Provides an experimental method for determining the heterogeneity of constitution which is required for the determination of the minimum sample mass. This Standard is identical with and has been reproduced from ISO 6138:1991.RECONFIRMATION NOTICETechnical Committee MN-003 has reviewed the content of this publication and inaccordance with Standards Australia procedures for reconfirmation, it has beendetermined that the publication is still valid and does not require change.Certain documents referenced in the publication may have been amended since theoriginal date of publication. Users are advised to ensure that they are using the latestversions of such documents as appropriate, unless advised otherwise in thisReconfirmation Notice.Approved for reconfirmation in accordance with Standards Australia procedures forreconfirmation on 19 August 2015.The following are represented on Technical Committee MN-003:Australian Aluminium CouncilMinerals Council of AustraliaRoyal Australian Chemical Institute