Paints and varnishes - Methods of exposure to laboratory light sources - Part 3: Fluorescent UV lamps (ISO 16474-3:2021)

This document specifies methods for exposing coatings to fluorescent UV lamps, heat and water in
apparatus designed to reproduce the weathering effects that occur when materials are exposed in
actual end-use environments to daylight, or to daylight through window glass.
The coatings are exposed to different types of fluorescent UV lamps under controlled environmental
conditions (temperature, humidity and/or water). Different types of fluorescent UV lamp can be used to
meet all the requirements for testing different materials.
Specimen preparation and evaluation of the results are covered in other ISO documents for specific
materials.
General guidance is given in ISO 16474-1.
NOTE Fluorescent UV lamp exposures for plastics are described in ISO 4892-3.

Beschichtungsstoffe - Künstliches Bestrahlen oder Bewittern in Geräten - Teil 3: UV-Fluoreszenzlampen (ISO 16474-3:2021)

Dieses Dokument legt Verfahren zum Beanspruchen von Beschichtungen mit UV-Leuchtstofflampen, Wärme und Wasser fest, um mit dafür entwickelten Geräten die Einflüsse der Bewitterung zu reproduzieren, die auftreten, wenn Materialien im Endgebrauch in den vorhandenen Umgebungen durch Tageslicht oder durch Fensterglas gefiltertes Tageslicht beansprucht werden.
Die Beschichtungen werden mit unterschiedlichen Typen von UV-Leuchtstofflampen unter geregelten Umweltbedingungen (Temperatur, Luftfeuchte und/oder Wasser) beansprucht. Verschiedene Typen von UV-Leuchtstofflampen können angewendet werden, um alle Anforderungen zu erfüllen, die bei der Prüfung verschiedener Materialien gestellt werden.
Die Herstellung der Probenplatten und die Bewertung der Ergebnisse werden in anderen Internationalen Normen für spezifische Materialien behandelt.
Eine allgemeine Anleitung wird in ISO 16474 1 gegeben.
ANMERKUNG   Die Beanspruchung von Kunststoffen mit UV-Leuchtstofflampen wird in ISO 4892 3 beschrieben.

Peintures et vernis - Méthodes d'exposition à des sources lumineuses de laboratoire - Partie 3: Lampes fluorescentes UV (ISO 16474-3:2021)

Le présent document spécifie des méthodes d'exposition de feuils à des lampes fluorescentes UV, en présence de chaleur et d'eau dans des appareils conçus pour reproduire les effets du vieillissement qui se produisent lorsque des matériaux sont exposés, dans les environnements d'utilisation finale réels, à la lumière du jour ou à la lumière du jour filtrée à travers un vitrage de fenêtre.
Les feuils sont exposés à différents types de lampes fluorescentes UV dans des conditions environnementales maîtrisées (température, humidité et/ou eau). Différents types de lampes fluorescentes UV peuvent être utilisés pour répondre à toutes les exigences relatives aux essais de différents matériaux.
La préparation des éprouvettes et l'évaluation des résultats sont traitées dans d'autres documents ISO concernant les matériaux spécifiques.
Des lignes directrices générales sont données dans l'ISO 16474‑1.
NOTE       L'exposition des matières plastiques aux lampes fluorescentes UV est décrite dans l'ISO 4892‑3.

Barve in laki - Metode izpostavljanja laboratorijskim virom svetlobe - 3. del: Fluorescentne UV-svetilke (ISO 16474-3:2021)

General Information

Status
Published
Public Enquiry End Date
02-Dec-2019
Publication Date
02-Feb-2021
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
13-Jan-2021
Due Date
20-Mar-2021
Completion Date
03-Feb-2021

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SLOVENSKI STANDARD
SIST EN ISO 16474-3:2021
01-marec-2021
Nadomešča:
SIST EN ISO 16474-3:2014
Barve in laki - Metode izpostavljanja laboratorijskim virom svetlobe - 3. del:
Fluorescentne UV-svetilke (ISO 16474-3:2021)
Paints and varnishes - Methods of exposure to laboratory light sources - Part 3:
Fluorescent UV lamps (ISO 16474-3:2021)
Beschichtungsstoffe - Künstliches Bestrahlen oder Bewittern in Geräten - Teil 3: UV-
Fluoreszenzlampen (ISO 16474-3:2021)
Peintures et vernis - Méthodes d'exposition à des sources lumineuses de laboratoire -
Partie 3: Lampes fluorescentes UV (ISO 16474-3:2021)
Ta slovenski standard je istoveten z: EN ISO 16474-3:2021
ICS:
87.040 Barve in laki Paints and varnishes
SIST EN ISO 16474-3:2021 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 16474-3:2021

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SIST EN ISO 16474-3:2021


EN ISO 16474-3
EUROPEAN STANDARD

NORME EUROPÉENNE

January 2021
EUROPÄISCHE NORM
ICS 87.040 Supersedes EN ISO 16474-3:2013
English Version

Paints and varnishes - Methods of exposure to laboratory
light sources - Part 3: Fluorescent UV lamps (ISO 16474-
3:2021)
Peintures et vernis - Méthodes d'exposition à des Beschichtungsstoffe - Künstliches Bestrahlen oder
sources lumineuses de laboratoire - Partie 3: Lampes Bewittern in Geräten - Teil 3: UV-Fluoreszenzlampen
fluorescentes UV (ISO 16474-3:2021) (ISO 16474-3:2021)
This European Standard was approved by CEN on 17 October 2020.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16474-3:2021 E
worldwide for CEN national Members.

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SIST EN ISO 16474-3:2021
EN ISO 16474-3:2021 (E)
Contents Page
European foreword . 3

2

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SIST EN ISO 16474-3:2021
EN ISO 16474-3:2021 (E)
European foreword
This document (EN ISO 16474-3:2021) has been prepared by Technical Committee ISO/TC 35 "Paints
and varnishes" in collaboration with Technical Committee CEN/TC 139 “Paints and varnishes” the
secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by July 2021, and conflicting national standards shall be
withdrawn at the latest by July 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 16474-3:2013.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 16474-3:2021 has been approved by CEN as EN ISO 16474-3:2021 without any
modification.

3

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SIST EN ISO 16474-3:2021

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SIST EN ISO 16474-3:2021
INTERNATIONAL ISO
STANDARD 16474-3
Second edition
2021-01
Paints and varnishes — Methods
of exposure to laboratory light
sources —
Part 3:
Fluorescent UV lamps
Peintures et vernis — Méthodes d'exposition à des sources lumineuses
de laboratoire —
Partie 3: Lampes fluorescentes UV
Reference number
ISO 16474-3:2021(E)
©
ISO 2021

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SIST EN ISO 16474-3:2021
ISO 16474-3:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

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SIST EN ISO 16474-3:2021
ISO 16474-3:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 3
5.1 Laboratory light source . 3
5.2 Test chamber . 6
5.3 Radiometer . 6
5.4 Black-standard/black-panel thermometer . 6
5.5 Wetting and humidity . 7
5.5.1 General. 7
5.5.2 Spray and condensation system . 7
5.6 Specimen holders . 7
5.7 Apparatus to assess changes in properties . 7
6 Test specimens (panels) . 7
6.1 General . 7
6.2 Preparation and coating . . 8
6.3 Drying and conditioning . 8
6.4 Thickness of coating . 8
6.5 Number of test panels . 8
7 Test conditions . 8
7.1 General . 8
7.2 Radiation . 8
7.3 Temperature . 8
7.4 Relative humidity of chamber air . 9
7.5 Condensation and spray cycles . 9
7.6 Complex cycles with dark periods . 9
7.7 Sets of exposure conditions . 9
8 Procedure and mounting of the test specimens .10
8.1 General .10
8.2 Exposure .10
8.3 Measurement of radiant exposure .11
8.4 Determination of changes in properties after exposure .11
9 Test report .11
Annex A (informative) Spectral distribution of radiation for typical fluorescent UV lamps .12
Bibliography .16
© ISO 2021 – All rights reserved iii

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SIST EN ISO 16474-3:2021
ISO 16474-3:2021(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee
SC 9, General test methods for paints and varnishes, in collaboration with the European Committee for
Standardization (CEN) Technical Committee CEN/TC 139, Paints and varnishes, in accordance with the
Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 16474-3:2013) which has been technically
revised. The main changes compared to the previous edition are as follows:
— in 7.2 the difference between the temperature of a black panel sensor and a black standard sensor
has been corrected;
— in Table 4 it has been changed that the black-panel temperature is not controlled during water spray;
— the text has been editorially revised and the normative references have been updated.
A list of all parts in the ISO 16474 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2021 – All rights reserved

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SIST EN ISO 16474-3:2021
ISO 16474-3:2021(E)

Introduction
Coatings of paints, varnishes and similar materials (subsequently referred to simply as coatings) are
exposed to laboratory light sources, in order to simulate in the laboratory the ageing processes which
occur during natural weathering or behind window glass.
© ISO 2021 – All rights reserved v

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SIST EN ISO 16474-3:2021

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SIST EN ISO 16474-3:2021
INTERNATIONAL STANDARD ISO 16474-3:2021(E)
Paints and varnishes — Methods of exposure to laboratory
light sources —
Part 3:
Fluorescent UV lamps
1 Scope
This document specifies methods for exposing coatings to fluorescent UV lamps, heat and water in
apparatus designed to reproduce the weathering effects that occur when materials are exposed in
actual end-use environments to daylight, or to daylight through window glass.
The coatings are exposed to different types of fluorescent UV lamps under controlled environmental
conditions (temperature, humidity and/or water). Different types of fluorescent UV lamp can be used to
meet all the requirements for testing different materials.
Specimen preparation and evaluation of the results are covered in other ISO documents for specific
materials.
General guidance is given in ISO 16474-1.
NOTE Fluorescent UV lamp exposures for plastics are described in ISO 4892-3.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 1514, Paints and varnishes — Standard panels for testing
ISO 2808, Paints and varnishes — Determination of film thickness
ISO 4618, Paints and varnishes — Terms and definitions
ISO 9370, Plastics — Instrumental determination of radiant exposure in weathering tests — General
guidance and basic test method
ISO 16474-1:2013, Paints and varnishes — Methods of exposure to laboratory light sources — Part 1:
General guidance
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4618 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
© ISO 2021 – All rights reserved 1

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SIST EN ISO 16474-3:2021
ISO 16474-3:2021(E)

3.1
radiant exposure
H
amount of radiant energy to which a test panel has been exposed
Note 1 to entry: Radiant exposure is given by the equation:
HE=∫ ⋅dt
where
2
H is the radiant exposure, in joules per square metre (J/m );
2
E is the irradiance, in watts per square metre (W/m );
t is the exposure time, in seconds (s).
Note 2 to entry: If the irradiance E is constant throughout the whole exposure time, the radiant exposure H is
given simply by the product of E and t.
4 Principle
4.1 Fluorescent UV lamps, when properly maintained, can be used to simulate the spectral irradiance
of daylight in the ultraviolet (UV) region of the spectrum.
4.2 Specimens are exposed to various levels of UV radiation, heat and moisture (see 4.4) under
controlled environmental conditions.
4.3 The exposure conditions may be varied by selection of:
a) the type of fluorescent lamp (spectral power distribution);
b) the irradiance level;
c) the temperature during the UV exposure;
d) the relative humidity of the chamber air during the light and dark exposures, when test conditions
requiring control of humidity are used;
NOTE Commercial fluorescent UV lamp devices generally do not provide means of relative humidity
control.
e) the type of wetting (see 4.4);
f) the wetting temperature and cycle;
g) the timing of the UV/dark cycle.
4.4 Wetting is usually produced by condensation of water vapour onto the exposed specimen surface
or by spraying the test specimens with demineralized/deionized water.
4.5 The procedure(s) may include measurement of the irradiance and the radiant exposure in the
plane of the specimen.
4.6 It is recommended that a similar material of known performance (a control) be exposed
simultaneously with the test specimens to provide a standard for comparative purposes.
2 © ISO 2021 – All rights reserved

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SIST EN ISO 16474-3:2021
ISO 16474-3:2021(E)

4.7 Intercomparison of results obtained from specimens exposed in different apparatus or to different
types of lamp should not be made unless an appropriate statistical relationship has been established
between the different types of equipment for the material to be tested.
5 Apparatus
5.1 Laboratory light source
5.1.1 Fluorescent UV lamps are fluorescent lamps in which radiant emission in the ultraviolet region of
the spectrum, i.e. below 400 nm, makes up at least 80 % of the total light output. There are three types of
fluorescent UV lamp used in this document:
— The spectral distribution of radiation for typical fluorescent lamps is described in Annex A. Type 1A
(UVA-340) fluorescent UV lamp: These lamps have a radiant emission below 300 nm of less than 1 %
of the total light output and a peak emission at 343 nm. They are more commonly identified as UVA-
340 for simulation of daylight from 300 nm to 340 nm (see Table 1, Spectral pass-band column).
Figure A.1 is a graph of spectral irradiance from 250 nm to 400 nm of a typical type 1A (UVA-340)
fluorescent UV lamp compared to daylight.
— Type 1B (UVA-351) fluorescent UV lamp: These lamps have a radiant emission below 310 nm of
less than 1 % of the total light output and a peak emission at 353 nm. They are more commonly
identified as UVA-351 for simulation of the UV portion of daylight behind window glass (see Table 2).
Figure A.2 is a graph of spectral irradiance from 250 nm to 400 nm of a typical type 1B (UVA-351)
fluorescent UV lamp compared to daylight filtered by window glass.
— Type 2 (UVB-313) fluorescent UV lamp: These lamps have a radiant emission below 300 nm of
more than 10 % of the total light output, and a peak emission at 313 nm. They are more commonly
identified as UVB-313 (see Table 3). Figure A.3 is a graph of the spectral irradiance from 250 nm to
400 nm of two typical type 2 (UVB-313) fluorescent UV lamps compared to daylight. Type 2 (UVB-
313) fluorescent UV lamps may be used only by agreement between the parties concerned. Such
agreement shall be stated in the test report.
NOTE 1 Type 2 (UVB-313) fluorescent UV lamps have a spectral distribution of radiation which peaks near
the 313 nm mercury line and might emit radiation down to λ = 254 nm, which can initiate ageing processes that
never occur in end-use environments.
NOTE 2 The solar spectral irradiance for a number of different atmospheric conditions is described in CIE
[7] [7]
85 . The benchmark daylight value used in this document is from CIE 85:1989, Table 4 .
5.1.2 Unless otherwise specified, type 1A (UVA-340) fluorescent UV lamps or corresponding type 1A
fluorescent UV lamp combinations shall be used to simulate the UV part of daylight (see Table 4, method
A). Unless otherwise specified, type 1B (UVA-351) fluorescent UV lamps shall be used to simulate the UV
part of daylight through window glass (see Table 4, method B).
5.1.3 Fluorescent UV lamps age significantly with extended use. If an automatic irradiance control
system is not used, follow the apparatus manufacturer’s instructions on the procedure necessary to
maintain the desired irradiance.
© ISO 2021 – All rights reserved 3

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SIST EN ISO 16474-3:2021
ISO 16474-3:2021(E)

5.1.4 Irradiance uniformity shall be in accordance with the requirements specified in ISO 16474-1.
Requirements for periodic repositioning of specimens when irradiance within the exposure area is less
than 90 % of the peak irradiance are described in ISO 16474-1.
Table 1 — Relative ultraviolet spectral irradiance for type 1A (UVA-340) fluorescent UV lamps
a, b
for daylight UV (method A)
c d, e c
Spectral passband Minimum CIE 85:1989, Table 4 Maximum
(λ = wavelength in nm) % % %
λ < 290 — 0 0,1
290 ≤ λ ≤ 320 5,9 5,4 9,3
320 < λ ≤ 360 60,9 38,2 65,5
360 < λ ≤ 400 26,5 56,4 32,8
a
 This table gives the relative values for irradiance in the given passband, expressed as a percentage of the total
irradiance between 290 nm and 400 nm. To determine whether a specific type 1A (UVA-340) fluorescent UV lamp meets
the requirements of this table, the spectral irradiance from 250 nm to 400 nm shall be measured. Typically, this is done
in 2 nm increments. The total irradiance in each passband is then summed and divided by the total irradiance between
290 nm and 400 nm.
b
 The minimum and maximum limits for type 1A (UVA-340) fluorescent UV lamps in this table are based on more
than 60 spectral irradiance measurements with type 1A (UVA-340) fluorescent UV lamps from different production lots
[8]
and of various ages . The spectral irradiance data are for lamps within the ageing recommendations of the apparatus
manufacturer. As more spectral irradiance data become available, minor changes in the limits are possible. The minimum
and maximum limits are at least three sigma from the mean for all the measurements. The range of the relative irradiance
of fluorescent UV lamp combinations is determined by radiation measurements at about 50 locations within the exposure
area recommended by the apparatus manufacturer.
c
 The minimum and maximum columns will not necessarily sum to 100 % because they represent the minima and
maxima for the measurement data used. For any individual spectral irradiance distribution, the percentages calculated for
the passbands in this table will sum up to 100 %. For any individual type 1A (UVA-340) fluorescent UV lamp, the calculated
percentage in each passband shall fall within the minimum and maximum limits given. Test results can be expected to
differ between exposures using type 1A (UVA-340) fluorescent UV lamps in which the spectral irradiance differs by as
much as that allowed by the tolerances. Contact the manufacturer of the fluorescent UV apparatus for specific spectral
irradiance data for the type 1A (UVA-340) fluorescent UV lamp used.
d [7]
 The data from CIE 85:1989, Table 4 , is the global solar irradiance on a horizontal surface for an air mass of
1,0, an ozone column of 0,34 cm at standard temperature and pressure (STP), 1,42 cm of precipitable water vapour and a
spectral optical depth of aerosol extinction of 0,1 at 500 nm. These data are provided for reference purposes only and are
intended to serve as a target.
e [7]
For the solar spectrum represented by CIE 85:1989, Table 4 , the UV irradiance (290 nm to 400 nm) is 11 % and the
visible irradiance (400 nm to 800 nm) is 89 %, expressed as a percentage of the total irradiance from 290 nm to 800 nm.
Because the primary emission of fluorescent UV lamps is concentrated in the 300 nm to 400 nm passband, there are limited
data available for the visible light emission of fluorescent UV lamps. The percentages of UV irradiance and visible irradiance
on specimens exposed in fluorescent UV apparatus might vary due to the number of specimens being exposed and their
reflectance properties.
4 © ISO 2021 – All rights reserved

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SIST EN ISO 16474-3:2021
ISO 16474-3:2021(E)

Table 2 — Relative ultraviolet spectral irradiance for type 1B (UVA-351) fluorescent UV lamps
a, b
for daylight behind window glass (method B)
CIE 85:1989, Table 4, plus
c c
Spectral passband Minimum Maximum
d, e
effect of window glass
(λ = wavelength in nm) % % %
λ < 300 — 0 0,2
300 ≤ λ ≤ 320 1,1 ≤1 3,3
320 < λ ≤ 360 60,5 33,1 66,8
360 < λ ≤ 400 30,0 66,0 38,0
a
 This table gives the relative values for irradiance in the given passband, expressed as a percentage of the total
irradiance between 290 nm and 400 nm. To determine whether a specific type 1B (UVA-351) fluorescent UV lamp meets
the requirements of this table, the spectral irradiance from 250 nm to 400 nm shall be measured. Typically, this is done
in 2 nm increments. The total irradiance in each passband is then summed and divided by the total irradiance between
290 nm and 400 nm.
b
 The minimum and maximum limits given in this table are based on 21 spectral irradiance measurements with
[8]
type 1B (UVA-351) fluorescent UV lamps from different production lots and of various ages . The spectral irradiance data
are for lamps within the ageing recommendations of the apparatus manufacturer. As more spectral irradiance
...

SLOVENSKI STANDARD
oSIST prEN ISO 16474-3:2019
01-november-2019
Barve in laki - Metode izpostavljanja laboratorijskim virom svetlobe - 3. del:
Fluorescentne UV-svetilke (ISO/DIS 16474-3:2019)
Paints and varnishes - Methods of exposure to laboratory light sources - Part 3:
Fluorescent UV lamps (ISO/DIS 16474-3:2019)
Beschichtungsstoffe - Künstliches Bestrahlen oder Bewittern in Geräten - Teil 3: UV-
Fluoreszenzlampen (ISO/DIS 16474-3:2019)
Peintures et vernis - Méthodes d'exposition à des sources lumineuses de laboratoire -
Partie 3: Lampes fluorescentes UV (ISO/DIS 16474-3:2019)
Ta slovenski standard je istoveten z: prEN ISO 16474-3
ICS:
87.040 Barve in laki Paints and varnishes
oSIST prEN ISO 16474-3:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 16474-3:2019

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oSIST prEN ISO 16474-3:2019
DRAFT INTERNATIONAL STANDARD
ISO/DIS 16474-3
ISO/TC 35/SC 9 Secretariat: BSI
Voting begins on: Voting terminates on:
2019-09-26 2019-12-19
Paints and varnishes — Methods of exposure to laboratory
light sources —
Part 3:
Fluorescent UV lamps
Peintures et vernis — Méthodes d'exposition à des sources lumineuses de laboratoire —
Partie 3: Lampes fluorescentes UV
ICS: 87.040
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 16474-3:2019(E)
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Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 3
5.1 Laboratory light source . 3
5.2 Test chamber . 6
5.3 Radiometer . 6
5.4 Black-standard/black-panel thermometer . 6
5.5 Wetting and humidity . 7
5.5.1 General. 7
5.5.2 Spray and condensation system . 7
5.6 Specimen holders . 7
5.7 Apparatus to assess changes in properties . 7
6 Test specimens (panels) . 7
6.1 General . 7
6.2 Preparation and coating . . 8
6.3 Drying and conditioning . 8
6.4 Thickness of coating . 8
6.5 Number of test panels . 8
7 Test conditions . 8
7.1 Radiation . 8
7.2 Temperature . 8
7.3 Relative humidity of chamber air . 9
7.4 Condensation and spray cycles . 9
7.5 Complex cycles with dark periods . 9
7.6 Sets of exposure conditions . 9
8 Procedure and mounting of the test specimens .10
8.1 General .10
8.2 Exposure .10
8.3 Measurement of radiant exposure .10
8.4 Determination of changes in properties after exposure .10
9 Test report .11
Annex A (informative) Spectral distribution of radiation for typical fluorescent UV lamps .12
Bibliography .16
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Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso
.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee
SC 9, General test methods for paints and varnishes.
This second edition cancels and replaces the first edition (ISO 16474-3:2013), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— in 7.2 the difference between the temperature of a black panel sensor and a black standard sensor
has been corrected;
— in Table 4 it has been changed that the black-panel temperature is not controlled during water spray;
— the text has been editorially revised and the normative references have been updated.
A list of all parts in the ISO 16474 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
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Introduction
Coatings of paints, varnishes and similar materials (subsequently referred to simply as coatings) are
exposed to laboratory light sources, in order to simulate in the laboratory the ageing processes which
occur during natural weathering or behind window glass.
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oSIST prEN ISO 16474-3:2019
DRAFT INTERNATIONAL STANDARD ISO/DIS 16474-3:2019(E)
Paints and varnishes — Methods of exposure to laboratory
light sources —
Part 3:
Fluorescent UV lamps
1 Scope
This document specifies methods for exposing coatings to fluorescent UV lamps, heat and water in
apparatus designed to reproduce the weathering effects that occur when materials are exposed in
actual end-use environments to daylight, or to daylight through window glass.
The coatings are exposed to different types of fluorescent UV lamps under controlled environmental
conditions (temperature, humidity and/or water). Different types of fluorescent UV lamp may be used
to meet all the requirements for testing different materials.
Specimen preparation and evaluation of the results are covered in other ISO documents for specific
materials.
General guidance is given in ISO 16474-1.
NOTE Fluorescent UV lamp exposures for plastics are described in ISO 4892-3.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 1514, Paints and varnishes — Standard panels for testing
ISO 2808, Paints and varnishes — Determination of film thickness
ISO 4618, Paints and varnishes — Terms and definitions
ISO 9370, Plastics — Instrumental determination of radiant exposure in weathering tests — General
guidance and basic test method
ISO 16474-1, Paints and varnishes — Methods of exposure to laboratory light sources — Part 1: General
guidance
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4618 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
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3.1
radiant exposure
H
amount of radiant energy to which a test panel has been exposed
Note 1 to entry: Radiant exposure is given by the equation HE=∫ ⋅dt
where
H is the radiant exposure, in joules per square metre;
E is the irradiance, in watts per square metre;
t is the exposure time, in seconds
Note 2 to entry: If the irradiance E is constant throughout the whole exposure time, the radiant exposure H is
given simply by the product of E and t.
4 Principle
4.1 Fluorescent UV lamps, when properly maintained, can be used to simulate the spectral irradiance
of daylight in the ultraviolet (UV) region of the spectrum.
4.2 Specimens are exposed to various levels of UV radiation, heat and moisture (see 4.4) under
controlled environmental conditions.
4.3 The exposure conditions may be varied by selection of:
a) the type of fluorescent lamp (spectral power distribution);
b) the irradiance level;
c) the temperature during the UV exposure;
d) the relative humidity of the chamber air during the light and dark exposures, when test conditions
requiring control of humidity are used;
NOTE Commercial fluorescent UV lamp devices mostly do not provide means of relative humidity
control.
e) the type of wetting (see 4.4);
f) the wetting temperature and cycle;
g) the timing of the UV/dark cycle.
4.4 Wetting is usually produced by condensation of water vapour onto the exposed specimen surface
or by spraying the test specimens with demineralized/deionized water.
4.5 The procedure(s) may include measurement of the irradiance and the radiant exposure in the
plane of the specimen.
4.6 It is recommended that a similar material of known performance (a control) be exposed
simultaneously with the test specimens to provide a standard for comparative purposes.
4.7 Intercomparison of results obtained from specimens exposed in different apparatus or to different
types of lamp should not be made unless an appropriate statistical relationship has been established
between the different types of equipment for the material to be tested.
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5 Apparatus
5.1 Laboratory light source
5.1.1 Fluorescent UV lamps are fluorescent lamps in which radiant emission in the ultraviolet region of
the spectrum, i.e. below 400 nm, makes up at least 80 % of the total light output. There are three types of
fluorescent UV lamp used in this document:
— Type 1A (UVA-340) fluorescent UV lamp: These lamps have a radiant emission below 300 nm of
less than 1 % of the total light output, have an emission peak at 343 nm, and are more commonly
identified as UVA-340 for simulation of daylight from 300 nm to 340 nm (see Table 1, column A.1).
Figure A.1 is a graph of spectral irradiance from 250 nm to 400 nm of a typical type 1A (UVA-340)
fluorescent lamp compared to daylight.
— Type 1B (UVA-351) fluorescent UV lamp: These lamps have a radiant emission below 310 nm of
less than 1 % of the total light output, have a peak emission at 353 nm, and are more commonly
identified as UVA-351 for simulation of the UV portion of daylight behind window glass (see Table 2).
Figure A.2 is a graph of spectral irradiance from 250 nm to 400 nm of a typical type 1B (UVA-351)
fluorescent UV lamp compared to daylight filtered by window glass.
— Type 2 (UVB-313) fluorescent UV lamp: These lamps are more commonly identified as UVB-313
and have a radiant emission below 300 nm that is more than 10 % of the total output and a peak
emission at 313 nm (see Table 3). Figure A.3 is a graph of the spectral irradiance from 250 nm to
400 nm of two typical type 2 (UVB-313) fluorescent lamps compared to daylight. Type 2 (UVB-313)
lamps may be used only by agreement between the parties concerned. Such agreement shall be
stated in the test report.
NOTE 1 Type 2 (UVB-313) lamps have a spectral distribution of radiation which peaks near the 313 nm
mercury line and might emit radiation down to λ = 254 nm, which can initiate ageing processes that never occur
in end-use environments.
NOTE 2 The solar spectral irradiance for a number of different atmospheric conditions is described in CIE No.
[2]
85 . The benchmark daylight used in this document is from CIE No. 85:1989, Table 4.
5.1.2 Unless otherwise specified, type 1A (UVA-340) fluorescent UV lamps or corresponding type 1A
fluorescent UV lamp combinations shall be used to simulate the UV part of daylight (see Table 4, method
A). Unless otherwise specified, type 1B (UVA-351) lamps shall be used to simulate the UV part of daylight
through window glass (see Table 4, method B).
5.1.3 Fluorescent lamps age significantly with extended use. If an automatic irradiance control system
is not used, follow the apparatus manufacturer’s instructions on the procedure necessary to maintain the
desired irradiance.
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5.1.4 Irradiance uniformity shall be in accordance with the requirements specified in ISO 16474-1.
Requirements for periodic repositioning of specimens when irradiance within the exposure area is less
than 90 % of the peak irradiance are described in ISO 16474-1.
a, b
Table 1 — Relative ultraviolet spectral irradiance for type 1A lamps for daylight UV (method A)
c d,e c
Spectral pass-band Minimum CIE No. 85:1989, Table 4 Maximum
(λ = wavelength in nm) % % %
λ < 290 0 0,1
290 ≤ λ ≤ 320 5,9 5,4 9,3
320 < λ ≤ 360 60,9 38,2 65,5
360 < λ ≤ 400 26,5 56,4 32,8
a
 This table gives the irradiance in the given passband, expressed as a percentage of the total irradiance between 290 nm
and 400 nm. To determine whether a specific type 1A (UVA-340) lamp meets the requirements of this table, the spectral
irradiance from 250 nm to 400 nm shall be measured. Typically, this is done in 2 nm increments. The total irradiance in
each passband is then summed and divided by the total irradiance between 290 nm and 400 nm.
b
 The minimum and maximum limits for type 1A (UVA-340) lamps in this table are based on more than 60 spectral
[3]
irradiance measurements with type 1A (UVA-340) lamps from different production lots and of various ages . The spectral
irradiance data are for lamps within the ageing recommendations of the apparatus manufacturer. As more spectral
irradiance data become available, minor changes in the limits are possible. The minimum and maximum limits are at
least three sigma from the mean for all the measurements. The range of the relative irradiance of fluorescent UV lamp
combinations is determined by radiation measurements at about 50 locations within the exposure area recommended by
the apparatus manufacturer.
c
 The minimum and maximum columns will not necessarily sum to 100 % because they represent the minima and
maxima for the measurement data used. For any individual spectral irradiance distribution, the percentages calculated
for the pass-bands in this table will sum to 100 %. For any individual type 1A (UVA-340) fluorescent lamp, the calculated
percentage in each pass-band shall fall within the minimum and maximum limits given. Test results can be expected
to differ between exposures using type 1A (UVA-340) lamps in which the spectral irradiance differs by as much as that
allowed by the tolerances. Contact the manufacturer of the fluorescent UV apparatus for specific spectral irradiance data
for the type 1A (UVA-340) lamp used.
d
 The data from CIE No. 85:1989, Table 4, is the global solar irradiance on a horizontal surface for an air mass of 1,0, an
ozone column of 0,34 cm at STP, 1,42 cm of precipitable water vapour and a spectral optical depth of aerosol extinction of
0,1 at 500 nm. These data are provided for reference purposes only and are intended to serve as a target.
e For the solar spectrum represented by CIE No. 85:1989, Table 4, the UV irradiance (290 nm to 400 nm) is 11 % and the
visible irradiance (400 nm to 800 nm) is 89 %, expressed as a percentage of the total irradiance from 290 nm to 800 nm.
Because the primary emission of fluorescent UV lamps is concentrated in the 300 nm to 400 nm pass-band, there are
limited data available for the visible light emission of fluorescent UV lamps. The percentages of UV irradiance and visible
irradiance on specimens exposed in fluorescent UV apparatus might vary due to the number of specimens being exposed
and their reflectance properties.
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Table 2 — Relative ultraviolet spectral irradiance for type 1B (UVA 351) lamps for daylight
a, b
behind window glass (method B)
c c
Spectral pass-band Minimum CIE No. 85:1989, Table 4, Maximum
plus effect of window
d,e
glass
(λ = wavelength in nm) % % %
λ < 300 0 0,2
300 ≤ λ ≤ 320 1,1 ≤ 1 3,3
320 < λ ≤ 360 60,5 33,1 66,8
360 < λ ≤ 400 30,0 66,0 38,0
a
 This table gives the irradiance in the given pass-band, expressed as a percentage of the total irradiance between
290 nm and 400 nm. To determine whether a specific type 1B (UVA-351) lamp meets the requirements of this table,
the spectral irradiance from 250 nm to 400 nm shall be measured. Typically, this is done in 2 nm increments. The total
irradiance in each pass-band is then summed and divided by the total irradiance between 290 nm and 400 nm.
b
 The minimum and maximum limits given in this table are based on 21 spectral irradiance measurements with type 1B
[3]
(UVA-351) lamps from different production lots and of various ages . The spectral irradiance data are for lamps within
the ageing recommendations of the apparatus manufacturer. As more spectral irradiance data become available, minor
changes in the limits are possible. The minimum and maximum limits are at least three sigma from the mean for all the
measurements.
c
 The minimum and maximum columns will not necessarily sum to 100 % because they represent the minima and
maxima for the measurement data used. For any individual spectral irradiance distribution, the percentages calculated
for the pass-bands in this table will sum to 100 %. For any individual type 1B (UVA-351) fluorescent lamp, the calculated
percentage in each pass-band shall fall within the minimum and maximum limits given. Test results can be expected
to differ between exposures using type 1B (UVA-351) lamps in which the spectral irradiance differs by as much as that
allowed by the tolerances. Contact the manufacturer of the fluorescent UV apparatus for specific spectral irradiance data
for the type 1B (UVA-351) lamp used.
d
 The data from CIE No. 85:1989, Table 4, plus the effect of window glass was determined by multiplying the CIE
No. 85:1989, Table 4 data by the spectral transmittance of typical 3-mm-thick window glass (see ISO 16474-2, Annex A).
These data are provided for reference purposes only and are intended to serve as a target.
e
 For the solar spectrum represented by CIE No. 85:1989, Table 4, plus window glass data, the UV irradiance from
300 nm to 400 nm is typically about 9 % and the visible irradiance (400 nm to 800 nm) is typically about 91 %, expressed
as a percentage of the total irradiance from 300 nm to 800 nm. Because the primary emission of fluorescent UV lamps is
concentrated in the 300 nm to 400 nm passband, there are limited data available for the visible light emission of fluorescent
UV lamps. The percentages of UV irradiance and visible irradiance on specimens exposed in fluorescent UV apparatus
might vary due to the number of specimens being exposed and their reflectance properties.
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a, b
Table 3 — Relative ultraviolet spectral irradiance for type 2 (UVB 313) lamps (method C)
c d, e c
Spectral passband Minimum CIE No. 85:1989, Table 4 Maximum
(λ = wavelength in nm) % % %
λ < 290 1,3 0 5,4
290 ≤ λ ≤ 320 47,8 5,4 65,9
320 < λ ≤ 360 26,9 38,2 43,9
360 < λ ≤ 400 1,7 56,4 7,2
a
 This table gives the irradiance in the given pass-band, expressed as a percentage of the total irradiance between
250 nm and 400 nm. To determine whether a specific type 2 (UVB-313) lamp meets the requirements of this table, the
spectral irradiance from 250 nm to 400 nm shall be measured. Typically, this is done in 2 nm increments. The total
irradiance in each pass-band is then summed and divided by the total irradiance between 250 nm and 400 nm.
b
 The minimum and maximum limits given in this table are based on 44 spectral irradiance measurements with type 2
[3]
(UVB-313) lamps from different production lots and of various ages . The spectral irradiance data are for lamps within
the ageing recommendations of the apparatus manufacturer. As more spectral irradiance data become available, minor
changes in the limits are possible. The minimum and maximum limits are at least three sigma from the mean for all the
measurements.
c
 The minimum and maximum columns will not necessarily sum to 100 % because they represent the minima and
maxima for the measurement data used. For any individual spectral irradiance distribution, the percentages calculated
for the pass-bands in this table will sum to 100 %. For any individual type 2 (UVB-313) fluorescent lamp, the calculated
percentage in each pass-band shall fall within the minimum and maximum limits given. Test results can be expected to
differ between exposures using type 2 (UVB-313) lamps in which the spectral irradiance differs by as much as that allowed
by the tolerance
...

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