Brookfield Engineering Labs., Inc.
Page 20
Manual No. M02-33E209
• In ambient conditions of 15°C to 30°C, accuracy is +/- 1.0°C when the temperature set
point on the viscometer is 101°C to 235°C.
• In ambient conditions outside of 15°C to 30°C, accuracy is +/- 2.0°C when the temperature
set point on the viscometer is 50°C to ≤100°C.
III.3 Calibration Verification
Accuracy of the CAP 2000+ Viscometer can be verified by performing a calibration verifica
-
tion.
The cones/spindles that were shipped with the viscometer were calibrated to the viscometer by
Brookfield prior to shipment. If your viscometer was returned to Brookfield or an authorized
Brookfield Dealer, then any cones/spindles that were returned for service will have been cali
-
brated to the viscometer prior to shipment.
When you receive the instrument, perform a calibration verification on each cone spindle to
ensure that each spindle is measuring correctly. Use the appropriate viscosity standard fluid
defined in Table III-5 or III-6 for each spindle. This will ensure that everything is in good
working order and that the instrument and/or cone spindles have not experienced a change
during shipment. If the calibration verification fails then you can take advantage of the CAP
Viscometer’s unique feature which allows the operator to recalibrate each cone spindle to the
CAP Viscometer (See Section III.4).
Calibration verification of your viscometer should also be performed when viscosity readings
with your product are suspect. Verifying the calibration will determine if the cone needs to
be recalibrated to the instrument. This will help you to determine if the discrepant readings
on your product are due to cone/instrument performance, or your method or your product.
Complete cone recalibration is discussed in Section III.4.
To perform a cone calibration verification, you will need a mineral oil from Table III-5 or Table
III-6. Determine what range model CAP 2000+ Viscometer you have (Low Torque or High
Torque), which temperature range (L = Low, H = High; consult the instrument serial tag) and
what cone your are using.
You must use the following method to verify calibration of each cone spindle.
1. Attach solvent trap and spindle and lower viscometer head. Put the cone in the down posi-
tion, and make sure that the solvent trap is covering the spindle.
2. Allow the viscometer to stabilize for at least 30 minutes at 25°C (Low Temp units) or at
60°C (High Temp) if the temperature that you normally operate is different; otherwise, wait
5 minutes, then make sure the cone is in the down position and that the solvent trap is on.
3. At the end of the temp stabilization period, dispense the appropriate volume of fluid (consult
Table III-5 or Table III-6). Figure III-1 shows how to dispense the fluid onto the plate and
determine visually if the amount is appropriate.
