BS EN ISO 7783:2018
$142.49
Paints and varnishes. Determination of water-vapour transmission properties. Cup method
| Published By | Publication Date | Number of Pages |
| BSI | 2018 | 28 |
This document specifies a method for determining the water-vapour transmission properties of coatings of paints, varnishes and related products.
It supplements ISO 12572. As far as possible, the procedure, the definitions and the calculations have been taken over from ISO 12572. ISO 12572 can be consulted, if necessary, to obtain a better understanding of the procedure specified in this document.
Water-vapour transmission rates of more than 680 g/(m2⋅d) (i.e. water-vapour diffusion-equivalent air layer thicknesses, sd, of less than 0,03 m) are not accurately quantified by the test method described in this document.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 2 | National foreword |
| 4 | European foreword |
| 6 | Foreword |
| 7 | Introduction |
| 9 | 1 Scope 2 Normative references 3 Terms and definitions |
| 11 | 4 Principle 5 Apparatus and materials 5.1 Substrate for non-self-supporting coatings 5.2 Test cup |
| 12 | 5.3 Ammonium dihydrogen phosphate (NH4H2PO4) solution for wet-cup method 5.4 Desiccant for dry-cup method 5.5 Sealing material 5.6 Test enclosure 5.7 Balance |
| 13 | 6 Preparation for the test 6.1 Sampling of coating material 6.2 Preparation of test pieces 6.2.1 Preparation of non-self-supporting coatings on a porous substrate 6.2.2 Preparation of self-supporting coatings 6.2.3 Conditioning |
| 14 | 6.3 Determination of the thickness of the coating 6.3.1 General 6.3.2 Determination of the thickness of the coating by calculation 6.3.3 Determination of the thickness of the coating by optical, mechanical or other suitable methods 6.4 Preparation of the test assemblies |
| 15 | 7 Procedure 8 Expression of results 8.1 Water-vapour transmission rate, V, of self-supporting coatings 8.1.1 Rate of flow of water vapour, G, through the test piece 8.1.2 Water-vapour transmission rate, V, of the coating |
| 16 | 8.2 Water-vapour transmission rate, V, of non-self-supporting coatings 8.2.1 General 8.2.2 Rate of flow of water vapour through the substrate, Gs, and through the substrate plus coating, Gcs |
| 17 | 8.2.3 Water-vapour transmission rate, Vs, of the substrate |
| 18 | 8.2.4 Water-vapour transmission rate, Vcs, of the substrate plus coating 8.2.5 Water-vapour transmission rate, V, of the coating 8.3 Water-vapour diffusion-equivalent air layer thickness, sd |
| 19 | 8.4 Water-vapour resistance factor, μ 9 Precision 9.1 Repeatability, (r) 9.2 Reproducibility, (R) |
| 20 | 10 Test report |
| 21 | Annex A (informative) Derivation of Formula (8) for the calculation of the water-vapour diffusion-equivalent air layer thickness, sd |
| 23 | Annex B (normative) Use of molten wax for sealing the test assembly |
| 27 | Bibliography |
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BS EN ISO 7783:2018 – TC:2020 Edition
Tracked Changes. Paints and varnishes. Determination of water-vapour transmission properties. Cup method Published By Publication…
