ISO 2647:1973

The method is applicable to woolen and worsted products, at all stages, from raw materials to yarn. It utilizes the same apparatus and technique as that described in ISO/R 137. Since the method of preparation and measurements gives a length-biased sample, the result given by this method is an estimate of the length of medullated fibres as a percentage of the total length of all fibres. It cannot be used to estimate the volume of medullation or fibre density.