ISO INTERNATIONAL STANDARD 13909-8 Second edition 2016-07-01 Hard coal and coke Mechanical sampling - Part 8: Methods of testing for bias Houille et coke - Echantillonnage mécanique - Partie 8: Méthodes de détection du biais Reference number IS0 13909-8:2016(E) ISO International Organization for Standardization ZHEJIANG INST OF STANDARDIZATION C1 5956617 @IS02016 vided by IHS underI itted without license from IHS IS0 13909-8:2016(E) COPYRIGHTPROTECTEDDOCUMENT IS0 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISOcopyrightoffice Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 [email protected] www.iso.org Internatinair PrganizationforStandardization ensee-ZHEJIANG INST.OF STANDARDIzARoISQ16- All rights reserved Not for Resale, 2016/8/16 08:27:34 etworking permitted without license from IHS IS0 13909-8:2016(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Normative references 3 Terms and definitions 4 Principles .1 5 Pretest inspection .2 6 Reference methods ..2 7 Test design .3 7.1 Choice of test parameters .3 7.2 Number of paired samples. .3 7.3 Selection of sample pairs .3 7.3.1 Composition of sample pairs .3 7.3.2 Paired-increment samples. 4 7.3.3 Paired-batch samples. 7.4 Choice of fuel for test. 4 7.5 Coke 4 8 Conduct of the test ..4 8.1 General 4 8.2 Collection and preparation of test samples .5 9 Outline of test procedure. .5 9.1 General .5 9.2 Special precautions for moisture-test samples. ..6 9.3 Documentation. .. 6 10 Statistical analysis and interpretation .6 10.1 Outline of statistical procedure ..6 10.2 Calculations.. .7 10.2.1 Statistical procedure for identifying outliers .7 10.2.2 Disposition of outliers .8 10.2.3 Calculation of confidence intervals and determining bias .8 10.2.4 Review of the 95 % confidence region for the bias. ..12 11 Test report. ..12 Annex A (informative) Example calculations ..13 Bibliography .28 iii =ZHEJIANG INST OF STANDARDIZATION C1 5956617 vided by IHS underI withoutlicense from IHS