EN ISO 11357-1:2016

SLOVENSKI STANDARD
01-december-2016
1DGRPHãþD
SIST EN ISO 11357-1:2010
3ROLPHUQLPDWHULDOL'LIHUHQþQDGLQDPLþQDNDORULPHWULMD'6&GHO6SORãQD
QDþHOD,62
Plastics - Differential scanning calorimetry (DSC) - Part 1: General principles (ISO 11357
-1:2016)
Kunststoffe - Dynamische Differenz-Thermoanalyse (DSC) - Teil 1: Allgemeine
Grundlagen (ISO 11357-1:2016)
Plastiques - Analyse calorimétrique différentielle (DSC) - Partie 1: Principes généraux
(ISO 11357-1:2016)
Ta slovenski standard je istoveten z: EN ISO 11357-1:2016
ICS:
17.200.10 Toplota. Kalorimetrija Heat. Calorimetry
83.080.01 Polimerni materiali na Plastics in general
splošno
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 11357-1
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2016
EUROPÄISCHE NORM
ICS 83.080.01 Supersedes EN ISO 11357-1:2009
English Version
Plastics - Differential scanning calorimetry (DSC) - Part 1:
General principles (ISO 11357-1:2016)
Plastiques - Analyse calorimétrique différentielle (DSC) Kunststoffe - Dynamische Differenz-Thermoanalyse
- Partie 1: Principes généraux (ISO 11357-1:2016) (DSC) - Teil 1: Allgemeine Grundlagen (ISO 11357-
1:2016)
This European Standard was approved by CEN on 13 August 2016.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11357-1:2016 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
European foreword
This document (EN ISO 11357-1:2016) has been prepared by Technical Committee ISO/TC 61 “Plastics”
in collaboration with Technical Committee CEN/TC 249 “Plastics” the secretariat of which is held by
NBN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by April 2017, and conflicting national standards shall be
withdrawn at the latest by April 2017.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document supersedes EN ISO 11357-1:2009.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 11357-1:2016 has been approved by CEN as EN ISO 11357-1:2016 without any
modification.
INTERNATIONAL ISO
STANDARD 11357-1
Third edition
2016-09-15
Plastics — Differential scanning
calorimetry (DSC) —
Part 1:
General principles
Plastiques — Analyse calorimétrique différentielle (DSC) —
Partie 1: Principes généraux
Reference number
ISO 11357-1:2016(E)
©
ISO 2016
ISO 11357-1:2016(E)
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved

ISO 11357-1:2016(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Basic principles . 8
4.1 General . 8
4.2 Heat-flux DSC . 8
4.3 Power-compensation DSC . 8
5 Apparatus and materials. 9
6 Specimen .10
7 Test conditions and specimen conditioning .11
7.1 Test conditions .11
7.2 Conditioning of specimens .11
8 Calibration .11
8.1 General .11
8.2 Calibration materials .12
8.3 Temperature calibration .12
8.3.1 General.12
8.3.2 Procedure .12
8.3.3 Accuracy of calibration .13
8.4 Heat calibration .13
8.4.1 General.13
8.4.2 Procedure .14
8.4.3 Accuracy of calibration .14
8.5 Heat flow rate calibration .15
8.5.1 General.15
8.5.2 Procedure .15
9 Procedure.17
9.1 Setting up the apparatus.17
9.1.1 Switching on .17
9.1.2 Purge gas . . .17
9.1.3 Experimental conditions .17
9.1.4 Baseline determination .17
9.2 Loading the specimen into the crucible .17
9.2.1 General.17
9.2.2 Selection of crucibles .18
9.2.3 Weighing the specimen crucible.18
9.2.4 Loading the specimen . .18
9.2.5 Determination of the mass of the specimen.18
9.3 Insertion of crucibles into the instrument .18
9.4 Performing measurements .18
9.4.1 General.18
9.4.2 Scanning mode .18
9.4.3 Isothermal mode .19
9.5 Post-run checks .20
9.5.1 Check for loss in mass .20
9.5.2 Inspection of specimens .20
9.5.3 Checking of crucibles and crucible holder .20
10 Test report .20
ISO 11357-1:2016(E)
[12]
Annex A (normative) Extended, high-precision, temperature calibration .22
Annex B (normative) Extended, high-precision, heat calibration .24
Annex C (informative) Recommended calibration materials .26
Annex D (informative) Interaction of calibration materials with different crucible materials .29
Annex E (informative) General recommendations .31
Bibliography .33
iv © ISO 2016 – All rights reserved

ISO 11357-1:2016(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 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 on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 61, Plastics, Subcommittee SC 5, Physical-
chemical properties
This third edition cancels and replaces the second edition (ISO 11357-1:2009), 3.7.2 of which has been
technically revised.
ISO 11357 consists of the following parts, under the general title Plastics — Differential scanning
calorimetry (DSC):
— Part 1: General principles
— Part 2: Determination of glass transition temperature and glass transition step height
— Part 3: Determination of temperature and enthalpy of melting and crystallisation
— Part 4: Determination of specific heat capacity
— Part 5: Determination of characteristic reaction-curve temperatures and times, enthalpy of reaction
and degree of conversion
— Part 6: Determination of oxidation induction time (isothermal OIT) and oxidation induction temperature
(dynamic OIT)
— Part 7: Determination of crystallization kinetics
ISO 11357-1:2016(E)
Introduction
ISO 11357 describes thermoanalytical DSC test methods which can be used for quality assurance
purposes, for routine checks of raw materials and finished products or for the determination of
comparable data needed for data sheets or databases. The procedures given in ISO 11357 apply as long
as product standards or standards describing special atmospheres for conditioning of specimens do
not specify otherwise.
vi © ISO 2016 – All rights reserved

INTERNATIONAL STANDARD ISO 11357-1:2016(E)
Plastics — Differential scanning calorimetry (DSC) —
Part 1:
General principles
SAFETY STATEMENT — 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
ISO 11357 specifies several differential scanning calorimetry (DSC) methods for the thermal analysis of
polymers and polymer blends, such as
— thermoplastics (polymers, moulding compounds and other moulding materials, with or without
fillers, fibres or reinforcements),
— thermosets (uncured or cured materials, with or without fillers, fibres or reinforcements), and
— elastomers (with or without fillers, fibres or reinforcements).
ISO 11357 is intended for the observation and measurement of various properties of, and phenomena
associated with, the above-mentioned materials, such as
— physical transitions (glass transition, phase transitions such as melting and crystallization,
polymorphic transitions, etc.),
— chemical reactions (polymerization, crosslinking and curing of elastomers and thermosets, etc.),
— the stability to oxidation, and
— the heat capacity.
This part of ISO 11357 specifies a number of general aspects of differential scanning calorimetry, such
as the principle and the apparatus, sampling, calibration and general aspects of the procedure and test
report common to all following parts.
Details on performing specific methods are given in subsequent parts of ISO 11357 (see Foreword).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 472, Plastics — Vocabulary
ISO 80000-5, Quantities and units — Part 5: Thermodynamics
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 472 and ISO 80000-5 and the
following apply.
ISO 11357-1:2016(E)
3.1
differential scanning calorimetry
DSC
technique in which the difference between the rate of flow of heat into a specimen crucible containing
the specimen and that into a reference crucible (3.3) is derived as a function of temperature and/or time
while the specimen and reference are subjected to the same controlled temperature programme in a
specified atmosphere using a symmetrical measurement system
Note 1 to entry: It is common practice to record, for each measurement run, a curve in which temperature or time
is plotted as the abscissa and heat flow rate (3.4) difference as the ordinate. The endothermic and/or exothermic
direction is indicated on the DSC curve.
Note 2 to entry: According to the principles of thermodynamics, energy absorbed by a system is considered
positive while energy released is negative. This approach implies that the endothermic direction points upwards
in the ordinate and the exothermic direction downwards (see Figures 1 and 2). It also has the advantage that the
direction of thermal effects in plots of heat flow rate (3.4) and specific heat is consistent.
3.2
calibration material
material for which one or more of the thermal properties are sufficiently homogeneous and
well established to be used for the calibration of a DSC instrument or for the assessment of a
measurement method
3.3
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: In special cases, such as the measurement of highly filled or reinforced polymers or specimens
having a heat capacity comparable to that of the crucible, a suitable material can be used inside the reference
crucible. This reference material should be thermally inactive over the temperature and time range of interest
and its heat capacity should be similar to that of the specimen. In the case of filled or reinforced products, the
pure filler or reinforcement can be used, for example.
3.4
heat flow rate
quantity of heat transferred per unit time (dQ/dt)
Note 1 to entry: It is expressed in watts (W) or milliwatts (mW).
Note 2 to entry: The total quantity of heat transferred, Q, corresponds to the time integral of the heat flow rate:
dQ
Q =∫ dt
dt
3.5
change in heat
ΔQ
quantity of heat absorbed (endothermic, ΔQ positive) or released (exothermic, ΔQ negative) within a
specified time, t, or temperature, T, range by a specimen undergoing a chemical or physical change
and/or a temperature change:
t
dQ
ΔQ = dt
∫
t
dt
or
T
60 dQ
ΔQ = dT
∫
T
β dt
2 © ISO 2016 – All rights reserved

ISO 11357-1:2016(E)
where
ΔQ is expressed in joules (J) or as a specific quantity, Δq, expressed in joules per amount of material
−1 −1
in grams (J⋅g ) or joules per amount of material in moles (J⋅mol );
−1
β is the constant heating or cooling rate, dT/dt, expressed in kelvins per minute (K⋅min ).
Note 1 to entry: If measurements are made at constant pressure, ΔQ corresponds to the change in enthalpy, ΔH.
3.6
specific heat capacity at constant pressure
c
p
quantity of heat necessary to raise the temperature of unit mass of material by 1 K at constant pressure:
 
1dQ
c =×
 
p
m dT
 
p
or
 
160 dQ
c =× ×
 
p
m β dt
 
p
where
dQ is the quantity of heat, expressed in joules (J), necessary to raise the temperature of an amount
of material of mass m, expressed in grams (g), by dT kelvins at constant pressure;
−1
β is the heating rate, expressed in kelvins per minute (K⋅min );
−1 −1
c is expressed in joules per gram per kelvin (J⋅g ⋅K ).
p
−1 −1
Note 1 to entry: c may also be expressed in joules per mole per kelvin (J⋅mol ⋅K ) when the amount of material,
p
m, is expressed in moles.
Note 2 to entry: When analysing polymers, ensure that the measured specific heat capacity does not include any
heat change due to a chemical reaction or a physical transition.
3.7
baseline
part of the recorded curve in which no reactions or transitions take place
Note 1 to entry: This can be an isothermal baseline when the temperature is maintained constant or a dynamic
baseline when the temperature is changed in accordance with a controlled temperature programme.
Note 2 to entry: The baselines defined in 3.7.1 to 3.7.3 refer to the quasi-stationary range only, i.e. when the
instrument is operating under stable conditions shortly after starting and shortly before ending the DSC run (see
Figure 1).
ISO 11357-1:2016(E)
Key
dQ/dt heat flow rate 4 virtual baseline
T temperature 5 instrument baseline
t time 6 quasi-stationary range
1 dQ/dt vs t (or T) 7 isothermal start baseline
2 T vs t 8 isothermal end baseline
a
3 specimen baselines Endothermic direction.
Figure 1 — Schematic drawing showing baselines
3.7.1
instrument baseline
curve obtained using only empty crucibles of identical mass and material in the specimen and reference
positions of the DSC cell
Note 1 to entry: The instrument baseline is required for heat capacity measurements.
3.7.2
specimen baseline
DSC curve obtained outside any reaction or transition zone(s) while the instrument is loaded with both
the specimen in the specimen crucible and the reference crucible (3.3)
Note 1 to entry: In this part of the curve, the difference in heat flow rate (3.4) between the specimen crucible and
the reference crucible (3.3) depends solely on the heat capacity of the specimen and the instrument baseline (3.7.1).
Note 2 to entry: The specimen baseline reflects the temperature dependence of the heat capacity of the specimen.
Note 3 to entry: For heat capacity determinations, a dynamic DSC curve is required and, in addition, the
instrument baseline (3.7.1) and the isothermal start and end baselines (see Figure 1).
4 © ISO 2016 – All rights reserved

ISO 11357-1:2016(E)
3.7.3
virtual baseline
imaginary line drawn through a reaction and/or transition zone assuming the heat of reaction and/or
transition to be zero
Note 1 to entry: Assuming the change in heat capacity with temperature to be linear, the virtual baseline is
drawn by interpolating or extrapolating the specimen baseline in a straight line. It is normally indicated on the
DSC curve for convenience (see Figures 1 and 2).
Note 2 to entry: The virtual baseline drawn from peak onset, T , to peak end, T , (the peak baseline) allows the
i f
determination of the peak area from which the heat of transition can be obtained. If there is no significant change
in heat capacity during the transition or reaction, the baseline can be drawn simply by connecting the peak onset
and peak end by a straight line. If significant heat capacity changes occur, a sigmoidal baseline can be drawn.
Note 3 to entry: Extrapolated and interpolated virtual baselines will not necessarily coincide with each other
(see Figure 2).
3.8
step
abrupt positive or negative change in the height of a DSC curve, taking place over a limited
temperature range
Note 1 to entry: A step in the DSC curve can be caused by, for example, a glass transition (see Figure 2).
3.8.1
step height
difference between the heights of the extrapolated baselines before and after a step, measured at the
time or temperature corresponding to the point on the DSC curve which is equidistant between the two
baselines
3.9
peak
part of the DSC curve which departs from the specimen baseline (3.7.2), reaches a maximum or minimum,
and subsequently returns to the specimen baseline (3.7.2)
Note 1 to entry: A peak in the DSC curve may indicate a chemical reaction or a first-order transition. The initial
departure of the peak from the virtual baseline (3.7.3) corresponds to the start of the reaction or transition.
3.9.1
endothermic peak
peak in which the rate of flow of heat into the specimen crucible is greater than that into the reference
crucible (3.3)
Note 1 to entry: This corresponds to a transition which absorbs heat.
3.9.2
exothermic peak
peak in which the rate of flow of heat into the specimen crucible is less than that into the reference
crucible (3.3)
Note 1 to entry: This corresponds to a transition which releases heat.
3.9.3
peak area
area enclosed by a peak and the interpolated virtual baseline (3.7.3)
ISO 11357-1:2016(E)
3.9.4
peak height
greatest distance in the ordinate direction between the interpolated virtual baseline (3.7.3) and the DSC
curve during a peak
Note 1 to entry: The peak height, which is expressed in watts (W) or watts per gram (W/g), is not necessarily
proportional to the mass of the specimen.
3.9.5
peak width
distance between the onset and end temperatures or times of a peak
3.10
characteristic temperatures, T, and times, t
values for temperature and time obtained from the DSC curve
Note 1 to entry: See Figure 2.
Note 2 to entry: For all types of DSC instrument, a distinction needs to be made between two different categories
of temperature:
— the temperature at the reference position;
— the temperature at the specimen position.
The reference position temperature is the one preferred for plotting thermograms. If the specimen position
temperature is used, then this information will need to be included in the test report.
Note 3 to entry: Characteristic temperatures are expressed in degrees Celsius (°C), relative temperatures and
temperature differences in kelvins (K) and characteristic times in seconds (s) or minutes (min) (see Figure 2).
Note 4 to entry: The DSC curve can also be plotted using time, t, as the abscissa instead of temperature, T.
6 © ISO 2016 – All rights reserved

ISO 11357-1:2016(E)
Key
dQ/dt heat flow rate 1 extrapolated baseline
T temperature (or t, time) 2 interpolated baseline
Characteristic temperatures
The first subscript, or pair of subscripts, denotes the position on the DSC curve with respect to the step or peak:
— onset temperature T first detectable departure of curve from
i
extrapolated start baseline;
— interpolated or extrapolated onset temperature T (for a peak) point of intersection of
ei
interpolated virtual baseline and tangent
drawn at point of inflection of near side of
peak or (for a step) point of intersection
of extrapolated start baseline and tangent
drawn at point of inflection of step;
— midpoint temperature T half-height of a step;
1/2
— peak temperature T greatest distance between curve and virtual
p
baseline during a peak;
— interpolated or extrapolated end temperature T (for a peak) point of intersection of
ef
interpolated virtual baseline and tangent
drawn at point of inflection 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;
— end temperature T last detectable deviation of curve from
f
extrapolated end baseline.
The second subscript indicates the type of transition:
g glass transition
c crystallization
m melting
a
Endothermic direction.
Figure 2 — Typical DSC curve (schematic)
ISO 11357-1:2016(E)
4 Basic principles
4.1 General
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.
4.2 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. From this
temperature difference, the difference in the rates of heat flow into the specimen and reference positions
is derived and is normally recorded against the temperature of the reference, T , or against time.
ref
A schematic drawing of a heat-flux DSC instrument is shown in Figure 3.
Key
1 specimen position 6 surrounding oven
2 reference position T temperature at specimen position (T )
1 specimen
3 thermocouples T temperature at reference position (T )
2 ref
4 single heater ΔT temperature difference between specimen and
reference positions
5 measurement circuit for T , T and ΔT
specimen ref
Figure 3 — Schematic diagram illustrating the basic principles of heat-flux DSC
4.3 Power-compensation DSC
In power-compensated DSC, individual heaters are used for the specimen and reference positions.
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.
For power-compensated isoperibolic calorimeters, the surrounding temperature (i.e. the temperature
of the heat sink) has to be kept constant.
A schematic drawing of a power-compensation DSC instrument is shown in Figure 4.
8 © ISO 2016 – All rights reserved

ISO 11357-1:2016(E)
Key
1 specimen position T temperature at specimen position (T )
1 specimen
2 reference position T temperature at reference position (T )
2 ref
3 thermometers
4 individual heaters
5 measurement circuit for T and T
specimen ref
6 heat-flux compensation circuit
7 surrounding heat sink
Figure 4 — Schematic diagram illustrating the basic principles of power-compensation DSC
5 Apparatus and materials
5.1 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 constant heating and cooling rates suitable for the intended
measurements.
c) The capability to maintain the test temperature constant to within ± 0,3 K or less for at least 60 min.
d) The capability to carry out step heating or step cooling.
NOTE Normally, this is achieved by a suitable combination of linear heating or cooling and constant-
temperature regimes.
e) The capability to maintain a constant purge gas flow rate controllable to within ±10 % over a range
−1 −1
of flow rates (e.g. 10 ml⋅min to 100 ml⋅min ).
NOTE The actual gas flow rate will depend on the design of the instrument used.
f) A temperature range in line with the experimental requirements.
g) A heat flow rate range of ±100 mW or more.
h) A recording device capable of automatically recording the measured curve of heat flow rate against
temperature and time.
i) The capability to measure temperature signals with a resolution of ±0,1 K and an accuracy of ±0,5 K
or better.
j) The capability to measure time with a resolution of ±0,5 s and an accuracy of ±1 s or better.
k) The capability to measure heat flow rates with a resolution of ±0,5 µW and an accuracy of ±2 µW
or better.
ISO 11357-1:2016(E)
5.2 Crucibles, for the specimen and reference positions. They shall be of the same type, made of the
same material and have similar masses. They shall be physically and chemically inert to the specimen,
the calibration materials and the purge gas under the measurement conditions (see Annexes C and D).
NOTE 1 If required, small variations in crucible mass can be arithmetically corrected for, given the specific
heat capacity of the crucible material.
Crucibles should preferably be made of a material with a high thermal conductivity, e.g. aluminium.
Ventilated crucibles should preferably be used to avoid changes in pressure during the measurement
run and to allow the exchange of gas with the surrounding atmosphere. However, for special purposes,
crucibles closed with lids or hermetically sealed crucibles may be required so that they will withstand
the overpressure arising during the measurement run.
When using special high-pressure or glass crucibles, their relatively high mass and poor thermal
conductivity shall be taken into account. Recalibration of the instrument may be required.
NOTE 2 When using high-pressure or hermetically closed crucibles, measurements are not necessarily
performed at constant pressure. Hence, the constant-pressure requirement for measuring enthalpies or c may
p
not be fulfilled.
5.3 Balance, capable of measuring the specimen mass with a resolution of ±0,01 mg and an accuracy
of ±0,1 mg or better.
5.4 Calibration materials, covering the temperature range of interest and preferably chosen from the
list of recommended calibration materials in Annex C.
5.5 Purge gas, preferably a dry and inert gas (e.g. nitrogen of purity 99,99 % or better), used to avoid
oxidative or hydrolytic degradation during testing.
For the investigation of chemical reactions, including oxidation, special reactant gases may be required.
If a gas generator is used to supply gas for purging and environmental control during testing, rather
than using a pressurized gas bottle purge, it is recommended that suitable drying and filtering systems
be installed.
6 Specimen
The specimen shall be in the liquid or solid state. Solid-state specimens may be in any form which fits
into the crucible (e.g. powder, pellets, granules, fibres) or may be cut from bigger pieces to a suitable
size. The specimen shall be representative of the sample being examined and shall be prepared and
handled with care. Particular care shall be taken to avoid any contamination of the specimen. If the
specimen is taken from larger pieces by cutting, care shall be taken to prevent heating, polymer
orientation or any other effect that may alter the specimen properties. Operations such as grinding that
could cause heating or reorientation and could therefore change the thermal history of the specimen
shall be avoided. The method of sampling and specimen preparation shall be stated in the test report.
If the specimen crucible is closed or sealed with a lid, this shall not cause any deformation of the bottom
of the crucible. Good thermal contact between the specimen and crucible and between the crucible and
holder shall be ensured.
Typical specimen masses are between 2 mg and 40 mg.
NOTE Incorrect specimen preparation can change the thermal properties of the polymers examined. For
further information, refer to Annex E.
10 © ISO 2016 – All rights reserved

ISO 11357-1:2016(E)
7 Test conditions and specimen conditioning
7.1 Test conditions
The instrument shall be maintained and operated in an atmosphere suitable for the intended test.
Unless excluded by special requirements for particular test procedures, all calibration and test
measurements shall be performed using closed, ventilated crucibles, preferably made of aluminium, to
improve reproducibility.
It is recommended that the instrument be protected from air draughts, exposure to direct sunlight and
abrupt changes in temperature, pressure or mains voltage.
7.2 Conditioning of specimens
Specimens shall be conditioned prior to the measurement run as specified in the relevant material
standard or by a method agreed between the interested parties.
Unless otherwise specified, specimens shall be dried to constant mass before performing measurements.
Care shall be taken to choose suitable drying conditions to prevent physical changes, such as ageing or
changes in crystallinity of the specimens.
NOTE Depending on the material and its thermal history, the methods of preparation and conditioning of the
sample and specimens may be crucial to the values obtained, the consistency of the results and their significance.
8 Calibration
8.1 General
Before commissioning a new instrument or after replacing or modifying essential components or after
cleaning the measuring cell by heating to elevated temperatures, the calorimeter shall be calibrated at
least with respect to temperature and heat. In addition, heat flow rate calibration may be required for heat
capacity measurements. Recalibration of the instrument shall be carried out regularly at the required
calibration intervals, e.g. when the instrument is being used as part of a quality assurance system.
NOTE In many cases, the calibration procedures will be built into the instrument control software and thus
at least partly automated.
Recalibration of the instrument should preferably be performed each time the test conditions are
significantly changed. More frequent checks may be carried out as required.
The calibration can be affected by the following:
— type of calorimeter used and its stability;
— heating and cooling rates;
— type of cooling system used;
— type of purge gas used and its flow rate;
— type of crucible used, the crucible size and the positions of the crucibles in the crucible holder;
— location of the specimen in the specimen crucible;
— mass and particle size of the specimen;
— thermal contact between the specimen crucible and the crucible holder.
ISO 11357-1:2016(E)
The conditions of the actual determination should therefore be defined as precisely as possible and
the calibration carried out under these conditions as closely as possible. Computer-controlled DSC
instruments may automatically correct for the effects of some of these sources of error.
The calibration shall be carried out using the same type of crucible, made of the same material, and
using the same purge g
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