ISO INTERNATIONAL STANDARD 2194 Second edition 1991-09-15 Industrial screens -- Woven wire cloth, perforated plate and electroformed sheet - Designation and nominal sizes of openings Cribles et tamis industriels -- Tissus métalliques, toles perforées et feuilles electroformees - Designation et dimensions nominales des ouvertures Reference number ISO 2194:1991(E) Not for Resale vorking permitted without license from IHS ISO 2194:1991(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 tiaison with IsO, also take part in the work. IsO collaborates closely with the international Electrotechnica! Commission (IEC) on alt matters of electrotechnica! standardization. Draft international Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an Inter- national Standard requires approvai by at least 75 % of the member bodies casting a vote. International Standard isO 2194 was prepared by Technical Committee IsO/TC 24, Sieves, sieving and other sizing methods, Sub-Committee SC 3, Industrial wire screens. This second edition cancels and replaces the first edition (iso 2194:1972), of which the scope has been extended to include per- forated plate and some additional sizes. Annex A of this International Standard is for information only. ?1SO1991 All rlghts reserved. No part of this publication may be reproduced or utilized In any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case Postale 56 : CH-1211 Geneve 20 · Swltzerland Printed in Switzerland right internationalOrganizationfor Standardization without license from IHS Not for Resale ISO 2194:1991(E) Introduction The nominal sizes of openings specified in this International Standard are taken from the R 10, R 20 and R 40 series of preferred numbers in accordance with Iso 3 and from the R'10, R'20 and R'40 series of rounded values in accordance with Iso 497. The sizes within each series follow a geometric progression. Therefore, each size of a series differs from the successive size by a constant percentage. Apart from the omission of a few unusuai values in the range of the very smalf sizes, the ratios of the successive sizes are as follows. Serles Step Ratio ISO 3 R 10 about 25 % 1,25 R 20 about 12 % 1.12 R 40 about 6 % 1,06 il1 nitted without license from IHS Not for Resale No reproductio