Fibre length distribution – tops and sliver

Most major standards institutions have developed or published fibre length measurement methods.  In consequence, over the years, a wide number of alternatives have been available. From the wool perspective, there have also been several IWTO methods available for measuring fibre length, and these are discussed in Info-bulletin 1.3 .

Only one IWTO method is currently available - that uses the Almeter, for certifying the mean fibre length and distribution of fibre length in tops and sliver (IWTO-17).  Whilst other methods have been used in the past, most notably the Comb Sorter, the Fibre Diagram, and Single Fibre Length, these have all been downgraded, due to poor precision, to draft methods which can only be used by agreement between buyer and seller.

A new instrument, the OFDA 4000, was introduced to IWTO in 2000, which resulted in a new draft method IWTO DTM 62.  The OFDA 4000 simultaneously measures both diameter and length distributions on lengths of top.  Some technical papers reviewing the performance of this instrument can be found on the Publications page.