Brookfield CAP2000 Viscometer - Manual (Page 20)

Brookfield Engineering Labs., Inc. Page 20 Manual No. M/94-310F
APPENDIX B - Calibration Procedures
Verification of Calibration
Normally there is no requirement to perform a cone calibration. Cones supplied at the time of
order are calibrated to the viscometer prior to shipment.
At selected intervals, depending upon usage and number of operators, the CAP Viscometer calibration
should be verified using NIST Fluids. Referring to Appendix A (Table A1), find the appropriate NIST
Fluid(s) for the cone(s) being used.
With the viscometer set up, perform viscosity measurements following the outline of Section III. Prior
to pressing the RUN key to initiate a cone calibration, we recommend a period of thermal equilibrium
of approximately 30 minutes for the fluid, cone and plate. This period should begin immediately after
entering the calibration temperature and associated viscosity value (in cP). Execute viscosity measure-
ments at three (3) rotational speeds (RPM) giving results within the 10% to 100% full scale viscosity
range of the selected cone.
Verify the results to have a precision according to the information in Section III, Table 3.1.
If the calibration is outside the precision limits (refer to Table 1), proceed with the following Cone
Calibration.
Cone Calibration
A special feature of the CAP Series Viscometers allows the user to perform cone calibration using
NIST Fluids.
Refer to Appendix A (Table A1) and choose the viscosity standard fluid for the cone being calibrated.
Place the appropriate amount of sample (refer to Appendix A, Table A1) onto the viscometer plate in
the center directly below the cone. Pull the handle down (gently), locking it into the lowest position,
placing the cone in contact with the plate.
NOTE: The solvent trap should be utilized when calibrating.
1. Press the CONE key. The current cone number (two digits) appears on the right of the display.
2. Using the CONE key alternating with the INDEX key, enter the two digit number of the cone
being calibrated.
3. After entering the second digit of the cone number, pressing the CONE key selects the cone
and displays the message: