelection
SwitchestotheirprevioussettingandreconnecttheMS2700E transmittertotheprobe.Ifthe
transmitteroutputshowsasignificantdifferencecomparedtotheMeterProvervalue,further
troubleshootingmayberequired.Refertopage16fortroubleshootingorcontactthefactoryfor
furtherassistance.

BesuretoreinstalltheenclosurecoverandtightentheLockScrewwhenputtingtheMS2700E
transmitterbackintoservice.



13

d.InterpretingData
i.MetalLoss
TheMS2700E transmittermeasurestheMetalLossofanERprobeandconvertsthatvaluetoadigital
16‐bitRS‐485Modbusoutput.ThisoutputisdirectlyproportionaltothecumulativeMetalLossofthe
ERprobeatanygiventime.Theoverallspanoftheoutputisproportionaltothelifeoftheprobein
use,soforDCS/PLCprogrammingtheRS‐485Modbusoutputcanbescaledasfollows:

0=0mils(0%MetalLoss)
65535=ProbeLifeinmils(100%MetalLoss)

TheProbeLifecanbefoundinTable1andisalsolistedontheMetalSamplesprobetag(asthe
“Multiplier”.)



Figure6.MetalSamplesProbeTag
Figure7illustratestherelationshipbetweenthedigitaloutputandMetalLoss.Inthisexamplea
probewitha10‐millifeisassumed.However,theXaxiscouldbechangedtorepresentanyProbeLife.
Figure7.OutputRelationship
Asseenhere,thetransmitteroutputbeginsat0foranewprobe(zeroMetalLoss)andincreasesas
theprobeelementcorrodes,eventuallyreachingamaximumof65535whentheprobesensing
elementhasbeencompletelyconsumedbycorrosion(inthiscase,10milsofMetalLoss.)Atthistime
theprobehasreacheditsend‐of‐lifeandmustbereplaced.


0
16384
32768
49151
65535
0.0 2.5 5.0 7.5 10.0
RS‐485ModbusOutput
MetalLoss(mils)
New
Probe
Probe
Consumed

14

ii.CalculatingCorrosionRate


Asexplainedpreviously,ERprobesandinstrumentsreportMetalLoss.However,thevaluethatisof
ultimateinterestisCorrosionRate.TheCorrosionRateisessentiallyMetalLossovertime,sothe
CorrosionRatecanbecalculatedusingthefollowingformula:
CorrosionRate󰇛mpy󰇜  ∆MetalLoss󰇛mils󰇜
∆Time󰇛days󰇜  365

where:
∆MetalLoss(mils)isthedifferencebetweentwoMetalLossreadings

 Time(days)isthetimedifferencebetweenthosetworeadings

Itisacommonpracticetoprogramthisformulaintothecontrol(DCS/PLC)systemandhaveit
calculateCorrosionRateonacontinualbasisfromtheMetalLossdata.Thechallengeindoingthisis
selectinganappropriatetimeinterval.Usinganintervalthatistooshortmaygiveerraticresults,
whileselectinganintervalthatistoolongmaygiveresultsthatareinsensitivetosystemupsets.The
idealtimeperioddependsonmanyfactors,andwillvaryfromsystemtosystem.Itmaytakesome
trialanderrortosettleonthebesttimeperiodforyourinstallation.

InsomecasesitmaybenecessarytoreviewtherawMetalLossdataandmanuallyapplythe
CorrosionRateformulatoperiodsofinterest.Forexample,lookatthegraphbelowandseehow
muchthecalculatedCorrosionRatecanvarydependingonthetimeperiodused.

Figure8.CorrosionRatescalculatedfromMetalLossdata
Whileeachoftheresultsisvalidfortheselectedtimeperiod,theoneofmostinterestisthevalueof
11.81mpywhichrepresentssometypeofsystemupset.WhentheCorrosionRateiscalculated
automaticallyonapre‐selectedtimeperiod,thereisnoguaranteethattheselectedtimeperiodwill
alwayscoincidewithsystemupsetssuchasthis.Thatiswhymanualreviewandinterpretationof
MetalLossdataisalsohelpful.

15

e.Commissioning

OncetheMS2700E transmitterhasbeeninstalled,tested,andproperlyconfiguredfortheprobeinuse,it
canthenbeclosedandputintoservice.First,performonelastvisualinspectiontoensurethatall
electricalconnectionsaresecureandthattheenclosureo‐ringisinplaceandisingoodcondition.Then
threadtheenclosurelidontothebasefully.Oncethelidhasbeenthreadedintoplace,tightentheLock
Screwtopreventunauthorizedtampering.



Figure9.EnclosureLockScrew

CAUTION:TheLockScrewontheinstrumentbasemustbetightenedsecurelytopreventunauthorized
personnelfromopeningtheMS2700E
transmitter,andensurethattheintrinsicsafetyisnotviolated.Only
qualifiedpersonnelshouldbeallowedtoinstall,operate,andmaintenancetheMS2700E
transmitter.


C.Maintenance
Onceinstalled,theMS2700E transmitterrequireslittlemaintenance.However,itisimportanttoverifythe
followingitemsperiodicallytoensurecontinuedsafeoperation.

CAUTION:BeforeperforminganytestsormaintenanceontheMS2700E
transmitter,ensurethatall
hazardousarearequirementsaremet.


InspectionItemFrequency
Inspecttheenclosureo‐ringforanysignsofdamage.Replaceasnecessary.Annually
Inspecttheprobeconnectoro‐ringforanysignsofdamage.Replaceasnecessary.Annually
Inspecttheexternalelectricalconnectionsforsignsofcorrosion,mechanicaldamage,or
foreignmatterthatcouldcausedamageorcauseanelectricalshort.Cleanasnecessary.
Annually
Ensurethatthelockingscrewisinplaceandissecure.Annually
TheMS2700E transmitterenclosureismadeofcorrosion‐resistant316stainlesssteel.
However,itshouldstillbecheckedperiodicallyforanysignsofcorrosion.
Annually
Checkforanysignsofmoistureingresswithintheenclosure.Annually

ContactMetalSamplesforreplacementpartsorifinstrumentrepairisnecessary.



16

D.Troubleshooting

IftheMS2700E transmitterdoesnotseemtoperformasexpected,checkthefollowingitems:


CAUTION:BeforeperforminganytestsormaintenanceontheMS2700E
transmitter,ensurethatall
hazardousarearequirementsaremet.


1. Ensurethattheprobeisoperationalandisnotcompletelycorroded.Thiscanbedoneintwoways.
a. TesttheprobewithaportableERmeterifavailable.
b. Testtheprobewithaportableresistanceorcontinuitymeterasfollows:
i. Connectonetestleadtopin‘A’oftheprobes6‐pinconnector.
ii. Measurecontinuitytoeachoftheotherpins.Thereshouldbecontinuity(low
resistance)toeachpin.
NOTE:Continuityoneachpindoesnotensurethattheprobeisgood.However,ifyou
findanopencircuitonanypinsthenitisalmostcertainthattheprobeisbadandshould
bereplaced.
2. EnsurethattheProbeSelectionSwitchesaresetcorrectlyfortheprobebeingused.Confirmthe
probetypeandrefertoTable2onpage9toverifytheappropriateswitchsettings.
3. Performavisualinspectionofthecircuitboardstolookforanysignsofmechanicalorelectrical
damage.
4. Ensurethatallelectricalcablesandwiringareingoodcondition.
5. Ensurethatallelectricalcontactsaresecureandfreeofcorrosion.
6. Ensurethatthereisadequatesupplyvoltageatthepowerconnector.
7. Verifythatthesupplyvoltagepolarityiscorrect.
8. Ifthereisinsufficientsupplyvoltageonthepowerconnector,checkthesafetybarrier(if
applicable)forablownfuseoranyotherfailure.
9. TesttheMS2700E transmitterusingthesuppliedMeterProver(seepage12.)

Thesebasicchecksshouldindicatethesourceofanyproblem(probe,powersupply,wiring,etc.).Ifitis
determinedthattheMS2700E transmitterismalfunctioning,orifyouneedfurtherassistancein
troubleshooting,contactMetalSamplesTechnicalSupport.


CAUTION:IftheMS2700E transmittershowsanysignsofdamage,removeitfromserviceimmediatelyand
consultthefactory.




