Paints and varnishes - Coating materials and coating systems for exterior wood - Part 3: Natural weathering test

This European Standard specifies a natural weathering test for exterior wood coating systems mainly intended for decoration and protection of planed and sawn wood.
The test provides a means of evaluating the performance of a wood coating system during outdoor exposure. It forms the basis for the performance specification in accordance with EN 927-2.

Beschichtungsstoffe - Beschichtungsstoffe und Beschichtungssysteme für Holz im Außenbereich - Teil 3: Freibewitterung

Dieses Dokument legt eine Freibewitterungsprüfung von Beschichtungssystemen für Holz im Außenbereich fest, die hauptsächlich zur Dekoration und zum Schutz von glattgehobeltem Schnittholz dienen.
Diese Prüfung dient zum Beurteilen des Verhaltens von Beschichtungssystemen für Holz, die dem Wetter ausgesetzt sind. Sie ist die Grundlage der Leistungsspezifikation nach EN 927 2. Sie erleichtert auch den Vergleich der Leistung verschiedener Beschichtungssysteme auf verschiedenen Substraten, einschließlich der Holzarten, oder anderen Holz Modifikationen.

Peintures et vernis - Produits de peinture et systèmes de peinture pour bois en extérieur - Partie 3 : Essais de vieillissement naturel

Le présent document spécifie un essai de vieillissement naturel des systèmes de peinture pour le bois en extérieur principalement prévus pour la décoration et la protection des bois sciés et rabotés.
L’essai fournit un moyen permettant d’évaluer les performances d’un système de peinture pour bois durant son exposition en extérieur. Il sert de base pour l’élaboration de la spécification de performance selon l’EN 927-2. Il facilite également la comparaison des performances des systèmes de peinture sur divers subjectiles, y compris l’essence de bois, ou d’autres modifications du bois.

Barve in laki - Premazi in premazni sistemi za zaščito lesa za zunanjo uporabo - 3. del: Preskus s staranjem v naravnih razmerah

Ta evropski standard določa preskus s staranjem v naravnih razmerah za premazne sisteme za zaščito lesa v zunanji uporabi, katerih namen je okrasiti in zaščititi obeljen in žagan les.
Preskus je sredstvo za ugotavljanje delovanja premaznega sistema za les, ko je izpostavljen zunanjim vplivom. Predstavlja podlago za zahteve učinkovitosti v skladu s standardom EN 927-2.

General Information

Status
Published
Public Enquiry End Date
04-Jun-2018
Publication Date
08-Oct-2019
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
23-Sep-2019
Due Date
28-Nov-2019
Completion Date
09-Oct-2019

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SLOVENSKI STANDARD
SIST EN 927-3:2019
01-november-2019
Nadomešča:
SIST EN 927-3:2012

Barve in laki - Premazi in premazni sistemi za zaščito lesa za zunanjo uporabo - 3.

del: Preskus s staranjem v naravnih razmerah

Paints and varnishes - Coating materials and coating systems for exterior wood - Part 3:

Natural weathering test
Beschichtungsstoffe - Beschichtungsstoffe und Beschichtungssysteme für Holz im
Außenbereich - Teil 3: Freibewitterung

Peintures et vernis - Produits de peinture et systèmes de peinture pour bois en extérieur

- Partie 3 : Essais de vieillissement naturel
Ta slovenski standard je istoveten z: EN 927-3:2019
ICS:
71.100.50 Kemikalije za zaščito lesa Wood-protecting chemicals
87.040 Barve in laki Paints and varnishes
SIST EN 927-3:2019 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 927-3:2019
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SIST EN 927-3:2019
EN 927-3
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2019
EUROPÄISCHE NORM
ICS 87.040
English Version
Paints and varnishes - Coating materials and coating
systems for exterior wood - Part 3: Natural weathering
test

Peintures et vernis - Produits de peinture et systèmes Beschichtungsstoffe - Beschichtungsstoffe und

de peinture pour le bois en extérieur - Partie 3 : Essai Beschichtungssysteme für Holz im Außenbereich - Teil

de vieillissement naturel 3: Freibewitterung
This European Standard was approved by CEN on 21 July 2019.

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

© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 927-3:2019 E

worldwide for CEN national Members.
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SIST EN 927-3:2019
EN 927-3:2019 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

1 Scope .................................................................................................................................................................... 4

2 Normative references .................................................................................................................................... 4

3 Terms and definitions ................................................................................................................................... 5

4 Principle ............................................................................................................................................................. 5

5 Apparatus and materials .............................................................................................................................. 6

6 Coating sampling ............................................................................................................................................. 6

7 Test panel selection ........................................................................................................................................ 6

7.1 Wood reference species ................................................................................................................................ 6

7.2 Preparation and selection of wood panels ............................................................................................ 7

7.3 Preparation of coated panels ...................................................................................................................... 8

8 Procedure........................................................................................................................................................ 10

8.1 General ............................................................................................................................................................. 10

8.2 Examination before exposure ................................................................................................................. 10

8.3 Exposure .......................................................................................................................................................... 10

8.4 Examination after exposure ..................................................................................................................... 10

9 Precision data ................................................................................................................................................ 11

10 Expression of results and test report .................................................................................................... 11

Annex A (normative) Details of test methods ................................................................................................. 12

Annex B (normative) Assessment requirements for panels of test coatings and WRM .................. 15

Annex C (informative) Example format for a test report ............................................................................ 16

Annex D (informative) Optional tests including variations to standard weathering test

procedure to obtain additional information on coating performance ..................................... 19

Annex E (informative) Explanatory notes ........................................................................................................ 22

Annex F (informative) Precision data ................................................................................................................ 23

Annex G (normative) Guidance on typical properties for some common wood species ................. 25

Annex H (informative) Determination of adhesive strength of tape on test surface ........................ 29

Annex I (informative) Thermal or chemical modification to protect the wood ................................. 30

Bibliography ................................................................................................................................................................. 32

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SIST EN 927-3:2019
EN 927-3:2019 (E)
European foreword

This document (EN 927-3:2019) has been prepared by 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 March 2020, and conflicting national standards shall

be withdrawn at the latest by March 2020.

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 927-3:2012.
The main technical changes in comparison with the previous edition are:
a) the provision for using alternative wood species has been updated;

b) the Internal Comparison Product (ICP) has been replaced by a nominated reference material as

Weathering Reference Material (WRM);

c) mould growth assessment has been extended to visual disfigurement by microorganisms;

d) former Annex A was deleted;
e) new Annex G for typical properties for common wood species was added;
f) new Annex H for adhesive tape testing was added;
g) new Annex I for thermal/chemical modification of wood was added;
h) standard editorially revised.

According to the CEN-CENELEC Internal Regulations, the national standards organisations 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.
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SIST EN 927-3:2019
EN 927-3:2019 (E)
1 Scope

This document specifies a natural weathering test for exterior wood coating systems mainly intended

for decoration and protection of planed and sawn wood.

The test provides a means of evaluating the performance of a wood coating system during outdoor

exposure. It forms the basis for the performance specification in accordance with EN 927-2. It also

facilitates the comparison of coating systems performance on different substrates including the wood

species, or other wood modifications.
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.

EN 927-2, Paints and varnishes — Coating materials and coating systems for exterior wood — Part 2:

Performance specification

EN 16492, Paints and varnishes — Evaluation of the surface disfigurement caused by fungi and algae on

coatings

EN ISO 1513, Paints and varnishes — Examination and preparation of test samples (ISO 1513)

EN ISO 2409, Paints and varnishes — Cross-cut test (ISO 2409)

EN ISO 2808:2007, Paints and varnishes — Determination of film thickness (ISO 2808:2007)

EN ISO 2810, Paints and varnishes — Natural weathering of coatings — Exposure and assessment (ISO

2810)

EN ISO 2813, Paints and varnishes — Determination of gloss value at 20°, 60° and 85° (ISO 2813)

EN ISO 4628-1:2016, Paints and varnishes — Evaluation of degradation of coatings — Designation of

quantity and size of defects, and of intensity of uniform changes in appearance — Part 1: General

introduction and designation system (ISO 4628-1:2016)

EN ISO 4628-2, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity

and size of defects, and of intensity of uniform changes in appearance — Part 2: Assessment of degree of

blistering (ISO 4628-2)

EN ISO 4628-4, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity

and size of defects, and of intensity of uniform changes in appearance — Part 4: Assessment of degree of

cracking (ISO 4628-4)

EN ISO 4628-5, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity

and size of defects, and of intensity of uniform changes in appearance — Part 5: Assessment of degree of

flaking (ISO 4628-5)

EN ISO 4628-6, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity

and size of defects, and of intensity of uniform changes in appearance — Part 6: Assessment of degree of

chalking by tape method (ISO 4628-6)

EN ISO 15528, Paints, varnishes and raw materials for paints and varnishes — Sampling (ISO 15528)

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SIST EN 927-3:2019
EN 927-3:2019 (E)
EN ISO 11664-4, Colorimetry — Part 4: CIE 1976 L*a*b* Colour space (ISO 11664-4)
ISO 554, Standard atmospheres for conditioning and/or testing — Specifications
ISO 18314-1, Analytical colorimetry — Part 1: Practical colour measurement
3 Terms and definitions
For the purposes of this document, the following term and definition applies.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
Weathering Reference Material
WRM
coating material of known aging performance
4 Principle

The resistance to natural weathering of the coating system under test, applied to a specified wood

substrate, is assessed. Durability is evaluated by determining the changes in decorative and protective

properties of coatings after 12 months of exposure.

The reference test substrate is Pinus sylvestris (European redwood or Scots pine, subsequently referred

to as pine) in order to obtain comparative results more rapidly. The sapwood, which is usually present

in joinery timber, was chosen as the substrate reference instead of heartwood, because paint failure is

more evident on the former. However heartwood and other grain orientations may be used as

alternatives.

Differences in nature and quality of wood, and in the weather and site conditions, are recognized and

allowed for in the method by comparing the test system with a nominated WRM . The WRM is subject

to agreement by the customer and test institution and could be a nominated commercial product.

The standard test substrate is pine sapwood. Performance on substrates additional to pine can be

carried out using the same test method principles on a nominated substrate (or substrates), e.g.

alternative wood species, wood pre-treatments, and wood modifications. The results can be assessed by

the criteria of EN 927-2 and subject to meeting them, conformity claimed for the tested

substrate/coating combination.

Optional tests are described in Annex D. They can provide valuable additional information. However to

facilitate comparisons the standard requires that pine panels are included as part of each exposure

series. An alternative version of the test panel has a machined water-trap. This can accelerate some

types of failure.

1) Previous versions of EN 927-3 have used a tightly specified semi-transparent wood stain as the WRM and

known as the Internal Comparison Product (ICP). It has proved increasing difficult to source the raw materials for

the ICP and legislation has made some materials unavailable. The ICP was primarily used to assess the severity of

the climatic exposure at the weathering site but proved to be relatively insensitive to location. Interpretation of

this revised Standard places more emphasis on the absolute test result but allows manufacturers and research

organisations to make comparison with tried and tested compositions.
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SIST EN 927-3:2019
EN 927-3:2019 (E)
5 Apparatus and materials

5.1 Exposure racks, inclined at an angle of 45° to the horizontal, on which the specimens are facing

towards the equator in accordance with EN ISO 2810.

5.2 Glossmeter, for the measurement of specular gloss in accordance with EN ISO 2813, at 60°

geometry.

5.3 Tristimulus colourimeter or spectrophotometer, for the measurement of colour and

calculation of colour difference in CIELAB colour coordinates in accordance with EN ISO 11664-4.

5.4 Tape and cutting tool, for the assessment of adhesion in accordance with EN ISO 2409.

5.5 Microscope, with a magnification of × 10 for the assessment of surface defects.

5.6 Microscope, for measurement of film thickness in accordance with ISO 2808:2007, method 6A.

5.7 Self-adhesive, transparent tape, in accordance with EN ISO 4628-6 for the assessment of

chalking.
5.8 Climate chamber.
6 Coating sampling

Take a representative sample of the product tested or of each product in the case of a multi-coat system,

as described in EN ISO 15528.
Examine and prepare each sample for testing as described in EN ISO 1513.
7 Test panel selection
7.1 Wood reference species

The reference test panel shall be pine that has been selected to be free from knots, cracks and resinous

streaks and to be straight-grained and of normal growth rate (i.e. 3 to 8 annual rings per 10 mm). The

inclination of the growth rings to the face shall be 5° to 45° (see Figure 1).

The wood shall be free from blue stain and evidence of surface or bulk fungal infection. Abnormal

porosity (caused by bacterial attack) shall be avoided (see Annex A, A.10).

The wood shall be conditioned at (20 ± 2) °C and a relative humidity of (65 ± 5) % to an equilibrium

moisture content of (13 ± 2) %.
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SIST EN 927-3:2019
EN 927-3:2019 (E)
Key
a) Example of a panel with no heartwood (if present) closer than 10 mm to the
test surface fulfilling the requirement for growth ring orientation (5° to
45°) at the front side.
b) This panel does not meet the specification because the heartwood is too close
to the front side.
c) This panel does not meet the specification because the growth ring
orientation is not within the 5° to 45° band. The growth rings incline −10°
at the left of the panel and 30° at the right. Consequently a part of the
surface contains tangentially cut wood surface (growth ring inclination
0°), with considerable risk of crack formation.
d) This panel does not meet the specification because the growth ring
orientation is not within the 5° to 45° band. The growth rings incline 45°
at the left of the panel and 70° at the right.
NOTE The top side of panels is the exposed side; the bottom is the rear face.
Figure 1 — Cross section of panels
7.2 Preparation and selection of wood panels
7.2.1 Reference (standard) test panels
The panels shall be cut from boards planed all round and shall be nominally

(375 ± 2) mm × (78 ± 3) mm and (20 ± 2) mm thick. For details of panel preparation see Figure 2. The

panels shall be planed to a smooth and uniform finish. In order to avoid aged wood surface, the panels

shall be hand sanded (mesh 150) immediately before coating. Rounding of edges is not permitted.

The panels shall be selected to give a sapwood test surface on the convex side of the growth rings, with

any heartwood confined to a zone no closer than 10 mm from the front side. Heartwood shall be

checked with the reagent described in A.11, at both ends of each panel.
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SIST EN 927-3:2019
EN 927-3:2019 (E)

Any panels showing surface splitting shall be rejected. Where the presence of some minor defects in the

test area is unavoidable, their position should be noted and their influence excluded during assessment

of coating performance.
7.2.2 Alternative test panels

Alternative substrates including other wood species than pine, modified or impregnated wood may be

tested according to the requirements of the test specifier (customer). Preparation of the panels should

follow the procedure for sizing, planning and sanding as in 7.2.1. However the requirements for

heartwood to sapwood ratio and grain orientation may be different. These should be agreed with the

user by the testing organization (if different) and the information recorded on the test report. Some

guidance on typical properties for some common wood species is given in Annex G.
7.3 Preparation of coated panels
7.3.1 Wood conditioning

Prior to coating, condition the panels at (20 ± 2) °C and a relative humidity of (65 ± 5) % according to

ISO 554 until constant mass. Keep the panels under the same conditions during drying of the coating

system and during subsequent storage of test panels before exposure. Panels may be transferred for

brief periods to other ambient conditions where this is required for the conduct of specific operations

or assessments.
7.3.2 Preparation of panels for the test coating

For each coating system, select four panels on a random basis from the available supply for each species

to be tested including the reference. Three panels shall be used for exposure and the fourth shall be for

unexposed reference.

Apply the coating system to the front and side faces of each panel. The front side of the panel is the side

facing the bark of the tree. The back of the panel and end-grains shall be left uncoated.

Apply the coating system using the method specified by the manufacturer to give a spreading rate

corresponding to the mean value (± 20 %) of the manufacturer's recommended spreading rate.

Record the quantity of coating applied to each test panel and subsequently calculate a mean value for

2 2

the four panels. The values should be stated preferably in l/m or g/m , but may also be expressed as

wet film thickness (in micrometres).
7.3.3 Preparation of panels for the Weathering Reference Material (WRM)

Prepare four panels by applying the WRM to the front and side faces of each panel. The back of the

panel and end-grains shall be left uncoated. Apply the WRM by applying the coating system according to

the manufacturer’s instructions and allowing for the necessary number of coats and the drying period

between coats. The dry film thickness shall be recorded in μm on pine.

One set of WRM panels exposed at the same time may serve as the comparison for one or more test

coatings on the reference substrate. The WRM should also be used on each alternative substrate tested

as the comparison for one or more test coatings.
7.3.4 Sealing and ageing

When all the coatings have dried, seal thoroughly the ends of the panels with at least two coats of a

flexible, moisture-impermeable white paint, for example, but not limited to, a long-oil alkyd type, and

capable of withstanding 2 years of natural exposure without breakdown. The ‘sealer’ may be applied by

brushing or dipping. The sealer shall be applied to the bands marked “a” and “c” at the ends of the panel

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SIST EN 927-3:2019
EN 927-3:2019 (E)

shown in Figure 2. It is important that the sealer is applied all round, i.e. that front, sides, end grains and

rear face of the bands are coated.

After sealing, age the panels for approximately 7 days in the controlled environment at (20 ± 2) °C and a

relative humidity of (65 ± 5) %, before carrying out initial panel examinations.
Exposure shall start at the latest 28 days after completion of sealing.
Dimensions in millimetres
Key
1, 2 and 3 exposure panels
R unexposed reference panel
a sealed end (may be used for numbering or marking of test panels)
b section for application of coating system
c sealed end
NOTE The figure is not to scale.
Figure 2 — Details of test panels
7.3.5 Thickness of the coating

Determine the dry film thickness of the WRM and the test coating(s) using the unexposed reference

panels. Examine three small chips of coated wood removed from each reference panel by microscopy in

accordance with EN ISO 2808:2007, method 6A. The three chips shall be removed at three different

places spaced evenly across the panel width. Make five measurements on each of the three chips and

calculate and record the mean value in micrometres.

The thickness is stated in micrometres and refers to the layer on (above) the wood surface. Coating

materials may penetrate the wood material to some extent, but this part is not included in the

determination.
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SIST EN 927-3:2019
EN 927-3:2019 (E)
8 Procedure
8.1 General
Carry out all examinations in accordance with Annex A and Annex B.
8.2 Examination before exposure

Before exposure, carry out the following measurements on all the test panels and the WRM:

— mass of coating system applied (by weighing) (see 7.3.2);
— coating thickness (see 7.3.5);
— gloss;
— colour.
Assess the adhesion on the reference panel for the test coating and the WRM.

As wood is a natural material, unexpected defects can be detected in the coated panels just before

exposure, even though the wood material has been selected, inspected and prepared along the

guidelines of 7.1 and 7.2. If such panels as an exception are exposed, the type, size and position of

defects shall be noted, so as to avoid any influence on the assessment after exposure.

For further details, see Annex A and Annex B.
8.3 Exposure

Expose three of the four panels with their long edge horizontal and the 50 mm band to the left of the

exposed face, for a period of 12 months, using the exposure racks (5.1). Record the starting and ending

dates.

Store the reference panels indoors at a temperature of (20 ± 2) °C and a relative humidity of (65 ± 5) %.

8.4 Examination after exposure
8.4.1 Examination on the exposure racks

At the end of the 12 months exposure period, examine the panels on the exposure racks and record any

blistering. Remove the panels from the racks to the laboratory and condition for 7 days at a

temperature of (20 ± 2) °C and a relative humidity of (65 ± 5) %.
8.4.2 Laboratory examination of unwashed panels
Assess the panels for the following properties:
— flaking;
— cracking;
— visual disfigurement by microorganisms;
— chalking;
— general appearance.
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SIST EN 927-3:2019
EN 927-3:2019 (E)
8.4.3 Laboratory examination of washed panels

After the first examinations (8.4.1 and 8.4.2), wash the panels by sponging with clean lukewarm water

to remove surface deposits and atmospheric pollutants, and allow to dry.
Examine the coating on the reference and exposed panels for gloss and colour.

Examine the coating on the exposed panels for visual disfigurement by microorganisms, adhesion and

general appearance.
9 Precision data
Further information for precision data is given in Annex F.
10 Expression of results and test report
The test report shall contain at least the following information:

a) all details necessary to identify the product tested, including name and address of the manufacturer

or supplier of the coating system tested, name or other identification marks of the coating system

tested, including the batch number, description of the coating system tested, method and date of

application, coating thickness and colour;

b) in the case of additional alternative substrates each substrate should be given a general description.

Where the alternative is a different wood species from the Pine reference then density, heartwood

sapwood ratio and grain orientation should be reported using the headings listed in Annex G. The

source of the wood should also be clearly stated in the test report.
c) reference to this part of EN 927 (i.e. EN 927-3);
d) name and address of the testing laboratory;
e) exposure site;
f) identification number of the test report;
g) name and address of the organization or the person who ordered the test;
h) method of sampling, date and person responsible for the sampling;
i) date of receipt of the coating system tested;
j) exposure period (start and finishing dates);
k) any deviations from the test methods specified;
l) test results (see 8.2, 8.4.2 and 8.4.3);
m) date of authorization of the test report;
n) type of cutting tool used for adhesion measurement (see A.9.2.1);

o) method of colour measurement, i.e. 45°:0° (specular component excluded) or di:8° (specular

component included); any deviations from the test methods specified.
An example for a suitable form is given in Annex C.

A copy of the test report together with data sheets should be stored to comply with quality assurance

requirements.
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SIST EN 927-3:2019
EN 927-3:2019 (E)
Annex A
(normative)
Details of test methods
A.1 Gloss and change of gloss

Measure the specular gloss in accordance with EN ISO 2813 using a glossmeter at 60° incident light

angle. Determine the value for each area along the grain, i.e. with the light beam parallel to the grain.

Obtain three measurements on separate areas along the length of the panel. Rotate the glossmeter 180°

and obtain another three measurements on adjacent areas. Take the mean of the six measurements

obtained.

Calculate the change of gloss CG of each of the three exposed panels, and of the unexposed reference

panel. Calculate the mean of the gloss change of the three exposed panels. State the final result to one

decimal place.
A.2 Colour and colour change

Measure the colour in accordance with ISO 18314-1 using the measurement geometry 45/0 or d/8 with

specular component included (sci/spin). The geometry used shall be stated in the test report.

Determine the CIE 1976 colour coordinates (L*, a*, b*) for the standard illuminant D65 and standard

observer 10° for each panel as a mean of 6 single measurements.

Calculate the colour change ∆E of each of the three exposed panels and of the unexposed reference

panel. Calculate the mean of the colour change of the three exposed panels. State the final result to one

decimal place.
A.3 Blistering

The assessment for quantity (density) and size is made on each exposed panel separately in accordance

with EN ISO 4628-2.
Calculate and record the mean value for quantity and size to one decimal place.
A.4 Flaking
Assessment for qu
...

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