<p class="MsoBodyText"><span lang="EN-GB">This document 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.</span></p>
<p class="MsoBodyText"><span lang="EN-GB">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.</span></p>
<p class="MsoBodyText"><span lang="EN-GB">Three different sets of temperature and humidity conditions are provided, as follows:</span></p>
<p class="ListNumber1" style="mso-list: l0 level1 lfo1;"><!-- [if !supportLists]--><span lang="EN-GB" style="mso-fareast-font-family: Cambria; mso-bidi-font-family: Cambria;"><span style="mso-list: Ignore;">a)<span style="font: 7.0pt 'Times New Roman';"> </span></span></span><!--[endif]--><span lang="EN-GB">38 °C and a relative-humidity gradient across the test specimen of 0 % to 88 %</span></p>
<p class="ListNumber1" style="mso-list: l0 level1 lfo1;"><!-- [if !supportLists]--><span lang="EN-GB" style="mso-fareast-font-family: Cambria; mso-bidi-font-family: Cambria;"><span style="mso-list: Ignore;">b)<span style="font: 7.0pt 'Times New Roman';"> </span></span></span><!--[endif]--><span lang="EN-GB">23 °C and a relative-humidity gradient across the test specimen of 0 % to 85 %</span></p>
<p class="ListNumber1" style="mso-list: l0 level1 lfo1;"><!-- [if !supportLists]--><span lang="EN-GB" style="mso-fareast-font-family: Cambria; mso-bidi-font-family: Cambria;"><span style="mso-list: Ignore;">c)<span style="font: 7.0pt 'Times New Roman';"> </span></span></span><!--[endif]--><span lang="EN-GB">23 °C and a relative-humidity gradient across the test specimen of 0 % to of 50 %</span></p>
<p class="MsoBodyText"><span lang="EN-GB">The results obtained by this method are suitable for design purposes and production control, and for inclusion in product specifications.</span></p>
<p class="MsoBodyText"><span lang="EN-GB">The method is suitable for materials which have water vapour transmission rates in the range 3 µg/(m<sup>2</sup>⋅s) to 1 400 µg/(m<sup>2</sup>⋅s).</span></p>
Registration number (WIID)
81900
Scope
<p class="MsoBodyText"><span lang="EN-GB">This document 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.</span></p>
<p class="MsoBodyText"><span lang="EN-GB">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.</span></p>
<p class="MsoBodyText"><span lang="EN-GB">Three different sets of temperature and humidity conditions are provided, as follows:</span></p>
<p class="ListNumber1" style="mso-list: l0 level1 lfo1;"><!-- [if !supportLists]--><span lang="EN-GB" style="mso-fareast-font-family: Cambria; mso-bidi-font-family: Cambria;"><span style="mso-list: Ignore;">a)<span style="font: 7.0pt 'Times New Roman';"> </span></span></span><!--[endif]--><span lang="EN-GB">38 °C and a relative-humidity gradient across the test specimen of 0 % to 88 %</span></p>
<p class="ListNumber1" style="mso-list: l0 level1 lfo1;"><!-- [if !supportLists]--><span lang="EN-GB" style="mso-fareast-font-family: Cambria; mso-bidi-font-family: Cambria;"><span style="mso-list: Ignore;">b)<span style="font: 7.0pt 'Times New Roman';"> </span></span></span><!--[endif]--><span lang="EN-GB">23 °C and a relative-humidity gradient across the test specimen of 0 % to 85 %</span></p>
<p class="ListNumber1" style="mso-list: l0 level1 lfo1;"><!-- [if !supportLists]--><span lang="EN-GB" style="mso-fareast-font-family: Cambria; mso-bidi-font-family: Cambria;"><span style="mso-list: Ignore;">c)<span style="font: 7.0pt 'Times New Roman';"> </span></span></span><!--[endif]--><span lang="EN-GB">23 °C and a relative-humidity gradient across the test specimen of 0 % to of 50 %</span></p>
<p class="MsoBodyText"><span lang="EN-GB">The results obtained by this method are suitable for design purposes and production control, and for inclusion in product specifications.</span></p>
<p class="MsoBodyText"><span lang="EN-GB">The method is suitable for materials which have water vapour transmission rates in the range 3 µg/(m<sup>2</sup>⋅s) to 1 400 µg/(m<sup>2</sup>⋅s).</span></p>
