Cannon Instrument miniPV-X - Manual (Page 28)

CANNON ® miniPV-Series Automatic Viscometer with VISCPRO ® Instruction & Operation Manual
Version 1.a— January, 2011; CANNON ® Instrument Company
2139 High Tech Road • State College, PA 16803 • USA
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*The term absolute viscosity, as used in this manual, is also known as
dynamic viscosity. For the purpose of VISCPRO® software viscosity
calculations, and per ASTM D 2857 specifications, the absolute viscosity
is defined by the equation ç = Ctñ - Eñ/t 2 where C is a constant, t is the
drop time, ñ is the solution or solvent density and E is the kinetic energy
correction constant.
Relative viscosity calculation
The relative viscosity (RV) ratio (solute to solvent blank) is therefore defined
by the equation:
Software selection of blank
Since determination of a relative viscosity involves a comparison of solution
and blank, the VISCPRO controlling software requires the identification of a
blank for any samples tested using the Determine Solution Relative Viscosity
sample action. The blank is ordinarily selected from a list of solvents main-
tained by the VISCPRO database. This list is accessible from the Polymer
Measurement Sample Options window by using the drop-down list feature:
To display the list, click on the arrow. If the correct blank has not yet been
defined, the user may create a new blank by typing an ID for the blank into the
open field in the Polymer Measurement Sample Options window:
Procedure for blank definition
New blanks are created by testing the solvent in the miniPV using the
Determine Solvent Viscosity sample action. Follow the procedure for
testing samples
1. Select Determine Solvent Viscosity as the sample action for the
desired sample.
2. Enter an ID for each blank that includes both a description of the
blank and also the temperature at which that blank is to be tested in
the miniPV. The blank must be tested at the same temperature
intended for the solution
NOTE In some MiniPV applications involving dilute solutions, it may not be
necessary to input the density for the solvent blank and/or solution. If you
choose not to input solvent density for either the blank or for the sample,