Appendix B: Calibration Check - Ametek BROOKFIELD RSO Operating Instructions Manual

Appendix B: Calibration Check

The calibration check procedure is performed to verify that your RSO Rheometer is making correct
viscosity measurements. It can be done in standalone mode or under control of Rheo3000 software.
Perform the calibration check with the spindle that is most frequently used with your instrument. You
do not need to perform a calibration check with additional spindles unless there is a concern that a
specific spindle is not measuring properly.
The calibration check can be performed at regularly scheduled time intervals determined by you
(before each shift, weekly, monthly, etc.) or at any time when there is concern that the instrument is
not measuring correctly. Before performing the calibration check, it is advisable to perform the Motor
Friction calibration.
Use the appropriate viscosity standard for the spindle that you want to test. Consult the following
table, which shows the fluid that is recommended for each type of spindle and the required sample
volume to perform the calibration check:
Cone Spindle
RCTO-25-1
RCTO-25-2
RCTO-50-1
RCTO-50-2
Prepare the proper sample volume for the test and condition to the defined temperature within
± 0.1 K. Mineral oil is highly temperature-sensitive, so it is important to do this correctly.
The calibration check procedure is performed at 3 separate controlled torque values: 12.5 mNm, 25
mNm, 37.5 mNm. The spindle rotates for a minimum of 15 seconds at each torque value. Observe that
the viscosity reading remains relatively constant vs. time. The viscosity reading at each torque value is
recorded after 15 seconds or a longer time interval of your choosing. The three viscosity readings must
each be within ± 5 % of the actual fluid value for the calibration check to pass.
If the calibration check fails, review each step to make sure that everything was done correctly in
accordance with the test procedure. Repeat the test procedure if necessary. Areas for potential error
are not having the proper sample volume and not conditioning the sample to the correct temperature.
It is also possible that shear heating may occur at the highest 37.5 mNm
If the viscosity value starts to drop, it may be due to shear heating. Record the viscosity reading 15
seconds after the test starts at this torque to minimize potential error. If the instrument fails when
you repeat the calibration check, contact AMETEK Brookfield or your local authorized dealer. See
Appendix E: Warranty and Repair.
M19-230-REV.B
Fluid
B41000
B73000
B10200
B21000
© 2020 AMETEK Brookfield Inc. All rights reserved.
Sample Volume
0.1 mL
0.2 mL
1.0 mL
2.0 mL
for certain spindle geometries.
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