ISO INTERNATIONAL STANDARD 7686 Second edition 2005-07-01 Plastics pipes and fittings Determination of opacity Tubes et raccords en matieres plastiques Détermination de I'opacité Reference number ISO 7686:2005(E) Copyright International Organization for Standardization @ISO2005 itted without license from IHS Not for Resale ISO 7686:2005(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by IsO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below ?ISO2005 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, 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 yemainagazainandardizato @ISO2005-All rights reserved mittedwithoutlicense from IHS Not for Resale ISO 7686:2005(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies technicalcommittees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeer International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEc Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adoptedbythetechnicalcommitteesarecirculatedtothememberbodiesforvoting.Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. rights. IsO shall not be held responsible for identifying any or all such patent rights. ISO 7686 was prepared by Technical Committee ISO/TC 138, Plastics pipes, fittings and valves for the transport of fluids, Subcommittee Sc 5, General properties of pipes, fittings and valves of plastic materials and their accessories Test methods and basic specifications. revision. It incorporates the following modifications: the incident beam is defined with respect to the size of the test piece and the entrance port of the integrating sphere; - production of test pieces from the sample is prescribed in greater detail; editorial changes have been introduced. ii maaaiandardizato orneworkingmitedwithout licene fromH Not for Resale INTERNATIONAL STANDARD ISO 7686:2005(E) Plastics pipes and fittings Determination of opacity 1 Scope This International Standard specifies a method for the determination of the opacity of plastics pipes and fittings. Annex A gives guidance on the light transmission of opaque pipes and fittings. NOTE It is necessary for a pipe or ftting used for water supply which is exposed to visible light during service to be sufficiently opaque to prevent algae growth. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 opacity light energy on the test piece 2.2 light intensity light energy which has passed through the test piece 2.3 maximum light intensity Im maximum light energy received from the light source 3 Principle Thescatteredandunscatteredlightenergyofawavelengthof540nmto560nmpassingthroughatestpiece cut from a pipe or fitting is measured and expressed as a percentage of the incident light energy on the test piece. 4. A