ISO/TR TECHNICAL REPORT 18231 First edition 2016-05-01 Iron ores - Wavelength dispersive X-ray fluorescence spectrometers Determination of precision Minerais de fer - Spectrometres a fluorescence a rayons X a longueur d'onde dispersive - Détermination de la précision Reference number ISO/TR 18231:2016(E) ISO International Organization for Standardization see=ZHEJIANG INST OF STANDARDIZATION C1 5956617 @IS02016 vided by IHS under I mitted without license from IHS IS0/TR 18231:2016(E) COPYRIGHT PROTECTEDDOCUMENT 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. ISO copyright office 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 Licensee-ZHEJIANG INST OF STANDARDIzRoISQ 6 - All rights reserved Not for Resale, 2016/7/20 08:19:41 networking permited without license from IHS IS0/TR 18231:2016(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Frequency of testing 3 Counter tests. ..2 3.1 Counter resolution. .2 3.1.1 General. 3.1.2 Procedure 4 3.1.3 Assessment of results .6 3.2 Conductivity of the gas flow proportional counter window .6 3.2.1 General ..6 3.2.2 Procedure. 7 3.2.3 Assessment of results .7 3.3 Pulse shift corrector. ..7 3.3.1 General. .7 3.3.2 Procedure. ..8 4 Spectrometer tests .8 4.1 General .8 4.2 Precision. 4.2.1 General. .9 4.2.2 Calculation of counting statistical error 10 4.3 Test specimen. .11 4.3.1 General .11 4.3.2 Sequential spectrometers .11 4.3.3 Simultaneous spectrometers .11 4.4 Instrumentalconditions .11 4.4.1 General. .11 4.4.2 Sequential spectrometers ..12 4.4.3 Simultaneous spectrometers .12 4.5 Stabilitytest 12 4.6 Specimen rotation test. 13 4.7 Carouselreproducibilitytest .13 4.8 Mounting and loading reproducibility test ..13 4.9 Comparison of sample holders .13 4.10 Comparison of carousel positions. ..14 4.11 Angular reproducibility ..14 4.12 Collimator reproducibility (for sequential spectrometers fitted with an interchangeablecollimator) ..14 4.13 Detector changing reproducibility (for sequential spectrometers fitted with more than one detector) ..14 4.14 Crystal changing reproducibility ..14 4.15 Othertests. .15 4.16 Note on glass bead curvature. 15 5 Determination of the dead time and the maximum usable count rate of the equipment....15 5.1 General. .15 5.2 Methods of determination of dead time. .. 16 5.2.1 General. ..16 5.2.2 Recommended method for determining dead time ..17 Annex A (informative) Calculation of the coefficient of variation of duplicates ..24 Bibliography. ..26 iii icensee=ZHEJIANG INST OF STANDARDIZATION C1 5956617 ed withoutlicense from IHS Not for Resale, 2016/7/20 08:19:41