ISO INTERNATIONAL STANDARD 8761 First edition 1989-12-01 Work-place air - Determination of mass concentration of nitrogen dioxide - Method using detector tubes for short-term sampling with direct indication Air des lieux de travail -Determination de la concentration en masse du dioxyde d'azote -- Methode utilisant des tubes detecteurs pour echantillonnage rapide a lecture directe Reference number ISO 8761:1989(E) with ISC No reproduction or networking permited without license from IHS Not for Resale ISO 8761:1989(E) Foreword iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO 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 the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with Iso, also take part in the work. Iso collaborates closely with the International Electrotechnica! Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance member bodies voting. International Standard iso 8761 was prepared by Technical Committee ISO/TC146,Airquality. AnnexA forms an integral part of this Interhational Standard.Annex B is forinformationonly. @1SO1989 All rights reserved, No part of this publicatlon may be reproduced or utlized In any form orbyanymeans,electronicormechanlcal,Includingphotocopyingandmlcrofllm,without permisslon in writingfrom thepublisher. International Organlzation for Standardization Case Postale 56 · CH-1211 Geneve 20 · Switzerland Printed In Switzerland No reproduction or networking permitted without license from IHS Not for Resale ISO 8761:1989(E) Introduction The determination of the mass concentration of nitrogen dioxide present in the air at work places (work areas or stationary. posts) by means of detector tubes for short-term sampling with direct indication, called de- tector tubes in the following text, is made with one of several suitable reagent systems. The most important of these are the reagent systems based on N,N-diphenyl-benzidine, N-(1-naphthyl)-ethylenediamine dihydrochloride, and o-tolidine. ili No reproduction or networking permited without license from IHS Not for Resale