ISO INTERNATIONAL STANDARD 16641 First edition 2014-10-01 Measurement of radioactivity in the environment Air Radon 220: Integrated measurement methods for the determination of the average activity concentration using passive solid-state nuclear track detectors Mesurage de la radioactivité dans I'environnement - Air - Radon 220: Méthode de mesure intégrée pour la détermination de I'activité volumique moyenne avec des détecteurs passifs solides de traces nucléaires Reference number IS0 16641:2014(E) ISO @ IS0 2014 ed without license from IHS Not for Resale IS0 16641:2014(E) COPYRIGHT PROTECTED DOCUMENT @ISO2014 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 copyright office Case postale 56 : CH-1211 Geneva 20 Tel, + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland @ IS0 2014 - All rights reserved Not for Resale IS0 16641:2014(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Normative references ..1 3 Terms, definitions, and symbols 3.1 Terms and definitions .1 3.2 Symbols.... 4 Principle of the measurement method ..4 5 Equipment ..5 6 Sampling. .6 6.1 Sampling objective. .6 6.2 Sampling characteristics 6.3 Sampling conditions ..6 7 Detection method with solid-state nuclear track detectors (SSNTD) .7 8 Measurement procedure .7 8.1 General. .7 8.2 Influencing variables ..8 8.3 Calibration ..8 9 Expression of results. .9 9.1 Average thoron activity concentration. 9.2 Standard uncertainty 9.3 Decision threshold 10 9.4 Detectionlimit 10 9.5 Confidence limits. .11 9.6 Example. ..11 10 Test report ..12 Annex A (informative) Radon-220 and its decay products .14 Bibliography ..16 ii se with ISt withoutlicense from IHS Not for Resale