IS 11239 : Part 4 : 2025/ISO 1663 : 2023 Method of Test for Rigid Cellular Thermal Insulation Materials - Part 4 Water Vapour Transmission Rate
NATIONAL FOREWORD
This Indian Standard (Part 4) (Second Revision) which is identical with ISO 1663 : 2023 'Rigid cellular plastics - Determination of water vapour transmission properties' issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards, on the recommendation of the Thermal Insulation Sectional Committee and approval of the Chemical Division Council.
This standard specifies a method of determining the water vapour transmission rate, water vapour permeance, water vapour permeability and water vapour diffusion resistance index for rigid cellular plastics.
This method is applicable for the testing of rigid cellular materials that have thicknesses from 10 mm upwards and can, as an integral part of the material, contain natural skins or adhered facings of some different material.
This standard was first published in 1985 and subsequently revised in 2014 by adopting the ISO 1663 : 2007 under dual numbering system. During the review of IS 11239 (Part 4), it was observed by the committee that ISO 1663 has been revised as ISO 1663 : 2023. This revision has been brought out in order to align the standard with the latest version of ISO 1663.
The following changes in the revision are as follows:
a) in the Scope (1);
b) the unit ng has been changed to μg;
c) the upper limit has been changed from 200 μg;/(m2.s) to 1 400 μg;/(m2.s);
d) Clause 9 has been modified as follows:
1) 9.1.2, "Blank specimen" has been added;
2) 9.3.2 "Corrections" has been added; and
3) in 9.5, Formula (8) has been modified;
e) in Clause 11, a new item (k) has been added; and
f) Formula (in equation B.8) has been modified.
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' appears referring to this standard, they should be read as 'Indian Standard'; and
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.