ISO INTERNATIONAL STANDARD 18917 First edition 1999-06-01 Photography Determination of residual thiosulfate and other related chemicals in processed photographic materials Methods using iodine-amylose, methylene blue and silver sulfide Photographie - Determination du thiosulfate residuel et d'autres produits chimiques dans les produits photographiques traites - Methodes a I'iode- amylose, au bleu de méthylene et au sulfure d'argent ISO Reference number ISO 18917:1999(E) Not for Resale ISO 18917:1999(E) Contents 1 Scope 2 Normative references 3 General requirements 4 lodine-amylose method... 3 5 Methylene blue method.. 6 Silver densitometric method Annex A (informative) Appraisal of keeping characteristics... .16 Annex B (informative) Guidance in the selection of test method.. .17 Annex C (informative) Preparation for 0,2 mol/l sodium hydroxide solution.. Annex D (informative) Preparation of 1,ooo mol/l sodium thiosulfate solution, Bibliography. 21 @ISO1999 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic InternationalOrganizationforStandardization Casepostale56·CH-1211Geneve20·Switzerland Internet iso@iso.ch Printed in Switzerland onal Organization for Standardization Not for Res @ISO ISO18917:1999(E) Foreword ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(lSo member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has liaison with isO, also take part in the work. IsO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 18917 was prepared by Technical Committee ISO/TC 42, Photography. levels have been modified to provide more reproducible results. ii