ISO INTERNATIONAL STANDARD 7347 First edition 1987-12-15 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION so ORGANISATION INTERNATIONALE DENORMALISATION MEKAYHAPOAHAA OPrAHM3ALWH NO CTAHAAPTV3ALWM Ferroalloys - Experimental methods for checking the bias of sampling and sample preparation Ferro-alliages -- Methodes experimentales de controle de I'erreur systematique de I'échantillonnage etde la preparation.des échantillons Referencenumber ISO 7347: 1987 (E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (iso member bodies). The work of preparing International Standards is normaily carried out through iso technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with Iso, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISo Council. They are approved in accordance with Iso procedures requiring at least 75 % approval by the member bodies voting. Ferroalloys. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latestedition,unlessotherwisestated. @ International Organization for Standardization, 1987 Printed in Switzerland i ational Organizati No reproduction or networking permitted without license from IHS Not for Resale ISO 7347 : 1987 (E) Contents Page Scope and field of application . References 3 General requirements 3.1 Methods for sampling, sample preparation and chemical analysis 3.2 Principle 3.3 Quality characteristic 3.4 Number of experiments 3.5Selection of methods of data analysis. 4 Experimental methods 4.1 Examples of experiment 4.2Sampling 2 4.3 Preparation of samples 2 4.4 Determination and recording 2 5 Data analysis 4 5.1 Test for significance of differenc 5.2 Paired data 5.3 Unpaired data 6Review of experimental results Annexes AMethodof calculationofthet-testforpaireddata 5 B Method of calculation of the F-test for unpaired data 6 CMethodof calculationofthet-testforunpaireddata D Exampleforthecalculationofpairedandunpaireddata ili No reproduction or networking permitted without license from IHS Not for Resale