Brookfield DV-I Prime - Manual (Page 45)

Brookfield Engineering Laboratories, Inc. Page 45 Manual No. M/07-022-D0613
A.4 Making Measurements with Cone/Plate Geometry
Viscosity measurements are made on the DV-I PRIME C/P viscometer in the same way as the
DV-I PRIME viscometer with several exceptions.
1. Prepare the viscometer as is described in Section III.2.
2. Brookfield recommends that you always make cone/plate measurements with temperature
control. Be sure that the sample cup is connected to a circulating waterbath and that it
is at the target temperature. If the set temperature is far from ambient, you may wish to
preheat the spindle as well as the cup. The spindle can be preheated by removing it from
the viscometer and resting it in the cup (be careful not to scratch the measurement surfaces
on the spindle or cup). Attach the spindle to the viscometer prior to the next step.
3. Set the Gap (see Appendix A; Section A.3) Brookfield recommends that the gap be set at
the same temperature at which the measurement will be made.
4. Remove the sample cup.
5. Measure the precise volume of sample required for the spindle. See Table A-1. Sample
volume can have a great affect on the measurement. In general it is better to over fill the
gap slightly than it is to under fill. It is also beneficial to establish a method of sampling
that is repeatable to contribute to the repeatability of your viscosity measurement.
6. Insert the sample into the center of the sample cup. Avoid air bubbles when possible.
7. Attach the sample cup to the viscometer (be careful not to tilt the sample cup as this would
reposition the sample from the center).
8. Wait for thermal equilibrium. Brookfield recommends a minimum of 1 minute for thermal
equilibrium. You may want to increase this time if; there is a large difference in temperature
between the sample and the control point, or if you have not preheated the spindle.
9. Operate the viscometer (see Section II.8, Steps 3 – 6). Refer to Section III.3 for assistance
in selecting a spindle or speed.
10. Remove the sample cup at the conclusion of the test. Be careful to lower the cup so that
no contact is made between the cup and spindle.
11. Remove the spindles (Refer to Appendix A; Section A.2, Step 4).
Cleaning:
Refer to Section I.8 for general cleaning recommendations. Clean the cup and spindle
at the conclusion of each test. Be careful not to let the sample dry or harden onto the spindle or
cup since mechanical scraping may damage the measurement surfaces. Brookfield recommends
that you remove the spindle prior to cleaning.
Take care not to scratch the measurement surface of the cup or spindle during the cleaning
process. Take care not to drop the spindle; any dent on the outer edge of the spindle will
affect the measurement.
The sample cup may be provided with an embedded temperature probe. The temperature probe
connection should not be exposed to the cleaning solution or the test sample. Do not immerse
the sample cup in a cleaning solution.