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CIPM 2007-09 (Part 2)
Evolving Needs for Metrology in Material Property Measurements Report of the CIPM ad hoc Working Group on Materials Metrology (WGMM) Part 2: draft Annexes October 2007
Evolving Need for
Metrology in
Material Property
Measurements
Report of the CIPM
ad hoc Working Group
on Materials Metrology
(WGMM) Part 2: draft Annexes
October 2007
1
ANNEX A - VIM 2007 Definitions
2.27 (3.9)
measurement uncertainty
uncertainty of measurement
uncertainty
parameter characterising the dispersion of the quantity values being attributed to a measurand,
based on the information used.
NOTES
1. Measurement uncertainty includes components arising from systematic effects, such as components
associated with corrections and the assigned quantity values of measurement standards, as well as the
definitional uncertainty. Sometimes known systematic effects are not corrected for but are instead treated as
uncertainty components.
2. The parameter may be, for example, a standard deviation called standard measurement uncertainty
(or a specified multiple of it), or the half-width of an interval, having a stated coverage probability.
3. Measurement uncertainty comprises, in general, many components. Some of these may be evaluated
by Type A evaluation of measurement uncertainty from the statistical distribution of the quantity values from
series of measurements and can be characterised by experimental standard deviations. The other components,
which may be evaluated by Type B evaluation of measurement uncertainty, can also be characterised by
standard deviations, evaluated from probability density functions based on experience or other information.
2
2.39
calibration
operation that, under specified conditions, in a first step establishes a relation between the
quantity values with measurement uncertainties provided by measurement standards and
corresponding indications with associated measurement uncertainties and, in a second step,
uses this information to establish a relation for obtaining a measurement result from an
indication.
NOTES
1. A calibration may be expressed by a statement, calibration function, calibration diagram, calibration
cure, or calibration table. In some cases it may consist of an additive or multiplicative correction of the
indication with associated uncertainty.
2. Calibration should not be confused with adjustment of a measuring system, often mistakenly called
‘self-calibration’, nor with verification of calibration.
3. Sometimes the first step alone in the above definition is perceived as being calibration.
2.41 (6.10)
metrological traceability
property of a measurement result whereby the result can be related to a stated reference through a
documented unbroken chain of calibrations, each contributing to the measurement uncertainty.
NOTES
1. For this definition, a ‘stated reference’ can be a definition of a measurement unit through its practical
realisation, or a measurement procedure including the measurement unit for a non-ordinal quantity, or a
measurement standard.
2. Metrological traceability requires an established calibration hierarchy.
3. Specification of the stated reference must include the time at which this reference was used, along
with any other relevant metrological information about the reference, such as when the first calibration in the
calibration hierarchy was performed.
4. For measurements with more than one input quantity in the measurement model, each of the input
quantities should itself be metrologically traceable and the calibration hierarchy involved may form a
branched structure or a network. The effort involved in establishing metrological traceability for each input
quantity should be commensurate with its relative contribution to the measurement result. 5. Metrological traceability by itself does not ensure adequate measurement uncertainty or absence of
mistakes. 6. A comparison between two measurement standards may be viewed as a calibration if the comparison
is used to check and, if necessary, correct the quantity value and measurement uncertainty attributed to one of
the measurement standards.
7. The abbreviated term “traceability” is sometimes used for ‘metrological traceability’ as well as for
other concepts, such as ‘sample traceability’ or ‘document traceability’ or ‘instrument traceability’, where the
history (‘trace’) of an item is meant. Therefore, the full term is preferred.
3
2.42
metrological traceability chain
traceability chain
sequence of measurement standards and calibrations that is used to relate a measurement
result to a stated reference
NOTES
1. A metrological traceability chain is defined through a calibration hierarchy.
2. The metrological traceability chain is used to establish metrological traceability of the measurement
result.
3. A comparison between two measurement standards may be viewed as a calibration if the comparison
is used to check and, if necessary, correct the quantity value and measurement uncertainty attributed to one of
the measurement standards.
2.43
metrological traceability to a measurement unit
metrological traceability to a unit
metrological traceability where the stated reference is the definition of a measurement
unit through its practical realisation
NOTE
The expression ‘traceability to the SI’ means metrological traceability to a measurement unit of the
International System of Units.
2.46
metrological comparability of measurement results
metrological comparability
comparability of measurement results that are metrologically traceable to the same
reference
EXAMPLE
Measurement results, for the distances from Earth to Moon and from Paris to London, are
comparable when they are both metrologically traceable to the same measurement unit, for
instance the metre.
NOTES
1 — See Note 1 to 2.41 metrological traceability.
2 — Metrological comparability of measurement results does not necessitate that the measured quantity
values and associated measurement uncertainties compared are of the same order of magnitude.
4
ANNEX B TASK GROUP 1 – MECHANICAL PROPERTIES
Table B1a Modulus measurement
Modulus Scope Determination of the stiffness in the elastic or visco-elastic range of response under tensile
deformation.
Material Category Metal, ceramic, polymer, composite, rubber, biomaterials
Material State and
Scale
Bulk, micro, film, nano, surface.
Regulation Need FIA Technical Regulations, nuclear industry material specifications; structural integrity,
fracture mechanics and design codes. ASME boiler & pressure vessel codes
User needs Reliable data for FE modelling and stiffness controlled design, material specifications,
measurements on novel materials (e.g. MMCs) and the variation with temperature.
Accreditation needs Yes, Formula One Technical Relegations
Comparability Yes, as above “some teams faced potential disqualification as results that were acceptable in
the in-house testing were actually exceeding the 40 limit when tested independently”.
Need for
intercomparison
Yes
Economic impact
studies
No
Number of existing
methods
Many existing standards (ISO, ASTM) cover different materials and test methods.
The European TENSTAND project has developed a preferred procedure for tensile testing.
Standardisation
situation
ASTM E111 is the only standard specifically for measuring the Young's modulus of metals
from the tensile test. EN 10002 does not mention modulus at all. Dynamic methods (ASTM
E1875 and E1876) designed for use with ceramics.
NMI/MRI activities NPL.
R & D phase? Yes, certification of a modulus reference material, development of dynamic methods.
Traceability issues Modulus traceable to mass and length
SI units relevant Length (strain), mass (force)
CCs coverage No
Prior studies (method
specific)
TWA20 and NPL activity on modulus of MMCs VAMAS TWA20 Report Validation of a
Draft Tensile Testing Standard for Discontinuously Reinforced MMC. B. Roebuck, J.D.
Lord and L.N. McCartney, May 1995B. Roebuck, J.D. Lord, P.M. Cooper and L.N.
McCartney. Data Acquisition and Analysis of Tensile Properties for Metal Matrix
Composites, ASTM J. Testing and Evaluation, JTEVA, 22(1), 1994, 63-69.TENSTAND
activity - generation and analysis of tensile ASCII datafiles, modulus study and
recommendations for future developments. TENSTAND WP2 Report – Digital Tensile
Software Evaluation. J D Lord, M S Loveday, M Rides, I McEnteggart. July 2004.
TENSTAND WP3 Report – Modulus Measurement Methods. J D Lord, M Rides, M S
Loveday. January 2005
Method comparability Some data has been generated from intercomparison exercises (TWA20 example attached).
Limited data on comparison with dynamic methods, or measurements at temperature.
No validated modulus reference materials.
Yes - universal tensile testing equipment, but requirements might include specialised
alignment cells and averaging strain measurement. Dynamic test equipment is less widely
available.
Standard test machines
Different machines have not been directly compared using a reference material and agreed
test method.
Calibration – reference
materials
No - a BCR tensile reference material is available, but it has not specifically been certified
for modulus measurement
5
Table B1b Modulus measurement
Modulus Issue / Evidence Comment / Plan
Material Property Modulus values are the normal starting point
for finite element analysis (FEA) that is used to
analyse the distortion and load carrying
capacity in most structural applications. Can
be a controlled parameter (e.g. specific stiffness
limit on materials that can be used in Formula
1).
Is the material property
important?
Round-robins and industrial experience (e.g.
Formula 1) demonstrate repeatably that
modulus measurements are unsatisfactory. Also
shown by round - robin data (see Figure 2).
Is there a problem with
consistency /
comparability of the
measured material
property?
Basic measurements of force (mass) and strain
(= displacement = length) should be
satisfactory. There can be differences in how
the displacement is measured, such as gauge
length used, sensor type used (e.g. clip gauge,
strain gauge, digital image correlation) and the
data analysis procedures used.
Is the problem caused
by an unaddressed need
for traceability?
Alignment is important for both the loading
machine and specimen.
What other aspects are
relevant to the problem?
Errors in analysis due to incorrect modulus
values could have serious and costly failures.
In the particular case of Formula 1, the
financial penalty of disqualification could be
extremely high and threaten the viability of the
company (e.g. Williams Grand Prix annual
expenditure is £100m).
Are there important
consequences if this
problem is not
addressed?
Modulus measurement relies on two CCs (i.e.
CCM and CCL) for traceable measurements,
who would not normally have a combined
study. A detailed study of the strain
measurement methods available and the data
analysis is needed. Both these aspects would
be suitable for CIPM and ILAC involvement.
A proposal has been made (see Annex A) to
undertake a RR in order to extend an existing
creep testing approved reference material to
modulus as well.
What is the way
forward?
Undertake a round-robin based on using the
BCR Nimonic 75 reference material, which is
certified for creep measurements but not for
modulus measurements.
6
Table B2a Hardness measurement
Nano-Indentation
Scope Mechanical properties of nano-size thin film, hardness, modulus, strain-
load, and adhesion strength. Hardness expressed in penetration depth or
indent size
Material Category Mostly Metal, ceramic, polymer, composite, thin film covered on base
materials
Material State and Scale Solid, bulk, film, nano, surface.
Regulation Need Yes, ISO 14577
User needs Material producer, semiconductor designer and fabricator, and end users.
There are strong needs from those industries. Especially for quality
control of heat treated material
Accreditation needs Yes
Compatibility Yes. Especially, strict test condition is required to provide more reliable
equivalency of test results
Need for intercomparison Intercomparison should be conducted. WGH is currently carrying
intercomparison for conventional hardness such as Rockwell, Vickers,
Brinell
Economic impact studies None. No. However, most of the NMIs are working together through
activities of WGH to reduce the scattering of data.
Number of existing methods At least three major methods for conventional hardness measurement.
There are many other test methods.
Standardization situation "Thin film" of TWA22, VAMAS Hardness (Nano-Indentation):
Standardization activities are under discussion at TWA22 of VAMAS.
ISO 6508, 6507, 6506, etc. including 14588 for Nano indentation..
NMI/MRI activities UK NPL, KRISS, MRI=Professor Takai of Nagoya University and NIMS
have studied.
R & D phase ? Yes, especially for the effect of indenter geometry on the measurement
and nano-hardness measurement. There are many basic research
activities in this field. Especially, nano-indentation researches under
various circumstances are active.
Traceability issues WGH under CCM is working to provide internationally agreed standard
reference value for the traceability issue. Comparability is an issue in
hardness. Accuracy of loading, displacement and in some cases
temperature measurements, record of temperature of specimen
throughout a test, measurement of dimension of scratch on specimen.
SI units relevant Temperature, length, stress, and time. (Unique unit such as HRC, HRB,
HV, etc. Not traceable back to SI unit directly).
CCs coverage (same as the above SI units)
Prior studies (method specific) TWA22 of VAMAS
Method comparability Still under discussion.
Standard test machines None.
Some reference materials are sold in the market. But there are no publicly
standardized references.
Calibration - reference
materials
CRM (DLC on steel) with certified critical failure loads under scratch test
(BCR-692); CRM with certified indentation stiffness under development
at NPL (ref. Nigel Jennett)
Comments Hardness (Nano-Indentation): Standardization activities are under
discussion at TWA22 of VAMAS. Although testing procedures are
standardized as ISO14577, there are still remaining discussions at ISO..
7
Table B2b Hardness measurement
Hardness Issue / Evidence Comment / Plan
Material Property Controlled property in many cases,
such as bolts
Property measurements are
very procedure-related (e.g.
Vickers, Brinell)
Is the material property
important?
Consistency is controlled through
reference blocks - normally steel
EU and VAMAS is studying
microinjection and developing
reference materials.
Is there a problem with
consistency / comparability of
the measured material property?
Scatter is acceptable
Is the problem caused by an
unaddressed need for
traceability?
Trend now to derive conventional
properties (e.g. modulus, strength)
from these measurements, especially
at micro-scale.
Work on micro-hardness is
more likely to be undertaken in
materials area than in Mass
groups.
What other aspects are relevant
to the problem?
The production of many industrial
goods from tool steels to bolts are
dependent almost solely on hardness
values that are dependent on material
transfer standards.
Are there important
consequences if this problem is
not addressed?
Hardness is probably one of the most
procedure dominated material
properties. It is also one of the most
frequently quoted.
Hardness could easily be
treated outside CCM as it does
not meet the scope of SI related
work, but is more akin to other
material property
measurement.
What is the way forward?
8
Table B3a Toughness
Toughness Scope Measurement of Mode I, II or mixed mode fracture toughness
Material Category Metal, ceramic, polymer, composite
Material State and Scale Bulk, film
Regulation Need ASME 10?
User needs To have confidence that the data used to design structures such as
pressure vessels that are safety critical are reliable.
Accreditation needs Checking pressure vessel codes
Comparability Yes, designs must be reliable regardless of source of data
Need for intercomparison Take advice from IRMM based on their current work
Economic impact studies Safety critical applications have major consequenes when failures
occur.
Number of existing methods Mode 1 standards well established, Mode II being developed,
Standardisation situation Many standards exist for metals, composites (ISO 15024), polymers
NMI/MRI activities IRMM running RR (NIST, IRMM, AIST, LNE)
R & D phase? Continuation, effect of different methods on measurand, adapting
procedures at ISO TC164 level C18
Traceability issues Fracture toughness is a critical property for safety analysis of structures
SI units relevant mass (kg), time (s),
CCs coverage No
Prior studies (method specific) Precision data given for ISO 15024
Method comparability Yes, Comparison of different Mode II tests for composites in VAMAS
USA/Japan reference machines Standard test machines
Calibration – reference
materials
Master batch CRM approach
9
Table B3b Toughness
Toughness Issue / Evidence Comment / Plan
Material Property Toughness data are normally used at a
later stage of product design to assess
component toughness and that
minimum values are obtained. This
particular important for applications,
such as, pressure vessels (see ASME
and CEN Standards)
Is the material property important? Currently, IRMM round-robin
underway aimed at comparing
procedures (e.g. ASTM vs. ISO).
Is there a problem with consistency
/ comparability of the measured
material property?
Basic measurements of force (mass),
strain (= displacement = length) and
time (second) should be satisfactory.
Is the problem caused by an
unaddressed need for traceability?
Quality and consistency of any pre-
cracking is important
What other aspects are relevant to
the problem?
Potentially severe consequence if
failure occurs as toughness values
have high uncertainty (e.g. pressure
vessels)
Are there important consequences if
this problem is not addressed?
Toughness measurement relies on
three CCs (i.e. CCM, CCL and
CCTF) for traceable measurements,
who would not normally have a
combined study. Propose to assess
IRMM study for the presence and
impact of any "metrology" aspects
that would be suitable for CIPM and
ILAC involvement.
What is the way forward? Evaluate other exercises, such as run
by IRMM to determine if further
work is justified.
10
Table B4a Ultimate Strength
Strength Scope Ultimate strength, or in some systems - yield strength
Material Category Metal, ceramic, polymer, composite, rubber, etc.?
Material State and Scale Bulk, micro, film,
Regulation Need ISO 898 Mechanical Properties of Fasteners - Part 1. Bolts, screws and studs
specifies heat bolts etc. shall have the properties specified in Table 3 [using
ISO 6892 - tensile strength (n/mx), lower yield stress (n/mx), proof stress
((n/mx), impact strength (mi), Brinell, Rockwell and surface hardness,
elongation after fracture]. Property lists are also shown for -20, 100, 200, 250
and 300C, although not part of the standard.
User needs Minimum (mi), nominal (n) or maximum (mx) values..
Accreditation needs ISO 898 and any document calling up ISO 898, such as Eurocode 1993-1-8,
Also BS 4882
Comparability Yes
Need for intercomparison Yes
Economic impact studies
Number of existing methods Many to be entered for all materials (e.g. ISO 527 for composites), Note no
common material independent method.
Standardisation situation
NMI/MRI activities
R & D phase? Biaxial strength measurement in VAMAS, Japan planned research on end-tab
design
Traceability issues Traceability via SI units and accredited test machines
SI units relevant Length (dimensions), mass (force)
CCs coverage No
Prior studies (method
specific)
Method comparability
No Standard test machines
No
Calibration – reference
materials
BCR material (see modulus)
Table B4b To be added
11
Table B5a Creep
Creep Scope Creep is a gradual change behaviour in shape under stress, and it is pronounced
especially at the elevated temperatures over about one third of the melting point in
absolute temperature. Generally, uniaxial tensile stress condition is used similar to
tensile test, and a deformation of gauge portion of a cylindrical specimen is measured
with time at a constant temperature, therefore, temperature of a specimen should be
also measured as well as deformation.
Material Category Metal, ceramic, polymer, and composite, etc, however, metallic materials are in highest
demand.
Especially, high temperature resistant metals that may be tested under 600 to 700
degree C and superalloy materials that may be tested under 1000 degree C or over are
the hottest issues.
Material State and
Scale
Bulk material for power engineering, engine, and petrochemical plant, and nanoscale
wire used in LSI.
Regulation Need Regulated in JIS, ISO, ASTM, etc.
Major regulations and standards are:
ISO 204:1997 Load: ±0.5%(Class 0.5), ±1.0%(Class 1), ±2.0%(Class 2)
Temperature: ±3oC (T � 900
oC), ±4
oC (900
oC < T � 1000
oC)
ASTM E139-96:1996 Temperature: ±3oF (T �1,800
oF), ±5
oF (1,800
oF < T)
JIS Z2271:1999 Load: ±0.5% (Creep test), ±1.0% (Creep rupture test)
Temperature: ±3oC (T �900
oC), ±4
oC (900
oC < T � 1,000
oC)
User needs Material producer, plant designer and fabricator, and end user of plant. LSI designer
and manufacturer.
There are several tens of companies, mainly steel, heavy, power-generation,
petrochemical plant industries, which have creep test equipments. There are more than
ten organizations which implement creep tests and provide data as a business. NIMS id
one of these testing organizations.
Accreditation needs Yes. Screening of data with its quality is required prior to evaluation. These needs are
not required by regulatory laws, but accuracy of load, temperature, displacement is
strictly required by various standards.
Compatibility Yes. Because It is impossible to obtain full set of creep data in one organization.
But, there exist no schemes to ensure comparability of creep test data. Data varies
testing organization by organization.
Need for
intercomparison
Intercomparison should be conducted.
But, even among domestic community, lack of data accuracy and comparability is
always argued.
Economic impact
studies
Yes, it has been conducted, however, it is insufficient.
1) Example of too big safety margins
Economic loss due to accidents and defects of industrial products is estimated as big as
4% of GDP. (Refer to the report, Takanobu Murakami, "Huge accidents and current
science and technology", NSK Technical Journal, No.675 (2003)�Prevention of those
accidents is important not only to secure safety of people, but also to support economic
growth. Major reasons of those accidents are generally defined as a result of
insufficient quality in fatigue, corrosion and abrasion, and creep of materials. For those
high temperature structural parts, which are used for power-generation plants,
petrochemical plants, and jet planes and automobiles, creep defects are one of major
reasons of material degradation.
For example, 81% of power-generation boilers failures are due to mechanical
destruction of boiler materials, and among those 81% of accidents, creep fracture is the
major reason. In order to design safe power-generation plants, long term creep strength
data are mandatory. In the case where no accurate creep data are provided, safety
margin is necessary and plants are to be operated at lower vapour temperature to
prevent creep degradation of boiler materials. Lower vapour temperature causes lower
generation efficiency. 20� change of vapour temperature causes 1% loss of generation
efficiency, and this means that 2,580,000kl of fuel (Heavy oil equivalent) is lost in
Japan annually. If accurate creep test data could be available and 1% increase in
efficiency could be obtained, 70,000,000,000 yen could have been saved, and
9,430,000tons of CO2 could have been reduced.
12
Economic impact
studies
Talking about recent power-generation plants in Japan, cost savings of approximately
100,000,000yen per day can be obtained based on creep test data acquisition and data
based design compared to plants operation of 20 to 30 years ago. However, death and
injury accidents such as accidents at Mihama Nuclear Power Plant and Hamaoka
Nuclear Power Plant due to creep fracture of pipes result in huge loss in human lives
and repair costs; and alternate plant construction and operation.
Number of existing
methods
There are several codes and standards for creep test, however, the contents are
essentially the same each other. For example, ISO 204:1997, ASTM E139-96:1996,
JIS Z2271:1999
Standardization
situation
NIMS Creep Data Sheets are the greatest precision creep data sources.
European Creep Collaborative Committee (ECCC) has summarized and has reported
"ECCC Recommendations" in 2001.
NMI/MRI activities NMI=No.
MRI=NIMS: Acquisition of creep property data for various materials, and those data
are open via internet homepage and NIMS Creep Data Sheets to the public. NIMS
Creep Data Sheets are the greatest precision creep data sources.
http://mits.nims.go.j
R & D phase? Yes, there are many basic research projects on creep properties, however new
measurement techniques are less studied.
Therefore, creep tests are in actually applied stage as a whole, but still R&D activities
are needed.
Traceability issues Accuracy of loading, displacement and temperature measurements, record of
temperature of specimen throughout a creep test, measurement of dimension of
specimen and calibration of thermocouples prior and after creep test.
SI units relevant Temperature, length, stress, and time.
CCs coverage Temperature=CCT, length=CCL, stress=CCM, and time=CCTF. However, creep
properties of materials are mixture of these areas, and systematic coverage for creep
properties of materials are not enough.
Prior studies (method
specific)
There are many studied have been conducted. The first creep test in continental Europe
area started nearly one century ago in Czech republic.
Recently, creep tests under higher temperature, more than 1000 degree C, are
investigated and some round robin tests are conducted in Japan.
Method comparability Although standardized test methods are completed, data for the same test specimens
vary, and international, even national, comparisons are impossible.
Influence of fluctuation in temperature and load, and dimension of specimen affect on
comparability and studies on these elements have been conducted.
Standard test
machines
There are many creep test machines and measuring devices, appropriate to the codes
and standards.
For example, ISO 204:1997, ASTM E139-96:1996, and JIS Z2271:1999.
Yes there were. However, it may be not at present. Calibration -
reference materials
BCR-425 (Nimonic with certified creep rate at 400 oC, time to 2 % strain, time to 4 %
strain, certified by IRMM, collaboration with NPL)
Comments Testing procedures have been already standardized. In reality, in order to get a set of
creep test data, several institutes must collaborate each other because creep test needs
very long term. Those collaboration tests sometimes cause discussion about
comparability of data among test results derived by different institutes. WGMM should
focus on conventional properties that have comparability problems. Leading edge
properties such as Nano-scale properties may be focused on because of its boom, but
these properties should be discussed and standardized by VAMAS or ISO first and it is
not the time to discuss at WGMM at this moment.
13
Table B5b Creep
Creep Issue / Evidence Comment / Plan
Material Property For example, 81% of power-generation boilers are
due to mechanical destruction of boiler materials, and
among those 81% of accidents, creep fracture is the
major reason. In order to design safe power-
generation plants, long term creep strength data are
mandatory. In the case where no accurate creep data
are provided, safety margin is necessary and plants are
to be operated at lower vapour temperature to prevent
creep degradation of boiler materials. Lower vapour
temperature causes lower generation efficiency. 20�
change of vapour temperature causes 1% loss of
generation efficiency, and this means that 2,580,000kl
of fuel (Heavy oil equivalent) is lost in Japan
annually. If accurate creep test data could be available
and 1% increase in efficiency could be obtained,
70,000,000,000 yen could have been saved, and
9,430,000tons of CO2 could have been reduced.
Is the material property
important?
Although standardized test methods are completed,
data for the same test specimens vary, and
international, even national, comparisons are
impossible.
Influence of fluctuation in temperature and load, and
dimension of specimen affect on comparability and
studies on these elements have been conducted.
Is there a problem with
consistency / comparability
of the measured material
property?
Although standardized test methods are completed,
data for the same test specimens vary, and
international, even national, comparisons are
impossible.
Influence of fluctuation in temperature and load, and
dimension of specimen affect on comparability and
studies on these elements have been conducted.
Is the problem caused by an
unaddressed need for
traceability?
Temperature=CCT, length=CCL, stress=CCM, and
time=CCTF. However, creep properties of materials
are mixture of these areas, and systematic coverage
for creep properties of materials are not enough.
What other aspects are
relevant to the problem?
Are there important
consequences if this problem
is not addressed?
What is the way forward?
14
Table B6a Fatigue properties
Gigacycle fatigue Scope Ultrasonic fatigue testing to evaluate fatigue properties beyond 10^7 cycles into
gigacycle regions.
Material Category Metal (steel, super alloy, titanium, aluminium, magnesium alloy)
Material State and Scale Bulk material.
Regulation Need None.
Gigacycle fatigue property is rather new methods and conventional evaluation
methods cannot be applied.
User needs Major steel makers, car makers, heavy industries, etc in Japan purchased the
ultrasonic fatigue testing machines in recent 2 or 3 years. They wish it to be a
standard.
Accreditation needs No.
Gigacycle fatigue test methods are under development.
Compatibility None.
Even comparison among different institutions has not been studied.
Need for intercomparison We are investigating the validity and limitation of these test methods, but this must
be done with many other institutes in the world.
Economic impact studies None.
Gigacycle fatigue property is rather new methods and conventional evaluation
methods cannot be applied. In the fields of gigacycle fatigue property, due to lack
of information and data, parts must be made with bigger safety margin and
relatively big economic impacts exist.
Number of existing methods None.
Standardization situation None.
Research works are under development.
NMI/MRI activities NMI=None.
NRI=NIMS has been one of the major research institutions in this field.
R & D phase? The ultrasonic fatigue testing machine is already on the market, but basic research
is still required to assure the validity and limitation.
Traceability issues The ultrasonic fatigue-testing machine is generally calibrated by measuring the
displacement at an edge of a specimen, and temperature of specimen during the test
or the pre-test must be checked. Regulations and standards are required for these
procedures.
SI units relevant Stress (MPa), length (mm), Frequency (kHz)
CCs coverage (same as the above SI units)
Prior studies (method specific) Studies for the ultrasonic fatigue testing began in 1950s and came to a peak in
1980s. Although the studies once declined in 1990s, they were stimulated again in
this century since several institutes (our institute) succeeded in demonstrating the
validity of the ultrasonic fatigue testing on several conditions.
Papers:
Method comparability None.
Standard test machines None.
Calibration - reference materials None.
Comments Traditional fatigue testing procedures are specified by various standards. NIMS do
not think that WGMM would better taking this issue as current issue to be
discussed. Among various methods for testing fatigue properties, Giga-cycle
fatigue test that extends more than 10E+07 cycles and new testing procedures are
under development could be an issue at WGMM.
Table B6b To be added
15
Table B7a Impact properties
Charpy impact test
Scope Resistance of structural steels to pendulum impact load; future: also
used more for checking quality of dispersion of strengthening phase
in brittle matrix (e.g. carbon nanotube in polymer)
Material Category steel, composites
Material State and Scale bulk, macroscopic
Regulation Need existing EU directive on Pressure Equipment
User needs global harmonisation of machine verification needs
Accreditation needs uncertainty budget (new documents at DIS stage in ISO)
Compatibility 2 different hammer tup (2 mm vs 8 mm radius)
Need for intercomparison currently organised between NIST, LNE, NMIJ and IRMM
Economic impact studies No recent studies available to the author's knowledge
Number of existing methods 2
Standardization situation ASTM E23: 8 mm, ISO-148 : now 2 and 8 mm, no more specific JIS
or EN
NMI/MRI activities NMIJ, LNE, IRMM, BAM, NIST
R & D phase? not active
Traceability issues ASTM: to NIST pendulums, ISO: to results obtained in accordance
with documentary standard
SI units relevant kg, m, s
CCs coverage CCM, CCL, CCT
Prior studies (method specific) intercomparisons 1999, 2004
Method comparability material-dependent difference between 2 mm and 8 mm method
Standard test machines 8 mm: NIST pendulums (defined in ASTM standard), 2 mm/8 mm:
reference machines defined by performance criteria in ISO
Calibration - reference
materials
CRMs from NIST, LNE, NMIJ, IRMM
Comments See also strength return - bolts standard - ISO 898
Table B7b To be added
16
Table B8a Rheological properties - viscosity
Viscosity Scope Rheological properties (& surface tension)
Material
Category
Polymers, polymer solutions, composites, rubbers, metals, ceramics
State and Scale Liquid, particle
Regulation Need Gas Industry Standard GIS/LC12: 200611 specification for sealant systems for joint repair on
metallic distribution systems operating at pressures equal to or less than 2 bar, buried in
locations subjected to low traffic loads.
User needs Viscosity when tested in accordance with Annex A shall not be less than 2 centistokes or
greater than 5 centistokes at 25C. Also a surface tension requirement between 25 and 30
mN/m at 25C.
Accreditation
needs
Comparability Yes, a multitude of methods exist for measuring rheological properties (other than Newtonian
viscosity) that do not necessarily produce the same values dependant on the deformation
history
Need for
intercomparison
Low viscosity Newtonian fluids at low deformation rates probably adequately covered. Need
for intercomparisons of Newtonian viscosities at higher values and rates, and non-Newtonian
viscous and viscoelastic behaviour.
Economic impact
studies
Number of
existing methods
Usually glass capillary viscometers (e.g. Ubbelohde capillary viscometers) used to measure
viscosity /reference fluids - restricted to low viscosity Newtonian fluids
Standardisation
situation
ISO 3104 Petroleum products -- Transparent and opaque liquids -- Determination of
kinematic viscosity and calculation of dynamic viscosity
ISO 3105 Glass capillary kinematic viscometers -- Specifications and operating instructions
ASTM D2162-06 Standard Practice for Basic Calibration of Master Viscometers and
Viscosity Oil Standards
For additional ISO standards see below. Many of these techniques are industry sector specific
and not expected to produce comparable values due to the method, but some purport to
determine true viscosity values.
NMI/MRI
activities
e.g. PTB, Germany for Newtonian reference fluids
R & D phase? Established reference fluids. High viscosity fluids and non-newtonian fluids NOT adequately
covered.
Traceability
issues
Through SI units, implemented through reference fluids
SI units relevant Length, mass (stress), time, temperature
CCs coverage Yes - for Newtonian viscosity (under Mass)
CCM.V-K1.A Viscosity measurements of standard liquids 2002,
CCM.V-K1.B1 Viscosity measurements of standard liquids 2002,
CCM.V-K1.B2 Viscosity measurements of standard liquids 2002,
CCM.V-K1.B3 Viscosity measurements of standard liquids 2002,
CCM.V-K1.C Viscosity measurements of standard liquids 2002,
COOMET.M.V-K1 Viscosity measurements of standard liquids 2005 - 2006, In progress
Prior studies
(method specific)
For high viscosity non-Newtonian fluid properties, several interlaboratory studies undertaken.
Method
comparability
Yes, for Newtonian fluids
Yes - for Newtonian fluids Standard test
machines Yes - for Newtonian fluids
Calibration –
reference
materials
Yes, e.g. as issued by PTB, Germany. These are relatively low in viscosity (0.001 Pa.s to 700
Pa.s) and are for Newtonian viscous behaviour only. The relative uncertainty of the viscosity
for reference liquids provided by the Physikalisch-Technische Bundesanstalt is from 0.2% up
to 1.0% of their value.
17
Table B8b To be added
18
ANNEX C TASK GROUP 2 – THERMAL PHYSICAL PROPERTIES
Table C1a To be added
Table C1b Thermal Conductivity
Thermal Conductivity Issue / Evidence Comment / Plan
Material Category - Thermal insulation, refractory materials,
metal, ceramic, glass, polymer, composite,
Material State and Scale - Foam, Blanket, Bulk, coating, thin
plate, ( +film)
Material Property Regulation Need - Council Directive 93/76/EEC of 13
September 1993 to limit carbon dioxide emissions by
improving energy efficiency (SAVE)
User needs - Customers for conductivity measurements: cars
manufacturers, airplane industry, nuclear industry, defence,
polymers, isolating building structures sectors, etc. Demands
are related to measurements (for establishment of predictive
models, for characterization) and to calibration of
instruments.
Accreditation needs - Accredited testing laboratories for
thermal conductivity measurement need traceability
Customers for
conductivity
measurements: cars
manufacturers, airplane
industry, nuclear industry,
Ministry of Defence,
polymers, isolating
building structures sectors,
etc. Demands are related
to measurements (for
establishment of
predictive models, for
characterisation) and to
calibration of instruments.
Is the material property
important?
ISO (x4) standards, ASTM (x4) standards, CEN standards
have been established.
NMI/MRI activities
NIM(China),
LNE(France),
PTB(Germany),
IPQ(Portugal),
VNIIM(Russia),
NPL(UK), NIST(USA),
JTCCM(Japan)
Is there a problem with
consistency /
comparability of the
measured material
property?
Traceability is well established for low conductivities, where
reference materials exist. For medium to high conductivities,
a demand of reference materials was identified, but few are
available on the market. A need is especially expressed for
the characterisation of ceramics and new polymers.
Manufacturers of instruments are also requiring reference
materials for the calibration of their instruments. For classic
materials, no specific problem of metrological traceability
was identified. Reference methods exist (available at NMIs),
but a lack of reference materials was observed.
Nevertheless, for new materials linked to micro and nano
scale, a real traceability problem has been identified.
Emergent sectors (electronic and bio) have expressed their
needs for conductivity measurements.
Is the problem caused by
an unaddressed need for
traceability?
Standardization situation - ISO (x4), ASTM (x4) and CEN
standards have been established.
What other aspects are
relevant to the problem?
Are there important
consequences if this
problem is not
addressed?
Thermophysical properties are covered by CCT WG9
“Thermophysical property”.
.
What is the way
forward?
Pilot comparison of thermal conductivity of insulation by the
guarded hot plate method is under progress by CCT WG9
19
Table C2a To be added
Table C2b Thermal Diffusivity
Thermal
diffusivity
Issue / Evidence Comment / Plan
Thermal diffusivity
above room
temperature
Material Category
Metal, ceramic, semiconductor, carbon, glass, polymer,
composite,
Material State and Scale
Bulk, coating, thin plate, ( +film)
Is the material
property
important?
Regulation Need
No
User needs
Basic information for thermal design. Production control in
metallurgy and ceramic industries
Accreditation needs
Accredited testing laboratories for thermal diffusivity
measurement need traceability
For example, gas turbine
used for electric power
plants and airplanes need
traceable und comparable
thermal diffusivity values of
turbine blade materials and
coatings.
Is there a problem
with consistency /
comparability of
the measured
material property?
Number of existing methods - There are a few papers, which
compare thermal diffusivity measured by laser flash method
and calculated from thermal conductivity measured by steady
method and heat capacity by differential scanning
calorimeter.
7 standards have been issued for the laser flash method.
NMI/MRI activities
NIM(China), LNE(France),
KRISS(Korea), NPL(UK),
NMIJ(Japan)
Is the problem
caused by an
unaddressed need
for traceability?
The laser flash method has been well established. A few round robin
measurements were
performed among research
institutes using laser flash
method. NMIs did not
participated in these and the
measurements were not SI
traceable.
What other aspects
are relevant to the
problem?
In order to measure thermal diffusivity of thin films, the ultra
fast laser flash method has been developed by picosecond and
nanosecond thermoreflectance technique.
Supply of certified reference material is the traceability rote
for thermal diffusivity.
Calibration – reference materials
Isotropic graphite (NMIJ, Japan), Alumina, Pure iron, Inconel
600, 310 Stainless steel, Nimonic 75 (NPL, UK), BCR-724
(IRMM)
Uncertainty budgets have been developed for these
measurements by NMIJ, Japan, and LNE, France.
Are there
important
consequences if
this problem is not
addressed?
What is the way
forward?
Thermophysical properties are covered by CCT WG9
“Thermophysical property”
Pilot comparison of thermal
diffusivity by the laser flash
method is under progress by
CCT WG9.
20
Table C3a To be added
Table C3b Thermal Expansion
Thermal expansion Issue / Evidence Comment / Plan
Material Category
Metal, ceramic, semiconductor, carbon, glass, polymer
Material State and Scale - Bulk, film
Is the material property
important?
Regulation Need - No
User needs - Basic information to evaluate
deformation of products and thermal stress dependent
of temperature. thermal shock resistance.
Accreditation needs - Accredited testing laboratories
for thermal expansivity measurement need traceability
Is there a problem with
consistency /
comparability of the
measured material
property?
Number of existing methods
Optical interference method and push-rod method
(TMA is included)
NMI/MRI activities
NIM (China), LNE (France), NMIJ
(Japan), KRISS (Korea), NPL
(UK),
Is the problem caused
by an unaddressed need
for traceability?
What other aspects are
relevant to the problem?
Traceability issues
Supply of certified reference material is the
traceability rote for thermal diffusivity.
Calibration – reference materials
NMIJ (Japan), NIST (USA), PTB (Germany)
Uncertainty
Uncertainty budgets have been developed for these
measurements by NMIJ, Japan
Are there important
consequences if this
problem is not
addressed?
A few round robin measurements
were performed among research
institutes using the laser flash
method.
NMIs did not participated in these
measurements and the
measurements were not SI
traceable.
What is the way
forward?
CCT WG9 “Thermophysical property” covers
Thermophysical properties.
Round robin measurement of
thermal expansivity of gauge block
is under progress by CCL.
21
Table C4a To be added
Table C4b Specific Heat Capacity
Specific heat
capacity
Issue / Evidence Comment / Plan
Heat capacity (Cp) All materials in liquid, micro, macro, particle, bulk
states
Is the material
property important?
Regulation Need
Cp of heat exchanger fluids necessary to determine
efficiency of thermal engines
Cp of building materials for fire protection
Uncertainty. Often 5 % is sufficient
Accreditation needs
Accredited testing laboratories for Cp testing need
traceability
For example, in Europe the
automobile industry has very
specific requirements on the
testing method. It is there
way to ensure comparability.
Aviation industry needs
traceable und comparable
results
Is there a problem
with consistency /
comparability of the
measured material
property?
Some discussion can be found in the literature
concerning apparent difference between drop
calorimetric results and adiabatic calorimetric
results (freezing in of defects)
Measurement with
calorimeters - DSC:
commercial, high uncertainty,
calibration with reference
materials. Adiabatic
calorimeters: low uncertainty,
traceable. Drop calorimeters:
low uncertainty, traceable,
high temperature range.
AC and pulse calorimeters:
suitable for low temperatures
Is the problem
caused by an
unaddressed need for
traceability?
Traceability issues - No traceability acc. to state of
the art. Good literature values exist for a number of
standards, e.g. Al2O3, Cu. no uncertainty budget.
Calibration – reference materials - yes
Uncertainty - yes, see D. Archer, 1993
What other aspects
are relevant to the
problem?
Standardized by standardization organizations like
ISO, DIN, ASTM etc.: 2 methods: DSC and drop
calorimetry ASTM E 1269: 2005: Standard Test
Method for Determining Specific Heat Capacity by
Differential Scanning Calorimetry: reproducibility:
8 %, repeatability: 6 %
ASTM E 968: 2002: Standard Practice for Heat
Flow Calibration of DSCs
DIN 51007: 1994-06: Thermal analysis;
differential thermal analysis; principles
DIN 53545: 1990-12: Determination of low-
temperature behaviour of elastomers; principles
and test methods
EN 821-3: 2005-04: Advanced technical ceramics
- Monolithic ceramics - Thermo-physical
properties - Part 3: Determination of specific heat
capacity
and many more material specific standards, mostly
without information about uncertainty
NMIJ/NMI activities
NIST: see D. Archer
PTB: setup of adiabatic
calorimeter
LNE: setup of drop
calorimeter
Are there important
consequences if this
problem is not
addressed?
What is the way
forward?
Thermophysical properties are covered by CCT
WG9 “Thermophysical property”
22
Table C5a To be added
Table C5b Glass Transition Temperature
Transition Temperature Issue / Evidence Comment / Plan
Material Property Glass-transition temperature Is the material property important?
(e.g. does it have importance in
trade, regulations, etc.?).
This material property is used extensively in the
high performance composite arena to access the
shelf-life and completeness of cure of thermoset
based resin matrices. The measurement is often
made by dynamic mechanical analysis (DMA). Is there a problem with consistency
/ comparability of the measured
material property?
It has been shown in round-robin studies that
reproducibility of these measurements is poor,
with many degrees variation in reported values. Is the problem caused by an
unaddressed need for traceability?
Currently there is no traceability of the specimen
temperature to a commensurate degree as the
result is required. Need is for (say) 1C, but
errors can be 5-20 degrees. What other aspects are relevant to
the problem?
This property can also be obtained from
dielectric, DSC, thermal expansion
measurements. These methods do not provide
equivalent data. Are there important consequences
if this problem is not addressed?
(e.g. Can the financial or regulatory
impact of the issue be estimated?)
The materials subjected to this test are mainly
those at the high cost end of composites. The
consequences of measuring incorrectly, and
thereby over-estimating the degree of cure or
that a material is within shelf-life are very
serious as these materials are used increasingly
in high-performance applications (e.g.
commercial and military aircraft) What is the way forward?
(e.g. Is the property covered by an
existing CC? (Inform and offer to
support any work they initiate?), Is
it suitable for VAMAS, a standards
development organisation, or a
regional metrology organisation
(Euromet) activities?, Is work in
conjunction with CIPM and/or
ILAC necessary?, Is a reference
material needed? )
Although, the reported value is a temperature,
the actual temperature accuracy is not the
highest as an accuracy of 0.5 to 1 C provides a fit
for purpose value. There is a need to ensure that
test equipment and operators can provide correct
data. A pilot study should be undertaken in
conjunction with ILAC and CIPM.
23
ANNEX D TASK GROUP 3 – COMPOSITION and MICRO-STRUCTURAL
Table D1a To be added
Table D1b Grain Size
Grain size Issue / Evidence Comment / Plan
Material Property Grain size (average diameter, average area,
number of grains per unit volume or area,
average intercept length, standard grain size
number).
Is the material property
important? (e.g. does it have
importance in trade,
regulations, etc.?).
Yes, material properties and performance depend
on grain size, but no evidence of trade,
regulatory, or accreditation needs or drivers.
Is there a problem with
consistency / comparability
of the measured material
property?
No evidence of a problem with consistency /
comparability when the method used to
determine and express grain size is provided.
Is the problem caused by an
unaddressed need for
traceability?
No.
What other aspects are
relevant to the problem?
Quantitative microscopy techniques are the
primary methods for measuring grain size in
conventional materials. Methods for very fine
grain materials (submicron) include x-ray
(systematic peak broadening) and transmission
electron microscopy techniques.
Are there important
consequences if this
problem is not addressed?
(e.g. Can the financial or
regulatory impact of the
issue be estimated?)
No evidence that there are.
What is the way forward?
(e.g. Is the property covered
by an existing CC? (Inform
and offer to support any
work they initiate?), Is it
suitable for VAMAS, a
standards development
organization, or a regional
metrology organization
(Euromet) activities?, Is
work in conjunction with
CIPM and/or ILAC
necessary?, Is a reference
material needed? )
No evidence to suggest that customers have
significant metrological issues related to
measuring grain size. No obvious role for the
CIPM.
24
Table D2a To be added
Table D2b Phase
Phase Issue / Evidence Comment / Plan
Material Property Phase (identification of one of the pure
compounds present in a material, including
chemical composition and arrangement)
Is the material property important?
(e.g. does it have importance in trade,
regulations, etc.?).
Important, but varies widely with industry
and application. No evidence of regulatory
or accreditation needs or drivers.
Is there a problem with consistency /
comparability of the measured
material property?
No evidence of a problem with consistency /
comparability. Users need low cost, ease of
use, user-friendly data interpretation
software, and databases of known quality to
identify unknown materials.
Is the problem caused by an
unaddressed need for traceability?
No.
What other aspects are relevant to the
problem?
Routine methods include x-ray diffraction
for crystalline materials augmented by
electron microscopy methods. Non-routine
methods include neutron diffraction and
synchrotron-based methods.
Are there important consequences if
this problem is not addressed? (e.g.
Can the financial or regulatory
impact of the issue be estimated?)
No evidence that there are.
What is the way forward?
(e.g. Is the property covered by an
existing CC? (Inform and offer to
support any work they initiate?), Is it
suitable for VAMAS, a standards
development organization, or a
regional metrology organization
(Euromet) activities?, Is work in
conjunction with CIPM and/or ILAC
necessary?, Is a reference material
needed? )
No evidence to suggest that customers have
significant metrological issues related to
measuring phase. No obvious role for the
CIPM.
25
Table D3a To be added
Table D3b Porosity
Porosity Issue / Evidence Comment / Plan Material Property Porosity (pore size, pore size
distribution, specific surface area)
Is the material property important? (e.g.
does it have importance in trade,
regulations, etc.?).
Yes, for catalysts and sintered
materials and for the effectiveness of
pharmaceutical and chromatographic
carriers; important in quality control;
important in the electronics, paper,
and concrete industries. No evidence
of regulatory or accreditation needs
or drivers.
Is there a problem with consistency /
comparability of the measured material
property?
Yes, to the extent that standards
development organizations such as
ASTM International, BSI, DIN, and
ISO develop and maintain numerous
standards in this area, and
organizations such as BAM, BCR,
LGC, and NIST develop and provide
reference materials.
Is the problem caused by an unaddressed
need for traceability?
No evidence to suggest that it is. What other aspects are relevant to the
problem?
Numerous methods exist for
measuring porosity in different
materials under different
circumstances, e.g., gas adsorption,
mercury intrusion, fluid flow, neutron
scattering, x-ray scattering, electron
microscopy, NMR, others.
Are there important consequences if this
problem is not addressed? (e.g. Can the
financial or regulatory impact of the issue
be estimated?)
No evidence to suggest new
consequences if the problem is not
addressed by the CIPM.
What is the way forward? (e.g. Is the
property covered by an existing CC?)
(Inform and offer to support any work
they initiate?), Is it suitable for VAMAS,
a standards development organization, or
a regional metrology organization
(Euromet) activities?, Is work in
conjunction with CIPM and/or ILAC
necessary?, Is a reference material
needed? )
Suitable for standards development
organizations and VAMAS and
developers of reference materials. No
obvious or compelling role for the
CIPM, at least at this time.
26
Table D4a To be added
Table D4b Crystalline Texture
Crystalline Texture Issue / Evidence Comment / Plan
Material Property Crystalline texture (uniaxial, typically developed
in thin films and rods; three dimensional,
typically developed in rolled sheets of metal)
Is the material property
important? (e.g. does it have
importance in trade,
regulations, etc.?).
Important in the hard disk drive industry and in
nanofabrication and nanomechanics. No
evidence of regulatory or accreditation needs or
drivers at this time.
Is there a problem with
consistency / comparability of
the measured material
property?
Little known activity in the development of
either documentary standards or reference
materials for texture per se. No evidence of a
problem with consistency / comparability.
Is the problem caused by an
unaddressed need for
traceability?
No evidence to suggest that it is.
What other aspects are relevant
to the problem?
Are there important
consequences if this problem
is not addressed? (e.g. Can
the financial or regulatory
impact of the issue be
estimated?)
No known consequences if not addressed by the
CIPM.
What is the way forward?
(e.g. Is the property covered by
an existing CC? (Inform and
offer to support any work they
initiate?), Is it suitable for
VAMAS, a standards
development organization, or a
regional metrology
organization (Euromet)
activities?, Is work in
conjunction with CIPM and/or
ILAC necessary?, Is a
reference material needed? )
May be suitable for standards development
organizations and VAMAS and developers of
reference materials. No obvious or compelling
role for the CIPM, at least at this time.
27
Table D5a To be added
Table D5b Particle Size
Particle Size Issue / Evidence Comment / Plan
Material Property Particle properties Size and concentration are considered
most important from the viewpoint of
metrology. In some specific areas,
other properties such as surface area
and density are important as well.
Is the material property
important? (e.g. does it
have importance in trade,
regulations, etc.?).
1. Traceable measurement of particle
concentration (in terms of number or
mass) is being required for regulating
Diesel nanoparticle emissions.
2. Traceable measurement of particle
size and concentration is being
required from the safety concern
about engineered nanoparticles
(concern about so called "nanorisk").
3. Particle size and concentration
have been important issues in powder
and pharmaceutical industries (for
quality control), and semiconductor
manufacturing (for contamination
control).
Discussions on regulating Diesel
nanoparticles have been made by the
United Nations GRPE (Working
Party on Pollution and Energy) for
several years.
Is there a problem with
consistency / comparability of
the measured material property?
Inconsistency is frequently observed
among measurement results for
particle size distributions and
concentrations.
This problem has rarely been
addressed from the traceability
viewpoint.
Is the problem caused by an
unaddressed need for
traceability?
Yes. Traceability in particle size is
established and maintained in only
few countries. There is no traceability
established for particle number
concentrations.
Research to establish a measurement
standard of particle number
concentration is being conducted in
some NMIs.
What other aspects are relevant
to the problem?
Are there important
consequences if this problem is
not addressed? (e.g. Can the
financial or regulatory impact of
the issue be estimated?)
Regulation on Diesel nanoparticles
attempted in the UN GRPE may lose
technical grounds, if no traceability is
established for particle concentration.
What is the way forward?
(e.g. Is the property covered by
an existing CC? (Inform and
offer to support any work they
initiate?), Is it suitable for
VAMAS, a standards
development organization, or a
regional metrology organization
(Euromet) activities?, Is work in
conjunction with CIPM and/or
ILAC necessary?, Is a reference
material needed? )
No CCs, nor other organizations,
have covered the traceability of
particle properties so far. It will be
desirable for experts of particle
measurements in NMIs to meet and
discuss the issue.
Because size is not the only issue in
particle properties, CCL will not be
an adequate place to discuss the issue
in. We need to organize
interlaboratory comparison for nano-
particle size covered by an
appropriate CC to evaluate
comparability between NMIs or other
major organizations. VAMAS can
give many private companies a
suitable opportunity to contribute
standardization and international
comparability.
28
Table D6a To be added
Table D6b Defects
Defects Issue / Evidence Comment / Plan
Material Property Defects (crystalline lattice defects, including
extended and point defects; and microscopic
defects, including inclusions and cracks)
Is the material property
important? (e.g. does it have
importance in trade,
regulations, etc.?).
There are numerous measurement needs related
to defects, expressed by multiple industries.
Defects are called out as a key challenge for
nanoelectronics, photonics, and magnetics. User
needs include assessment of defect type, number
density, and statistical characteristics of defect
populations. Two common themes: sensors, in-
line monitoring. No evidence of regulatory or
accreditation needs or drivers at this time.
Is there a problem with
consistency / comparability of
the measured material
property?
Little known activity in the development of
either documentary standards or reference
materials for defects per se, especially for
crystalline defects. Numerous comparisons of
different techniques, but usually semi-
quantitative.
Is the problem caused by an
unaddressed need for
traceability?
No.
What other aspects are
relevant to the problem?
Numerous and diverse methods exist for
measuring both crystalline and microscopic
defects.
Are there important
consequences if this problem
is not addressed? (e.g. Can
the financial or regulatory
impact of the issue be
estimated?)
No known consequences if not addressed by the
CIPM.
What is the way forward?
(e.g. Is the property covered
by an existing CC? (Inform
and offer to support any work
they initiate?), Is it suitable for
VAMAS, a standards
development organization, or a
regional metrology
organization (Euromet)
activities?, Is work in
conjunction with CIPM and/or
ILAC necessary?, Is a
reference material needed? )
May be suitable for standards development
organizations and VAMAS and developers of
reference materials. No obvious or compelling
role for the CIPM, at least at this time.
29
ANNEX E TASK GROUP 4 – FUNCTIONAL PROPERTIES
Table E1a To be added
Table E1b Dielectric Properties: permittivity
Complex
permittivity
Issue/Evidence Comment /
Plan Scope Complex permittivity
Material
Category
Ceramic, polymer, composite, rubber, organic
State and Scale Bilk, liquid, film, micro, nano, (surface)
Regulation Need 1) Dielectric reference liquids used in mobile communications for SAR
(specific absorption rate). 2) Insulation oils for transformers (conductivity
limits). 3) MRI scans – Hugo model – phantom solid tissue equiv.
Phantoms currently employs dielectric liquids. 4) Dielectric approach to
moisture measurement is common, but lacks standardisation.
User needs Insufficient accuracy of dielectric input data in electromagnetic
modelling (e.g. modelling of radomes, antennae, bio-tissues).
Accreditation
needs
UKAS laboratories – small number in past
Yes, see SAR above – reference liquids. Comparability
Some NPL published data on liquids – NIST now starting work (note:
sources of reproducible solid reference material are difficult e.g. pure
quartz, YAG, otherwise batches of material must be traceably measured)
Euromet 685 on solids – laminar dielectrics. Need for
intercomparison (possibly a WGMM could follow 685 depending on results).
Economic impact
studies
No known data, but case could be made in comms. and defence area as
the technology depends on dielectric materials. SAR is a major potential
risk risk.
Number of
existing methods
Many, but most are too loose in detail to be useful for full traceability and
to guarantee reproducibility between labs. There are some good standards
for specific technical measurements (where industrial reproducibility is
more important than absolute accuracy). SAR standards are relatively
new & good as they had real metrological input.
Standardisation
situation
Many obsolete standards (except key areas such as SAR: IEEE Standard
1528-2003, ISBN 0-7381-3716-2, CENELEC standard EN 50361:2001,
IEC Standard 62209-1, 2005)
NMI/MRI
activities
Euromet 685 involves NIST, VNIIMS, NPL, BAM and Polish designated
lab (Technical University of Warsaw).
R & D phase? Rf & Microwave: general movement into smaller scale (e.g. micro)
measurements. Low frequency (LF) research on nano-composites,
breakdown, electrokinesis, etc.
Traceability
issues
NMIs ensure traceability, but most industry and academic. RF &
microwave measurements are not traceable.
SI units relevant Microwave: length (dimensions, displacement), time (frequency), LF &
RF via impedance/capacitance.
CCs coverage CCEM
Prior studies Intercomparisons every so often – informal results available.
Method
comparability
See above
Standard test
machines
Mostly bespoke (i.e. different cell sizes)
Calibration –
reference
materials
Reference liquids (controlled by composition). Very few solid material
standards, though most measurements on solids – only pure crystals
suitable.
Uncertainty NMIs promote this- 2003 meeting on Dielectric Measurement
Uncertainties.
30
Table E2a To be added
Table E2b Electrical Properties
Electrical properties Issue / Evidence Comment / Plan Material Property Dielectric These comments apply to the
RF, Microwave and THz regions
of spectrum
Is the material property
important? (e.g. does it have
importance in trade,
regulations, etc.?).
Traceable measurement of dielectric
properties is stipulated in international
standards Health and Safety standards
relating to RF interactions with humans
(e.g. RF generated by mobile phones) and
in 2008 the EC Physical Agents (EMF)
Directive will require all employers to
abide by these standards. There is a more
general problem of supplying good
quality dielectric data as input to EM
field-modelling programmes: these days
the algorithms are of good quality and the
predicted performance of
component/system designs is often
limited rather by the large uncertainties
and/or errors in the dielectric data.
Computer-based EM field
modelling is widely used by
European electronics-based
industries.
Is there a problem with
consistency / comparability of
the measured material
property?
Yes, measurement comparisons between
labs often exhibit discrepancies, which
exceed joint estimated uncertainties -
sometimes to a considerable extent.
Education of those involved in
dielectric measurements should
help: the dielectrics community
is in general far less aware of the
value of realistic uncertainty
estimation than other
metrological disciplines are.
Is the problem caused by an
unaddressed need for
traceability?
In some cases, yes. Many existing
dielectric measurement standards do not
mention the need for traceability
What other aspects are
relevant to the problem?
The large number of degrees of freedom
that dielectric measurements suffer from
measurements (e.g. types of material,
frequency range, temperature, moisture,
available specimen size) makes it difficult
and potentially costly to standardise good
practice over a very wide field.
Are there important
consequences if this problem
is not addressed? (e.g. Can
the financial or regulatory
impact of the issue be
estimated?)
Performance of systems will not be
optimised. In some cases Health & Safety
may be compromised
What is the way forward?
(e.g. Is the property covered by
an existing CC? (Inform and
offer to support any work they
initiate?), Is it suitable for
VAMAS, a standards
development organisation, or a
regional metrology
organisation (Euromet)
activities?, Is work in
conjunction with CIPM and/or
ILAC necessary?, Is a
reference material needed? )
A microwave measurement comparison is
currently being run by the Euromet High
Frequency Electromagnetics Sub-field,
which may highlight some of these
problems (Internationally it comes under
the remit of CCEM).
Growing demand from industry
for better measurements may
trigger a need for a more
comprehensive programme of
international metrology here.
31
Table E3a Magnetic Properties
Magnetic Properties Scope AC and DC B versus H properties and related quantities such as specific total loss and
relative magnetic permeability. Measurements made on a range of test specimen dimension
that meet material property requirements.
Material
Category
Bulk, laminates, soft magnetic composites, polymer-bonded permanent magnets.
Material State
and Scale
Bulk, 2D (laminates) nano-composite (permanent magnets)
Regulation
Need
IEC standards require the material properties to meet certain values and that standard
measurement methods are used to determine these.
User needs Users need material properties that are suitable for their application. Often this means making
measurements for conditions that are far from the laboratory. Standard methods underpin any
approach adopted.
Accreditation
needs
Manufactures of transformers have to meet certain energy loss requirements and the
underpinning measurement of specific total loss is traceable to National Standards.
Comparability A number of different measurement systems are used for the same magnetic quantity and
reproducibility is extremely important.
Need for
intercomparison
If a suitable quantity could be identified and a suitable reference standard established then the
community would benefit from such an activity.
Economic
impact studies
Not aware of any, although electrical steel manufacturers presumably have such information.
Number of
existing
methods
The IEC have a number of standards covering magnetic measurements and the number is
growing as new measurement techniques reach FDIS status. NPL can provide measurements
compliant with 7 standards.
Standardisation
situation
See last statement – Lowest measurement uncertainties possible are required.
NMI/MRI
activities
PTB have a similar capability.
R & D phase? UK project finishing March 08 developing a measurement method for the AC properties of
soft magnetic materials for operational waveforms, under stress and at elevated temperatures
applied simultaneously.
Traceability
issues
Each of the discrete instruments used in the measurement system has a suitable calibration.
Examples are calibrated micrometers, calibrated mass balance, calibrated resistors and
calibrated digital voltmeters.
SI units relevant All are derived units.
CCs coverage Properties have a number of CC entries.
Prior studies A CCEM comparison of magnetic field strength (the required H) was performed using a
special solenoid as the transfer standard.
Method
comparability
Bilateral measurements with PTB have been performed for specific total loss.
Standard test
machines
No - measurement systems are established from discrete instruments.
Calibration –
reference
materials
Reference cores calibrated to the users requirements.
Uncertainty Uncertainty budgets exist for all material measurements that have CC entries.
32
Table E3b Magnetic Properties
Magnetic Properties Issue / Evidence Comment / Plan Material Property e.g. Magnetic Property - Specific Total Loss
Is the material property
important? (e.g. does it have
importance in trade, regulations,
etc.?).
Determines the energy loss in electrical
machines and other devices. Accurate
measurement of this quantity is required for
future energy efficient applications.
Units -
Is there a problem with
consistency / comparability of
the measured material property?
Measurement of specific total loss requires a
magnetic circuit and the realisation of this
circuit is a known problem. New materials are
measured using a different circuit and this
makes comparisons difficult.
What is the way forward?
(e.g. Is the property covered by
an existing CC? (Inform and
offer to support any work they
initiate?), Is it suitable for
VAMAS, a standards
development organisation, or a
regional metrology organisation
(Euromet) activities?, Is work in
conjunction with CIPM and/or
ILAC necessary?, Is a reference
material needed? )
An CC exist for Epstein and Single Sheet
measurements at 50 and 400 Hz.
What other aspects are relevant
to the problem?
Conditions of material use are key.
Measurements are made for standard
conditions but the material is used in an
environment that is very different.
Effect of stress
Are there important
consequences if this problem is
not addressed? (e.g. Can the
financial or regulatory impact of
the issue be estimated?)
Without traceable measurements to develop
the materials and optimise device performance
considerable energy will be wasted. With the
move to more electric transport being driven
by environmental issues the impact is large
and far-reaching.
What is the way forward?
(e.g. Is the property covered by
an existing CC? (Inform and
offer to support any work they
initiate?), Is it suitable for
VAMAS, a standards
development organisation, or a
regional metrology organisation
(Euromet) activities?, Is work in
conjunction with CIPM and/or
ILAC necessary?, Is a reference
material needed? )
An WG exist for Epstein and Single Sheet
measurements at 50 and 400 Hz.
33
Table E4a Optical Properties
Optical - Fluorescence
Scope Fluorescence lifetime, intensity (quantum yield) & spectrum
Material Category Biological, Organic LED materials
Material State and
Scale
Liquid (dyes), micro (cells), particle (single particle), bulk (e.g. dyes on textiles, dried
paints), film (OLED), nano (cell structures)
Regulation Need Not aware of any at present
User needs What are the user requirements? Intercomparisons in biological studies, product
development (pharmaceuticals, OLEDs), new molecular probes, or old probes in “new”
environments
Accreditation needs Not sure
Is there a need for comparability of data? Comparability
Yes (e.g. in clinical diagnostics)
Need for
intercomparison
Fluorescence lifetime imaging (instrument manufacturers, research labs), Quantum yield
(NMI’s)
Economic impact
studies
Not sure
5 methods for Quantum yield (most common: comparison with ref standard);
2 methods for lifetime (time or frequency based);
Number of existing
methods
spectrum (scanning or array system)
Quantum yield ref standard (quinine sulphate calibrated by NIST) Standardisation
situation Spectral ref standards (fluorescein calibrated by NIST, proprietary standards sold by BAM,
commercial proprietary standards)
NMI/MRI activities Recent NIST/NRC/BAM spectral intercomparison (2005)
R & D phase? Single-molecule spectroscopy
Spectra via reference standard materials; Traceability issues
None for lifetime standards
SI units relevant None
CCs coverage No
Prior studies
(method specific)
(ref standards described above, NMI intercomparison…)
Method
comparability
Standard test
machines
Yes, commercial instruments available for lifetime, spectrum and quantum yield
Calibration –
reference materials
Yes, see above
Uncertainty Yes, for reference materials
34
Table E4b Optical Properties
Optical Properties Issue / Evidence Issue / Evidence Issue / Evidence
Material Property Apparent texture (i.e.
texture as manifested
optically)
Gloss
Colour
Is the material property
important? (e.g. does it
have importance in
trade, regulations,
etc.?).
Yes, apparent texture
affects consumer trade
Yes, e.g. where it
affects or determines
visibility of displays
Yes, colour matching
and perception
important for consumer
trade
Is there a problem with
consistency /
comparability of the
measured material
property?
There is currently no
standard measurement
to enable apparent
texture comparisons
Commercial gloss
meters exist, but are
based on a very small
subset of possible
measurements.
Therefore comparing
materials through gloss
meter measurements is
often misleading or
uninformative.
Not in terms of the
standard colour
measurements, which
commercial instruments
can make. However,
“apparent” colour (i.e.
both colour rendering in
different lighting
situations and
appearance of coloured
objects in different
surrounds) can lead to
problems. Colour
rendering issues are the
leading cause of
products being returned
to shops.
Is the problem caused
by an unaddressed need
for traceability?
No scale or traceability
exists at present
Traceability exists, but
addresses only specific
gloss meter measure-
ment(s) rather than a
full characterisation of
glossiness
The problems raised
above are well known,
but to date no
traceability chain exists.
What other aspects are
relevant to the problem?
Apparent texture is
correlated with physical
texture.
Some increasingly
popular materials
coatings (e.g.
interference pigments)
have a viewing-angle-
dependent colour.
Are there important
consequences if this
problem is not
addressed?
(e.g. Can the financial
or regulatory impact of
the issue be estimated?)
There would be
positive consequences
to developing standards
(e.g. to specific
industries such as CGI
or decorative surface
manufacturers), but it’s
hard to estimate
negative consequences
if these are not
developed in the near
future.
Probably not major, so
long as custom
measurements can be
made when required.
There is a financial
impact to industry, but
it’s hard to estimate
What is the way
forward? (e.g.
undertake a round-
robin, develop a
reference procedure,
develop and validate a
reference material,
research a new method)
Develop reference
procedures and/or a new
method.
Develop reference
procedures and/or a new
method
Develop reference
procedures and/or a new
method. .
35
Table E5a To be added
Table E5b Acoustic Properties
Acoustic
Properties
Issue / Evidence Comment /
Plan Scope Speed of sound, attenuation and/or absorption, or scattering cross-
section measurements of materials, typically tissue-mimicking
(TMM) or tissue-like materials.
Material Category Water based gelatin, loaded with scattering materials to generate
the ‘correct’ properties.
Material State and Scale Macro, semi-solid – samples will be typically 50 mm � and 10
mm – 40 mm thick.
Regulation Need The properties of the TMM material are specified in and IEC
Standard for realising a reference flow phantom for testing
Doppler ultrasound equipment and for use in a thermal test object
(used to measure temperature rise generated by medical ultrasound
equipment).
User needs Uncertainty: fit-for-purpose. Most user requirement relate to
uniformity and ease-of-manufacture and medium and long-term
stability.
Accreditation needs No.
Comparability Not sure.
Need for
intercomparison
I would anticipate that, if it is felt that such a comparison between
NMIs is important, then this will be done through the CCAUV.
Economic impact
studies
No.
Number of existing
methods
Currently, none.
Standardisation
situation
None.
NMI/MRI activities Probably carried out in underpinning other projects.
R & D phase? Yes for scattering cross-section: For other properties: no, not
really.
Traceability issues This is a relative measurement, carried out with reference to a
standard liquid, water, whose properties are well established.
SI units relevant Sample thickness is an important measurement.
CCs coverage Probably CCAUV.
Prior studies (method
specific)
Purely informally, as part of an EU project, but also through a UK
intercomparison which used reference oils. Also, a comparison of
TMM properties was carried out in the US.
Method comparability No.
Standard test machines None. Have machines been compared? No.
Calibration – reference
materials
NPL has provided these in the past, on a limited scale (these are
based on reference oils – Dow Corning-710 oil).
Uncertainty Yes, within NPL, for attenuation and speed-of-sound.
36
ANNEX F TASK GROUP 5 – ELECTROCHEMICAL PROPERTIES
Table F1a To be added
Table F1b Electrochemical Properties
Electrochemical Issue / Evidence Comment / Plan
Material Property Corrosion 1 (Electrochemistry)
Is the material property
important? (e.g. trade,
regulations)
Corrosion is a major reason for materials failure
and economic loss;
Is there a problem with
consistency /
comparability of the
measured material
property?
The measurement of corrosion rates is mainly
based on mass loss, optical analysis and
electrochemical measurements of corrosion
currents. Measurements mainly rely on standards
with well-established boundary conditions and
well-characterised materials. Data are available
for certain standards and established materials in
certain corrosive environments. Problems arise
for new materials, the prediction of corrosion
behaviour on the basis of accelerated tests and
for new corrosive environments.
In polycrystalline materials the different
grain orientations and thereby induced
different local surface energies and
reactivities are often leading to locally
varying corrosion phenomena. This will
strongly influence the corrosion of the
material as whole. Resolving this
question will lead to more reliable
corrosion measurement and improved
corrosion protection.
Is the problem caused
by an unaddressed need
for traceability?
No. Development of methods to detect the
evolution of very thin (nanoscale)
protective layers of economic relevance
for new materials is required.
What other aspects are
relevant to the problem?
Materials are complex in the variability of their
microstructure, orientation and composition of
grains, leading to local reactivity. Particularly, as
corrosion is concerned, these materials
properties cannot be generalised but extremely
specific for the interplay between materials
structure and environmental conditions.
Bridging the gap between high
precision electrochemical, microscopic,
optical and spectroscopic measurements
and routine testing procedures applied
in industry.
Are there important
consequences if this
problem is not
addressed? (e.g. Can
the financial or
regulatory impact of the
issue be estimated?)
If the problem of advanced corrosion analysis is
not addressed, lifetime prediction of new
functional materials and the prediction of the
influence of the release of materials on their
environment (e.g. human body in case of
implants, …) will not be possible. This
significantly hampers the development of new
materials and therefore has a dramatic economic
and ecological impact.
What is the way
forward? (e.g.
Is the property covered
by an existing CC?
(Inform and offer to
support any work they
initiate?), Is it suitable
for VAMAS, a
standards development
organisation, or a
regional metrology
organisation (Euromet)
activities?, Is work in
conjunction with CIPM
and/or ILAC
necessary?, Is a
reference material
needed? )
The existing knowledge and standards do not
sufficiently allow to understand the grain
orientation dependant corrosion rates (e.g.
surface energy and etching rate and surface
chemistry are often grain orientation dependant).
However, most engineering materials are
polycrystalline and the texture is designed with
regard to functional properties). CCs addressed
are CC-Length, CC-Electricity and Magnetism,
CC-Mass and Related Quantities and CC-
Amount of Substance - Metrology in Chemistry.
The scientific implications should be treated in a
VAMAS working group. The relevance for
trade, standardization and international rules for
quality and trade might be treated by ILAC
To solve this issue it is suggested to
combine the methods EBSD (electron
backscattering diffraction) with
profilometry on the nanoscale (best
suited method to be determined) and
local optical metrology for thickness
analysis of formed oxide films. In an
initial phase the orientation of grains in
polycrystalline material and individual
dissolution (corrosion) rates should be
measured and correlated. In a second
stage, by means of spectroscopy, the
evolution of protective thin layers have
to be assessed and applied to the
observation of corrosion depending on
the crystal orientation. Finally, the
combination of the topographic and
optical methods should lead to a better
prediction and control of the
polycrystalline corrosion behaviour.
37
ANNEX G PILOT STUDIES (outline proposals)
G1. MEASUREMENT OF MODULUS ROUND ROBIN
Introduction
In spite of the long history of testing metals, recent experience suggests that the measurement of
modulus is not trivial and there can be large discrepancies in the values measured even from
experienced practitioners. Currently the only standard available for measuring the Young’s
modulus of metals from the tensile test is ASTM E111, and there are many issues that contribute to
the variability, which still need to be addressed. The European TENSTAND project reported on
the accuracy of modulus measurement from the conventional tensile test, with recommendations
for a separate procedure for modulus measurement, but this has not been progressed. Work has
been carried out in the past on metal matrix composites, which has also highlighted strain
measurement and data analysis as key factors affecting the quality and accuracy of the results.
Dynamic methods are sometimes used, but the tests are primarily those developed for the testing of
ceramics.
There are also issues with the testing of modulus at temperature, where reliable data and test
methods are not available.
Although there are no reference materials specifically developed for modulus measurement, a BCR
Nimonic 75 tensile reference material does exist. This has not been fully certified for modulus; and
the proposal within this exercise is to examine the tensile and dynamic modulus techniques with
the aim of validating and certifying the material for modulus measurement.
Round-robin organisation
•Source BCR Nimonic tensile reference material and prepare test pieces.
•Circulate manufactured test pieces for tensile and dynamic measurement
•Specify test conditions – alignment, loading, strain measurement and data analysis
•Collate results and report
•Report Young’s Modulus
Time schedule
•Sign up for the study:
•Distribution of samples:
•Reporting:
38
G2. GLASS TRANSITION (Tg) OF CURING RESIN SYSTEMS
Introduction
One example of materials metrology is the measurement of Tg - the glass transition temperature,
which is a materials property but reported as a temperature value, which is actually determined
through a wide range of other measurement techniques, including:-
- ultrasonics,
- dielectrics,
- calorimetry (DSC)
- expansion
- mechanical vibration (DMA)
- optical coherence tomography (OCT)
The value of Tg is often used as in materials qualification and specification requirements, as Tg is
related to service temperature capability. See Standard Qualification Plan.
These above techniques are all used as secondary measures of degree of cure and shelf-life. Some
of these techniques are better for off-line, rather than on-line measurements.
Standards exist for DSC (ISO 11357-3/ASTM E 1356), DMA (ISO 6721-11, ASTM D 3418). No
standards for Tg by ultrasonic, dielectric, calorimetry and OCT.
NPL has a project to calibrate these techniques for material of different cure state against a
"chemical" measure of cure (e.g. FTIR).
Round-robin activities
Supply panel of fully cured material
Glass-transition temperature to be determined by a range of techniques, as above.
Note NPL will supply a temperature reference specimen for calibration of DMA equipment.
Report
Report the glass-transition temperature
Time schedule
6-12 months
39
G3. MAGNETIC MEASUREMENTS ON NPL REFERENCE CORE T1002
An outline proposal for measuring magnetic properties is given below.
DC MEASUREMENTS
• Measure the normal magnetization curve and from this determine the maximum relative
magnetic permeability.
• Determine the B versus H hysteresis curve up to a magnetic field strength of 2200 A/m.
• From the measured B versus H hysteresis curve determine the remanence, Br, and the
magnetic flux density coercivity, HcB.
• The values determined should be sent to the organiser along with the estimated uncertainty
in these values within one month of completing the measurements.
AC MEASUREMENTS
• Measurements to be made at a frequency of 50 Hz. For all measurements the secondary
voltage waveform should be sinusoidal as defined in BS EN 60404 parts 2 and 3.
• Determine the specific total loss, Ps, and the specific apparent power, Ss, at peak values of
the magnetic flux density, Bpeak, of 1.0 T, 1.1 T, 1.3 T, 1.5 T and 1.6 T.
• Determine the peak magnetic flux density, Bpeak, for a peak magnetic field strength of 1000
A/m.
• The values determined should be sent to NPL along with the estimated uncertainty in these
values within one month of completing the measurements.
The following physical data can be assumed for the measurements:
Mass of core = 0.5075 kg
Cross-sectional area of core = 1.5030 × 10 -4
m2
Mean magnetic path length of core = 0.44061 m
Number of primary turns = 300
Number of secondary turns = 150
N.B. While the windings are identical, the left pair of secondary terminals (when viewing the core
with the secondary terminals at the top) should be used.
To limit contributions due to temperature coefficients, the properties of the core should be
measured for an ambient temperature of 20 ± 1 °C.
The laboratory should follow their own technical procedure for measuring the required properties.