SIST EN ISO 19628:2025

SLOVENSKI STANDARD
01-januar-2025
Fina keramika (sodobna keramika, sodobna tehnična keramika) - Termofizikalne
lastnosti keramičnih kompozitov - Ugotavljanje specifične toplotne kapacitete (ISO
19628:2024)
Fine ceramics (advanced ceramics, advanced technical ceramics) - Thermophysical
properties of ceramic composites - Determination of specific heat capacity (ISO
19628:2024)
Hochleistungskeramik - Thermophysikalische Eigenschaften von keramischen
Verbundwerkstoffen - Bestimmung der spezifischen Wärmekapazität (ISO 19628:2024)
Céramiques techniques - Propriétés thermophysiques des composites céramiques -
Détermination de la capacité thermique massique (ISO 19628:2024)
Ta slovenski standard je istoveten z: EN ISO 19628:2024
ICS:
81.060.30 Sodobna keramika Advanced ceramics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 19628
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2024
EUROPÄISCHE NORM
ICS 81.060.30 Supersedes EN ISO 19628:2021
English Version
Fine ceramics (advanced ceramics, advanced technical
ceramics) - Thermophysical properties of ceramic
composites - Determination of specific heat capacity (ISO
19628:2024)
Céramiques techniques - Propriétés thermophysiques Hochleistungskeramik - Thermophysikalische
des composites céramiques - Détermination de la Eigenschaften von keramischen Verbundwerkstoffen -
capacité thermique massique (ISO 19628:2024) Bestimmung der spezifischen Wärmekapazität (ISO
19628:2024)
This European Standard was approved by CEN on 21 July 2024.

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 19628:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 19628:2024) has been prepared by Technical Committee ISO/TC 206 "Fine
ceramics" in collaboration with Technical Committee CEN/TC 184 “Advanced technical ceramics” the
secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2025, and conflicting national standards shall be
withdrawn at the latest by May 2025.
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 19628:2021.
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 19628:2024 has been approved by CEN as EN ISO 19628:2024 without any modification.

International
Standard
ISO 19628
Second edition
Fine ceramics (advanced
2024-11
ceramics, advanced technical
ceramics) — Thermophysical
properties of ceramic composites
— Determination of specific heat
capacity
Céramiques techniques — Propriétés thermophysiques des
composites céramiques — Détermination de la capacité
thermique massique
Reference number
ISO 19628:2024(en) © ISO 2024
ISO 19628:2024(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: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 19628:2024(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Method A – drop calorimetry . 2
4.1 Principle .2
4.2 Apparatus .2
4.3 Standard reference materials .3
4.4 Containers .3
4.5 Test specimens.3
4.6 Calibration of the calorimeter . .3
4.6.1 General .3
4.6.2 Electrical calibration .3
4.6.3 Calibration using standard reference material .4
4.7 Test procedures .4
4.7.1 General .4
4.7.2 Test without a container .4
4.7.3 Test with a container .5
4.7.4 Description of test .5
4.8 Calculations .6
4.8.1 General .6
4.8.2 Determination of the calorimetric calibration factor .6
4.8.3 Determination of mean specific heat capacity C .
p
4.8.4 Determination of the specific heat capacity C .7
p
5 Method B – differential scanning calorimetry . 7
5.1 Principle .7
5.1.1 General .7
5.1.2 Stepwise heating method .8
5.1.3 Continuous heating method .8
5.2 Apparatus .9
5.3 Standard reference materials, SRM .9
5.4 Test specimens.9
5.5 Temperature calibration .9
5.6 Test procedure for the determination of C .10
p
5.6.1 General .10
5.6.2 Method 1: Measurements requiring the knowledge of the K factor .10
5.6.3 Method 2: measurements requiring the use of a reference standard material
(SRM) . 12
5.7 Calculation of results . 15
5.7.1 Method requiring the knowledge of the K factor . 15
5.7.2 Method using an SRM.17
6 Test report .18
Annex A (Informative) Drop calorimetry – determination of the calibration factor using
standard reference material . 19
Annex B (informative) Standard reference material .21
Annex C (informative) Materials for calorimeter calibrations .27
Bibliography .28

iii
ISO 19628:2024(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 206, Fine ceramics, in collaboration with
the European Committee for Standardization (CEN) Technical Committee CEN/TC 184, Advanced technical
ceramics, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna
Agreement).
This second edition cancels and replaces the first edition (ISO 19268:2017), which has been technically
revised.
The main changes are as follows:
— revised scope to extend the maximum temperature of use of Method A to 3 000 K;
— revised Clause 4 by introducing the possibility to apply the drop calorimetry method for temperatures
T1 > T2 (conventional drop calorimetry);
— relevant specifications added concerning the containers and thermometers to be used;
— description of in-situ calibration methods of the calorimeter and thermometers;
— addition of a paragraph dealing with the determination of specific heat capacity at given temperatures
from measurements performed by drop calorimetry;
— updated list of references in the Bibliography.
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 19628:2024(en)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Thermophysical properties of ceramic
composites — Determination of specific heat capacity
1 Scope
This document specifies two methods for the determination of the specific heat capacity of ceramic matrix
composites with continuous reinforcements (1D, 2D, 3D).
Unidirectional (1D), bi-directional (2D) and tridirectional (XD, with 2 < X ≤ 3).
The two methods are:
— method A: drop calorimetry;
— method B: differential scanning calorimetry.
The two methods are applicable from ambient temperature up to a maximum temperature that is method
dependent: method A can be used up to 3 000 K, while method B is limited to 1 900 K.
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 19634, Fine ceramics (advanced ceramics, advanced technical ceramics) — Ceramic composites — Notations
and symbols
IEC 60584-1, Thermocouples — Part 1: EMF specifications and tolerances
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 19634 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
specific heat capacity
C
p
amount of heat required to raise the temperature of a mass unit of material by 1 K at constant temperature
and pressure
1 dQ
C = (1)
p
mdT
where Q is the heat required for a test-piece of mass m.

ISO 19628:2024(en)
3.2
mean specific heat capacity
CT(,T )
p 12
amount of heat required to raise the temperature of a mass unit of a material from temperature T to
temperature T at a constant pressure, divided by the temperature increase (T – T ) expressed in K
2 2 1
3.3
representative volume element
RVE
minimum volume which is representative of the material considered
4 Method A – drop calorimetry
4.1 Principle
In “conventional” drop calorimetry, the test piece is heated in a furnace at a constant temperature T then
dropped in a calorimeter at a constant temperature T . The quantity measured is the amount of heat Q
released in cooling the test piece to the calorimeter temperature T .
In “inverse” drop calorimetry, the test piece is maintained in a conditioning chamber at a constant
temperature T near to room temperature and then dropped in a calorimeter heated at a constant
temperature T . The quantity measured is the amount of heat Q absorbed in heating the test piece to the
calorimeter temperature T .
Whatever the method, “conventional” drop calorimetry or “inverse” drop calorimetry, T > T .
2 1
In both methods, the tested material must not undergo a phase transition in the temperature increment (T – T ).
2 1
Transfer of the test piece shall be done under conditions as close as possible to adiabatic conditions.
Specific heat capacity and mean specific heat capacity are determined from the amount of heat absorbed or
released by the test piece in the calorimeter depending on the drop calorimetry mode applied.
4.2 Apparatus
4.2.1 Drop calorimeter, there are several types of drop calorimeters. They include one (or more)
conditioning chambers and measuring chambers, which can be operated under controlled atmosphere and
which are all equipped with a temperature control system. It is recommended that these control systems
enable a temperature stability better than 1 K below 1 300 K, better than 2 K from 1 300 K to 2 300 K and
better than 4 K above 2 300 K.
The conditioning chamber shall have a homogeneous temperature zone size greater than the test specimen
size. The measuring chamber shall have a homogeneous temperature zone of a sufficient length to accept
several specimens and a sufficient thermal inertia to limit the temperature disturbance, due to the drop.
Heat transfer by radiation during the drop shall be avoided as far as possible.
4.2.2 Balance, with an accuracy of 0,1 mg for test pieces over 10 mg and an accuracy of 0,01 mg for test
pieces below 10 mg.
4.2.3 Temperature detectors, thermocouples in accordance with IEC 60584-1 shall be used for the
measurement of temperature up to 1 920 K.
For temperatures higher than 1 273 K, radiation thermometers (also named pyrometers) can be used.
Thermocouples and radiation thermometers shall be periodically calibrated in their operating temperature
ranges as they can be subjected to drift over time.

ISO 19628:2024(en)
Thermocouples may be calibrated by measurement either at a series of fixed-point temperatures (e.g.
melting/freezing points) or by comparison with reference thermometers in thermally stabilised baths or
furnaces.
[2]
NOTE 1 Guidelines on the Calibration of Thermocouples are available at the following address: https:// www
.euramet .org/ publications -media -centre/ calibration -guidelines/ .
Pyrometers are usually calibrated in radiance temperature using reference blackbodies. In addition to
these calibrations performed outside the drop calorimeter facility, it is recommended to perform in-situ
[3]
calibrations of the pyrometers by using fixed-point temperatures .
4.2.4 Data acquisition system, the sampling period during the test shall be less than 0,5 s.
4.3 Standard reference materials
Standard reference materials which can be used for calibration purposes are listed in Annex B.
4.4 Containers
When containers are used, care shall be taken to choose suitable containers to avoid any chemical reaction
or contamination of the specimen from the container material, in particular at high temperature.
4.5 Test specimens
The test specimens shall be representative of the material.
This criterion is generally met by test specimens containing the maximum number of representative volume
elements compatible with the volume of the crucible. If this number is less than five, several solutions are
possible:
a) the test specimens should have an exact number of representative volume elements;
b) the material should be cut into specimens; a number of similar test specimens should be tested and an
average value determined.
4.6 Calibration of the calorimeter
4.6.1 General
Calibration of calorimeters may be done according to two different methods. The first consists of dissipating
a known amount of thermal power using a calibrated resistor introduced in the second chamber of the
calorimeter. In the second method, a reference specimen with known specific heat capacity is dropped
according to the procedure described in 4.7.
4.6.2 Electrical calibration
The calibration factor is the ratio of a known amount of thermal power dissipated in the resistor to the
steady-state calorimetric output signal, and is measured at temperature T . It is recommended to let the
calibrated resistor in the calorimeter during the electrical calibration and the tests, so that the experimental
[4,5]
conditions during both steps remain strictly unchanged .
NOTE 1 For the “inverse” drop calorimetry, the method using power dissipation in a resistor is limited to 1 350 K to
avoid damaging the resistor at high temperature.
NOTE 2 This method can only be used if the sensitivity of the calorimeter is not affected by the filling of the
measuring chamber.
ISO 19628:2024(en)
4.6.3 Calibration using standard reference material
This calibration is called “drop calibration”. A specimen made of a standard reference material with a known
specific heat capacity is dropped according to the test procedures described in 4.7. (See Annex B for standard
reference material). The calibration factor is determined according to Annex A.
4.7 Test procedures
4.7.1 General
The test procedures described in sub-clauses 4.7.2 to 4.7.4 shall be applied depending on the experimental
configuration (test performed with or without a container) and the calibration method (electrical calibration
or calibration with standard reference material).
In the case of determination of the mean specific heat capacity CT(,T ) (cf. sub-clause 4.8.3), the tests are
p 12
performed for one couple of temperatures T and T .
1 2
For performing specific heat capacity C measurement (cf. sub-clause 4.8.4), the tests shall be carried out for
p
different couples of temperatures T and T covering the temperature range of investigation.
1 2
— In “conventional” drop calorimetry, the tests are repeated by varying the temperature of the furnace T ,
the temperature of the calorimeter T being kept constant.
— In “inverse” drop calorimetry, the tests are repeated by varying the temperature of the calorimeter T ,
the temperature of the conditioning chamber T being kept constant.
4.7.2 Test without a container
4.7.2.1 Test with drop calibration
The test without a container and with drop calibration is done in the following order:
R, T, R, T, R, T, R
where
R is the test of standard reference material;
T is the test of test specimen.
Carry out each test as described in 4.7.4.
4.7.2.2 Test with electrical calibration
The test without a container and with calibration using power dissipation in a resistor is done in the
following order:
— calibration of calorimeter;
— test on three test specimens.
Carry out each test as described in 4.7.4.
NOTE The avoidance of interaction between the test specimen and the calorimetric conditioning and measuring
chambers can require the use of a sealed container.

ISO 19628:2024(en)
4.7.3 Test with a container
4.7.3.1 General
The mass of all empty containers used for the test shall not differ by more than 5 %.
4.7.3.2 Test with drop calibration
The test with a container and with drop calibration is carried out in the following order:
C, C + R, C + T, C, C + R, C + T, C, C + R, C + T, C
where
C is the test with the empty container;
C + R is the test of container plus standard reference material;
C + T is the test of container plus test specimen.
Carry out each test as described in 4.7.4.
4.7.3.3 Test with electrical calibration
The test with a container and with calibration using power dissipation in a resistor is done in the following order:
— calibration of calorimeter;
— carry out the following sequence:
C, C + T, C, C + T, C, C + T, C
where
C is the test with the empty container;
C + T is the test with container plus test specimen.
Carry out each test as described in 4.7.4.
4.7.4 Description of test
The test piece (test specimen, standard material or empty container) and reference material shall be dried
at (110 ± 5) °C until the difference in weight of two successive weighings is lower than 0,2 mg:
— measure the mass when a container is not used with an accuracy of ±0,1 mg or ±0,1 %, whichever is the
smaller;
— when a container is used, measure the mass of each assembly dropped (empty container, container and
standard reference material, container and test specimen);
— place the test piece (test specimen, standard material or empty container) in the conditioning chamber
at temperature T and wait for a sufficient period to reach thermal equilibrium of the test piece with its
environment;
— measure T and T ;
1 2
— start recording the calorimetric signal before the test piece is dropped;
— drop the test piece;
ISO 19628:2024(en)
— stop the recording when the steady-state output signal is reached.
4.8 Calculations
4.8.1 General
The change in heat Q corresponding to the drop of the test piece is related to the area A under the calorimetric
output signal by Formula (2).
QK=⋅A (2)
where K is the calorimeter calibration factor.
4.8.2 Determination of the calorimetric calibration factor
4.8.2.1 Electrical calibration
The calibration factor K at a temperature T is determined by dividing the amount of heat Q dissipated by the
calibrated resistor inside the calorimeter maintained at temperature T by the area A under the calorimetric
output
...