Brookfield DV2T Extra Viscometer - Manual (Page 61)

Brookfield Engineering Labs., Inc. Page 61 Manual No. M13-167-B0614
A.4 Verifying Calibration
1. Determine the appropriate sample volume. Refer to Table A-1 to determine the correct
sample volume required for the spindle to be utilized.
2. Select a Brookfield 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.
Brookfield uses mineral oil viscosity standard fluids to calibrate Wells Brookfield Cone/
Plate Viscometers at the factory. Brookfield recommends that customers use mineral
oil viscosity standard fluids when you perform a calibration check.
If you decide to use a silicone viscosity standard fluid, do not use a fluid with a viscosity
value greater than 5000 cP with a Cone/Plate. Brookfield offers a complete range of
mineral oil viscosity standards suitable for use with Cone/Plates for viscosities above
5,000 cP or shear rates above 500 sec
-1
; see Table F-2 in Appendix F for a list of available
fluids.
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
: DV2TLV Viscometer, Cone Spindle CPA-42Z, Brookfield Silicone Viscosity
Standard having a viscosity of 9.7 cP at 25°C
At 60 RPM, the full scale viscosity range is 10.0 cP. Thus, the Viscometer reading
should be 97% torque and 9.7 cP viscosity ± 0.197 cP. The allowable error (±0.197 cP)
is a combination of Viscometer accuracy and fluid tolerance (refer to Interpretation of
Calibration Test Results
in Appendix F).
3. With the motor off, remove the sample cup and place the viscosity standard fluid into
the cup.
Table A-1
Cone Part No.
CPA-40Z, CPE-40, CP-40
CPA-41Z, CPE-41, CP-41
CPA-42Z, CPE-42, CP-42
CPA-51Z, CPE-51, CP-51
CPA-52Z, CPE-52, CP-52
Sample Volume
0.5 mL
2.0 mL
1.0 mL
0.5 mL
0.5 mL
4. Attach the sample cup to the Viscometer and allow sufficient time for the sample, cup
and cone to reach temperature equilibrium.
5. Turn the motor on. Set the desired speed(s). Measure the viscosity and record the
reading in both % torque and centipoise (cP).
6. Verify that the viscosity reading is within the allowable 1% deviation, as explained earlier,
for the specific viscosity standard fluid(s) that you are using.
The CPE or CPA designation on the cone spindle indicates use with Electronic Gap
Setting Cone/Plate Viscometers/Rheometers only.