Adequate assessment of factory extraction performance

A method is presented which enables the variation in milling train performance results to be quantified. The use of this method at one factory has shown that the overall variation in the moisture, Brix, fibre and pol measurements is mostly due to variation in the cane supply. More consistent analysis results could be obtained by increasing the frequency of sampling. The variation in the pol in open cells measurement, however, is largely due to the analysis procedure. The pol in open cells analysis procedure is discussed. The determination of free pol is an arbitrary one that affects the accuracy of the measurement but does not seem to significantly affect the precision of the measurement. The use of the same sample for both free pol and total pol measurements is proposed as one approach that may reduce the analysis error.