Brookfield DVE - Introduction to the Brookfield DVE Viscometer

AMETEK Brookeld Page 5 Manual No. M15-356-B0916
I. INTRODUCTION
e Brookeld DVE Viscometer measures uid viscosity at given shear rates. Viscosity is a measure
of a uid’s resistance to ow. You will nd a detailed description of the mathematics of
viscosity in the Brookeld publication “More Solutions to Sticky Problems”, a copy of which
was included with your DVE and can be downloaded in pdf form from the Brookeld website,
www.brookeldengineering.com.
e principle of operation of the DVE is to rotate a spindle (which is immersed in the test uid)
through a calibrated spring. e viscous drag of the uid against the spindle is measured by the spring
deection. Spring deection is determined optically by measuring the shi in the spindle position
due to the viscous drag of the uid against the spindle. e measurement range of a DVE (in Poise,
centiPoise, Pascal or milliPascal seconds) is determined by the rotational speed of the spindle, the size
and shape of the spindle, the container in which the spindle is rotating, and the full scale torque of the
calibrated spring.
ere are four basic spring torque series oered by Brookeld:
Spring Torque
Model dyne-cm milli Newton-m
DVELV 673.7 0.0673
DVERV 7,187.0 0.7187
DVEHA 14,374.0 1.4374
DVEHB 57,496.0 5.7496
e higher the spring torque, the higher the measurement range. e viscosity measurement range for
each spring torque may be found in Appendix A.
All units of measurement are displayed according to either the CGS (cP) system or the SI (mPa•s) system.
1. Viscosity appears in units of Poise (shown as “P”), centipoise (shown as “cP”), Pascal Seconds
(shown as “Pa•S”) or milliPascal-seconds (shown as “mPa•s”) on the DVE display.
2. Torque appears in units of dyne-centimeters or Newton-meters (shown as percent “%” in both
cases) on the DVE display.
e equivalent units of measurement in the SI system are calculated using the following conversions:
SI CGS
Viscosity: 1 mPa•s = 1 cP
Torque: 1 Newton-m = 10
7
dyne-cm
1 Pa•S = 10 P
References to viscosity throughout this manual are made in CGS units. e DVE Viscometer provides
equivalent information in SI units (see Section II.5: Viscosity Units).