Brookfield DV-III Rheometer - Manual (Page 70)

Brookfield Engineering Laboratories, Inc. Page 70 Manual No. M/98-211-A0701
Calibration Procedure using a Helipath Stand and T-Bar Spindles
When a Helipath Stand and T-Bar spindles are used:
Remove the T-bar spindle and select a standard LV(#1-4) or RV,HA,HB(#1-7) spindle. Follow the
procedures for LV(#1-4) and RV,HA,HB (#1-7) Brookfield spindles outlined above.
T-Bar spindles should not be used for verifying calibration of the DV-III+ Rheometer.
Calibration Procedure for Spiral Adapter
1) Place the viscosity standard fluid (in the proper container) into the water bath.
2) Attach the spindle to the viscometer. Attach chamber (SA-1Y) and clamp to the viscometer.
3) Lower the DV-III+ into measurement position. Operate the viscometer at 50 or 60 RPM until
the chamber is fully flooded.
4) The viscosity standard fluid, together with the spindle, should be immersed in the bath for a
minimum of 1 hour, stirring the fluid periodically (operate at 50 or 60 RPM periodically), prior
to taking measurements.
5) After 1 hour, check the temperature of the viscosity standard fluid with an accurate thermometer.
6) If the fluid is at test temperature ( + /- 0.1
°
C of the specified temperature, normally 25
°
C),
measure the viscosity and record the viscometer reading.
Note: The spindle must rotate at least five (5) times for one minute, whichever is greater
before readings are taken.
7) The viscosity reading should equal the cP value on the viscosity fluid standard to within the
combined accuracies of the viscometer and the standard (as discussed in the section entitled,
Interpretation of Calibration Test Results).
Calibration Procedure for Cone/Plate Viscometers:
1) Follow the above procedures for mechanically adjusting the setting of the cone spindle to the
plate.
2) Refer to Appendix A, Table A1, and determine the correct sample volume required for the
selected spindle.
3) Select a viscosity standard fluid that will give viscosity readings between 10% and 100% of full
scale range. Refer to Appendix B for viscosity ranges of cone spindles. Consult with Brookfield
or an authorized dealer to determine which fluid is appropriate.
It is best to use a viscosity standard fluid that will be close to the maximum viscosity for a given
cone spindle/speed combination.
Example: LVDV-III Viscometer, Cone CP-42, Fluid 10
Having a viscosity of 9.7 cP at 25
°
C
At 60 RPM, the full scale viscosity range is 10.0 cP. Thus, the Rheometer reading should be 97%
torque and 9.7 cP viscosity
±
0.197 cP (0.1 cP for the rheometer plus 0.97 cP for the fluid). The
accuracy is a combination of Rheometer and fluid tolerance (refer to Interpretation of Calibra-
tion Test Results).