User guide
- 3 -
I. INTRODUCTION
The Brookfield DV-III Programmable Rheometer measures fluid parameters of Shear Stress and
Viscosity at given Shear Rates. Viscosity is a measure of a fluid’s resistance to flow. You will find
a detailed description of the mathematics of viscosity in the Brookfield publication “More Solutions
to Sticky Problems”, a copy of which was included with your DV-III. The principle of operation
of the DV-III is to drive a spindle (which is immersed in the test fluid) through a calibrated spring.
The viscous drag of the fluid against the spindle is measured by the spring deflection. Spring
deflection is measured with a rotary transducer. The measuring range of a DV-III (in centipoise)
is determined by the rotational speed of the spindle, the size and shape of the spindle, the container
the spindle is rotating in, and the full scale torque of the calibrated spring.
There are four basic spring torque series offered by Brookfield:
Spring Torque
Model dyne-cm milli Newton - m
LVDV-III 673.7 .0673
RVDV-III 7,187.0 .7187
HADV-III 14,374.0 1.4374
HBDV-III 57,496.0 5.7496
The higher the torque calibration, the higher the measurement range. The measurement range for
each torque calibration may be found in Appendix - B.
All units of measurement are displayed according to either the CGS system or the SI system.
1. Viscosity appears in units of centipoise (shown as “cP”) or milliPascal-seconds (shown
as mPa•s) on the DV-III Rheometer display.
2. Shear Stress appears in units of dynes/square centimeter (“D/cm
2
”) or Newtons/square
meter (“N/m
2
”).
3. Shear Rate appears in units of reciprocal seconds (“1/SEC”).
4. Torque appears in units of dyne-centimeters or Newton-meters (shown as percent “%”
in both cases) on the DV-III Rheometer display).
The digital display reads from 00.0-99.9 in the % mode. Overrange is indicated by "EEE";
underrange is "---".
The equivalent units of measurement in the SI system are calculated using the following conver-
sions:
SI CGS
Viscosity: 1 mPa•s = 1 cP
Shear Stress: 1 Newton/m
2
= 10 dyne/cm
2
Torque: 1 Newton-m = 10
7
dyne-cm
References to viscosity throughout this manual are done in CGS units.
I.1 Components
Component Part Number
DV-III Rheometer depends on model
Powerbase, includes: DVP-2Y
Leveling Screws (3) VS-3
Upright Rod VS-20
Jam Nut VS-21
Clamp Assembly VS-27