Correction method of Flow Cup

As long as the test temperature is accurate and consistent, for Newtonian fluids, using a Flow Cup (Viscosity Cup) of the same size will measure the same outflow time. Using such fluids to correct Flow Cups provides a useful means of initially verifying that the performance of Flow Cups of opposite sizes is still within acceptable tolerances, and from time to time to verify whether the Flow Cup has undergone abrasion or damage that exceeds the allowable tolerances.

For the correction of any particular Flow Cup, use a standard oil with known kinematic viscosity and plot the Linear dispersion of kinematic viscosity to temperature based on the data given by the standard oil supplier.

The outflow time of the oil was measured at a known temperature in the range of 20 ℃ to 30 ℃ (flanking to 0.1 ℃).

Record this outflow time, it should be in the range of 30s to 100s, better close to the middle value of this range, accurate to 0.2s.

Linear dispersion diagram has been drawn to find the kinematic viscosity at the test temperature.

Using the appropriate formula, calculate the outflow time corresponding to this kinematic viscosity.

These correction formulas are as follows:

3Mm Flow Cup v = 0.443t- (200/t)

4Mm Flow Cup v = 1.37t- (200/t)

5Mm Flow Cup v = 3.28t- (200/t)

6Mm Flow Cup. V = 6.90t- (570t)

If the difference between the measured outflow time and the calculated standard outflow time is not greater than 3% of their average value, this Flow Cup may be considered suitable.