kata pengantar
ISO (Organisasi Internasional untuk Standardisasi) adalah aliansi global badan standar nasional (badan anggota ISO). Pengembangan standar internasional biasanya dilakukan melalui komite teknis ISO. Setiap lembaga anggota yang tertarik pada suatu mata pelajaran yang telah dibentuk komite teknisnya berhak untuk diwakili dalam komite tersebut. Organisasi pemerintah dan non-pemerintah internasional yang bekerja sama dengan ISO juga terlibat dalam pekerjaan ini. ISO bekerja sama dengan Komisi Elektroteknik Internasional (IEC) tentang semua masalah standardisasi elektroteknik.

Prosedur yang digunakan untuk mengembangkan dokumen ini dan yang digunakan untuk pemeliharaan lebih lanjut dijelaskan di Bagian 1 dari Petunjuk ISO/IEC. Secara khusus, perhatikan standar persetujuan berbeda yang diperlukan untuk berbagai jenis dokumen ISO. This document has been drafted in accordance with the editing rules in Part 2 dari Petunjuk ISO/IEC (lihat iso.org/directives).

Harap dicatat bahwa isi tertentu dari dokumen ini mungkin memiliki hak paten. ISO tidak bertanggung jawab untuk mengidentifikasi salah satu atau semua paten tersebut. 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 (lihat 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 (TBT) 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, Cat dan Pernis, Subkomite SC 9, Metode Uji Umum untuk Cat dan Pernis.

The second edition rescinded and replaced the first edition (ISO 7783:2011), in which it constituted a minor revision to correct the conversion factor in formula (3) and to add a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

ISO 7783-2018 “Cat dan pernis — Penentuan karakteristik transmisi uap air dengan metode cawan”

memperkenalkan
This document is one of a series of standards dealing with the sampling and testing of paints, pernis dan produk terkait. 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, suhu, or relative humidity difference. Measurements made under one set of conditions are not necessarily comparable to those made under other conditions. Karena itu, 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. Karena itu, 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.

ISO 7783-2018 “Cat dan pernis — Penentuan karakteristik transmisi uap air dengan metode cawan”

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

It complements ISO 12572. Prosedur, definisi, and calculations have been taken over from ISO 12572 as far as possible. Jika diperlukan, refer to ISO 12572 for a better understanding of the procedures specified in this document.

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

2 Acuan normatif
File-file berikut direferensikan dalam teks sedemikian rupa sehingga sebagian atau seluruh konten merupakan persyaratan dokumen ini. Untuk referensi bertanggal, versi hanya kutipan berlaku. Untuk referensi tidak bertanggal, referensi versi terbaru (termasuk revisi apa pun) berlaku.

ISO 1513, Cat dan pernis – Pemeriksaan dan penyiapan sampel uji

ISO 2808, Cat dan pernis – penentuan ketebalan film

ISO 3233-1, Cat dan pernis – Determination of non-volatile substances as a percentage by volume – Bagian 1: Method for determination of non-volatile substances using a coating test panel and dry film density by Archimedean principle

ISO 3696, Air laboratorium analitik – spesifikasi dan metode pengujian

ISO 4618, Cat dan pernis — Istilah dan definisi

ISO 15528, Cat, pernis dan bahan baku cat dan pernis — Contoh

3 Istilah dan Definisi
Untuk keperluan dokumen ini, istilah dan definisi yang diberikan dalam ISO 4618 dan artikel berikut ini berlaku.

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

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

Catatan 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) nilai (melihat 3.3).

Catatan 3: Syarat “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

Catatan 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

Catatan 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

Catatan 1: It is dimensionless.

Catatan 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, itu adalah, independent of thickness, yang, Namun, is not usually the case for coatings.

ISO 7783-2018 “Cat dan pernis — Penentuan karakteristik transmisi uap air dengan metode cawan”

3.5 Contoh

< Non-self-supporting coating > Coated supporting material

3.6 Contoh

< Self-supporting coating > 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

Catatan 1: This is the most convenient method for determining water vapor permeability at high relative humidity (between 93% Dan 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

Catatan 1: This is the most convenient method for determining water vapor permeability at low relative humidity (between 50% Dan 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 Daerah Tes

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

Catatan 1: It is measured in square metres.

Hanya bagian informasi standar yang bersifat publik. Untuk melihat konten selengkapnya, Anda perlu membeli standar melalui saluran resmi.