Revised Standard from Last Update.

NATIONAL FOREWORD

This Indian Standard (Part 5) (Second Revision) which is identical with ISO 4590 : 2016 ‘Rigid cellular plastics - Determination of the volume percentage of open cells and of closed cells’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on recommendation of the Thermal Insulation Sectional Committee and approval of the Chemical Division Council.

This standard specifies a general procedure for the determination of the volume percentage of open and closed cells of rigid cellular thermal insulation materials. To measure air impenetrable volume of test specimens, three methods are prescribed, which involves the principles of pressure variation and volume expansion.

This standard was originally published in 1985 and subsequently revised in 2009. First revision of this standard was identical with ISO 4590 : 2002. Second revision of this standard has been undertaken to align it with ISO 4590 : 2016.

The major changes in this revision are as follows:

a) Changes in clause 2;

b) Introduction of a new test method based on the variation of the volume, which is named 2b;

c) References to the test methods have been revised consequently and the cross references; and

d) Certain editorial changes.

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’ appears 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.