EN ISO 5659-2:2012

SLOVENSKI STANDARD
01-maj-2014
1DGRPHãþD
SIST EN ISO 5659-1:2000
SIST EN ISO 5659-2:2007
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SUHVNXVRPYHQLSUHVNXVQLNRPRUL,62
Plastics - Smoke generation - Part 2: Determination of optical density by a single-
chamber test (ISO 5659-2:2012)
Kunststoffe - Rauchentwicklung - Teil 2: Bestimmung der optischen Dichte durch
Einkammerprüfung (ISO 5659-2:2012)
Plastiques - Production de fumée - Partie 2: Détermination de la densité optique par un
essai en enceinte unique (ISO 5659-2:2012)
Ta slovenski standard je istoveten z: EN ISO 5659-2:2012
ICS:
13.220.40 Sposobnost vžiga in Ignitability and burning
obnašanje materialov in behaviour of materials and
proizvodov pri gorenju products
83.080.01 Polimerni materiali na Plastics in general
splošno
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 5659-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2012
ICS 13.220.40; 83.080.01 Supersedes EN ISO 5659-1:1999, EN ISO 5659-2:2006
English Version
Plastics - Smoke generation - Part 2: Determination of optical
density by a single-chamber test (ISO 5659-2:2012)
Plastiques - Production de fumée - Partie 2: Détermination Kunststoffe - Rauchentwicklung - Teil 2: Bestimmung der
de la densité optique par un essai en enceinte unique (ISO optischen Dichte durch Einkammerprüfung (ISO 5659-
5659-2:2012) 2:2012)
This European Standard was approved by CEN on 30 November 2012.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 5659-2:2012: E
worldwide for CEN national Members.

Contents Page
Foreword .3

Foreword
This document (EN ISO 5659-2:2012) has been prepared by Technical Committee ISO/TC 61 "Plastics" in
collaboration with Technical Committee CEN/TC 249 “Plastics” the secretariat of which is held by NBN.
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 June 2013, and conflicting national standards shall be withdrawn at
the latest by June 2013.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 5659-1:1999 and EN ISO 5659-2:2006.
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, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 5659-2:2012 has been approved by CEN as a EN ISO 5659-2:2012 without any modification.

INTERNATIONAL ISO
STANDARD 5659-2
Third edition
2012-12-01
Plastics — Smoke generation —
Part 2:
Determination of optical density by a
single-chamber test
Plastiques — Production de fumée —
Partie 2: Détermination de la densité optique par un essai en
enceinte unique
Reference number
ISO 5659-2:2012(E)
©
ISO 2012
ISO 5659-2:2012(E)
© ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any
means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the
address below or ISO’s member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved

ISO 5659-2:2012(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principles of the test . 3
5 Suitability of a material for testing . 3
5.1 Material geometry . 3
5.2 Physical characteristics . 3
6 Specimen construction and preparation. 3
6.1 Number of specimens . 3
6.2 Size of specimens . 3
6.3 Specimen preparation . 4
6.4 Wrapping of specimens . 4
6.5 Conditioning . 4
7 Apparatus and ancillary equipment . 5
7.1 General . 5
7.2 Test chamber . 5
7.3 Specimen support and heating arrangements . 9
7.4 Gas supply .14
7.5 Photometric system .15
7.6 Chamber leakage .17
7.7 Cleaning materials .17
7.8 Ancillary equipment .17
8 Test environment .18
9 Setting-up and calibration procedures .18
9.1 General .18
9.2 Alignment of photometric system .19
9.3 Selection of compensating filter(s) .19
9.4 Linearity check .20
9.5 Calibration of range-extension filter .20
9.6 Chamber leakage rate test .20
9.7 Burner calibration .20
9.8 Radiator cone calibration.21
9.9 Cleaning .21
9.10 Frequency of checking and calibrating procedure .21
10 Test procedure .22
10.1 General .22
10.2 Preparation of test chamber .22
10.3 Tests with pilot flame .22
10.4 Preparation of the photometric system .22
10.5 Loading the specimen .22
10.6 Recording of light transmission .23
10.7 Observations .23
10.8 Termination of test .24
10.9 Testing in different modes .24
11 Expression of results .25
11.1 Specific optical density D .
s 25
11.2 Clear-beam correction factor D .
c 25
ISO 5659-2:2012(E)
12 Precision .25
13 Test report .26
Annex A (normative) Calibration of heat flux meter .27
Annex B (informative) Variability in the specific optical density of smoke measured in the single-
chamber test .28
Annex C (informative) Determination of mass optical density .30
Annex D (informative) Precision data from tests on intumescent materials .35
Annex E (informative) Guidance on optical density testing .37
Bibliography .45
iv © ISO 2012 – All rights reserved

ISO 5659-2:2012(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International
Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies
casting a vote.
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.
ISO 5659-2 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 4, Burning behaviour.
This third edition cancels and replaces the second edition (ISO 5659-2:2006), which has been technically
revised. It also replaces ISO 5659-1:1996 (Plastics — Smoke generation — Part 1: Guidance on optical-
density testing), which will be withdrawn upon publication of this edition.
ISO 5659 consists of the following parts, under the general title Plastics — Smoke generation:
— Part 2: Determination of optical density by a single-chamber test
— Part 3: Determination of optical density by a dynamic-flow method (Technical Report)
ISO 5659-2:2012(E)
Introduction
Fire is a complex phenomenon: its development and effects depend upon a number of interrelated factors.
The behaviour of materials and products depends upon the characteristics of the fire, the method of use
[1]
of the materials and the environment in which they are exposed (see also ISO/TR 3814 and ISO 13943).
A test such as is specified in this part of ISO 5659 deals only with a simple representation of a particular
aspect of the potential fire situation, typified by a radiant heat source, and it cannot alone provide any
direct guidance on behaviour or safety in fire. A test of this type may, however, be used for comparative
purposes or to ensure the existence of a certain quality of performance (in this case, smoke production)
considered to have a bearing on fire behaviour generally. It would be wrong to attach any other meaning
to results from this test.
The term “smoke” is defined in ISO 13943 as a visible suspension of solid and/or liquid particles in gases
resulting from incomplete combustion. It is one of the first response characteristics to be manifested
and should almost always be taken into account in any assessment of fire hazard as it represents one of
the greatest threats to occupants of a building or other enclosure, such as a ship or train, on fire.
The responsibility for the preparation of ISO 5659 was transferred during 1987 from ISO/TC 92 to
ISO/TC 61 on the understanding that the scope and applicability of the standard for the testing of
materials should not be restricted to plastics but should also be relevant to other materials where
possible, including building materials.
vi © ISO 2012 – All rights reserved

INTERNATIONAL STANDARD ISO 5659-2:2012(E)
Plastics — Smoke generation —
Part 2:
Determination of optical density by a single-chamber test
1 Scope
1.1 This part of ISO 5659 specifies a method of measuring smoke production from the exposed surface
of specimens of materials, composites or assemblies. It is applicable to specimens that have an essentially
flat surface and do not exceed 25 mm in thickness when placed in a horizontal orientation and subjected
to specified levels of thermal irradiance in a closed cabinet with or without the application of a pilot
flame. This method of test is applicable to all plastics and may also be used for the evaluation of other
materials (e.g. rubbers, textile-coverings, painted surfaces, wood and other materials).
1.2 It is intended that the values of optical density determined by this test be taken as specific to the
specimen or assembly material in the form and thickness tested, and are not to be considered inherent,
fundamental properties.
1.3 The test is intended primarily for use in research and development and fire safety engineering in
buildings, trains, ships, etc. and not as a basis for ratings for building codes or other purposes. No basis
is provided for predicting the density of smoke that might be generated by the materials upon exposure
to heat and flame under other (actual) exposure conditions. This test procedure excludes the effect of
irritants on the eye.
NOTE This test procedure addresses the loss of visibility due to smoke density, which generally is not related
to irritancy potency (see Annex E).
1.4 It is emphasized that smoke production from a material varies according to the irradiance level to
which the specimen is exposed. The results yielded from the method specified in this part of ISO 5659 are
2 2
based on exposure to the specific irradiance levels of 25 kW/m and 50 kW/m .
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 13943, Fire safety — Vocabulary
ISO 14934-3, Fire tests — Calibration and use of heat flux meters — Part 3:Secondary calibration method
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13943 and the following apply.
3.1
assembly
fabrication of materials and/or composites
NOTE 1 Sandwich panels are an example of an assembly.
NOTE 2 The assembly may include an air gap.
ISO 5659-2:2012(E)
3.2
composite
combination of materials which are generally recognized in building construction as discrete entities
NOTE Coated or laminated materials are examples of composites.
3.3
essentially flat surface
surface which does not deviate from a plane by more than 1 mm
3.4
exposed surface
surface of the product subjected to the heating conditions of the test
3.5
irradiance
radiant flux incident on an infinitesimal element of the surface containing the point divided by the area
of that element
3.6
material
basic single substance or uniformly dispersed mixture
NOTE Metal, stone, timber, concrete, mineral fibre and polymers are examples.
3.7
mass optical density
MOD
measure of the degree of opacity of smoke in terms of the mass loss of the material
3.8
optical density of smoke
D
measure of the degree of opacity of smoke, taken as the negative common logarithm of the relative
transmission of light
3.9
product
material, composite or assembly about which information is required
3.10
specific optical density
D
s
optical density multiplied by a factor which is calculated by dividing the volume of the test chamber by
the product of the exposed area of the specimen and the path length of the light beam
NOTE See 11.1.1.
3.11
specimen
representative piece of the product to be tested together with any substrate or surface coating.
NOTE The specimen may include an air gap.
3.12
intumescent material
dimensionally unstable material, developing a carbonaceous expanded structure of thickness > 10 mm
during the test, with the cone heater 25 mm from the specimen
2 © ISO 2012 – All rights reserved

ISO 5659-2:2012(E)
4 Principles of the test
Specimens of the product are mounted horizontally within a chamber and exposed to thermal radiation
on their upper surfaces at selected levels of constant irradiance up to 50 kW/m .
The smoke evolved is collected in the chamber, which also contains photometric equipment. The
attenuation of a light beam passing through the smoke is measured. The results are reported in terms
of specific optical density.
5 Suitability of a material for testing
5.1 Material geometry
5.1.1 The method is applicable to essentially flat materials, composites and assemblies not exceeding
25 mm in thickness.
5.1.2 The method is sensitive to small variations in geometry, surface orientation, thickness (either
overall or of the individual layers), mass and composition of the material, and so the results obtained by
this method only apply to the thickness of the material as tested.
NOTE It is not possible to calculate the specific optical density of one thickness of a material from the specific
optical density of another thickness of the material.
5.2 Physical characteristics
Materials submitted for evaluation by this method could have faces which differ or could contain
laminations of different materials arranged in a different order in relation to the two faces. If either of
the faces is likely to be exposed to a fire condition when in use, then both faces shall be evaluated.
6 Specimen construction and preparation
6.1 Number of specimens
6.1.1 The test sample shall comprise a minimum of 12 specimens if all four modes are to be tested: six
specimens shall be tested at 25 kW/m (three specimens with a pilot flame and three specimens without
a pilot flame) and six specimens shall be tested at 50 kW/m (three specimens with a pilot flame and
three specimens without a pilot flame).
If fewer than four modes are to be tested, a minimum of three specimens per mode shall be tested.
6.1.2 An additional number of specimens as specified in 6.1.1 shall be used for each face, in accordance
with the requirements of 5.2.
6.1.3 An additional 12 specimens (i.e. three specimens per test mode) shall be held in reserve if required
by the modes specified in 10.9.
6.1.4 In case of intumescent materials, it is necessary to make a preliminary test with the cone heater
at 50 mm from the specimen, so at least two additional specimens are required.
6.2 Size of specimens
6.2.1 The specimens shall be square, with sides measuring 75 mm ± 1 mm.
ISO 5659-2:2012(E)
6.2.2 Materials of 25 mm nominal thickness or less shall be evaluated at their full thickness. For
comparative testing, materials shall be evaluated at a thickness of 1,0 mm ± 0,1 mm. All materials consume
oxygen when they burn in the chamber, and the smoke generation of some materials (especially rapid-
burning or thick specimens) is influenced by the reduced oxygen concentration in the chamber. As far as
possible, materials shall be tested in their end-use thickness.
6.2.3 Materials with a thickness greater than 25 mm shall be cut to give a specimen thickness of 25 mm
± 0,1 mm, in such a way that the original (uncut) face can be evaluated.
6.2.4 Specimens of multi-layer materials with a thickness greater than 25 mm, consisting of core
material(s) with facings of different materials, shall be prepared as specified in 6.2.3 (see also 6.3.2).
6.3 Specimen preparation
6.3.1 The specimen shall be representative of the material and shall be prepared in accordance with the
procedures described in 6.3.2 and 6.3.3. The specimens shall be cut, sawn, moulded or stamped from identical
sample areas of the material, and records shall be kept of their thicknesses and, if required, their masses.
6.3.2 If flat sections of the same thickness and composition are tested in place of curved, moulded or
speciality parts, this shall be stated in the test report. Any substrate or core materials for the specimens
shall be the same as those used in practice.
6.3.3 When coating materials, including paints and adhesives, are tested with the substrate or core as
used in practice, specimens shall be prepared following normal practice, and in such cases the method of
application of the coating, the number of coats and the type of substrate shall be included in the test report.
6.4 Wrapping of specimens
6.4.1 All specimens shall be covered across the back, along the edges and over the front surface
periphery, leaving a central exposed specimen area of 65 mm × 65 mm, using a single sheet of aluminium
foil (approximately 0,04 mm thick) with the dull side in contact with the specimen. Care shall be taken not
to puncture the foil or to introduce unnecessary wrinkles during the wrapping operation. The foil shall be
folded in such a way as to minimize losses of any melted specimen material at the bottom of the specimen
holder. After mounting the specimen in its holder, any excess foil along the front edges shall be trimmed off.
6.4.2 Wrapped specimens of a thickness less than 25 mm shall be backed with a low density (nominal
65 kg/m ) refractory fibre blanket.
Wrapped specimens of a thickness of 25 mm shall be tested without a refractory fibre blanket.
6.4.3 For resilient materials, each specimen in its aluminium foil wrapper shall be installed in the
holder in such a way that the exposed surface lies flush with the inside face of the opening of the specimen
holder. Materials with uneven exposed surfaces shall not protrude beyond the plane of the opening in the
specimen holder.
6.4.4 When thin impermeable specimens, such as thermoplastic films, become inflated during the test
owing to gases trapped between the film and backing, they shall be maintained essentially flat by making
two or three cuts (20 mm to 40 mm long) in the film to act as vents.
6.5 Conditioning
6.5.1 Before preparing the specimens for test, they shall be conditioned to constant mass at 23 °C ± 2
°C and a relative humidity of (50 ± 10) % where constant mass shall be considered to have been reached
4 © ISO 2012 – All rights reserved

ISO 5659-2:2012(E)
when two successive weighing operations, carried out at an interval of 24 h, do not differ by more than
0,1 % of the mass of the test specimen or 0,1 g, whichever is the greater.
6.5.2 While in the conditioning chamber, specimens shall be supported in racks so that air has access to
all surfaces.
Forced-air movement in the conditioning chamber may be used to assist in accelerating the
conditioning process.
The results obtained from this method are sensitive to small differences in specimen conditioning. It is
important therefore to ensure that the requirements of 6.5 are followed carefully.
7 Apparatus and ancillary equipment
7.1 General
The apparatus (see Figure 1) shall consist of an air-tight test chamber with provision for containing
a specimen holder, radiation cone, pilot burner, light transmission and measuring system and other,
ancillary facilities for controlling the conditions of operation during a test.
7.2 Test chamber
7.2.1 Construction
7.2.1.1 The test chamber (see Figure 1 and Figure 2) shall be fabricated from laminated panels, the
inner surfaces of which shall consist of either a porcelain enamelled metal not more than 1 mm thick or an
equivalent coated metal which is resistant to chemical attack and corrosion and capable of easy cleaning.
The internal dimensions of the chamber shall be 914 mm ± 3 mm long, 914 mm ± 3 mm high and 610
mm ± 3 mm deep. It shall be provided with a hinged front-mounted door with an observation window
and a removable opaque door cover to the window to prevent light entering the chamber. A safety blow-
out panel, consisting of a sheet of aluminium foil of thickness not greater than 0,04 mm and having a
minimum area of 80 600 mm , shall be provided in the chamber, fastened in such a way as to provide an
airtight seal.
The blow-out panel may be protected by a stainless-steel wire mesh. It is important that any such mesh
is spaced at least 50 mm from the blow-out panel to prevent any obstruction in the event of an explosion.
NOTE A design with a wide door occupying a complete side of the smoke chamber has been found suitable for
facilitating cleaning and maintenance operations.
7.2.1.2 Two optical windows, each with a diameter of 75 mm, shall be mounted, one each in the top and
bottom of the cabinet, at the position shown in Figure 2, with their interior faces flush with the outside
of the chamber lining. The underside of the window in the floor shall be provided with an electric heater
of approximately 9 W capacity in the form of a ring, which shall be capable of maintaining the upper
surface of the window at a temperature just sufficient to minimize smoke condensation on that face (a
temperature of 50 °C to 55 °C has been found suitable) and which shall be mounted around its edge so as
not to interrupt the light path. Optical platforms 8 mm thick shall be mounted around the windows on the
outside of the chamber and shall be held rigidly in position relative to each other by three metal rods, with
a diameter of at least 12,5 mm, extending through the chamber and fastened securely to the platforms.
7.2.1.3 Other openings in the chamber shall be provided for services as specified and where appropriate.
They shall be capable of being closed so that a positive pressure up to 1,5 kPa (150 mm water gauge) above
atmospheric pressure can be developed inside the chamber (see 7.2.2) and maintained when checked in
accordance with 7.6 and 9.6. All components of the chamber shall be capable of withstanding a greater
positive internal pressure than the safety blow-out panel.
ISO 5659-2:2012(E)
7.2.1.4 An inlet vent with shutter shall be provided in the front of the chamber at the top or on the roof
of the chamber and away from the radiator cone, and an exhaust vent with shutter shall be provided in
the bottom of the chamber lead, via flexible tubing with a diameter of 50 mm to 100 mm, to an extraction
fan capable of creating a negative pressure of at least 0,5 kPa (50 mm water gauge).
7.2.2 Chamber pressure control facilities
Provision shall be made for controlling the pressure inside the test chamber. A manometer, with a range
of up to 1,5 kPa (150 mm water gauge) shall be provided for connection to a pressure regulator and to
a tube in the top of the chamber. The manometer can be either electronic or a suitable fluid in a tube
(water or an appropriate indicating fluid).
A suitable pressure regulator (see Figure 3) consists of a vented water-filled bottle and a length of
flexible tubing of diameter 25 mm, inserted 100 mm below the water surface: the other end of the tubing
is connected to the manometer and the chamber. The regulator shall be vented to the exhaust system.
6 © ISO 2012 – All rights reserved

ISO 5659-2:2012(E)
a) Typical example of commercially available test apparatus
7 8
b) Schematic drawing of typical test apparatus
Key
1   optical measurement system 8   pilot burner
2   pressure controller 9   specimen in specimen holder
3   optical path 10  weighing device
4   exhaust 11  full front open door
5   chamber 12  optical system floor window
6   conical heater 13  light source
7   window
Figure 1 — Test apparatus
ISO 5659-2:2012(E)
Dimensions in millimetres (not to scale)
Key
1   exhaust vent 5   optical window
2   wall thermocouple 6   blow-out panel
3   optical platform 7   window heater
4   radiator cone assembly
Figure 2 — Plan view of typical chamber
8 © ISO 2012 – All rights reserved

ISO 5659-2:2012(E)
Dimensions in millimetres
(kPa)
1,5
0,5
0,5
1,5
Key
1   to exhaust system 4   effluent from chamber
2   chamber wall 5   water bottle
3   restriction to prevent chamber blow-out 6   glass manometer opt U-tube (filled to zero mark with
water-dye solution)
Figure 3 — Typical chamber pressure relief manometer
7.2.3 Chamber wall temperature
A thermocouple measuring junction, made from wires of diameter not greater than 1 mm, shall be
mounted on the inside of the back wall of the chamber, at the geometric centre, by covering it with an
insulating disc (such as polystyrene foam) having a thickness of approximately 6,5 mm and a diameter
of not more than 20 mm, attached to the wall of the chamber with a suitable cement. The thermocouple
junction shall be connected to a recorder or meter and the system shall be suitable for measuring
temperatures in the range 35 °C to 80 °C (see 10.2.2).
7.3 Specimen support and heating arrangements
7.3.1 Radiator cone
7.3.1.1 The radiator cone shall consist of a heating element, of nominal rating 2600 W, contained within
a stainless-steel tube, approximately 2 210 mm in length and 6,5 mm in diameter, coiled into the shape of
a truncated cone and fitted into a shade. The shade shall have an overall height of 45 ± 0,4 mm, an internal
ISO 5659-2:2012(E)
diameter of 55 mm ± 1 mm and an internal base diameter of 110 mm ± 3 mm. It shall consist of two layers of
1 mm thick stainless steel with a 10 mm thickness of ceramic-fibre insulation of nominal density 100 kg/m
sandwiched between them. The heating element shall be clamped at the top and bottom of the shade.
2 2
7.3.1.2 The radiator cone shall be capable of providing irradiance in the range 10 kW/m to 50 kW/m
at the centre of the surface of the specimen.
When the irradiance is determined at two other positions 25 mm each side of the specimen centre, the
irradiance at these two positions shall be not less than 85 % of the irradiance at the centre of the specimen.
The temperature controller for the radiator cone shall be a proportional, integral differential-type
3-term controller with solid-state relay, thyristor stack fast-cycle or phase angle control of not less than
10 A maximum rating. Capacity for adjustment of integral time up to 50 s and differential time up to 30 s
shall be provided to permit reasonable matching with the response characteristics of the heater. The
temperature at which the heater is to be controlled shall be set on a scale capable of being held steady to
± 2 °C. An input range of temperature of 0 °C to 1 000 °C is suitable; an irradiance of 50 kW/m is typically
given by a heater temperature in the range 770 °C to 840 °C for the specimen position 25 mm below the
edge of the heater. Automatic cold-junction compensation of the thermocouple shall be provided.
NOTE 1 The heater temperature range for testing with 50 mm distance between the edge of the radiator cone
and specimen is given in Table D.3.
The irradiance of the radiator cone shall be controlled by reference to the reading of two type K sheathed
thermocouples mounted diametrically opposite and in contact with, but not welded to, the element.
The thermocouples shall be of equal length and wired in parallel to the temperature controller and be
positioned one-third of the distance from the top surface of the cone.
NOTE 2 While phase angle control is allowed for in the temperature controller of the radiator cone, it should be
noted that this will usually require electrical filtering to avoid risk of low-level signal lines.
7.3.2 Framework for support of the radiator cone, specimen holder and heat flux meter
The radiator cone shall be located and secured from the vertical rods of the support framework so
that for non-intumescent materials the lower rim of the radiator cone shade junction is 25 mm ± 1 mm
above the upper surface of the specimen when oriented in the horizontal position. For intumescent
materials this distance shall be 50 mm. Details of the radiator cone and supports are shown in Figure 4
and Figure 5.
10 © ISO 2012 – All rights reserved

ISO 5659-2:2012(E)
Key
1   heat flux meter and mount 3   thermocouple mount and shield
2   heating element 4   pilot burner
Figure 4 — Typical framework for support of radiator cone, specimen holder and flux meter
ISO 5659-2:2012(E)
Key
1   thermocouple 4   radiator shield
2   radiator cone 5   heat flux meter
3   specimen holder 6   spark ignition housing
Figure 5 — Typical arrangement of radiator cone, specimen holder and radiator shield (side view)
Key
1   spark ignition housing 3   pilot burner and ignition electrode
2   specimen holder 4   propane and air
Figure 6 — Typical arrangement of radiator cone, specimen holder and radiator shield (front view)
12 © ISO 2012 – All rights reserved

ISO 5659-2:2012(E)
7.3.3 Radiator shield
A remotely controllable metallic and/or inorganic shield (see Figure 5 and Figure 6) of minimum
diameter 130 mm and upper surface situated (when in place) approximately mid-way between the base
of the radiator cone and the specimen surface shall be provided to stop irradiance of the specimen
before and after the required exposure period.
NOTE This facility is necessary in order to enable repeat tests to be carried out without switching off the
radiator cone.
7.3.4 Heat flux meter
7.3.4.1 The heat flux meter shall be of a thermopile (Schmidt–Boelter) type with a design range of at
least 50 kW/m . The body shall have an external diameter of approximately 12,7 mm. The target receiving
the radiation (see Figure 4) shall have a flat, circular face of approximately 10,0 mm diameter, coated with
a durable matt-black finish. The target shall be water-cooled.
7.3.4.2 The heat flux meter shall be connected, directly to a suitable recorder or meter in accordance
2 2
with 7.8.6, so that it is capable, when calibrated, of recording heat fluxes of 25 kW/m and 50 kW/m to
an accuracy of ± 1 kW/m .
If a recorder which only displays a mV output is used, the mV value shall be converted to kW/m using
th
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