ISO 2478:2025
(Main)Dense shaped refractory products — Determination of permanent change in dimensions on heating
Dense shaped refractory products — Determination of permanent change in dimensions on heating
This document specifies two methods for determining the permanent change in dimensions of a dense shaped refractory product. Shaped refractories are those which have fixed geometry and dimensions when delivered to the user. This document is accordingly applicable to standard shape refractory bricks, but also special shapes refractory products and pre-cast products. This document does not apply to products containing carbon. NOTE The methods can be applied to materials sensitive to oxidation. However, some of these materials can be affected during the test in such a way as to make the measurement of the dimensional changes impossible to carry out to the required accuracy.
Produits réfractaires façonnés denses — Détermination de la variation permanente de dimensions sous l'action de la chaleur
General Information
Relations
Standards Content (Sample)
International
Standard
ISO 2478
Third edition
Dense shaped refractory
2025-09
products — Determination of
permanent change in dimensions
on heating
Produits réfractaires façonnés denses — Détermination de la
variation permanente de dimensions sous l'action de la chaleur
Reference number
© ISO 2025
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
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
6 Test pieces . 4
6.1 Number of test pieces .4
6.2 Preparation of test pieces .4
7 Procedure . 5
7.1 Drying of the test pieces .5
7.2 Measurement of the test pieces .5
7.2.1 Linear measurement by dial gauge apparatus (Method 1A) .5
7.2.2 Linear measurement by Vernier callipers (Method 1B) .5
7.2.3 Volume measurement (Method 2) .6
7.3 Mounting of test pieces in the furnace .6
7.4 Test temperature .6
7.5 Temperature measurement and distribution .6
7.6 Heating.7
7.7 Maintenance of test temperature .7
7.8 Sampling of furnace atmosphere .7
7.9 Cooling .7
7.10 Measurement of test pieces after firing .7
7.10.1 Linear measurement (Methods 1A and 1B) .7
7.10.2 Volume measurement (Method 2) .8
8 Expression of results . 8
9 Test report . 8
Annex A (informative) Precision and bias . 9
Bibliography .10
iii
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 33, Refractories.
This third edition cancels and replaces the second edition (ISO 2478:1987), which has been technically
revised.
The main changes are as follows:
— revised definition of sample, item and test piece;
— addition of a method 1B based on a change of linear dimensions as measured using callipers;
— addition of an informative annex on precision and bias.
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 2478:2025(en)
Dense shaped refractory products — Determination of
permanent change in dimensions on heating
1 Scope
This document specifies two methods for determining the permanent change in dimensions of a dense
shaped refractory product.
Shaped refractories are those which have fixed geometry and dimensions when delivered to the user. This
document is accordingly applicable to standard shape refractory bricks, but also special shapes refractory
products and pre-cast products.
This document does not apply to products containing carbon.
NOTE The methods can be applied to materials sensitive to oxidation. However, some of these materials can
be affected during the test in such a way as to make the measurement of the dimensional changes impossible to
carry out to the required accuracy.
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 5017, Dense shaped refractory products - Determination of bulk density, apparent porosity and true porosity
ISO 13385-1, Geometrical product specifications (GPS) — Dimensional measuring equipment — Part 1: Design
and metrological characteristics of callipers
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
permanent change in dimensions on heating
expansion or contraction that remains in a shaped refractory product that is heated to a specified
temperature for a specified time and then cooled to ambient temperature
Note 1 to entry: Change is either on the basis of length (∆L) or volume (∆V).
3.2
dense shaped refractory product
product with specific dimensions, having a true porosity of less than 45 % by volume when measured
Note 1 to entry: The measurement of porosity is done in accordance with ISO 5017.
3.3
sample
representative collection of items that can be obtained by sampling according to a sampling plan agreed
upon by the interested parties
Note 1 to entry: An example of an applicable sampling plan is given in ISO 5022.
3.4
item
refractory brick or shape
3.5
test piece
test specimen
piece of material extracted from an item (3.4) and suitably shaped and prepared for the test
4 Principle
Test pieces in the shape of rectangular prisms or cylinders are cut from each item, then dried, and their
linear dimensions (Method 1) or volume (Method 2) measured. The test pieces are heated in a furnace
having an oxidizing atmosphere, at a prescribed rate, to a specified temperature, which is maintained for a
specified time. After cooling to ambient temperature, the measurements on the test pieces are repeated, and
the permanent change in dimensions or volume is calculated.
5 Apparatus
5.1 Furnace, either electric or gas-fired, capable of heating the test pieces described in 6.2, in a
continuously oxidizing atmosphere, at the specified rate (see 7.6), and of maintaining the test temperature
for the required time.
NOTE The use of an electric furnace is recommended, but a gas fired furnace may be used provided that the
furnace atmosphere is continuously oxidizing and there is provision for monitoring this condition.
5.2 Thermocouples, a minimum of three, to measure the temperature and the temperature distribution
over the space occupied by the test pieces.
5.3 Temperature/time registration device, for use in conjunction with the thermocouples (5.2), so
that a continuous record of the temperature is obtained. Temperature shall be recorded with a minimum
accuracy of ±5 °C.
5.4 Length-measuring device (Method 1)
5.4.1 General
Two measuring devices may be used:
a) Method 1A - a dial gauge apparatus;
b) Method 1B - callipers.
Method 1A is the recommended one.
5.4.2 Dial gauge apparatus (Method 1A) consisting of a dial-gauge or micrometer with an accuracy of
0,01 mm, mounted on a stand which has a surface ground base plate (see Figure 1), and a test piece carrier
(see Figure 2), with three studs of equal length ±0,01 mm to support the test piece and two pins to locate it.
The dimensions of the locating pins shall be as shown in Figure 2. The under surface of the carrier shall be
ground flat. A diagonal mark shall be inscribed at one corner to enable a rectangular test piece
...
International
Standard
ISO 2478
Third edition
Dense shaped refractory
products — Determination of
permanent change in dimensions
on heating
Produits réfractaires façonnés denses — Détermination de la
variation permanente de dimensions sous l'action de la chaleur
PROOF/ÉPREUVE
Reference number
© ISO 2025
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
PROOF/ÉPREUVE
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
6 Test pieces . 4
6.1 Number of test pieces .4
6.2 Preparation of test pieces .4
7 Procedure . 5
7.1 Drying of the test pieces .5
7.2 Measurement of the test pieces .5
7.2.1 Linear measurement by dial gauge apparatus (Method 1A) .5
7.2.2 Linear measurement by Vernier callipers (Method 1B) .5
7.2.3 Volume measurement (Method 2) .6
7.3 Mounting of test pieces in the furnace .6
7.4 Test temperature .6
7.5 Temperature measurement and distribution .6
7.6 Heating.7
7.7 Maintenance of test temperature .7
7.8 Sampling of furnace atmosphere .7
7.9 Cooling .7
7.10 Measurement of test pieces after firing .7
7.10.1 Linear measurement (Methods 1A and 1B) .7
7.10.2 Volume measurement (Method 2) .8
8 Expression of results . 8
9 Test report . 8
Annex A (informative) Precision and bias . 9
Bibliography .10
PROOF/ÉPREUVE
iii
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 33, Refractories.
This third edition cancels and replaces the second edition (ISO 2478:1987), which has been technically
revised.
The main changes are as follows:
— revised definition of sample, item and test piece;
— addition of a method 1B based on a change of linear dimensions as measured using callipers;
— addition of an informative annex on precision and bias.
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.
PROOF/ÉPREUVE
iv
International Standard ISO 2478:2025(en)
Dense shaped refractory products — Determination of
permanent change in dimensions on heating
1 Scope
This document specifies two methods for determining the permanent change in dimensions of a dense
shaped refractory product.
Shaped refractories are those which have fixed geometry and dimensions when delivered to the user. This
document is accordingly applicable to standard shape refractory bricks, but also special shapes refractory
products and pre-cast products.
This document does not apply to products containing carbon.
NOTE The methods can be applied to materials sensitive to oxidation. However, some of these materials can
be affected during the test in such a way as to make the measurement of the dimensional changes impossible to
carry out to the required accuracy.
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 5017, Dense shaped refractory products - Determination of bulk density, apparent porosity and true porosity
ISO 13385-1, Geometrical product specifications (GPS) — Dimensional measuring equipment — Part 1: Design
and metrological characteristics of callipers
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
permanent change in dimensions on heating
expansion or contraction that remains in a shaped refractory product that is heated to a specified
temperature for a specified time and then cooled to ambient temperature
Note 1 to entry: Change is either on the basis of length (∆L) or volume (∆V).
3.2
dense shaped refractory product
product with specific dimensions, having a true porosity of less than 45 % by volume when measured
Note 1 to entry: The measurement of porosity is done in accordance with ISO 5017.
PROOF/ÉPREUVE
3.3
sample
representative collection of items that can be obtained by sampling according to a sampling plan agreed
upon by the interested parties
Note 1 to entry: An example of an applicable sampling plan is given in. ISO 5022.
3.4
item
refractory brick or shape
3.5
test piece
test specimen
piece of material extracted from an item (3.4) and suitably shaped and prepared for the test
4 Principle
Test pieces in the shape of rectangular prisms or cylinders are cut from each item, then dried, and their
linear dimensions (Method 1) or volume (Method 2) measured. The test pieces are heated in a furnace
having an oxidizing atmosphere, at a prescribed rate, to a specified temperature, which is maintained for a
specified time. After cooling to ambient temperature, the measurements on the test pieces are repeated, and
the permanent change in dimensions or volume is calculated.
5 Apparatus
5.1 Furnace, either electric or gas-fired, capable of heating the test pieces described in 6.2, in a
continuously oxidizing atmosphere, at the specified rate (see 7.6), and of maintaining the test temperature
for the required time.
NOTE The use of an electric furnace is recommended, but a gas fired furnace may be used provided that the
furnace atmosphere is continuously oxidizing and there is provision for monitoring this condition.
5.2 Thermocouples, a minimum of three, to measure the temperature and the temperature distribution
over the space occupied by the test pieces.
5.3 Temperature/time registration device, for use in conjunction with the thermocouples (5.2), so
that a continuous record of the temperature is obtained. Temperature shall be recorded with a minimum
accuracy of ±5 °C.
5.4 Length-measuring device (Method 1)
5.4.1 General
Two measuring devices may be used:
a) Method 1A - a dial gauge apparatus;
b) Method 1B - callipers.
Method 1A is the recommended one.
5.4.2 Dial gauge apparatus (Method 1A) consisting of a dial-gauge or micrometer with an accuracy of
0,01 mm, mounted on a stand which has a surface ground base plate (see Figure 1), and a test piece carrier
(see Figure 2), with three studs of equal length ±0,01 mm to support the test piece and two pins to locate it.
The dimensions of the locating pins shall be as shown in Figure 2. The under surface of the carrier shall be
PROOF/ÉPREUVE
ground flat. A diagonal mark
...
ISO/FDISPRF 2478:2025(en)
ISO/TC 33
Secretariat: BSI
Date: 2025-05-3007-16
Dense shaped refractory products — Determination of permanent
change in dimensions on heating
Produits réfractaires façonnés denses — Détermination de la variation permanente de dimensions sous l'action
de la chaleur
PROOF
ISO/PRF 2478:2025(en)
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
EmailE-mail: copyright@iso.org
Website: www.iso.orgwww.iso.org
Published in Switzerland
ii
ISO/PRF 2478:2025(en)
Contents
Foreword . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
6 Test pieces . 7
7 Procedure . 7
8 Expression of results . 11
9 Test report . 11
Annex A (informative) Precision and bias . 12
Bibliography . 13
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
6 Test pieces . 3
6.1 Number of test pieces . 3
6.2 Preparation of test pieces . 3
7 Procedure . 3
7.1 Drying of the test pieces . 3
7.2 Measurement of the test pieces . 3
7.3 Mounting of test pieces in the furnace . 4
7.4 Test temperature . 4
7.5 Temperature measurement and distribution . 4
7.6 Heating . 4
7.7 Maintenance of test temperature . 5
7.8 Sampling of furnace atmosphere . 5
7.9 Cooling . 5
7.10 Measurement of test pieces after firing . 5
8 Expression of results . 5
9 Test report . 6
Annex A (informative) Precision and bias . 9
A.1 Interlaboratory study . 9
A.2 Precision data . 9
iii
ISO/PRF 2478:2025(en)
Bibliography . 11
iv
ISO/PRF 2478:2025(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.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.htmlwww.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 33, Refractories.
This third edition cancels and replaces the second edition (ISO 2478:1987), which has been technically
revised.
The main changes are as follows:
— — revised definition of sample, item and test piece;
— — addition of a method 1B based on a change of linear dimensions as measured using callipers;
— — addition of an informative annex on precision and bias.
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.
Field Code Changed
v
DRAFT International Standard ISO/FDIS 2478:2025(en)
Dense shaped refractory products — Determination of permanent
change in dimensions on heating
1 Scope
This document specifies two methods for determining the permanent change in dimensions of a dense shaped
refractory product.
Shaped refractories are those which have fixed geometry and dimensions when delivered to the user. This
document is accordingly applicable to standard shape refractory bricks, but also special shapes refractory
products and pre-cast products.
This document does not apply to products containing carbon.
NOTE The methods can be applied to materials sensitive to oxidation. However, some of these materials can
be affected during the test in such a way as to make the measurement of the dimensional changes impossible to
carry out to the required accuracy.
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 5017, Dense shaped refractory products - Determination of bulk density, apparent porosity and true porosity
ISO 13385--1, Geometrical product specifications (GPS) — Dimensional measuring equipment — Part 1: Design
and metrological characteristics of callipers
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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/obphttps://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/https://www.electropedia.org/
3.1 3.1
permanent change in dimensions on heating
expansion or contraction that remains in a shaped refractory product that is heated to a specified temperature
for a specified time and then cooled to ambient temperature
Note 1 to entry: change Change is either on the basis of length (∆L) or volume (∆V).
3.2 3.2
dense shaped refractory product
product with specific dimensions, having a true porosity of less than 45 % by volume when measured
ISO/PRF 2478:2025(en)
Note 1 to entry: The measurement of porosity is done in accordance with ISO 5017.
3.3 3.3
sample
representative collection of items that can be obtained by sampling according to a sampling plan agreed upon
by the interested parties
Note 1 to entry: An example of an applicable sampling plan is given in. ISO 5022.
3.4 3.4
item
refractory brick or shape
3.5 3.5
test piece
test specimen
piece of material extracted from an item (3.4)(3.4) and suitably shaped and prepared for the test
4 Principle
Test pieces in the shape of rectangular prisms or cylinders are cut from each item, then dried, and their linear
dimensions (Method 1) or volume (Method 2) measured. The test pieces are heated in a furnace having an
oxidizing atmosphere, at a prescribed rate, to a specified temperature, which is maintained for a specified
time. After cooling to ambient temperature, the measurements on the test pieces are repeated, and the
permanent change in dimensions or volume is calculated.
5 Apparatus
5.1 5.1 Furnace, either electric or gas-fired, capable of heating the test pieces described in 6.2,6.2,
in a continuously oxidizing atmosphere, at the specified rate (see 7.6),7.6), and of maintaining the test
temperature for the required time.
NOTE The use of an electric furnace is recommended, but a gas fired furnace may be used provided that the furnace
atmosphere is continuously oxidizing and there is provision for monitoring this condition.
5.2 5.2 Thermocouples, a minimum of three, to measure the temperature and the temperature
distribution over the space occupied by the test pieces.
5.3 5.3 Temperature/time registration device, for use in conjunction with the thermocouples
(5.2),(5.2), so that a continuous record of the temperature is obtained. Temperature shall be recorded with
a minimum accuracy of ±5 °C.
5.4 5.4 Length-measuring device (Method 1)
5.4.1 5.4.1 General
Two measuring devices may be used:
a) a) Method 1A - a dial gauge apparatus;
b) b) Method 1B - callipers.
Method
...
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