предговор
ИСО (Међународна организација за стандардизацију) је глобални савез националних тела за стандардизацију (Тела чланица ИСО). Развој међународних стандарда се обично спроводи преко ИСО техничких комитета. Свака институција чланица заинтересована за предмет за који је основан технички комитет има право да буде заступљена у тој комисији. Међународне владине и невладине организације које су у вези са ИСО такође су укључене у овај посао. ИСО блиско сарађује са Међународном електротехничком комисијом (ИЕЦ) о свим питањима електротехничке стандардизације.

Процедуре које се користе за израду овог документа и оне које се користе за даље одржавање описане су у Делу 1 ИСО/ИЕЦ директиве. Нарочито, обратите пажњу на различите стандарде одобрења који су потребни за различите типове ИСО докумената. Овај документ је израђен у складу са правилима уређивања у Дел 2 ИСО/ИЕЦ директиве (види исо.орг/дирецтивес).

Please note that certain contents of this document may be subject to patent rights. ИСО није одговоран за идентификацију било ког или свих таквих патената. Details of any patent rights identified during the preparation of the document will be in the introduction and/or list of patent claims received by ISO (see iso.org/patents).

Any trade names used in this document are information provided for the convenience of the user and do not constitute an endorsement.

Voluntary, related standards and conformity assessment related ISO specific terminology and express the meaning of and the ISO in the technical barriers to trade (ТБТ) adhere to the principle of the world trade organization (WTO) information, please see the iso.org/iso/foreword.html.

This document has been prepared by Technical Committee ISO/TC 35, Боје и лакови, Subcommittee SC 9, Common Test Methods for Paints and varnishes.

The second edition rescinded and replaced the first edition (ИСО 7783:2011), in which it constituted a minor revision to correct the conversion factor in formula (3) and to add a reference to ISO 4618 paint and varnish terms in Article 3.

Any feedback or questions about this document should be directed to the user’s national standards body. A complete list of these institutions can be found at iso.org/members.html.

ИСО 7783-2018 “Боје и лакови — Determination of water vapor transmission characteristics cup method”

увести
This document is one of a series of standards dealing with the sampling and testing of paints, varnishes and related products. It describes a method for determining the water vapor transmittance of self-supporting and non-self-supporting coatings.

Water vapor transmittance is not necessarily a linear function of film thickness, температура, or relative humidity difference. Measurements made under one set of conditions are not necessarily comparable to those made under other conditions. Стога, you must choose a test condition that is as close to the usage condition as possible.

Under conditions of high humidity, the propagation of water vapor is of greatest concern. Стога, the wet cup method has been adopted as the reference method. Depending on the agreement, other procedures and conditions may be used, such as the Cheers method.

ИСО 7783-2018 “Боје и лакови — Determination of water vapor transmission characteristics cup method”

1 домет
This document specifies the method for determining the water vapour permeability of paints, varnishes and coatings for related products.

It complements ISO 12572. Procedures, definitions, and calculations have been taken over from ISO 12572 as far as possible. If necessary, refer to ISO 12572 for a better understanding of the procedures specified in this document.

Vapor transmittance exceeding 680 g/ (m 2⋅d) (i.e., the vapor diffusion equivalent air layer thickness sd is less than 0.03 м) cannot be accurately quantified by the test method described in this document.

2 Normative references
The following files are referenced in the text in such a way that some or all of the content constitutes the requirements of this document. За датиране референце, citation-only versions apply. For undated references, the latest version of the reference (укључујући све ревизије) примењује.

ИСО 1513, Боје и лакови – Examination and preparation of test samples

ИСО 2808, Боје и лакови – determination of film thickness

ИСО 3233-1, Боје и лакови – Determination of non-volatile substances as a percentage by volume – Парт 1: Method for determination of non-volatile substances using a coating test panel and dry film density by Archimedean principle

ИСО 3696, Analytical laboratory water – specifications and test methods

ИСО 4618, Боје и лакови — Terms and definitions

ИСО 15528, Paints, varnishes and raw materials for paints and varnishes — Sampling

3 Terms and Definitions
For the purposes of this document, the terms and definitions given in ISO 4618 and the following articles apply.

3.1 Water vapor transmittance

The mass of water vapor transmitted over a given surface area of the sample under a specified constant relative humidity on each surface of the sample under test over a given period of time

Белешка 1: It is measured in grams/square meters per day [g/ (m2⋅d)].

Белешка 2 Water vapor transmittance p measured at atmospheric pressure can be converted to the equivalent value at standard atmospheric pressure p0 by multiplying p/p0. This allows for a linear correlation of 20,4, with the water vapor diffusion equivalent air layer thickness (sd) вредност (види 3.3).

Белешка 3: Термин “water vapor transfer” is often incorrectly used for water vapor transfer rates.

3.2 Velocity G of steam flowing through the sample under test

The mass of constant water vapor passing through each surface of the sample under test at a specified constant relative humidity during a given period of time

Белешка 1: It is expressed in grams per hour.

3.3 Vapor diffusion equivalent air layer thickness SD

The thickness of a static air layer with the same water vapor transmittance as the test coating under the same measurement conditions

Белешка 1: It is measured in meters.

3.4 Water vapor drag coefficient M

A coefficient indicating how many times more resistant a material is to water vapor than a static air layer of the same thickness at the same temperature and pressure

Белешка 1: It is dimensionless.

Белешка 2 The calculation and use of the water vapor drag coefficient is meaningful only if the water vapor transmittance of a particular material is constant, то је, independent of thickness, which, Међутим, is not usually the case for coatings.

ИСО 7783-2018 “Боје и лакови — Determination of water vapor transmission characteristics cup method”

3.5 Specimen

< Non-self-supporting coating &гт; Coated supporting material

3.6 Specimen

< Self-supporting coating &гт; Separate coating

3.7 Wet Cup Method

Method for measuring water vapor permeability in which the sample is sealed around the rim of a cup containing a saturated aqueous solution of ammonium dihydrogen phosphate

Белешка 1: This is the most convenient method for determining water vapor permeability at high relative humidity (between 93% и 50%).

3.8 Cheers

A method of measuring the permeability of water vapor in which a sample is sealed around the edge of a cup containing a desiccant

Белешка 1: This is the most convenient method for determining water vapor permeability at low relative humidity (between 50% и 3%).

3.9 Testing Components

An assembly consisting of a test cup sealed at the edge of a test cup containing a saturated ammonium dihydrogen phosphate solution in contact with an undissolved ammonium dihydrogen phosphate crystal (wet cup method) or containing a desiccant (cheers method)

3.10 Test Area

The surface area of the sample under test through which water vapor flows during the test

Белешка 1: It is measured in square metres.

Јаван је само одељак са стандардним информацијама. Да бисте видели цео садржај, морате купити стандард преко званичних канала.