ISO INTERNATIONAL STANDARD 20998-3 First edition 2017-04 Measurement and characterization of particles by acoustic methods Part 3: Guidelines for non-linear theory Mesurage et caractérisation des particules par des méthodes acoustiques- Partie 3: Lignes directrices pour la théorie non linéaire Reference number IS0 20998-3:2017(E) International Organization for Standardization @ IS0 2017 HEJIANG INSTOFSTANDARDIZATION C15956617 ed without license from IHS IS0 20998-3:2017(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 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 Licensee-ZHEJIANG INST OF STANDARDIZRoSQ017 - All rights reserved Not for Resale, 2017/6/28 00:52:31 etworking permitted without license from IHS IS0 20998-3:2017(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope ..1 2 Normative references ..1 3 Terms and definitions 4 Symbols and abbreviated terms .1 5 Limits of applicability of linear theory .3 5.1 Multiple scattering. .3 5.2 Concentration considerations. .3 5.3 Steric repulsion. .6 6 Measurement issues in concentrated systems .7 6.1 General .1 6.2 Path length limitation. .7 6.3 High attenuation. 6.4 Increased viscosity .7 6.5 Change in velocity 6.6 Change in pulse shape .8 6.7 Homogeneity ..8 7 Nonlinear attenuation ..8 8 Determination of particle size 8.1 Calculation ..8 8.2 Limits of application. .9 9 Instrument qualification .9 9.1 Calibration 9 9.2 Precision .9 9.2.1 Reference materials .9 9.2.2 Repeatability .9 9.2.3 Reproducibility .9 9.3 Accuracy .9 9.3.1 Qualification procedure 9.3.2 Reference materials.. .10 9.3.3 Instrument preparation 10 9.3.4 Accuracytest ..10 9.3.5 Qualification acceptance criteria ..10 10 Reporting of results ..10 Annex A (informative) Theories of attenuation in concentrated systems ..11 Annex B (informative) Practical example of PsD measurement (coupled phase model) ..14 Bibliography .22 iii ee=ZHEJIANG INSTOFSTANDARDIZATION C15956617 without license from IHS Not for Resale, 2017/6/28 00:52:31