SIST EN ISO 22007-1:2012
(Main)Plastics - Determination of thermal conductivity and thermal diffusivity - Part 1: General principles (ISO 22007-1:2009)
Plastics - Determination of thermal conductivity and thermal diffusivity - Part 1: General principles (ISO 22007-1:2009)
ISO 22007-1:2009 describes the background to methods for the determination of the thermal conductivity and thermal diffusivity of polymeric materials. Different techniques are available for these measurements and some may be better suited than others for a particular type, state and form of material. ISO 22007-1 provides a broad overview of these techniques. Standards specific to these techniques, as referenced in ISO 22007-1, are used for the actual test methods.
Kunststoffe - Bestimmung der Wärmeleitfähigkeit und der Temperaturleitfähigkeit - Teil 1: Allgemeine Grundlagen (ISO 22007-1:2009)
Dieser Teil von ISO 22007 beschreibt die Grundlagen für Verfahren zur Bestimmung der Wärmeleitfähigkeit und Temperaturleitfähigkeit polymerer Materialien. Für diese Messungen stehen unterschiedliche Verfahren zur Verfügung, und für einen bestimmten Materialtyp, eine bestimmte Materialbeschaffenheit oder form können einige Verfahren geeigneter als andere sein. Dieser Teil von ISO 22007 gibt einen umfassenden Überblick über diese Verfahren. Die für diese Verfahren entwickelten Normen werden entsprechend den Verweisungen in diesem Teil von ISO 22007 für die Durchführung des jeweiligen Prüfverfahrens angewendet.
Plastiques - Détermination de la conductivité thermique et de la diffusivité thermique - Partie 1: Principes généraux (ISO 22007-1:2009)
L'ISO 22007-1:2009 décrit les principes de base des méthodes permettant de déterminer la conductivité thermique et la diffusivité thermique des matériaux polymères. Différentes techniques de mesurage sont disponibles et certaines peuvent être mieux adaptées que d'autres pour un type, un état et une forme particuliers du matériau. L'ISO 22007-1 donne un aperçu général de ces techniques. Les normes propres à ces techniques, telles que mentionnées dans l'ISO 22007-1, sont utilisées pour la mise en œuvre de la méthode d'essai réelle.
Polimerni materiali - Ugotavljanje toplotne prevodnosti in toplotne razprševalnosti - 1. del: Splošna načela (ISO 22007-1:2009)
Ta del standarda ISO 22007 opisuje ozadje metod za ugotavljanje toplotne prevodnosti in toplotne razprševalnosti polimernih materialov. Za te meritve so na voljo različne tehnike, pri čemer so nekatere lahko primernejše od drugih za posamezno vrsto, stanje in obliko materiala. Ta del standarda ISO 22007 vsebuje obsežen pregled teh tehnik. Za izvajanje dejanske preskusne metode se uporabljajo standardi za te tehnike, kakor je opisano v tem delu standarda ISO 22007.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 22007-1:2012
01-marec-2012
3ROLPHUQLPDWHULDOL8JRWDYOMDQMHWRSORWQHSUHYRGQRVWLLQWRSORWQHUD]SUãHYDOQRVWL
GHO 6SORãQDQDþHOD ,62
Plastics - Determination of thermal conductivity and thermal diffusivity - Part 1: General
principles (ISO 22007-1:2009)
Kunststoffe - Bestimmung der Wärmeleitfähigkeit und der Temperaturleitfähigkeit - Teil 1:
Allgemeine Grundlagen (ISO 22007-1:2009)
Plastiques - Détermination de la conductivité thermique et de la diffusivité thermique -
Partie 1: Principes généraux (ISO 22007-1:2009)
Ta slovenski standard je istoveten z: EN ISO 22007-1:2012
ICS:
83.080.01 Polimerni materiali na Plastics in general
splošno
SIST EN ISO 22007-1:2012 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 22007-1:2012
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SIST EN ISO 22007-1:2012
EUROPEAN STANDARD
EN ISO 22007-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2012
ICS 83.080.01
English Version
Plastics - Determination of thermal conductivity and thermal
diffusivity - Part 1: General principles (ISO 22007-1:2009)
Plastiques - Détermination de la conductivité thermique et Kunststoffe - Bestimmung der Wärmeleitfähigkeit und der
de la diffusivité thermique - Partie 1: Principes généraux Temperaturleitfähigkeit - Teil 1: Allgemeine Grundlagen
(ISO 22007-1:2009) (ISO 22007-1:2009)
This European Standard was approved by CEN on 24 December 2011.
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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
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© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 22007-1:2012: E
worldwide for CEN national Members.
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SIST EN ISO 22007-1:2012
EN ISO 22007-1:2012 (E)
Contents Page
Foreword .3
2
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SIST EN ISO 22007-1:2012
EN ISO 22007-1:2012 (E)
Foreword
The text of ISO 22007-1:2009 has been prepared by Technical Committee ISO/TC 61 “Plastics” of the
International Organization for Standardization (ISO) and has been taken over as EN ISO 22007-1:2012 by
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 July 2012, and conflicting national standards shall be withdrawn at the
latest by July 2012.
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.
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, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 22007-1:2009 has been approved by CEN as a EN ISO 22007-1:2012 without any
modification.
3
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SIST EN ISO 22007-1:2012
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SIST EN ISO 22007-1:2012
INTERNATIONAL ISO
STANDARD 22007-1
First edition
2009-07-01
Plastics — Determination of thermal
conductivity and thermal diffusivity —
Part 1:
General principles
Plastiques — Détermination de la conductivité thermique et de la
diffusivité thermique —
Partie 1: Principes généraux
Reference number
ISO 22007-1:2009(E)
©
ISO 2009
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SIST EN ISO 22007-1:2012
ISO 22007-1:2009(E)
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ii © ISO 2009 – All rights reserved
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SIST EN ISO 22007-1:2012
ISO 22007-1:2009(E)
Contents Page
Foreword. iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Principles. 2
5 Test methods. 3
5.1 General. 3
5.2 Hot-wire method. 5
5.3 Line-source method. 6
5.4 Transient plane source method . 6
5.5 Temperature wave analysis method. 7
5.6 Laser flash method. 8
5.7 Guarded methods . 8
5.7.1 Guarded hot-plate method. 8
5.7.2 Guarded heat flow meter method. 9
6 Test report . 10
Annex A (informative) Sources of uncertainty in transient methods . 11
Bibliography . 17
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SIST EN ISO 22007-1:2012
ISO 22007-1:2009(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 22007-1 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 5, Physical-
chemical properties.
ISO 22007 consists of the following parts, under the general title Plastics — Determination of thermal
conductivity and thermal diffusivity:
⎯ Part 1: General principles
⎯ Part 2: Transient plane heat source (hot disc) method
⎯ Part 3: Temperature wave analysis method
⎯ Part 4: Laser flash method
⎯ Part 5: Determination of thermal conductivity and thermal diffusivity of poly(methyl methacrylate)
[Technical Report] (in preparation)
iv © ISO 2009 – All rights reserved
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SIST EN ISO 22007-1:2012
INTERNATIONAL STANDARD ISO 22007-1:2009(E)
Plastics — Determination of thermal conductivity and thermal
diffusivity —
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
This part of ISO 22007 describes the background to methods for the determination of the thermal conductivity
and thermal diffusivity of polymeric materials. Different techniques are available for these measurements and
some may be better suited than others for a particular type, state and form of material. This part of ISO 22007
provides a broad overview of these techniques. Standards specific to these techniques, as referenced in this
part of ISO 22007, are used to carry out the actual test method.
2 Normative references
The following referenced documents are indispensable for the application 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 472, Plastics — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 472 and the following apply.
3.1
heat pulse
heat change in the form of a pulse produced by a heat source
3.2
heat pulse energy
amount of heat produced by a heat source within the heat pulse
NOTE It is expressed in joules (J).
3.3
heat source
heater in the form of a wire, strip, plate or foil embedded within or attached to a test specimen or an area
irradiated by incident light, e.g. a laser
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SIST EN ISO 22007-1:2012
ISO 22007-1:2009(E)
3.4
heat flux
q
heat source output produced by a planar source per unit time and unit area
2
NOTE It is expressed in watts per square metre (W/m ).
3.5
linear heat flow
heat source output produced by a linear source per unit time and unit length
NOTE It is expressed in watts per metre (W/m).
3.6
penetration depth
characteristic depth used for describing the extent of heat penetration into the specimen during a transient
measuring process
NOTE It is expressed in metres (m).
3.7
temperature transient
temporary perturbation of temperature in a system initially at a uniform temperature due to a heat pulse for a
period during which the system does not attain equilibrium
3.8
volumetric heat capacity
product of the density and the heat capacity
3
NOTE It is expressed in joules per cubic metre kelvin [J/(m ⋅K)].
3.9
thermal effusivity
b
heat transport property given by the square root of the product of thermal conductivity and volumetric heat
capacity:
bc=⋅λρ⋅
p
where
λ is the thermal conductivity;
ρ is the density;
c is the heat capacity
p
2 ½
NOTE It is expressed in joules per square metre kelvin square root second [J/(m ·K·s )].
3.10
thermal resistivity
reciprocal of thermal conductivity
NOTE It is expressed in metre kelvins per watt [(m·K)/W].
4 Principles
Thermal conductivity refers specifically to the mode of heat transfer via conduction. In thermal conductivity
measurements, other modes of heat transfer, such as convection, radiation and mass transfer, may occur.
Where these modes are significant, the measured property is usually referred to as apparent or effective
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SIST EN ISO 22007-1:2012
ISO 22007-1:2009(E)
thermal conductivity. Thermal conductivity is affected by the conditions under which it is measured, such as
temperature and pressure, as well as compositional variation of the material and orientation of the specimen
since some materials are not isotropic.
In steady-state methods, an appropriately sized specimen of simple geometry in contact with a heat source,
together with one or more temperature sensors, which may be combined with the heat source or separate
from it, is allowed to equilibrate at a given temperature. Transient methods may be contact or non-contact. A
thermal transient is produced by a heat pulse to generate a dynamic temperature field within the specimen.
The temperature change with time (temperature response) is measured by one or more sensors which may
be combined with the heat source, placed at a fixed distance from the source or, as in the case of the laser
flash method, located on the other side of the specimen. The response is then analysed in accordance with a
model, and a set of solutions developed for the representative set-up and designed for the specific geometry
and the assumed boundary conditions. Depending upon the geometry of the specimen and source and the
means of generating the temperature field, one or more thermo-physical properties can be obtained, either
separately or simultaneously. Table 1 contains a summary of the characteristics of different types of contact
transient method and the properties that may be determined by their use.
NOTE 1 Most unfilled plastics fall into the category of materials of intermediate thermal conductivity (0,1 W/m·K to
1 W/m·K). They are an order of magnitude more conductive than foams and insulation but about five times less conductive
than ceramics and glass. Their thermal conductivity can increase dramatically if fillers are added. A variety of test methods
may be used, depending on the form and state of the plastic. An overview of these methods is given in Clause 5. Detailed
test methods are contained in other parts of ISO 22007 and in other standards referenced.
NOTE 2 Reference materials are necessary to verify the performance of primary methods and to calibrate secondary
methods. A number of solid materials have been characterized by national standards laboratories, such as NPL, NIST,
® 1)
LNE, NMIJ and PTB, but currently only poly(methyl methacrylate) and Pyrex 7740 glass have a thermal conductivity
which is in the same range as those of most polymer and polymer-filled materials. Polydimethylsiloxane and glycerol are
well characterized fluid reference materials with thermal conductivities in the same range as those of plastics.
Table 1 — Basic characteristics of contact transient methods
Heat source Mode of heat Heat source/temperature Measured and/or derived
Type of method
geometry generation sensor configuration parameters
λ, α
Hot wire/line source/hot
a b
Line, strip Step-wise Combined or separate (C and b in some
p
strip
versions of the method)
Pulse transient Plane Pulse Separate α, C , λ
p
Plane source transient Disc Pulse Combined α, C , λ
p
λ = thermal conductivity; α = thermal diffusivity; b = thermal effusivity; C = specific heat
p
a
One sensor.
b
Two sensors.
5 Test methods
5.1 General
A number of test methods have been developed to provide a means of measuring thermal conductivity and
thermal diffusivity based upon the basic principle outlined above. An overview of these methods is given in the
following subclauses. Some of these methods are summarized in Table 2 and then further explained in more
[14]
detail. Complete details of the test methods described in 5.4 to 5.6 can be found in ISO 22007-2 ,
[15] [16]
ISO 22007-3 and ISO 22007-4 .
1) Pyrex is a registered trademark of Corning Incorporated. This information is given for the convenience of users of this
part of ISO 22007 and does not constitute an endorsement by ISO of this product.
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SIST EN ISO 22007-1:2012
ISO 22007-1:2009(E)
Table 2 — Schematic diagrams of various contact transient experimental methods showing critical
dimensions
Characteristic
Method Specimen set-up Ideal model
parameters
a
Hot wire l = specimen length 200d < w
p
w = specimen width, l > 4w
thickness
d = wire probe diameter
p
a
Line source w = active zone w > 1,5l
s s p
l = probe length l > 33d
p p p
d = probe diameter d > 6d
p s p
d = specimen diameter
s
b
Hot plate w = width, thickness
wh,,d >3 αt
smax
h = height
where t = maximum
max
d = specimen diameter measurement time
s
Plane source d = heat source diameter
dd−> 4 αt
p
sp max
b
transient
d = specimen diameter
s
where t = maximum
max
w = specimen thickness measurement time
a
Unless the specimen is a liquid, a suitable groove or hole has to be made for the hot wire or line source.
b
Good thermal contact has to be established between the strip or disc and the specimen.
In contact methods, enough uniaxial pressure should be applied to press the various parts of the specimen
and the heat source together in order to obtain good thermal contact. Heat sink paste can be used to improve
contact, but there should be no heat sink paste outside the heater, or the temperature field can be disturbed.
Furthermore, the use of heat sink pastes can contribute to the uncertainty of the measurement and their effect
must be adequately quantified for accurate results.
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5.2 Hot-wire method
This method can be used to determine the thermal conductivity of polymers as a function of temperature. It is
applicable only to isotropic materials, but in any form, e.g. plates, foams, pellets or powders.
NOTE The hot-wire method is mainly used for solid polymers as the temperature-measuring element may be
destroyed when working with molten polymers.
The hot-wire method is a transient method. A wire heater is placed in a test specimen or between two test
specimens of the same material. The temperature is measured either by the wire itself acting as a platinum
resistance temperature detector or by a thermocouple placed in close proximity to the wire. The heater current
is switched on and the temperature rise in the thermocouple is measured as a function of time.
Starting with the Fourier differential equation, it is possible to describe the transient heat flow for an infinitely
long wire as follows:
2
⎛⎞
Φ r
∆=Tr(),Et− i⎜⎟− (1)
⎜⎟
44πLλ αt
⎝⎠
where
t is the time, in s;
Φ is the rate of heat flow generated by the wire, in W;
r is the distance between the heater and the thermocouple, in m;
L is the length of the wire, in m;
λ is the thermal conductivity, in W/(m⋅K);
2
α is the thermal diffusivity, in m /s (α = λ/ρC );
p
3
ρ is the density, in kg/m ;
C is the isobaric specific heat, in J/(kg⋅K);
p
Ei(x) is the exponential integral, given by:
∞
−u
e
−=Ei(xu) d (2)
∫
u
x
2
For values of r /4αt less than 1, Equation (1) can be simplified to:
Φα4 t
∆=Tr(,t)− ln (3)
2
4πLλ
rC
where
γ
C = e where γ is Euler’s constant (= 0,577 216).
According to Equation (3), the variation in the temperature, ∆T(r,t), is a linear function of the natural logarithm
of time, and the thermal conductivity of the sample can be determined using the equation:
Φ
λ = (4)
4πLK
where K is the slope of the linear part of the curve of temperature variation plotted against the natural
logarithm of time.
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ISO 22007-1:2009(E)
With the correct specimen and heater dimensions as indicated in Table 2, Equation (4) can be used for
practical applications.
[12] [13]
Details of the test method can be found in ISO 8894-1 and ISO 8894-2 .
5.3 Line-source method
[2]
This technique , sometimes called a needle-probe method, is a variant of the hot-wire method. It uses a line-
source probe in the form of a needle, which permits repeated measurements of thermal conductivity to be
made without destruction of the sensor. This transient method is capable of very fast measurements and is
suited to both melt and solid-state thermal-conductivity measurements. It is not suited to the measurement of
directional solid-state properties in anisotropic materials.
A line source is located at the centre of the specimen being tested. Both the line source and specimen are
kept at a constant initial temperature. During the course of the measurement, a known amount of heat is
produced by the line source, resulting in a heat wave propagating radially into the specimen. The governing
equations are the same as those for the hot-wire method. The line source takes the form of a needle-sensor
probe of finite length and diameter. Typical probes are 50 mm to 100 mm long and about 1,5 mm to 2 mm in
diameter and contain a heater element that runs the whole length of the needle. A thermocouple sensor
located within the needle, with its sensing point half-way down the length of the probe, measures the
temperature rise associated with the transient. Deviations from the model, such as the finite probe dimensions,
require the probe to be calibrated against a reference material. A probe constant, C, is introduced into
Equation (4); it is the ratio of the actual thermal conductivity of the reference material to that measured by the
instrument:
CΦ
λ = (5)
4πLK
[3]
NOTE 1 Silicone fluids and glycerol have been used as reference materials . If using glycerol as a reference material,
caution is advised since its properties are sensitive to moisture.
Typical transients show an initial non-linearity due to the heat wave propagating through the finite thermal
capacity of the probe. This is a region of high conductivity and, hence, low slope. With typical melt state
transients, where the specimen has no contact resistance, the transient approaches linearity directly after it
overcomes this effect, typically within a few seconds. The slope of interest is the linear region that follows the
initial non-linearity. Acquisition durations typically range from 30 s to 60 s. This is very important in gathering
melt state thermal-conductivity data because it dramatically reduces the possibility of thermal degradation.
NOTE 2 Scanning methods have been devised which permit the automated acquisition of data at different
temperatures, so that measurements over a wide range of temperatures are possible. With such methods, the same
specimen that was used for the melt state measurements can be used for solid-state measurements, thereby permitting
measurements across the melt-to-solid transition.
[17]
Details of the test method can be found in ASTM D 5930 .
5.4 Transient plane source method
The transient plane source method is capable of solid-state measurements on sheets of materials. It can be
applied to cases where orientation effects exist and can also be extended to thin films.
[4]
The technique uses a thin, plane, electrically insulated resistive element as both the heat source and the
temperature sensor to measure the thermal conductivity and the thermal diffusivity from one transient
recording. This resistive-element sensor is brought into thermal contact with two halves of a specimen of the
material under investigation. Each of the specimen halves must have one flat surface so that the sensor can
be fitted snugly between these surfaces.
By supplying constant electrical power to the sensor, which is of known radius, and by recording the increase
in resistance as a function of time, it is possible to deduce both the thermal conductivity and the thermal
diffusivity from one single transient recording. In order to be able to deduce both these heat transport
properties from a single transient recording, it is important that the probing depth, ∆p — defined as
prob
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SIST EN ISO 22007-1:2012
ISO 22007-1:2009(E)
½
∆p = 2(αt) , where α is the thermal diffusivity of the sample material and t is the total time of the
prob
transient — used for the test be larger than the radius but less than the diameter of the sensor.
The sensor can have different designs and be composed of different materials. A spiral pattern is in common
use. Nickel and molybdenum have been used as sensing materials, with the sensing spiral and its connecting
leads etched or cut out of a thin foil with a thickness of around 10 µm. Other sensing materials can be used,
provided the sensing material has a reasonably large temperature coefficient of resistivity. The reason for this
requirement is that the sensor is used not only for increasing its own temperature and that of the specimen
near it, but also for recording the temperature changes.
To electrically insulate the sensing material, it is possible to use a variety of materials: so far thin sheets of a
® 2)
polymer (Kapton ), a micaceous material and solid sapphire have been used. When selecting insulating
sheets, it is important that these be kept as thin as possible, preferably in the range 25 µm to 100 µm, in order
to guarantee good thermal contact between the sensing material and the flat surfaces of the surrounding
specimen halves.
For analysing the transient recordings, the heat transfer equations have been solved for a number of
concentric, circular line sources embedded in an infinite medium. To fulfil this condition in a test, the size of
the specimen must be such that the distance from any part of the sensor to the nearest outer surface of the
specimen is not less than the probing depth. Sensors with diameters from 1 mm to 60 mm have so far been
used successfully.
[14]
Details of the test method can be found in ISO 22007-2 .
5.5 Temperature wave analysis method
[8], [9]
The temperature wave analysis method describes a procedure for determining the thermal diffusivity in
the thickness direction of a thin polymer film as a function of temperature. It can be used for both solid and
molten polymers at a constant temperature or for a temperature scan. Measurements c
...
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