This part of GB/T 12704 specifies the method to determine water-vapor transmission of fabrics with water method. This part includes two methods: Method A “upright cup method” and Method B “inverted cup method”.
This part is applicable to various sheet fabrics with thickness less than 10mm. Thereinto, Method B is only applicable to testing of waterproofing permeable fabric.
2 Normative References
The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of GB/T 12704. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this part of GB/T 12704. However parties to agreements based on this part of GB/T 12704 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 3820 Determination of Thickness of Textiles and Textile Products (GB/T 3820-1997, eqv ISO 5084: 1996)
GB/T 6529 Textiles - Standard Atmospheres for Conditioning and Testing (GB/T 6529-2008, ISO 139: 2005, MOD)
GB/T 8170 Rules of Rounding for Numerical Values & Expression and Judgment of Limiting Values
3 Terms and Definitions
For the purposes of this part of GB/T 12704, the following terms and definitions apply.
3.1
water-vapor transmission rate
WVT
the mass of water-vapor vertically passing through the specimen per unit area in specified time under specified temperature and humidity condition for both faces of specimen, with unit of g/(m2?h) or g/(m2?24h)
