Brookfield DV-I Prime - Manual (Page 20)

Brookfield Engineering Laboratories, Inc. Page 20 Manual No. M/07-022-D0613
cP 78.0 S01
10 RPM20 % 7.8
Figure II-14
Negative % (Torque) will be displayed as shown in Figure II-15:
cP ---- S01
10 RPM20 % -0.2
Figure II-15
Viscosity values will be displayed as “- - - -” when the % (Torque) is below zero.
II.8 Operation
The following procedure is outlined for making a viscosity measurement in a 600 mL low form
Griffin beaker.
1. Mount the guardleg on the DV-I PRIME Viscometer (LV and RV series). Attach the spindle
to the lower shaft. Lift the shaft slightly, holding it firmly with one hand while screwing
the spindle on with the other (note left-hand thread). Avoid putting side thrust on the shaft.
2. Insert and center spindle in the test material until the fluid’s level is at the immersion
groove in the spindle’s shaft. With a disc-type spindle, it is sometimes necessary to tilt
the spindle slightly while immersing to avoid trapping air bubbles on its surface. You
may find it more convenient to immerse the spindle in this fashion before attaching
it to the Viscometer.
3. To make a viscosity measurement, select the desired speed setting. Allow time for the
indicated reading to stabilize. The time required for stabilization will depend on the
speed at which the Viscometer is running and the characteristics of the sample fluid. For
maximum accuracy, readings below 10% should be avoided. Additional information on
making viscosity measurements is available in Appendix C or the Brookfield publication
“More Solutions to Sticky Problems”.
4. Record the reading and relevant test parameters. Brookfield recommends you record both
% torque and viscosity in centipoise. Relevant test parameters might include: viscometer
model, spindle, speed, temperature, container and time of test.
5. Press the
MOTOR ON/OFF
key to turn the motor “OFF” when changing a spindle or changing
samples. Remove spindle and guardleg before cleaning. Clean spindles and guardleg after
use, see Section I.8 for general cleaning recommendations.
6. Interpretation of results and the instrument’s use with non-Newtonian and thixotropic
materials is discussed in the booklet, “More Solutions to Sticky Problems”, and in
Appendix C: Variables in Viscosity Measurements.