Brookfield DV-III Rheometer - Manual (Page 55)

Brookfield Engineering Laboratories, Inc. Page 55 Manual No. M/98-211-A0701
5. Attach the sample cup to the Viscom-
eter and allow sufficient time for the
sample, cup and cone to reach tem-
perature equilibrium.
6. Turn the motor on. Set the desired
speed(s). Measure the viscosity and
record the reading in both % torque
and centipoise (cP).
Note: The cone spindle must rotate
at least five (5) times before a visco-
sity reading is taken.
7. 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 designation on the cone
spindle indicates use with Electronic
Gap Setting Cone/Plate Viscometers/
Rheometers only.
A.4 VERIFYING CALIBRATION
1. Determine the appropriate sample vol-
ume. Refer to Table A1 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; ranges listed
apply to CPE cones.
Do not use a silicone viscosity standard 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 E2 in Appendix
E 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: LVDV-III+ Viscometer, Cone
Spindle CPE-42, 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 E).
3. Set the gap as described in Section A.3.
4. With the motor off, remove the sample cup
and place the viscosity standard fluid into
the cup.
C o n e S a m p l e Vo l u m e
P a r t N o .
C P E - 4 0 0 . 5 m l
C P E - 4 1 2 . 0 m l
C P E - 4 2 1 . 0 m l
C P E - 5 1 0 . 5 m l
C P E - 5 2 0 . 5 m l
Ta b l e A 6
Table A1