ISO INTERNATIONAL STANDARD 12800 Second edition 2017-06 Nuclear fuel technology Guidelines on the measurement of the specific surface area of uranium oxide powders by the BET method Technologie du combustible nucleaireLignes directrices pourle mesurage de I'aire massique (surface spécifique) des poudres d'oxyde d'uranium par la méthode BET Reference number IS0 12800:2017(E) [so International Organization for Standardization @ IS0 2017 HEJIANG INSTOFSTANDARDIZATIONC15956617 ed without license from IHS IS0 12800:2017(E) COPYRIGHTPROTECTEDDOCUMENT IS0 2017, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyrightoffice Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +4122 749 09 47 copyright@iso.org www.iso.org Intenatinir PrganizationforStandardization ensee-ZHEJIANG INSTOF STANDARDIzARoISQa7 - All rights reserved Not for Resale, 2017/9/12 02:35:14 etworking permitted without license from IHS IS0 12800:2017(E) Contents Page Foreword ..iv 1 Scope .1 2 Normative references ..1 3 Terms and definitions 4 Principle 4.1 Summary of the BET method .1 4.2 Isothermal adsorption curves. 4.3 Conditions and assumptions. .2 5 Procedure. .3 5.1 Sample preparation 5.2 Volumetric measurement 3 5.3 Gravimetricmeasurement 5.4 Original and single-point methods .3 5.5 Dynamic method (carrier gas method) ..4 5.6 Alternative methods. 4 6 Expression of results ..4 6.1 Methods of calculation ..4 6.1.1 Multipoint determination ..4 6.1.2 Single-point determination .7 6.2 Precision and accuracy. ..7 7 Test report .7 Bibliography ..8 iii See=ZHEJIANG INST OF STANDARDIZATION C1 5956617 vided by IHS under lic without license from IHS Not for Resale, 2017/9/12 02:35:14