This calibration check form can be used to verify the measurement performance of your ROTAVISC viscometer. Please follow the step-by-step instructions provided to ensure a correct calibration procedure.
1. Select the appropriate ROTAVISC model and spindle
Ensure that the correct ROTAVISC model and spindle type are selected. Note that the SP 4 and SP 12 spindles are not recommended for calibration checks due to their small surface area and the required accuracy which precludes their use.
2. Sample preparation and temperature control
- For relative measurements: Fill a 600 ml beaker (low profile) with standard lubricating oil and adjust the temperature to 25 °C (± 0.1 °C). This may take several hours. It is recommended to immerse the spindle and guard in the oil during the incubation period. The guard is required for lo-vi and me-vi instruments. To control the temperature inside the beaker, a circulating device (e.g. HRC 2 controller) can be used.
- For absolute measurements: Fill the corresponding measuring chamber with oil (refer to the operating instructions for the spindle type) and adjust to 25 °C (± 0.1 °C). This process may also take several hours. It is recommended to immerse the spindle in the oil during the incubation period. To control the temperature inside the measuring chamber, a circulation device (e.g. HRC 2 controller) can be used.
3. Enter the standard viscosity value
Enter the viscosity value of the standard oil at 25 °C, as indicated on the certificate or packaging label. Example: CAL-O-500 with a viscosity of 493 mPas at 25 °C.
4. Proceed with the viscosity measurement
Enter the first speed value to check the calibration, e.g. 10 rpm. Start the viscosity measurement at this speed and wait until the value stabilizes. The minimum speed must produce a torque of at least 10%.
The combination of speed and spindle should be selected so that the viscosity measurement takes place in the laminar flow region. The maximum recommended speed for calibration testing is:
- ROTAVISC lo-vi: 60 rpm
- ROTAVISC me-vi, hi-vi I & hi-vi II: 100 rpm
Recommended test conditions for ROTAVISC model calibration checks are: