StroboscopicTimer
NOTE1—1in.=25.4mm.
FIG.2Paddle-TypeRotorforUseWithStormerViscometer
where:
O=viscosityofoilinpoisesandD=densityofoil.
8.Calibration48.1Removetherotorandweightcarrierfromtheviscom-eter.Makesurethestringiswoundevenlyonthedrumanddoesnotoverlapitself.
8.2Attacha5-gweightontothestringandthenreleasethebrake.Iftheviscometerstartstorunfromthisdeadstartandcontinuestorunthroughseveralrevolutionsofthestringdrum,itissatisfactoryforuse.Ifitdoesnotstartunaidedwhenthe5-gweightisapplied,theinstrumentshouldbereconditioned.8.3Checkthedimensionsofthepaddle-typerotor.Theyshouldbewithin0.1mm(60.004in.)ofthedimensionsshowninFig.2.
8.4Selecttwostandardoilshavingassignedvaluesofloadtoproduce200r/minwithintherangeofthevaluesexpectedforthecoatingstobemeasured(see7.1).
8.5Adjustthetemperatureofthestandardoilsto2560.2°C.ThetemperatureoftheStormerapparatusshouldbethesame.Ifthespecifiedtemperaturecannotbeobtained,recordthetemperatureoftheoilatthebeginningandendoftestto0.2°C.
8.6Determinetheloadingramstoproduce200r/minwitheachofthetwooils,usingeitherProcedureAdescribedinSection9orProcedureBdescribedinSection10.
8.6.1Iftheoiltemperaturewasnotat2560.2°Cduringthetest,correctthemeasuredloadingramsforthedeviationfromthattemperature.
NOTE2—Loadcorrectionsfordeviationsofoiltemperaturefromthespecifiedtemperaturecanbemadebymeansofapreviouslyestablishedplotofloadversusoiltemperature(seeAppendixX1).
8.7Ifthemeasuredload(correctedforanytemperaturedeviationfromstandard)iswithin615%oftheassignedloadvaluesfortheoils,theStormerapparatuscanbeconsideredtobeinsatisfactorycalibration.
9.ProcedureA(WithoutStroboscopicAttachment)
9.1Thoroughlymixthesampleandstrainitintoa1-pt(500-mL)containertowithin20mm(3⁄4in.)ofthetop.
9.2Bringthetemperatureofthespecimento2560.2°Candmaintainitatthattemperatureduringthetest.ThetemperatureoftheStormerapparatusshouldbethesame.9.2.1Ifthespecifiedtemperaturecannotbeobtained,recordthetemperatureofthespecimenatthebeginningandendoftestto0.2°C.
9.3Whenthetemperatureofthespecimenhasreachedequilibrium,stiritvigorously,beingcarefultoavoidentrap-pingair,andplacethecontainerimmediatelyontheplatformoftheviscometersothatthepaddle-typerotorisimmersedinthematerialtothemarkontheshaftoftherotor.
9.4Placeweightsonthehangeroftheviscometeranddeterminealoadthatwillproduce100revolutionsintherangeof25to35s.
9.5Usingtheinformationgainedin9.4,selecttwoloadsthatwillprovidetwodifferentreadings(timetogive100revolutions)withintherangeof27to33s.Makethese
4Jackson,C.F.,andMadson,W.H.,“AMethodfortheStandardizationofKrebsModifiedStormerViscometers,”ASTMBulletin,No.161,1949.
measurementsfromarunningstart,thatis,permittherotortomakeatleast10revolutionsbeforestartingthetimingfor100revolutions.
9.6Repeatthemeasurementsoutlinedin9.5untiltworeadingsforeachloadareobtainedthatagreewithin0.5s.10.ProcedureB(WithStroboscopicTimer)
10.1FollowProcedureA(9.1-9.3)forthepreparationofthespecimen.
10.2Connectthelampcircuitofthestroboscopicattach-menttoanelectricalpowersource.
10.3Placeweightsonthehangeroftheviscometeranddeterminealoadthatwillproduce100revolutionsintherangefrom25to35s.
10.4Usingtheinformationgainedin10.3,selectaweight(tothenearest5g)thatwillproducethe200-r/minpattern(Fig.3)onthestroboscopictimer,thatis,wherethelinesappeartobestationary.
10.4.1Linesmovinginthedirectionofpaddlerotationindicateaspeedgreaterthan200r/minandtherefore,weightshouldberemovedfromthehanger.Conversely,linesmovingoppositetodirectionofpaddlerotationindicateaspeedlessthan200r/minandweightshouldbeadded.
NOTE3—Thereareotherpatternsthatappearatspeedsotherthan200r/min(SeeFig.4).Thepatternfor200r/minshouldbedeterminedbeforerunninganytests.
10.5Repeatthedeterminationin10.4untilaconsistentvalueofloadisobtained(thatis,towithin5g).
11.Calculation11.1ProcedureA:
11.1.1Calculatetheloadtowithin5g,toproduce100revolutionsin30sbyinterpolatingbetweentheloadweightsrecordedforthereadingsmadebetween27and33sfor100revolutions.
11.1.2Correcttheloaddeterminedforanydeviationofthespecimentemperaturefromthespecifiedtemperature(seeAppendixX1).
11.1.3Ifdesired,determinefromTable1theKUcorre-spondingtotheloadtoproduce100revolutionsin30s.
NOTE4—Table1hasbeenconstructedsothatitisnotnecessarytointerpolatebetweenloadstoobtaintheKUcorrespondingtotheloadtoproduce100revolutionsin30s.ThetableprovidesKUvaluescomputedforarangeof27to33sfor100revolutions.
11.2ProcedureB:
11.2.1Ifdesired,determinefromTable2theKUvaluecorrespondingtotheloadtoproduce200r/min.12.Report
12.1Reportthefollowinginformation:
FIG.3StroboscopicLinesOpeningWhenTimerisAdjustedto
Exactly200r/min
FIG.4StroboscopicLinesAppearingasMultiplesthatMaybe
ObservedBefore200-r/minReached
12.1.1Theloadingramstoproduce200r/min(100revolutionsin30s),
12.1.2ThecalculatedKU,
12.1.3Thetemperatureofthespecimenduringthetestandwhetheracorrectionwasappliedforanydeviationfrom25°C,and
12.1.4WhetherProcedureAorProcedureBwasused.13.PrecisionandBias
13.1Precision—Onthebasisofastudyinwhichdetermi-nationsweremadeonfivepaintsbytwooperatorsateachoffivelaboratoriesoneachoftwodifferentdays;thewithin-laboratorycoefficientofvariationwasfoundtobe3%inloadgramsor1.5%inKU,andthebetween-laboratorycoefficientofvariationwasfoundtobe10%inloadgramsor4%inKU.13.1.1Thefollowingcriteriashouldbeusedforjudgingtheacceptabilityofresultsatthe95%confidencelevel.
13.1.1.1Repeatability—Tworesultseachthemeanoftwomeasurements,obtainedonthesamematerialbythesameoperatoratdifferenttimesshouldbeconsideredsuspectiftheydifferbymorethan1.7%inKU.
13.1.1.2Reproducibility—Tworesults,eachthemeanoftwomeasurementsonthesamematerial,obtainedbyoperatorsindifferentlaboratoriesshouldbeconsideredsuspectiftheydifferbymorethan5.1%inKU.
METHODB(DigitalDisplayStormer-TypeViscometer)14.Apparatus
14.1Viscometer,DigitalDisplay,withthepaddle-typerotorasillustratedinFig.1andFig.5.
14.2Container,500mL(1pt),85mm(33⁄8in.indiameter.14.3Thermometer,ASTMStormerviscositythermometerhavingarangefrom20to70°CandconformingtotherequirementsforThermometer49CasprescribedinSepcifi-cationE1.
15.Materials
15.1StandardOils,two,calibratedinabsoluteviscositythatarewithintheviscosityrangeofthecoatingstobemeasured.Theseoilsshoiulddifferinviscositybyatleast25KU.
15.2SuitableHydrocarbonOils,calibratedinKUandtraceabletoNIST,availablecommercially.
16.Calibration
16.1Checkthedimensionsofthepaddle-typerotor.Theyshouldbewithin60.1mm(0.004in.)ofthedimensionsshowninFig.2.
16.2SelecttwostandardoilshavingviscositiesinKUwithintherangeofthevaluesexpectedforthecoatingstobemeasured(see15.1).
TABLE1Krebs’StormerChartwithInterpolationsLoad,gSecondsfor100Revolu-tionsKrebsUnits798081828283848384858686878886878889909091899091929393949293949595969695969798989999979899100100101101100100101102102103103102102103104104105105104105105106106107107106107107108108109109109110110110111111112111112112112113113114113114114114115115116114115115116116116117116117117118118118119118118119120120120121120120121121122122122121121122122123123123123123124124125125125124124125125126126126126126127127128128128127127128128129129129129129130130131131131130130131131132132132131131132133133133134132132133134134134135133133134135135135136134134135136136136137136137137138138138139751001251501752002252502753003253503754004254504755005255505756006256506757007257507758008258508759009501000272829303132334951535455565757596061626364636566676869706970717273747574757677787980138139139140140140141TABLE2KrebsUnitsCorrespondingtoLoadRequiredtoProduce200-r/minRotation
(ForusewithStormerViscometerequippedwithStroboscopicTimer)
GramsKU
GramsKU1006110562110631156412065125671306813569140701457115072155731607416575
705375548055855790589560
170761757718078185791908019581
GramsKU2008220583210832158422085225862308623587240882458825089255902609026591270912759228093285932909429594
GramsKU30095
GramsKU400104
GramsKU500112
GramsKU600120
GramsKU700125
GramsKU800131
GramsKU900136
GramsKU1000140
310964101055101136101207101268101329101361010140
320974201065201146201217201268201329201371020140
330984301065301146301217301278301339301371030140
340994401075401156401227401278401339401381040140
3501004501085501166501227501288501349501381050141
3601014601095601176601237601298601349601381060141
3701024701105701186701237701298701359701391070141
3801024801105801186801247801308801359801391080141
3901034901115901196901247901318901369901401090141
temperatureoftheoilatthebeginningandendofthetestto0.2°C.
16.4Iftheoiltemperaturewasnotat2560.2°Cduringthetest,correctthemeasuredKUviscosityforthedeviationfromthattemperature.
NOTE5—Correctionsfordeviationsofoiltemperaturefromthespeci-fiedtemperaturecanbemadebymeansofapreviouslyestablishedplotofloadgramsversusoiltemperature(seeAppendixX1).
16.5Ifthemeasuredviscosity(correctedforanytempera-turedeviationfromstandard)iswithin65%ofthespecifiedKUvaluesforthestandardoils,theviscometercanbeconsideredtobeinsatisfactorycalibration.
17.Procedure
17.1Thoroughlymixthespecimenandpourintoa500–mL(1–pt)containertowithin20mm(3⁄4in.)ofthetop.
17.2Bringthetemperatureofthespecimentto2560.2°C,andmaintainitatthattemperatureduringthetest.Thetemperatureoftheviscometershouldbethesame.
17.3Ifthespecifiedtemperaturecannotbeobtained,recordthetemperatureofthespecimenatthebeginningandendofthetestto0.2°C.
17.4Whenthetemperatureofthespecimenhasreachedequilibrium,stiritvigorously,beingcarefultoavoidentrap-pingair,movetheoperatinghandletothetopposition,pullthefrontlocatoroutandplacethecontainerimmediatelyonthebaseoftheviscometeragainstthelocatingpinsandreleasethefrontlocatorlockingandcenteringthecan.
17.5TurnonthemainpowerswitchandselecteitherKUorGram(gm)display.BesurethattheHOLDreadingswitchisintheupposition.
FIG.5DigitalStormer-TypeViscometer
16.3Adjustthetemperatureofthestandardoilsto2560.2°C.Thetemperatureoftheviscometershouldbethesame.Ifthespecificdtemperaturecannotbeobtained,recordthe
17.6Movetheoperatinghandletothelower(immersingthepaddlespindleintothespecimen).Thefluidshouldbeclosetotheimmersiongrooveonthepaddleshaft.Thepaddlewillstartrotaingwhenitiswithinabout12mm(1⁄2in.)ofthelowerposition.
17.7Wait5sforthedisplayreadingtostablilize.
17.8PresstheHOLDreadingswitchdownto“hold”thedisplayandusethedisplayselectorknobtodisplayKUorgramunits,orboth.
17.9Raisetheoperatinghandletothetopposition,andletthespecimendrainfromthepaddlespindle.
17.10Loosenthethumbscrewandremovethepaddlespindleforcleaning.
18.Report
18.1Reportthefollowinginformation:
18.1.1ThemeasuredKrebsUnits(KU)andtheGrams(gm).
18.1.2Thetemperatureofthespecimenduringthetestandwhetheracorrectionwasappliedforanydeviationfrom25°C.19.PrecisionandBias
19.1Precision—Onthebasisofastudyinwhichmeasure-
mentsweremadeonfivepaintsbytwooperatorsineachofsixlaboratories(fivewithBrookfieldKU-1viscometerandonewithanelectronicStormerviscometer)oneachoftwodifferentdays,thefollowingcriteriashouldbeusedforjudgingtheacceptabilityofresultsatthe95%confidencelevel.
19.1.1Repeatability—Tworesults,eachthemeanoftwomeasurementsonthesamematerialbythesameoperatoratdifferenttimes,shouldbeconsideredsuspectiftheydifferbymorethan2.0%inKU.
19.1.2Reproducability—Tworesults,eachthemeanoftwomeasurementsonthesamematerial,obtainedbyoperatorsindifferentlaboratoriesshouldbeconsideredsuspectiftheydifferbymorethan5.0%inKU.
19.2Bias—Sincethereisnoacceptedreferencematerialforthistestmethod,biascannotbedetermined.20.Keywords
20.1consistency;Krebsunits(KU);Stormer-typeviscom-eter;viscosity
APPENDIX
(NonmandatoryInformation)
X1.EFFECTOFSPECIMENTEMPERATUREONSTORMERCONSISTENCY
X1.1Formaximumaccuracyindeterminingtheeffectofspecimentemperatureonconsistency,measurementsshouldbeperformedatthreedifferentspecimentemperaturescoveringtherangeofinterest.ThechangeinloadorKUper1°Cchangecanbedeterminedfromtheseresults.
X1.2Ithasbeenobservedthattheconsistencyofanoilisconsiderablymoresensitivetotemperaturethanistheconsis-tencyofapaint.
X1.3Sometypicaleffectsoftemperaturesontheconsis-tencyofoilsandpaintsaregivenbelow:
MeanValueat
25°CLoad,KUgvalue
HydrocarbonoilNo.1
HydrocarbonoilNo.2HydrocarbonoilNo.3Bodiedlinseedoil
HeavilybodiedlinseedoilWater-basedexteriorpaintWater-basedexteriorpaint
149217286195440300425
7285938110895105
Changeper1°C
ChangeLoad,KUgvalue14181184044
2.52.01.51.02.00.50.5
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