BSISO8791-2:2013 BSl Standards Publication Paper and board - Determination of roughnessl smoothness (air leak methods) Part 2: Bendtsen method bsi. ..making excellence a habit. BS ISO 8791-2:2013 BRITISH STANDARD National foreword This British Standard is the UK implementation of IS0 8791-2:2013. It supersedes BS 4420:1990 (ISO 8791-2:1990) which is withdrawn. This latest edition of BS ISO 8791-2 concerning Bendtsen roughness makes reference to both electronic and variable-area flow instrumentation for the first time. In doing so new material has been included to describe the electronicinstrumentation.Parts of the standard related to the variable-areaflowinstrumentswerealsoupdated,whileotherpartswere used verbatim from previous editions. With the paper industry constituting a global industry, the UK committee accepted that the standard should be available for use in the UK. However, the committee's main concern is that in previous standards it was stipulated that samples of high surface roughness, sufficient to give values above 1 200 ml/min, were unsuitable for measurement using this method.Inthiseditionaninconsistencynow existsregardingroughness values. Whilst in the Scope the Bendsten roughness values are between 5 ml/min and 3 000 ml/min, Clause 10.2.2 states that users should not use airflows above 1 200 ml/min, and thus maintains the previous edition's measurement parameters. This foreword is aimed at highlighting this issue. In particular it is aimed at advising users that whilst the Scope suggests a change in what is permitted for variable-area flow instrumentation, this is not in practice carried through in the section relating to measurement parameters, which constitutesacontinuationfromthepreviousedition. The UK participation in its preparation was entrusted to Technical Committee PAl/11, Methods of test for paper, board and pulps. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions ofacontract.Usersareresponsibleforitscorrectapplication. The British Standards Institution 2014. Published by BSI Standards Limited 2014 ISBN 978 0 580 74528 7 ICS 85.060 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 January 2014. Amendments/corrigenda issued since publication Date Text affected BS ISO 8791-2:2013 INTERNATIONAL ISO STANDARD 8791-2 Second edition 2013-09-15 Paper and board Determination of roughness/smoothness (air leak methods) - Part 2: Bendtsen method Papier et carton - Détermination de la rugosite/du lissé (meéthodes du débit d'air) - Partie 2: Méthode Bendtsen Reference number IS08791-2:2013(E) @IS02013