Brookfield DV3T Rheometer - Manual (Page 110)

Brookfield Engineering Labs., Inc. Page 110 Manual No. M13-2100
Calibration Procedure for Cone/Plate Rheometers
1) Follow the above procedures for mechanically adjusting the setting of the cone spindle to the
plate.
2) Refer to Appendix A; Table A-1, 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: DV3TLV Rheometer, 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 0.097 cP for the
fluid). The accuracy is a combination of Rheometer and fluid tolerance (refer to Interpretation
of Calibration Test Results).
4) With the rheometer stopped, remove the sample cup and place the viscosity standard fluid into
the cup, waiting 10 minutes for temperature equilibrium.
5) Connect the sample cup to the Rheometer. Allow sufficient time for temperature to reach
equilibrium. Typically 15 minutes is the maximum time that you must wait. Less time is
required if spindle and cup are already at test temperature.
6) Measure the viscosity and record the Rheometer reading in both % torque and centipoise (cP).
Notes: 1) The spindle must rotate at least five (5) times before a viscosity reading is
taken.
2) The use of Brookfield Viscosity Standard fluids in the range of 5 cP to 5000 cP is
recommended for cone/plate instruments. Please contact Brookfield Engineering
Laboratories or an authorized dealer if your calibration procedure requires more
viscous standards.
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. Do not use a silicone viscosity standard fluid with a viscosity
value greater than 5000 cP with a Cone/Plate Rheometer. Brookfield offers a
complete range of mineral oil viscosity standards suitable for use with Cone/Plate
Rheometers as shown in Table E-2. Consult with Brookfield or an authorized
dealer to determine which fluid is appropriate.
Interpretation of Calibration Test Results:
When verifying the calibration of the DV3T, the instrument and viscosity standard fluid error
must be combined to calculate the total allowable error.
The DV3T is accurate to (+/-) 1% of the range in use when using spindles LV #1-3, RV #2-6,
HA #2-6 and HB #2-6. When using an accessory device with the DV3T such as Small Sample
Adapter, UL Adapter, Thermosel, Spiral Adapter, and DIN Adapter the accuracy value may be
increased. In general the increase in accuracy will be minimal, however, it could be as much as
1% for a total accuracy of +/- 2% of the range in use.