ISO 24087:2023

Rubber, vulcanized — Determination of the glass transition temperature and enthalpy by differential scanning calorimetry

This document specifies a method of thermal analysis of vulcanized rubber by differential scanning calorimetry (DSC). This method is intended for the observation and measurement of various properties and phenomena associated, such as physical transitions (glass transition, melting and crystallization, polymorphic transitions, etc.).

Caoutchouc vulcanisé — Détermination de la température de transition vitreuse et de l'enthalpie par analyse calorimétrique différentielle

Le présent document spécifie une méthode pour l’analyse thermique des caoutchoucs vulcanisés par analyse enthalpique différentielle (DSC). Cette méthode est destinée à l'observation et à la mesure de diverses propriétés et phénomènes associés, tels que les transitions physiques (transition vitreuse, fusion et cristallisation, transitions polymorphes, etc.).

General Information

• Status: Published
• Publication Date: 11-Jun-2023
• ICS: 83.060 - Rubber
• Technical Committee: ISO/TC 45/SC 2 - Testing and analysis
• Drafting Committee: ISO/TC 45/SC 2/WG 5 - Chemical tests
• Current Stage: 6060 - International Standard published
• Start Date: 12-Jun-2023
• Due Date: 04-Dec-2023
• Completion Date: 12-Jun-2023

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 24087
First edition
2023-06
Rubber, vulcanized — Determination
of the glass transition temperature
and enthalpy by differential scanning
calorimetry
Caoutchouc vulcanisé — Détermination de la température de
transition vitreuse et de l'enthalpie par analyse calorimétrique
différentielle
Reference number
ISO 24087:2023(E)
© ISO 2023

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ISO 24087:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
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
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ISO 24087:2023(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 2
5 Principle . 4
6 Apparatus and materials .4
7 Calibration .5
7.1 General . 5
7.2 Temperature calibration . 6
7.3 Heat calibration . 6
8 Test portion . 6
9 Conditioning . 6
10 Procedure .7
10.1 General . 7
10.1.1 Switching on . 7
10.1.2 Baseline determination . 7
10.1.3 Test portion and crucible . 7
10.1.4 Performing measurements . 7
10.2 Determination of the glass transition temperature, T . 8
g
10.2.1 Test performance . 8
10.2.2 Use and expression of results . 8
10.3 Determination of the transition temperature and enthalpy of other thermal
phenomena . 8
10.3.1 General . 8
10.3.2 Test performance . 8
10.3.3 Use and expression of results . 9
11 Precision . 9
12 Test report . 9
Annex A (informative) Recommended calibration materials .10
Annex B (informative) Precision .12
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ISO 24087:2023(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 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 45, Rubber and rubber products,
Subcommittee SC 2, Testing and analysis.
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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INTERNATIONAL STANDARD ISO 24087:2023(E)
Rubber, vulcanized — Determination of the glass transition
temperature and enthalpy by differential scanning
calorimetry
WARNING — Persons using this document should be familiar with normal laboratory practice,
if applicable. This document does not purport to address all of the safety concerns, if any,
associated with its use. It is the responsibility of the user to establish appropriate safety and
health practices.
1 Scope
This document specifies a method of thermal analysis of vulcanized rubber by differential scanning
calorimetry (DSC). This method is intended for the observation and measurement of various properties
and phenomena associated, such as physical transitions (glass transition, melting and crystallization,
polymorphic transitions, etc.).
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 11357-1, Plastics — Differential scanning calorimetry (DSC) — Part 1: General principles
ISO 23529, Rubber — General procedures for preparing and conditioning test pieces for physical test
methods
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11357-1 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
glass transition temperature
T
g
temperature of change from a glassy or hard condition to a rubbery or viscous condition
3.2
melting
transition stage between a fully crystalline or partially crystalline solid state and an amorphous liquid
of variable viscosity
Note 1 to entry: The transition, also referred to as “fusion”, is characterized by an endothermic peak in the DSC
curve (see Figure 1).
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ISO 24087:2023(E)
3.3
crystallization
transition stage between an amorphous liquid state and a fully crystalline or partially crystalline solid
state
Note 1 to entry: The transition is characterized by an exothermic peak in the DSC curve (see Figure 1).
3.4
enthalpy of fusion
heat required to melt a material at constant pressure
Note 1 to entry: It is expressed in kilojoules per kilogram (kJ/kg) or joules per gram (J/g).
3.5
enthalpy of crystallization
heat released by the crystallization (3.3) of a material at constant pressure
Note 1 to entry: It is expressed in kilojoules per kilogram (kJ/kg) or joules per gram (J/g).
3.6
reference crucible
crucible used on the reference side of the symmetrical crucible holder assembly
Note 1 to entry: Normally, the reference crucible is empty.
Note 2 to entry: This reference material should be thermally inactive over the temperature and time range of
interest.
4 Symbols
A typical DSC curve, with conventional temperatures, is shown in Figure 1 and explained in Table 1.
Key
dQ/dt heat flow rate
T temperature
T onset temperature
i
T extrapolated onset temperature
ei
T midpoint temperature
1/2,g
2
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ISO 24087:2023(E)
T point of inflection temperature
infl
T peak temperature
p
T extrapolated end temperature
ef
T end temperature
f
1 virtual baseline
a
Endothermic direction.
NOTE All these thermal phenomena are not necessarily present for all rubbers.
Figure 1 — Typical DSC curve
Table 1 — Symbols for conventionnal temperatures
Conventionnal temperatures
The first subscript, or pair of subscripts, denotes the position on the DSC curve with respect to the step or
peak:
T first detectable departure of DSC curve from extrapolated start baseline
i
T (for a peak) point of intersection of virtual baseline and tangent drawn at point of inflection of near side
ei
of peak or (for a step) point of intersection of start baseline and tangent drawn at point of inflection of
step (onset)
T half-height of a step
1/2,g
T point of inflection (maximum of the first-derivative curve) in the range of transition
infl
NOTE 1 For the purposes of this document, the glass transition temperature T corresponds to value of
g
T
infl
T greatest distance between DSC curve and virtual baseline during a peak
p
T (for a peak) point of intersection of interpolated virtual baseline and tangent drawn at point of inflection
ef
of far side of peak or (for a step) point of intersection of extrapolated end baseline and tangent drawn at
point of inflection of step (offset)
T last detectable deviation of DSC curve from extrapolated end baseline
f
The second subscript indicates the type of transition:
g glass transition
c crystallization
m melting
If a peak of internal relaxation appears on the high-temperature side of the glass-transition
temperature, find the glass-transition end temperature (T ) from the intersection of the two straight
ef,g
lines according to Figure 2.
One is a straight line that extends the high-temperature side baseline to the low-temperature side. The
other is the tangent line drawn at the point where the slope of the curve on the hot side of the peak is
maximum.
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ISO 24087:2023(E)
Key
dQ/dt heat flow rate
T temperature
1 virtual baseline
a
Endothermic direction.
Figure 2 — Curve for the glass-transition temperature determination with enthalpy relaxation
5 Principle
The difference between the rate of heat flow into a specimen and that into a reference crucible is
measured as a function of temperature and/or time while the specimen and the reference are subjected
to the same temperature-control programme under a specified atmosphere.
Two types of DSC can be carried out: heat-flux DSC and power-compensation DSC.
— Heat-flux DSC: The specimen and reference positions are subjected to the same temperature-control
programme by a single heater. A difference in temperature, ΔT, occurs between the specimen
position and the reference position because of the difference in heat capacity between the specimen
and the reference.
— Power-compensation DSC: The difference in electrical power required to maintain both the specimen
position and the reference position at the same temperature is recorded against temperature or
time, while each position is subjected to the same temperature-control programme;
6 Apparatus and materials
6.1 Differential scanning calorimeter, with the following features.
a) A symmetrical crucible holder assembly which has holders for the specimen and reference
crucibles.
b) The capability to generate heating and cooling rates between 0,5 K/min and 50 K/min.
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ISO 24087:2023(E)
c) The capability to carry out step heating or step cooling.
d) The capability to cool the target temperature for measuring the T of the sample.
g
e) The capability to maintain a constant purge gas flow rate controllable to within 10 ml/min and
100 ml/min.
f) The capability to measure temperature signals with a resolution of 0,1 °C and an accuracy o
...

NORME ISO
INTERNATIONALE 24087
Première édition
2023-06
Caoutchouc vulcanisé —
Détermination de la température de
transition vitreuse et de l'enthalpie
par analyse calorimétrique
différentielle
Rubber, vulcanized — Determination of the glass transition
temperature and enthalpy by differential scanning calorimetry
Numéro de référence
ISO 24087:2023(F)
© ISO 2023

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ISO 24087:2023(F)
DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2023
Tous droits réservés. Sauf prescription différente ou nécessité dans le contexte de sa mise en œuvre, aucune partie de cette
publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique,
y compris la photocopie, ou la diffusion sur l’internet ou sur un intranet, sans autorisation écrite préalable. Une autorisation peut
être demandée à l’ISO à l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
ISO copyright office
Case postale 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Genève
Tél.: [phone]
E-mail: [e-mail]
Web: www.iso.org
Publié en Suisse
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ISO 24087:2023(F)
Sommaire Page
Avant-propos .iv
1 Domaine d’application . 1
2 Références normatives .1
3 Termes et définitions . 1
4 Symboles . 2
5 Principe. 4
6 Appareillage et matériaux .4
7 Étalonnage . 5
7.1 Généralités . 5
7.2 Étalonnage en température . 6
7.3 Étalonnage en énergie . 6
8 Prise d’essai . 6
9 Conditionnement .6
10 Mode opératoire . 7
10.1 Généralités . 7
10.1.1 Mise sous tension . 7
10.1.2 Détermination de la ligne de base . 7
10.1.3 Prise d’essai et capsule . 7
10.1.4 Réalisation de mesurages . 7
10.2 Détermination de la température de transition vitreuse, T . 8
g
10.2.1 Réalisation de l’essai . 8
10.2.2 Exploitation et expression des résultats . . 8
10.3 Détermination de la température de transition et l’enthalpie d’autres phénomènes
thermiques . 8
10.3.1 Généralités . 8
10.3.2 Réalisation de l’essai . 8
10.3.3 Exploitation et expression des résultats . . 9
11 Fidélité . 9
12 Rapport d’essai . 9
Annexe A (informative) Matériaux d'étalonnage recommandés .10
Annexe B (informative) Fidélité .12
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ISO 24087:2023(F)
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes
nationaux de normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est
en général confiée aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude
a le droit de faire partie du comité technique créé à cet effet. Les organisations internationales,
gouvernementales et non gouvernementales, en liaison avec l'ISO participent également aux travaux.
L'ISO collabore étroitement avec la Commission électrotechnique internationale (IEC) en ce qui
concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier, de prendre note des différents
critères d'approbation requis pour les différents types de documents ISO. Le présent document a
été rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2 (voir
www.iso.org/directives).
L’ISO attire l’attention sur le fait que la mise en application du présent document peut entraîner
l’utilisation d’un ou de plusieurs brevets. L’ISO ne prend pas position quant à la preuve, à la validité
et à l’applicabilité de tout droit de brevet revendiqué à cet égard. À la date de publication du présent
document, l’ISO n'avait pas reçu notification qu’un ou plusieurs brevets pouvaient être nécessaires à sa
mise en application. Toutefois, il y a lieu d’avertir les responsables de la mise en application du présent
document que des informations plus récentes sont susceptibles de figurer dans la base de données de
brevets, disponible à l'adresse www.iso.org/brevets. L’ISO ne saurait être tenue pour responsable de ne
pas avoir identifié tout ou partie de tels droits de propriété.
Les appellations commerciales éventuellement mentionnées dans le présent document sont données
pour information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un
engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions
spécifiques de l'ISO liés à l'évaluation de la conformité, ou pour toute information au sujet de l'adhésion
de l'ISO aux principes de l’Organisation mondiale du commerce (OMC) concernant les obstacles
techniques au commerce (OTC), voir www.iso.org/avant-propos.
Le présent document a été élaboré par le comité technique ISO/TC 45, Élastomères et produits à base
d'élastomères, sous-comité SC 2, Essais et analyses.
Il convient que l’utilisateur adresse tout retour d’information ou toute question concernant le présent
document à l’organisme national de normalisation de son pays. Une liste exhaustive desdits organismes
se trouve à l’adresse www.iso.org/fr/members.html.
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NORME INTERNATIONALE ISO 24087:2023(F)
Caoutchouc vulcanisé — Détermination de la température
de transition vitreuse et de l'enthalpie par analyse
calorimétrique différentielle
AVERTISSEMENT — Il convient que l'utilisateur du présent document connaisse bien les
pratiques courantes de laboratoire. Le présent document n'a pas pour but de traiter tous les
problèmes de sécurité qui sont, le cas échéant, liés à son utilisation. Il incombe à l'utilisateur
d'établir des pratiques appropriées en matière d'hygiène et de sécurité.
1 Domaine d’application
Le présent document spécifie une méthode pour l’analyse thermique des caoutchoucs vulcanisés par
analyse enthalpique différentielle (DSC). Cette méthode est destinée à l'observation et à la mesure de
diverses propriétés et phénomènes associés, tels que les transitions physiques (transition vitreuse,
fusion et cristallisation, transitions polymorphes, etc.).
2 Références normatives
Les documents suivants sont cités dans le texte de sorte qu’ils constituent, pour tout ou partie de leur
contenu, des exigences du présent document. Pour les références datées, seule l'édition citée s'applique.
Pour les références non datées, la dernière édition du document de référence s'applique (y compris les
éventuels amendements).
ISO 11357-1, Plastiques — Analyse calorimétrique différentielle (DSC) — Partie 1: Principes généraux
ISO 23529, Caoutchouc — Procédures générales pour la préparation et le conditionnement des éprouvettes
pour les méthodes d'essais physiques
3 Termes et définitions
Pour les besoins du présent document, les termes et les définitions données dans l’ISO 11357-1 ainsi que
les suivants s'appliquent.
L'ISO et l'IEC tiennent à jour des bases de données terminologiques destinées à être utilisées en
normalisation, consultables aux adresses suivantes:
— ISO Online browsing platform: disponible à l'adresse https:// www .iso .org/ obp
— IEC Electropedia: disponible à l'adresse https:// www .electropedia .org/
3.1
température de transition vitreuse
T
g
température de passage de l’état vitreux ou rigide à l’état caoutchoutique ou viscoélastique
3.2
fusion
transition entre un état solide entièrement ou partiellement cristallin et un état liquide amorphe de
viscosité variable
Note 1 à l'article: La transition, également appelée “fusion”, se caractérise par un pic endothermique sur la courbe
DSC (voir Figure 1).
1
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ISO 24087:2023(F)
3.3
cristallisation
transition entre un état liquide amorphe et un état solide entièrement ou partiellement cristallin
Note 1 à l'article: La transition se caractérise par un pic exothermique sur la courbe DSC (voir Figure 1).
3.4
enthalpie de fusion
énergie requise pour faire fondre une matière à pression constante
Note 1 à l'article: Elle est exprimée en kilojoules par kilogramme (kJ/kg) ou en joules par gramme (J/g).
3.5
enthalpie de cristallisation
énergie dégagée par la cristallisation (3.3) d’une matière à pression constante
Note 1 à l'article: Elle est exprimée en kilojoules par kilogramme (kJ/kg) ou en joules par gramme (J/g).
3.6
capsule de référence
capsule utilisée sur le côté de référence du montage du porte-capsule symétrique
Note 1 à l'article: Normalement, la capsule de référence est vide.
Note 2 à l'article: Ce matériau de référence doit être inerte thermiquement sur les plages de températures et de
temps considérées.
4 Symboles
Une courbe type DSC, avec des températures conventionnelles, est représentée à la Figure 1 et explicité
dans le Tableau 1.
Légende
dQ/dt flux thermique
T température
T température initiale
i
T température initiale extrapolée
ei
T température médiane
1/2,g
2
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ISO 24087:2023(F)
T température au point d’inflexion
infl
T température du pic
p
T température finale extrapolée
ef
T température finale
f
1 ligne de base virtuelle
a
Direction endothermique.
NOTE L’ensemble des phénomènes thermiques n’est pas obligatoirement présent pour tous les caoutchoucs.
Figure 1 — Courbe DSC type
Tableau 1 — Symboles pour les températures conventionnelles
Températures conventionnelles
Le premier indice, ou couples d’indices, indique la position sur la courbe DSC relative au palier ou au pic:
T premier écart détectable de la courbe DSC par rapport à la ligne de base initiale extrapolée;
i
T (pour un pic) intersection de la ligne de base virtuelle et de la tangente au niveau du point d'inflexion du
ei
début de pic ou (pour un palier) de la ligne de base initiale et de la tangente au niveau du point d'inflexion
du palier (onset)
T demi hauteur d’un palier
1/2,g
T point d’inflexion (extremum de la dérivée première) dans le domaine de transition
infl
NOTE 1  Dans le cadre du présent document, la température de transition vitreuse T correspond à la
g
valeur de T
infl
T différence la plus importante entre la courbe DSC et la ligne de base virtuelle au cours d’un pic
p
T (pour un pic) intersection de la ligne de base virtuelle et de la tangente au niveau du point d'inflexion de
ef
la fin du pic ou (pour un palier) de la ligne de base finale et de la tangente au niveau du point d'inflexion
du palier (offset)
T dernier écart détectable de la courbe DSC par rapport à la ligne de base virtuelle
f
Le second indice indique le type de transition:
g transition vitreuse
c cristallisation
m fusion
Si un pic de relaxation interne apparaît du côté haute température de la température de transition
vitreuse, trouver la température de transition vitreuse finale (T ) à partir de l'intersection des deux
ef,g
droites conformément à la Figure 2.
L'une est une ligne droite qui prolonge la ligne de base du côté haute température jusqu'au côté basse
température. L'autre est la tangente tracée au point où la pente de la courbe du côté chaud du pic est
maximale.
3
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ISO 24087:2023(F)
Légende
dQ/dt flux thermique
T température
1 ligne de base virtuelle
a
Direction endothermique.
Figure 2 — Courbe de détermination de la température de transition vitreuse avec relaxation
enthalpique
5 Principe
La différence entre les flux thermiques fournis à un échantillon et à une capsule de référence est
mesurée en fonction de la température et/ou du temps, lorsque l’échantillon et la référence sont soumis
au même programme contrôlé de températures, dans une atmosphère spécifiée.
Deux types de DSC peuvent être effectués: la DSC à compensation de puissance et la DSC à flux
thermique.
— DSC à compensation de puissance: La différence de puissance électrique nécessaire pour maintenir
la position de l'échantillon et la position de référence à la même température est enregistrée en
fonction de la température ou du temps, alors que chaque position est soumise au même programme
contrôlé de températures;
— DSC à flux thermique: Les positions de l'échantillon et de la référence sont soumises au même
programme contrôlé de températures par un seul appareil de chauffage. Une différence de
température, ΔT, se produit entre la position de l'échantillon et la position de référence en raison de
la différence de capacité thermique entre de l'échantillon et la référence.
6 Appareillage et matériaux
6.1 Calorimètre différentiel, avec les caractéristiques suivantes:
a) Montage symétrique de support de capsule comportant des supports pour l’échantillon et les
capsules de référence.
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ISO 24087:2023(F)
b) Capacité de générer des vitesses linéaires de chauffage et de refroidissement comprises entre
0,5 K/min et 50 K/min.
b) Capacité d'effectuer un chauffage ou un refroidissement par paliers.
d) Capacité de refroidir la température cible pour mesurer la T de l'échantillon.
g
e) Capacité de maintenir un débit gazeux de purge constant réglable à 10 ml/min et 100 ml/min près.
f) Capacité de mesurer les signaux de température avec une résolution de 0,1 °C avec une précision
égale ou supérieure à ± 0,5 °C.
g) Étalonnage et fonctionnement possibles avec une prise d’essai de 1 mg minimum (ou des quantités
plus réduites si cela est exigé pour certaines applications).
6.2 Système d’acquisition et de traitement des données.
6.3 Capsules, pour les positions de l’échantillon et de la référence.
Elles doivent être du même type, être réalisées à partir du
...

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Space After: 12 pt, Line spacing: At least 12 pt
ISO/TC 45/SC 2/WG 5
Formatted: English (United Kingdom)
Formatted: English (United Kingdom)
Secretariat:  JISC
Formatted: English (United Kingdom)
Formatted: Font: Not Bold
Formatted: Don't adjust space between Latin and Asian
First edition
text, Don't adjust space between Asian text and numbers
Formatted: Font: Bold
2023-02-23
Rubber, vulcanized — Determination of the glass transition temperature and
enthalpy by differential scanning calorimetry
Formatted: French (Switzerland)
Caoutchouc brut — Détermination de la température de transition vitreuse et de
Formatted: Right, Don't adjust space between Latin and
l'enthalpie par analyse calorimétrique différentielle
Asian text, Don't adjust space between Asian text and
numbers
First edition
Formatted: Don't adjust space between Latin and Asian
text, Don't adjust space between Asian text and numbers
2022-07-05
Formatted: Font: Bold
Document type:  Error! Reference source not found.
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---------------------- Page: 2 ----------------------
ISO/FDIS 24087:20222023(E)
© ISO 2022 2023 Formatted: Font: 11 pt, Font color: Blue
Formatted: Don't adjust space between Latin and Asian
All rights reserved. Unless otherwise specified, or required in the context of its implementation,
text, Don't adjust space between Asian text and numbers
no part of this publication may be reproduced or utilized otherwise in any form or by any means,
Formatted: Font: 11 pt, Font color: Blue
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 Formatted: Font: 11 pt, Font color: Blue
CP 401 • CH-1214 Vernier, Geneva Formatted: Font: 11 pt, Font color: Blue
Phone: + 41 22 749 01 11 Formatted: Font: 11 pt, Font color: Blue
Email: [e-mail] Formatted: Font: 11 pt, Font color: Blue
Formatted: English (United States)
Website: www.iso.org
Formatted: Font: 11 pt, Font color: Blue
Formatted: English (United States)
Published in Switzerland.
Formatted: Font: 11 pt, Font color: Blue
iv © ISO 20222023 – All rights reserved

---------------------- Page: 3 ----------------------
ISO/FDIS 24087:20222023(E)
Contents Page
Foreword . 7
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 2
5 Principle . 5
6 Apparatus and materials . 6
7 Calibration . 7
7.1 General . 7
7.2 Temperature calibration . 7
7.3 Heat calibration . 7
8 Test portion . 8
9 Conditioning . 8
10 Procedure . 8
10.1 General . 8
10.2 Determination of the glass transition temperature, T . 9
g
10.3 Determination of the transition temperature and enthalpy of other thermal
phenomena . 10
11 Precision . 10
12 Test report . 10
Annex A (informative) Recommended calibration materials . 12
Annex B (informative) Precision . 14
Foreword . 7
1 Scope . 1
2 Normative references . 1
© ISO 20222023 – All rights reserved v

---------------------- Page: 4 ----------------------
ISO/FDIS 24087:20222023(E)
3 Terms and definitions . 1
4 Symbols . 2
5 Principle . 5
6 Apparatus and materials . 6
7 Calibration . 7
8 Test portion . 8
9 Conditioning . 8
10 Procedure . 8
11 Precision . 10
12 Test report . 10
Annex A (informative) Recommended calibration materials . 12
Annex B (informative) Precision . 14

vi © ISO 20222023 – All rights reserved

---------------------- Page: 5 ----------------------
ISO/FDIS 24087:20222023(E)
Formatted: Line spacing: At least 15.5 pt, Tab stops: Not
Foreword
at 20 pt
ISO (the International Organization for Standardization) is a worldwide federation of national Formatted: English (United States)
standards bodies (ISO member bodies). The work of preparing International Standards is normally
Formatted: Adjust space between Latin and Asian text,
carried out through ISO technical committees. Each member body interested in a subject for which a
Adjust space between Asian text and numbers
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. Formatted: English (United States)
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). Formatted: English (United States)
Formatted: English (United States)
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). Formatted: English (United States)
Formatted: English (United States)
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement. Formatted: English (United States)
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 Formatted: English (United States)
www.iso.org/iso/foreword.html.
Formatted: English (United States)
Formatted: English (United States)
This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products,
Subcommittee SC 2, Testing and analysis.
Any feedback or questions on this document should be directed to the user’s national standards body. A
Formatted: English (United States)
complete listing of these bodies can be found at www.iso.org/members.html.
Formatted: Adjust space between Latin and Asian text,
Adjust space between Asian text and numbers
Formatted: English (United States)
Formatted: English (United States)
© ISO 20222023 – All rights reserved vii

---------------------- Page: 6 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 24087:20222023(E)

Rubber, vulcanized — Determination of the glass transition
temperature and enthalpy by differential scanning
calorimetry
WARNING — Persons using this document should be familiar with normal laboratory practice, if
applicable. This document does not purport to address all of the safety concerns, if any, associated with
its use. It is the responsibility of the user to establish appropriate safety and health practices and to
ensure compliance with any regulatory requirements.
1 Scope
This document specifies a method of thermal analysis of vulcanized rubber by differential scanning
calorimetry (DSC). This method is intended for the observation and measurement of various properties
and phenomena associated, such as physical transitions (glass transition, melting and crystallization,
polymorphic transitions, etc.).
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
Formatted: Default Paragraph Font
undated references, the latest edition of the referenced document (including any amendments) applies.
Formatted: Default Paragraph Font
ISO 11357-1, Plastics — Differential scanning calorimetry (DSC) — Part 1: General principles
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
ISO 23529, Rubber — General procedures for preparing and conditioning test pieces for physical test
methods Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
3 Terms and definitions
Formatted: Default Paragraph Font
Formatted: Don't adjust space between Latin and Asian
For the purposes of this document, the terms and definitions given in ISO 11357-1 and the following
text, Don't adjust space between Asian text and numbers
apply.
Formatted: Default Paragraph Font
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
Formatted: Default Paragraph Font
— ISO Online browsing platform: available at https://www.iso.org/obp
Formatted: Default Paragraph Font
Formatted: Font: Cambria, 11 pt
— IEC Electropedia: available at https://www.electropedia.org/
Formatted: Don't adjust space between Latin and Asian
text, Don't adjust space between Asian text and numbers,
3.1
Tab stops: 19.85 pt, Left + 39.7 pt, Left + 59.55 pt, Left +
glass transition temperature
79.4 pt, Left + 99.25 pt, Left + 119.05 pt, Left + 138.9 pt,
T
g Left + 158.75 pt, Left + 178.6 pt, Left + 198.45 pt, Left
temperature of change from a glassy or hard condition to a rubbery or viscous condition
Formatted: English (United States)
3.2
Formatted: English (United States)
melting
Formatted: Font: Cambria
Formatted: Font: Bold
© ISO 20222023 – All rights reserved
1

---------------------- Page: 7 ----------------------
ISO/FDIS 24087:2023(E)
Formatted: German (Germany)
Formatted: Left, Space After: 34 pt
transition stage between a fully crystalline or partially crystalline solid state and an amorphous liquid
of variable viscosity
Note 1 to entry: The transition, also referred to as “fusion”, is characterized by an endothermic peak in the DSC
curve (see Figure 1). Formatted: Default Paragraph Font
3.3
crystallization
transition stage between an amorphous liquid state and a fully crystalline or partially crystalline solid
state
Note 1 to entry: The transition is characterized by an exothermic peak in the DSC curve (see Figure 1).
Formatted: Default Paragraph Font
3.4
enthalpy of fusion
heat required to melt a material at constant pressure
Note 1 to entry: It is expressed in kilojoules per kilogram (kJ/kg) or joules per gram (J/g).
3.5
enthalpy of crystallization
heat released by the crystallization (3.3) of a material at constant pressure
Note 1 to entry: It is expressed in kilojoules per kilogram (kJ/kg) or joules per gram (J/g).
3.6
reference crucible
crucible used on the reference side of the symmetrical crucible holder assembly
Note 1 to entry: Normally, the reference crucible is empty.
Note 2 to entry: This reference material should be thermally inactive over the temperature and time range of
interest.
4 Symbols
A typical DSC curve, with conventional temperatures, is shown in Figure 1 and are explained in Table 1.
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
© ISO 20222023 – All rights reserved
2

---------------------- Page: 8 ----------------------
ISO/FDIS 24087:20222023(E)


Key
dQ/dt heat flow rate
T temperature
Ti onset temperature
Tei extrapolated onset temperature
T1/2g midpoint temperature
Tinfl point of inflection temperature
Tp peak temperature
Tef extrapolated end temperature
T end temperature
f
© ISO 20222023 – All rights reserved
3

---------------------- Page: 9 ----------------------
ISO/FDIS 24087:2023(E)
Formatted: German (Germany)
Formatted: Left, Space After: 34 pt
1 virtual baseline
a
Endothermic direction.

NOTE All these thermal phenomena are not necessarily present for all rubbers.
Figure 1 — Typical DSC curve
Table 1 — Symbols for conventionnal temperatures Formatted: Table title, None, Adjust space between Latin
and Asian text, Adjust space between Asian text and
Conventionnal temperatures numbers
The first subscript, or pair of subscripts, denotes the position on the DSC curve with respect to the step or peak:
T first detectable departure of DSC curve from extrapolated start baseline
i
T (for a peak) point of intersection of virtual baseline and tangent drawn at point of inflection of near side of
ei
peak or (for a step) point of intersection of start baseline and tangent drawn at point of inflection of step
(onset)
T half-height of a step
1/2g
T point of inflection (maximum of the first-derivative curve) in the range of transition
infl
NOTE 1  For the purposes of this document, the glass transition temperature Tg corresponds to value of
Formatted: Don't adjust space between Latin and Asian
T text, Don't adjust space between Asian text and numbers
infl
T greatest distance between DSC curve and virtual baseline during a peak
p
T (for a peak) point of intersection of interpolated virtual baseline and tangent drawn at point of inflection of
ef
far side of peak or (for a step) point of intersection of extrapolated end baseline and tangent drawn at
point of inflection of step (offset)
T last detectable deviation of DSC curve from extrapolated end baseline
f
The second subscript indicates the type of transition:
Formatted Table
g glass transition
c crystallization
m melting
If a peak of internal relaxation appears on the high -temperature side of the glass -transition
temperature, find the glass -transition end temperature (Tef,g) from the intersection of the two straight
lines according to Figure 2. Formatted: Default Paragraph Font
One is a straight line that extends the high -temperature side baseline to the low -temperature side. The
other is the tangent line drawn at the point where the slope of the curve on the hot side of the peak is
maximum.
© ISO 20222023 – All rights reserved
4

---------------------- Page: 10 ----------------------
ISO/FDIS 24087:20222023(E)


Key
Formatted: Don't keep with next, Adjust space between
dQ/dt heat flow rate Latin and Asian text, Adjust space between Asian text and
numbers, Tab stops: Not at 19.85 pt + 39.7 pt + 59.55 pt
T temperature
+ 79.4 pt + 99.25 pt + 119.05 pt + 138.9 pt + 158.75 pt
1 virtual baseline
+ 178.6 pt + 198.45 pt
a
Endothermic direction.
Formatted: Justified
Formatted: Justified
Figure 2 — Curve for the glass -transition temperature determination with enthalpy relaxation
Formatted: Justified
Formatted: Justified
5 Principle
The difference between the rate of heat flow into a specimen and that into a reference crucible is
measured as a function of temperature and/or time while the specimen and the reference are subjected
to the same temperature-control programme under a specified atmosphere.
© ISO 20222023 – All rights reserved
5

---------------------- Page: 11 ----------------------
ISO/FDIS 24087:2023(E)
Formatted: Left, Space After: 34 pt
Formatted: German (Germany)
Two types of DSC can be carried out: heat-flux DSC and power-compensation DSC.
— Heat-flux DSC: The specimen and reference positions are subjected to the same temperature-
control programme by a single heater. A difference in temperature, ΔT, occurs between the
specimen position and the reference position because of the difference in heat capacity between the
specimen and the reference.
— Power-compensation D
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 24087
ISO/TC 45/SC 2
Rubber, vulcanized — Determination
Secretariat: JISC
of the glass transition temperature
Voting begins on:
2023-03-10 and enthalpy by differential scanning
calorimetry
Voting terminates on:
2023-05-05
Caoutchouc vulcanisé — Détermination de la température de
transition vitreuse et de l'enthalpie par analyse calorimétrique
différentielle
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 24087:2023(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO 2023

---------------------- Page: 1 ----------------------
ISO/FDIS 24087:2023(E)
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 24087
ISO/TC 45/SC 2
Rubber, vulcanized — Determination
Secretariat: JISC
of the glass transition temperature
Voting begins on:
and enthalpy by differential scanning
calorimetry
Voting terminates on:
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
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.
RECIPIENTS OF THIS DRAFT ARE INVITED TO
ISO copyright office
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
CP 401 • Ch. de Blandonnet 8
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
CH-1214 Vernier, Geneva
DOCUMENTATION.
Phone: [phone]
IN ADDITION TO THEIR EVALUATION AS
Reference number
Email: [e-mail]
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/FDIS 24087:2023(E)
Website: www.iso.org
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
Published in Switzerland
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN­
DARDS TO WHICH REFERENCE MAY BE MADE IN
ii
  © ISO 2023 – All rights reserved
NATIONAL REGULATIONS. © ISO 2023

---------------------- Page: 2 ----------------------
ISO/FDIS 24087:2023(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 2
5 Principle . 4
6 Apparatus and materials .5
7 Calibration .6
7.1 General . 6
7.2 Temperature calibration . 6
7.3 Heat calibration . 6
8 Test portion . 7
9 Conditioning . 7
10 Procedure .7
10.1 General . 7
10.1.1 Switching on . 7
10.1.2 Baseline determination . 7
10.1.3 Test portion and crucible . 7
10.1.4 Performing measurements . 8
10.2 Determination of the glass transition temperature, T . 8
g
10.2.1 Test performance . 8
10.2.2 Use and expression of results . 8
10.3 Determination of the transition temperature and enthalpy of other thermal
phenomena . 9
10.3.1 General . 9
10.3.2 Test performance . 9
10.3.3 Use and expression of results . 9
11 Precision . 9
12 Test report . 9
Annex A (informative) Recommended calibration materials .11
Annex B (informative) Precision .13
iii
© ISO 2023 – All rights reserved

---------------------- Page: 3 ----------------------
ISO/FDIS 24087:2023(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 non­governmental, 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 45, Rubber and rubber products,
Subcommittee SC 2, Testing and analysis.
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 2023 – All rights reserved

---------------------- Page: 4 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 24087:2023(E)
Rubber, vulcanized — Determination of the glass transition
temperature and enthalpy by differential scanning
calorimetry
WARNING — Persons using this document should be familiar with normal laboratory practice,
if applicable. This document does not purport to address all of the safety concerns, if any,
associated with its use. It is the responsibility of the user to establish appropriate safety and
health practices and to ensure compliance with any regulatory requirements.
1 Scope
This document specifies a method of thermal analysis of vulcanized rubber by differential scanning
calorimetry (DSC). This method is intended for the observation and measurement of various properties
and phenomena associated, such as physical transitions (glass transition, melting and crystallization,
polymorphic transitions, etc.).
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 11357-1, Plastics — Differential scanning calorimetry (DSC) — Part 1: General principles
ISO 23529, Rubber — General procedures for preparing and conditioning test pieces for physical test
methods
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11357-1 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
glass transition temperature
T
g
temperature of change from a glassy or hard condition to a rubbery or viscous condition
3.2
melting
transition stage between a fully crystalline or partially crystalline solid state and an amorphous liquid
of variable viscosity
Note 1 to entry: The transition, also referred to as “fusion”, is characterized by an endothermic peak in the DSC
curve (see Figure 1).
1
© ISO 2023 – All rights reserved

---------------------- Page: 5 ----------------------
ISO/FDIS 24087:2023(E)
3.3
crystallization
transition stage between an amorphous liquid state and a fully crystalline or partially crystalline solid
state
Note 1 to entry: The transition is characterized by an exothermic peak in the DSC curve (see Figure 1).
3.4
enthalpy of fusion
heat required to melt a material at constant pressure
Note 1 to entry: It is expressed in kilojoules per kilogram (kJ/kg) or joules per gram (J/g).
3.5
enthalpy of crystallization
heat released by the crystallization (3.3) of a material at constant pressure
Note 1 to entry: It is expressed in kilojoules per kilogram (kJ/kg) or joules per gram (J/g).
3.6
reference crucible
crucible used on the reference side of the symmetrical crucible holder assembly
Note 1 to entry: Normally, the reference crucible is empty.
Note 2 to entry: This reference material should be thermally inactive over the temperature and time range of
interest.
4 Symbols
A typical DSC curve, with conventional temperatures, is shown in Figure 1 and explained in Table 1.
2
  © ISO 2023 – All rights reserved

---------------------- Page: 6 ----------------------
ISO/FDIS 24087:2023(E)
Key
dQ/dt heat flow rate
T temperature
T onset temperature
i
T extrapolated onset temperature
ei
T midpoint temperature
1/2g
T point of inflection temperature
infl
T peak temperature
p
T extrapolated end temperature
ef
T end temperature
f
1 virtual baseline
a
Endothermic direction.
NOTE All these thermal phenomena are not necessarily present for all rubbers.
Figure 1 — Typical DSC curve
Table 1 — Symbols for conventionnal temperatures
Conventionnal temperatures
The first subscript, or pair of subscripts, denotes the position on the DSC curve with respect to the step or
peak:
T first detectable departure of DSC curve from extrapolated start baseline
i
T (for a peak) point of intersection of virtual baseline and tangent drawn at point of inflection of near side
ei
of peak or (for a step) point of intersection of start baseline and tangent drawn at point of inflection of
step (onset)
T half­height of a step
1/2g
T point of inflection (maximum of the first-derivative curve) in the range of transition
infl
NOTE 1 For the purposes of this document, the glass transition temperature T corresponds to value of
g
T
infl
T greatest distance between DSC curve and virtual baseline during a peak
p
3
© ISO 2023 – All rights reserved

---------------------- Page: 7 ----------------------
ISO/FDIS 24087:2023(E)
TTabablele 1 1 ((ccoonnttiinnueuedd))
Conventionnal temperatures
T (for a peak) point of intersection of interpolated virtual baseline and tangent drawn at point of inflection
ef
of far side of peak or (for a step) point of intersection of extrapolated end baseline and tangent drawn at
point of inflection of step (offset)
T last detectable deviation of DSC curve from extrapolated end baseline
f
The second subscript indicates the type of transition:
g glass transition
c crystallization
m melting
If a peak of internal relaxation appears on the high-temperature side of the glass-transition
temperature, find the glass-transition end temperature (T ) from the intersection of the two straight
ef,g
lines according to Figure 2.
One is a straight line that extends the high-temperature side baseline to the low-temperature side. The
other is the tangent line drawn at the point where the slope of the curve on the hot side of the peak is
maximum.
Key
dQ/dt heat flow rate
T temperature
1 virtual baseline
a
Endothermic direction.
Figure 2 — Curve for the glass-transition temperature determination with enthalpy relaxation
5 Principle
The difference between the rate of heat flow into a specimen and that into a reference crucible is
measured as a function of temperature and/or time while the specimen and the reference are subjected
to the same temperature-control programme under a specified atmosphere.
4
  © ISO 2023 – All rights reserved

---------------------- Page: 8 ----------------------
ISO/FDIS 24087:2023(E)
Two types of DSC can be carried out: heat-flux DSC and power-compensation DSC.
— Heat-flux DSC: The specimen and reference positions are subjected to the same temperature-control
programme by a single heater. A difference in temperature, ΔT, occurs between the specimen
position and the reference position because of the difference in heat capacity between the specimen
and the reference.
— Power-compensation DSC: The difference in electrical power required to maintain both the specimen
position and the reference position at the same temperature is recorded against temperature or
time, while each position is subjected to the same temperature-control programme;
6 Apparatus and material
...