
Brookeld Engineering Labs., Inc. Page 48 Manual No. M13-2100
IV.3 Selecting a Spindle/Speed
TheDV3Thasthecapabilityofmeasuringyieldstressoveranextremelywiderange.Forexample,
theDV3TRVcanmeasureuidswithintherangeof0.5-400Pa.Thisrangeisachievedthrough
theuseofseveralvanespindlesovermanyspeeds.SeeAppendixBfordetails.
Theprocessofselectingaspindleandspeedforanunknownuidisnormallytrialanderror. An
appropriate selection will result in measurements made between 10-100 on the instrument %
torque scale.Therearetwogeneralruleswillhelpinthetrialanderrorprocess:
1)Viscosityrangeisinverselyproportionaltothesizeofthespindle.
2)Viscosityrangeisinverselyproportionaltotherotationalspeed.
Inotherwords:tomeasurehighyield,chooseasmallspindleand/oraslowspeed.Ifthechosen
spindle/speedresultsinareadingabove100%,thenreducethespeedorchooseasmallerspindle.
Experimentation may reveal that several spindle/speed combinations will produce satisfactory
resultsbetween10-100%.Whenthiscircumstanceoccurs,anyofthespindlesmaybeselected.
When yield data must be compared, be sure to use the same test methodology: namely the
same instrument, spindle, speed, container, temperature and test time.
VanespindlesareoptionalequipmentandarenotpartofthestandardDV3Tpackage.DV3TLV
Rheometersareprovidedwithasetoffourspindlesandanarrowguardleg;DV3TRVRheometers
comewithasetofsixspindlesandawiderguardleg;DV3THAandDV3THBRheometerscome
withasetofsixspindlesandno guardleg.(SeeAppendixFformoreinformationontheguardleg.)
Do not use the guard leg with vane spindles.
Thespindlesareattachedtotherheometerbyscrewingthemonto
thecouplingnutonthelowershaft(seeFigureIV-1).Notethatthe
spindleshavealeft-handthread.Thelowershaftshouldbesecured
andslightlyliftedwithonehandwhilescrewingthespindletothe
left.Thefaceofthespindlenutandthematchingsurfaceonthe
lowershaftshouldbesmoothandcleantopreventeccentricrotation
ofthespindle.Spindlescanbeidentiedbythenumberontheside
ofthespindlecouplingnut.
ThemotorshouldbeOFF whenever
spindlesarebeingremovedorattached.
Figure IV-1
Kommentare zu diesen Handbüchern