NATIONAL FOREWORD

The Indian Standard (Part 4) (Second Revision) which is identical with ISO 975 : 2013 ‘Brown coals and lignites — Determination of yield of benzene-soluble extract — Semi-automatic method’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Solid Mineral Fuels and Solid Biofuels Sectional Committee and approval of the Petroleum, Coal and Related Products Division Council.

This Indian Standard was originally published in 1969 and subsequently revised in 2004. The original standard was essentially based on the ‘Draft Recommendation No. 1126’ issued by ISO. Since this draft recommendation has subsequently been published as ISO 975 : 1975 and revised in 1985, 2000 and 2013. The second revision of this standard has been undertaken to align it with the latest version of ISO 975 : 2013.

The text of 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 ‘International Standard’ 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.