Mathematical Combination by Subtraction of Measured Fibre Diameter Distributions of Greasy and Scoured Wool

Abstract

At the IWTO conference in Nice in December 1995 Semmel and Sommerville submitted a paper to the Raw Wool Group which described a new equation that enabled the combination of fibre diameter distributions for individual lots to obtain a distribution for a delivery.

The paper also recommended the IWTO-31-86 should be amended to include the new formula and other formulae for combining data derived from measurement systems which provided distribution information. This recommendation was accepted and a revision of IWTO-31-86 has been submitted to the Raw Wool Group at the Cape Town Conference2. As part of this process the formula was further developed to provide a formula for calculation the diameter distribution
of the remainder of a delivery after a small portion (<5%)has been removed from the delivery.

The derivation of this formula is provided in this paper for future reference. The paper is supplementary to the previous paper, which contains a more detailed description of the process involved and the assumptions made. 

Citation

"Mathematical Combination by Subtraction of Measured Fibre Diameter Distributions of Greasy and Scoured Wool", P. J. Sommerville, Submission to IWTO Technology and Standards Committee: RAW WOOL GROUP, Cape Town - April 1996