scope:

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. The scope of this method provides for the testing of rigid cellular plastics that have thicknesses from 10 mm or over and which may, as an integral part of the material, contain natural skins or adhered facings of some different material. Three different sets of temperature and humidity conditions are provided as follows:

a) 38°C and a relative-humidity gradient across the specimen of 0 % to 88 %;

b) 23°C and a relative-humidity gradient across the specimen of 0 % to 85 %;

c) 23°C and a relative-humidity gradient across the specimen of 0 % to 50 %.

The results obtained by this method are suitable for design purposes, production control, and for inclusion in product specifications.

The method is suitable for materials which have water vapour transmission rates in the range 3 μg/(m². s) to 200 μg/(m². s).

NOTE The International Standard corresponding to this Standard and the symbol of degree of correspondence is as follows.

ISO 1663: 2007 Rigid cellular plastics-Determination of water vapour transmission properties (MOD)

In addition, symbols which denote the degree of correspondence in the contents between the relevant International Standard and JIS are IDT (identical), MOD (modified), and NEQ (not equivalent) according to ISO/IEC Guide 21-1.