NATIONAL FOREWORD

The Indian Standard (Part 3) (First Revision) which is identical with ISO 12213-3 : 2006 ‘Natural gas — Calculation of compression factor — Part 3: Calculation using physical properties’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Methods of Test for Petroleum, Petroleum Products and Lubricants Sectional Committee and approval of the Petroleum, Coal and Related Products Division Council.

This standard was first published in 2003. Consequent to revision of ISO 12213-3 in 2006, the Committee decided to revise it to completely align it with latest version of ISO Standard.

The text of ISO Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain 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.