Brookfield DV2T - Page 37

Brookeld Engineering Labs., Inc. Page 37 Manual No. M13-167
asthixotropyorpseudoplasticity(shearthinning).Materialsthatexhibitthixotropywillshowa
steadilydecreasingmeasuredviscosityovertime.Materialsthatexhibitpseudoplasticitywillshow
achangingviscosityasthespindlespeedchanges.
TIP: Whenaveraging datafor a thixotropicmaterial, begin theAveragingDuration after the
periodofmostsignicantchangeinmeasuredviscosity.Thiswillreducethevariabilityin
theaveragedvalue.
TIP: Whenaveragingdataforapseudoplasticmaterial,donotaveragetogether(TestAveraging)
datacollectedatdifferentspeeds(orshearrates).
Live Averaging of data occurs during actual testing of a sample. Data can be collected as an average
ofreadingsoveraspecictimeinterval;eachdatapointsavedintheleisanaveragedvalue.This
averagingisdenedintheDataCollectionsectionofCongureViscosityTest.
Single Point AveragingrequiresadenitionofAveragingDuration,theamountoftimefor
whichreadingswillbeaveraged.ThistimeparameterwillbeappliedattheendoftheEnd
Condition.Inthiscaseasingledatapointwillbecollectedwhichrepresentstheaverageofall
datameasuredduringthespeciedtimeperiod(AveragingDuration).
Multi Point Averagingrequiresadenitionof1)DataInterval,thefrequencyofdatacollection
and2)AveragingDuration,theamountoftimeforwhichreadingswillbeaveraged.Thesetwo
parameterswillworkinconjunctiontogeneratemultipledatapointseachofwhichrepresent
theaverageofalldatameasuredduringtheaveragedurationwithinthespeciedDataInterval.
PostTestAveragingofdataoccursafterthetestiscomplete,throughtheResultsscreen.Averages
and standard deviation values can be generated for data collected in a single step or across several
stepsofatestgeneratedthroughPGFlashsoftware.IfthetestusedtocollectdatautilizedLive
Averaging(describedabove),thenthePostTestAveragingwillproduceanaveragevalueofaveraged
data points.
PostTestAveragingcanbespeciedintheReportsectionofCongureViscosityTest(seeSection
III.7).Whenconguredaspartofthetest,theaveragevalueswillbedisplayedimmediately
upontestconclusion.IfnotspeciedinReport,PostTestAveragingcanbeselectedfromthe
DownArrowintheResultsscreen(seeSectionIII.9).
PostTestAveragingofferstwooptions:StepAveragingandTestAveraging(seeFigureIII-13).
Figure III-13