Sets out a method for determining the average yellowness of a sample of greasy wool cores taken from a lot by the method described in AS 1980. The procedures to be used to clean and prepare the sample prior to measurement are those in AS 1133 and are not described in this Standard. This method is only applicable to the determination of the yellowness of greasy wool prepared for mean fibre diameter measurement in accordance with AS 1133. The result is the average yellowness after cleaning and carding. This method is not suitable for detecting dark fibre contamination, or the presence of urine-stained wool. For coloured wools only the yellowness component is measured.