ISO INTERNATIONAL STANDARD 20485 Firstedition 2017-11 Non-destructive testingLeak testing Tracer gas method Essais non destructifs-Controle d'étancheite -Methode par gaz traceur Reference number ISO 20485:2017(E) O ISO 2017 ISO 20485:2017(E) COPYRIGHTPROTECTEDDOCUMENT O IS02017,Published in Switzerland Allrights 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·CP401 CH-1214 Vernier,Geneva,Switzerland Tel.+41227490111 Fax+41227490947 [email protected] www.iso.org ii O ISO 2017-All rights reserved ISO 20485:2017(E) Contents Page Foreword iv 1 Scope 2 Normative references 3 Terms and definitions 4 Principles of detection 5 Generation and detection of tracer gas flow 5.1 Tracer gas flows into the object (Group Atechniques) 5.2 Tracergas flows out of the object (GroupB techniques) 6 Apparatus 7 Object preparation 8 Group A techniques , tracer gas flows into the object 8.1 General 8.2 Initial system set -up procedure 8.3 Vacuum technique (total)test procedure (A.1) 8.4 Vacuum technique (partial ) test procedure (A.2) 8.5 Vacuum technique (local )test procedure(A.3) Group B techniques , tracer gas flows out of object 9 9.1 General 9.2 Initial system set upprocedure 9.2.1 Ammonia test withcolour-change reagents (B.1) 9.2.2 Tracer gas flowing out of the object (B.2, B.3, B.4, B.6) 9.2.3 Pressurisation Evacuation test (B.5) 9.3 Ammonia test procedure (B.1) 9.3.1 General 9.3.2 Test object preparation 9.3.3 Reagent application 9.3.4 Ammoniapressurization 9.3.5 Impregnation time 9.3.6 Visual examination 9.3.7 Post test cleaning 9.4 Vacuum box test procedure (B.2.1, B.2.2) 6 9.4.1 General 9.4.2 Vacuum box technique for closed objects B.2.1 9.4.3 Vacuum box technique for open objects B.2.2 10 9.5 Accumulationtechnique (B.3) 10 9.5.1 General 10 9.5.2 Accumulation technique procedure (B.3) 10 9.6 Sniffing test (B.4) .12 9.7 Bombing technique (B.5) 12 9.8 Vacuum chamber technique 9.9 Carrier gas technique (B.7) 15 10 Test report 16 Annex A (informative)Accumulation technique :calibrated leak connected to enclosure of unknownvolume Bibliography OISO 2017-All rights reserved ili