Reaffirmed 2023

NATIONAL FOREWORD

This Indian Standard (Part 5/Sec 21) which is identical with ISO 8791-3 : 2017 ‘Paper and board - Determination of roughness/smoothness (air leak methods) - Part 3: Sheffield method’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on recommendation of the Paper and its Products Sectional Committee and approval of the Chemical Division Council.

Considering the importance of test method for determination of roughness/smoothness in paper and board by Sheffield method and to follow the uniform practices globally, the Committee felt that it would be more convenient to prepare this standard method by adoption of ISO 8791-3 on dual number basis.

This method is applicable to papers and boards which have Sheffield roughness values between 10 and about 3000 ml/min. While adopting ISO Standards on different test methods it is observed that there are three broad based titles given by ISO namely ‘paper, board and pulps’, ‘paper and board’ and ‘Pulps’ under which most of the test methods are published. The series of published Indian Standards namely IS 1060 ‘Methods of sampling and test for paper and allied products’ are widely used and known to all concerned. There is an IS 6213 series of standards published for ‘Methods of test for pulps’. Therefore, to maintain the continuity and also to find the relevant test methods instantly, all the adopted standards on test methods are being published under the following titles:

IS No. Title

1060 (Part 1, 2 and 3) Methods of sampling and test for paper and allied products

(Part 4) Methods of test for paper, board and pulps

(Part 5) Methods of test for paper and board

(Part 6) Methods of test for paper

(Part 7) Methods of test for board

6213 Methods of test for pulp

All the adopted standards are also being accommodated as different sections of each series based on their titles and accordingly, this standard is being adopted under the series of IS 1060 (Part 5) as section 21.

The text of the ISO Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain terminologies and conventions are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following:

a) Wherever the words ‘Document’ appear referring to this standard, they should be read as ‘Indian Standard’.

b) Comma (,) has been used as a decimal marker, while in Indian Standards, the current practice is to use a point (.) as the decimal marker.