EN ISO 22007-4:2024

Plastics - Determination of thermal conductivity and thermal diffusivity - Part 4: Light flash method (ISO 22007-4:2024)

This document specifies a method for the determination of the thermal diffusivity of a thin solid disc of plastics in the thickness direction by the light flash method. This method is based upon the measurement of the temperature rise at the rear face of the thin-disc specimen produced by a short energy pulse on the front face.
The method is applicable to homogeneous solid plastics as well as composites having an isotropic or orthotropic structure. In general, it covers materials having a thermal diffusivity, α, in the range 1 × 10−7 m2⋅s−1 < α < 1 × 10−4 m2⋅s−1. Measurements can be carried out in gaseous and vacuum environments over a temperature range from −100 °C to +400 °C.
NOTE          For inhomogeneous specimens, the measured values can be specimen thickness dependent.

Kunststoffe - Bestimmung der Wärmeleitfähigkeit und der Temperaturleitfähigkeit - Teil 4: Lichtblitzverfahren (ISO 22007-4:2024)

Dieses Dokument legt ein Verfahren zur Bestimmung der Temperaturleitfähigkeit dünner fester Kunststoffscheiben in der Dickenrichtung mit dem Lichtblitzverfahren fest. Dieses Verfahren beruht auf der Messung des Temperaturanstiegs an der Rückseite des Probekörpers in Form einer dünnen Scheibe, der durch einen kurzen Energiepuls an der Vorderseite bewirkt wird.
Das Verfahren ist anwendbar für homogene Kunststoffe im festen Zustand und Verbundstoffe, die eine isotrope oder orthotrope Struktur aufweisen. Allgemein deckt es Werkstoffe ab, die eine Temperaturleitfähigkeit α im Bereich von 1 × 10−7 m2 · s−1 < α < 1 × 10−4 m2 · s−1 aufweisen. Die Messungen können in gasförmigen Umgebungen und unter Vakuum in einem Temperaturbereich von −100 °C bis +400 °C durchgeführt werden.
ANMERKUNG   Bei inhomogenen Probekörpern können die Messwerte von der Probekörperdicke abhängen.

Plastiques - Détermination de la conductivité thermique et de la diffusivité thermique - Partie 4: Méthode flash lumineux (ISO 22007-4:2024)

Le présent document spécifie une méthode de détermination de la diffusivité thermique d’un disque plein mince en plastique suivant la direction de l’épaisseur par la méthode flash lumineux. Cette méthode est fondée sur le mesurage de l’élévation de température sur la face arrière d’une éprouvette sous forme de disque mince due à une courte impulsion énergétique sur la face avant.
La méthode est applicable aux plastiques compacts homogènes ou composites présentant une structure isotrope ou orthotrope. En général, cela inclut les matériaux ayant une diffusivité thermique, α, comprise dans la plage 1 × 10−7 m2⋅s−1 < α < 1 × 10−4 m2⋅s−1. Les mesurages peuvent être effectués en environnements gazeux et sous vide sur une plage de températures comprises entre −100 °C et +400 °C.
NOTE          Pour des éprouvettes non homogènes, les valeurs mesurées peuvent dépendre de l’épaisseur de l’éprouvette.

Polimerni materiali - Ugotavljanje toplotne prevodnosti in toplotne razprševalnosti - 4. del: Metoda z laserskim bliskom (ISO 22007-4:2024)

Ta dokument določa metodo za ugotavljanje toplotne razprševalnosti tanke trdne ploščice
iz polimernih materialov v smeri debeline z uporabo metode z laserskim bliskom. Ta metoda temelji na merjenju dviga temperature na zadnji strani tankega diska, do katerega pride zaradi kratkega energetskega impulza na sprednji strani.
Metoda se uporablja za homogene polimerne materiale v trdnem stanju in kompozite z izotropno ali ortotropno strukturo. Splošno zajema materiale, ki imajo toplotno razprševalnost, α, v območju 1 × 10−7 m2⋅s−1 < α < 1 × 10−4 m2⋅s−1. Meritve je mogoče opravljati v plinskem in vakuumskem okolju
pri temperaturi v območju od −100 °C do +400 °C.
OPOMBA: Za nehomogene primerke so izmerjene vrednosti lahko odvisne od debeline primerka.

General Information

• Status: Published
• Publication Date: 16-Jan-2024
• ICS: 83.080.01 - Plastics in general
• Technical Committee: CEN/TC 249 - Plastics
• Drafting Committee: CEN/TC 249 - Plastics
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 17-Jan-2024
• Completion Date: 17-Jan-2024
• Ref Project: SIST EN ISO 22007-4:2024 - Plastics - Determination of thermal conductivity and thermal diffusivity - Part 4: Light flash method (ISO 22007-4:2024)

Relations

• Replaces: EN ISO 22007-4:2017 - Plastics - Determination of thermal conductivity and thermal diffusivity - Part 4: Laser flash method (ISO 22007-4:2017)
• Effective Date: 18-Jan-2023

Overview

EN ISO 22007-4:2024 - "Plastics - Determination of thermal conductivity and thermal diffusivity - Part 4: Light flash method" specifies a standardized laboratory method to determine the thermal diffusivity of thin solid plastic discs in the thickness direction using the light flash method. The technique measures the transient temperature rise at the rear face of a specimen produced by a short energy pulse on the front face and derives thermal diffusivity by comparing the recorded thermogram with theoretical models.

Key topics and requirements

• Scope and applicability
  • Applies to homogeneous plastics and composites with isotropic or orthotropic structure.
  • Typical covered diffusivity range: 1 × 10⁻⁷ to 1 × 10⁻⁴ m²·s⁻¹.
  • Temperature range: −100 °C to +400 °C; measurements possible in gaseous or vacuum environments.
  • Note: measured values for inhomogeneous specimens can be thickness dependent.
• Measurement principle
  • A short, spatially uniform light pulse (previously called "laser flash", now "light flash") heats the front face; the rear-face thermogram (temperature vs time) is recorded.
  • Key parameters: pulse width, time origin, half-rise time (t1/2) and maximum temperature rise (ΔTmax).
  • Thermal diffusivity is obtained by data analysis against theoretical or numerical models (see Annex B).
• Apparatus and calibration
  • Core components: furnace or climatic chamber, flash source (e.g., laser/light pulse), pulse detector, transient IR detector, specimen holder and data acquisition/analysis unit.
  • Requirements for thermal control (±0.5 K stability for ≥30 min) and measurement device performance are specified.
  • Clauses cover specimen preparation, coating, thickness measurement, calibration/verification, and uncertainty estimation.
• Documentation
  • Test report requirements and normative/ informative annexes (pulse correction, alternative calculation methods, specimen prep for mouldable thermoplastics/thermosets).

Applications and who uses it

• Materials testing laboratories and certification bodies for polymer thermal property data.
• R&D and quality control teams in plastics, composites, electronics packaging, automotive and aerospace industries.
• Use cases:
  • Thermal characterization for heat-transfer modeling and simulation.
  • Selection and development of insulating or thermally conductive polymeric materials.
  • Performance assessment of composite laminates and orthotropic materials.
  • Design validation for thermal management in electronics and transport components.

Related standards

• ISO 22007-1 (General principles for thermal conductivity/diffusivity testing)
• ISO 291 (Conditioning and testing atmospheres)
• ISO 527-1 (Tensile properties - general principles)
• ISO/IEC Guide 98-3 (Guide to the expression of uncertainty in measurement)

EN ISO 22007-4:2024 is the latest edition (supersedes the 2017 version) and reflects the updated terminology and procedural clarifications for consistent, reproducible measurement of polymer thermal properties.

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2024
Polimerni materiali - Ugotavljanje toplotne prevodnosti in toplotne razprševalnosti
- 4. del: Metoda z laserskim bliskom (ISO 22007-4:2024)
Plastics - Determination of thermal conductivity and thermal diffusivity - Part 4: Light flash
method (ISO 22007-4:2024)
Kunststoffe - Bestimmung der Wärmeleitfähigkeit und der Temperaturleitfähigkeit – Teil
4: Lichtblitzverfahren (ISO 22007-4:2024)
Plastiques - Détermination de la conductivité thermique et de la diffusivité thermique -
Partie 4: Méthode par flash lumineux (ISO 22007-4:2024)
Ta slovenski standard je istoveten z: EN ISO 22007-4:2024
ICS:
83.080.01 Polimerni materiali na Plastics in general
splošno
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 22007-4
EUROPEAN STANDARD
NORME EUROPÉENNE
January 2024
EUROPÄISCHE NORM
ICS 83.080.01 Supersedes EN ISO 22007-4:2017
English Version
Plastics - Determination of thermal conductivity and
thermal diffusivity - Part 4: Light flash method (ISO 22007-
4:2024)
Plastiques - Détermination de la conductivité Kunststoffe - Bestimmung der Wärmeleitfähigkeit und
thermique et de la diffusivité thermique - Partie 4: der Temperaturleitfähigkeit - Teil 4:
Méthode par flash lumineux (ISO 22007-4:2024) Lichtblitzverfahren (ISO 22007-4:2024)
This European Standard was approved by CEN on 12 June 2023.

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, Türkiye 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
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 22007-4:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 22007-4:2024) 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 SIS.
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 2024, and conflicting national standards shall be
withdrawn at the latest by July 2024.
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 22007-4:2017.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 22007-4:2024 has been approved by CEN as EN ISO 22007-4:2024 without any
modification.
International
Standard
ISO 22007-4
Third edition
Plastics — Determination of
2024-01
thermal conductivity and thermal
diffusivity —
Part 4:
Light flash method
Plastiques — Détermination de la conductivité thermique et de la
diffusivité thermique —
Partie 4: Méthode flash lumineux
Reference number
ISO 22007-4:2024(en) © ISO 2024

ISO 22007-4:2024(en)
© ISO 2024
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: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 22007-4:2024(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
5.1 General .2
5.2 Furnace or climatic chamber .2
5.3 Flash source .4
5.4 Transient detectors .4
5.5 Thickness measurement device .5
6 Test specimen . 5
6.1 Shape and dimension of the specimen .5
6.2 Preparation and conditioning of test specimen .5
6.3 Coating the specimen .5
7 Calibration and verification . . 6
7.1 Calibration of apparatus .6
7.2 Verification of apparatus .6
8 Procedure . 6
9 Data analysis . 7
10 Uncertainty . 9
11 Test report . 9
Annex A (informative) Correction for finite pulse duration . 10
Annex B (informative) Alternative methods of calculating thermal diffusivity .11
Annex C (normative) Samples and test specimen preparation for injection mouldable
thermoplastics and thermosets.12
Bibliography .16

iii
ISO 22007-4:2024(en)
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 61, Plastics, Subcommittee SC 5, Physical-
chemical properties, in collaboration with the European Committee for Standardization (CEN) Technical
Committee CEN/TC 249, Plastics, in accordance with the Agreement on technical cooperation between ISO
and CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 22007-4:2017), which has been technically
revised.
The main changes are as follows:
— the term laser flash has been replaced by the more general term light flash.
A list of all parts in the ISO 22007 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
International Standard ISO 22007-4:2024(en)
Plastics — Determination of thermal conductivity and
thermal diffusivity —
Part 4:
Light flash method
1 Scope
This document specifies a method for the determination of the thermal diffusivity of a thin solid disc of
plastics in the thickness direction by the light flash method. This method is based upon the measurement of
the temperature rise at the rear face of the thin-disc specimen produced by a short energy pulse on the front
face.
The method is applicable to homogeneous solid plastics as well as composites having an isotropic
or orthotropic structure. In general, it covers materials having a thermal diffusivity, α, in the range
−7 2 −1 −4 2 −1
1 × 10 m ⋅s < α < 1 × 10 m ⋅s . Measurements can be carried out in gaseous and vacuum environments
over a temperature range from −100 °C to +400 °C.
NOTE For inhomogeneous specimens, the measured values can be specimen thickness dependent.
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/IEC Guide 98-3, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
me a s ur ement (GUM: 1995)
ISO 291, Plastics — Standard atmospheres for conditioning and testing
ISO 527-1, Plastics — Determination of tensile properties — Part 1: General principles
ISO 22007-1, Plastics — Determination of thermal conductivity and thermal diffusivity — Part 1: General
principles
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 22007-1 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
pulse width
t
p
duration for which the light pulse intensity is larger than half of its maximum value
Note 1 to entry: It is expressed in seconds (s).

ISO 22007-4:2024(en)
3.2
time origin
t
start of the light pulse
Note 1 to entry: It is expressed in seconds (s).
3.3
maximum temperature rise
ΔT
max
difference between the maximum temperature reached by the rear face of the specimen after the light pulse
has passed and its steady temperature before the pulse
Note 1 to entry: It is expressed in kelvins (K).
3.4
half-rise time
t
1/2
time from the time origin (3.2) until the rear-face temperature increases by one-half of ΔT
max
Note 1 to entry: It is expressed in seconds (s).
3.5
thermogram
temperature versus time curve for the rear face of the specimen
3.6
thickness
d
dimension of the test specimen in the direction of heat transfer measurement
Note 1 to entry: It is expressed in metres (m).
4 Principle
One side of a flat-sheet test specimen is subjected to an energy pulse which has a very short duration
compared with the half-rise time (see 6.1) and a uniform spatial energy distribution. The transient
temperature rise on the opposite face (rear face) is recorded as a function of time (see Figure 1). The thermal
diffusivity is obtained by comparing the experimental thermogram with a theoretical model (see Clause 9
and Annex B).
5 Apparatus
5.1 General
The apparatus shall be designed to obtain the thermal diffusivity as described in Clause 4 and shall consist
of the following main components as shown in Figure 2. These are the furnace or climatic chamber with a
specimen holder and temperature measurement device (e.g. thermocouple), the flash source (e.g. laser), the
pulse detector, the transient detector (IR detector) and the control, data acquisition and analysis unit.
5.2 Furnace or climatic chamber
The furnace or climatic chamber shall meet the following requirements.
a) The temperature range shall be appropriate to the range of materials to be studied. Depending on
the range of temperature, the specimen is maintained at a constant temperature by a cryostat or by a
furnace.
ISO 22007-4:2024(en)
b) It shall be capable of maintaining the test temperature constant to within ±0,5 K or less for at least
30 min.
c) The temperature measurement device shall be capable of measuring the furnace or climatic chamber
temperature with a resolution of ±0,1 K and an accuracy of ±0,5 K or better.
d) The furnace or climatic chamber shall be fitted with two windows, one transparent to the pulse
radiation and the other transparent to the working wavelength range of the IR detector.
e) If required, the test environment shall be vacuum or inert-gas atmosphere to avoid oxidative degradation
during heating and testing of the specimen. For cryoscopic measurements, care shall be taken to avoid
water condensation on the windows.
NOTE Measurement under vacuum will eliminate convection effects.
The specimen holder shall be designed to minimize thermal contact with the specimen and to suppress stray
light transmitted from the light beam to the IR detector.
The test temperature shall be measured using a calibrated temperature measurement device that is
preferably in contact with the specimen or the specimen holder but at least within 1 mm of the specimen
holder.
The temperature measurement device shall be designed so as not to significantly disturb the temperature
field generated in the specimen by the light pulse.
Key
t time
ΔT temperature rise
a
Baseline.
b
Transient-rise period.
c
Cooling period.
Figure 1 — Example of thermogram

ISO 22007-4:2024(en)
Key
1 flash source
2 pulse detector
3 specimen
4 furnace or climatic chamber
5 temperature measurement device
6 windows
7 transient detector
Figure 2 — Schematic diagram of light flash set-up for measuring thermal diffusivity
5.3 Flash source
The energy level of the flash source shall produce a temperature rise not exceeding 3 K at the rear face of the
specimen.
The spatial energy distribution of the pulse heating shall be as uniform as possible over the front face of the
specimen.
The pulse duration shall be shorter than 1 ms.
The heat pulse source may be a laser or a flash tube.
A photodiode can be used to determine the duration and form of the pulse and the time origin.
5.4 Transient detectors
The transient temperature rise at the rear face of the specimen shall be measured with an IR detector. The
transient detector shall be able to detect a variation of 5 mK in the specimen rear face temperature. Its
response shall be linear with temperature over a temperature range of at least 3 K.
The frequency response of the detector and its associated electronics (amplifiers, analogue/digital
converters, etc.) shall be faster than 10 kHz. If electronic filters are used, they shall meet the requirements
defined above and shall not decrease the accuracy of temperature measurement, otherwise they could
distort the shape of the temperature-time curve.
NOTE The choice of IR detector depends also on the temperature range. For the range −100 °C to +400 °C,
photovoltaic or photoconductor detectors can be used.

ISO 22007-4:2024(en)
The temperature of the rear face, or a quantity directly proportional to it (e.g. voltage), shall be measured
and recorded continuously over the duration of the test. The data acquisition system, which may be analogue
or digital, shall be able to sample more than 1 000 data points on the thermogram with a sampling frequency
−5
higher than 100/t . The accuracy of the time base shall be better than ±1 × 10 s.
1/2
5.5 Thickness measurement device
The specimen thickness shall be measured with an accuracy of ±5 µm by a calibrated thickness measurement
device having a resolution of ±1 µm. For soft materials, a micrometer with reproducibly low compression is
required.
6 Test specimen
6.1 Shape and dimension of the specimen
The specimen shall be a thin disc. The specimen diameter is usually from 5 mm to 20 mm. The specimen
thickness shall be chosen according to the pulse width and the thermal diffusivity of the material. It shall
be selected such that the pulse width is less than 0,01 of the half-rise time. Typically, the thickness will
be between 0,5 mm and 3 mm. The aspect ratio of the specimen shall be chosen such that 2D effects are
negligible during the test. The ratio of the diameter to the thickness shall be larger than 3:1.
The faces shall be flat and parallel. Any variation in the thickness of the specimen should preferably be less
than 1 % of the mean thickness. The effect of greater non-uniformity can be estimated in the measurement
uncertainty.
6.2 Preparation and conditioning of test specimen
The test specimen shall be representative of the material being examined and shall be prepared and handled
with care. If the specimen is taken from sample pieces by cutting, care shall be taken to prevent heating,
changes in molecular orientation or any other effect that can alter the sample properties.
The preparation of specimens of oriented, anisotropic samples shall be done as specified in Annex C.
The test specimen shall be conditioned prior to the measurement as specified in the relevant material
standard or by a method agreed between the parties involved. Unless other conditions are specified, the
specimen shall be conditioned in accordance with ISO 291.
NOTE Depending on the material and its t
...