Metallic materials - Calibration of extensometer systems used in uniaxial testing (ISO 9513:2012)

ISO 9513:2012 specifies a method for the static calibration of extensometer systems used in uniaxial testing, including axial and diametral extensometer systems, both contacting and non-contacting.

Metallische Werkstoffe - Kalibrierung von Längenänderungs-Messeinrichtungen für die Prüfung mit einachsiger Beanspruchung (ISO 9513:2012)

Diese Internationale Norm legt ein Verfahren fest für die statische Kalibrierung von Längen-änderungs Messsystemen (Extensometer Systemen) für die Prüfung mit einachsiger Beanspruchung einschließlich axialer Systeme und diametraler Systeme (Querdehnungsaufnehmer) für berührungslose und für berührende Messungen.

Matériaux métalliques - Étalonnage des chaînes extensométriques utilisées lors d'essais uniaxiaux (ISO 9513:2012)

L'ISO 9513:2012 spécifie une méthode pour l'étalonnage statique des chaînes extensométriques utilisées lors d'essais uniaxiaux, y compris les chaînes extensométriques axiales et diamétrales, avec contact ou sans contact.

Kovinski materiali - Kalibracija ekstenzometrov, ki se uporabljajo pri enoosnem preskušanju (ISO 9513:2012

Ta mednarodni standard določa metodo za statično kalibracijo ekstenzometričnih sistemov, ki se uporabljajo pri enoosnem preskušanju, vključno z osnimi in diametričnimi ekstenzometričnimi sistemi, ki so kontaktni ali nekontaktni.

General Information

Status
Withdrawn
Publication Date
30-Mar-2013
Withdrawal Date
29-Jun-2013
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Start Date
01-Dec-2012
Due Date
14-Jan-2011
Completion Date
01-Dec-2012

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SLOVENSKI STANDARD
SIST EN ISO 9513:2013
01-junij-2013
1DGRPHãþD
SIST EN ISO 9513:2004
Kovinski materiali - Kalibracija ekstenzometrov, ki se uporabljajo pri enoosnem
preskušanju (ISO 9513:2012

Metallic materials - Verification and calibration of extensometers used in uniaxial testing

(ISO 9513:2012)
Metallische Werkstoffe - Zugversuch - Teil 5: Prüfung und Kalibrierung von
Längenänderungs-Messeinrichtungen für die Prüfung mit einachsiger Beanspruchung
(ISO 9513:2012

Matériaux métalliques - Matériaux métalliques - Etalonnage des extensomètres utilisés

lors d''essais uniaxiaux (ISO 9513:2012
Ta slovenski standard je istoveten z: EN ISO 9513:2012
ICS:
77.040.10 Mehansko preskušanje kovin Mechanical testing of metals
SIST EN ISO 9513:2013 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 9513:2013
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SIST EN ISO 9513:2013
EUROPEAN STANDARD
EN ISO 9513
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2012
ICS 77.040.10 Supersedes EN ISO 9513:2002
English Version
Metallic materials - Calibration of extensometer systems used in
uniaxial testing (ISO 9513:2012)

Matériaux métalliques - Étalonnage des chaînes Metallische Werkstoffe - Kalibrierung von

extensométriques utilisées lors d'essais uniaxiaux (ISO Längenänderungs-Messeinrichtungen für die Prüfung mit

9513:2012) einachsiger Beanspruchung (ISO 9513:2012)
This European Standard was approved by CEN on 14 December 2012.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European

Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national

standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation

under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same

status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United

Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 9513:2012: E

worldwide for CEN national Members.
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SIST EN ISO 9513:2013
EN ISO 9513:2012 (E)
Contents Page

Foreword ..............................................................................................................................................................3

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SIST EN ISO 9513:2013
EN ISO 9513:2012 (E)
Foreword

This document (EN ISO 9513:2012) has been prepared by Technical Committee ISO/TC 164 "Mechanical

testing of metals" in collaboration with Technical Committee ECISS/TC 101 “Test methods for steel (other

than chemical analysis)” the secretariat of which is held by AFNOR.

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 June 2013, and conflicting national standards shall be withdrawn at

the latest by June 2013.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent

rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN ISO 9513:2002.

According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following

countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech

Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,

Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,

Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

Endorsement notice

The text of ISO 9513:2012 has been approved by CEN as a EN ISO 9513:2012 without any modification.

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SIST EN ISO 9513:2013
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SIST EN ISO 9513:2013
INTERNATIONAL ISO
STANDARD 9513
Third edition
2012-12-01
Metallic materials — Calibration of
extensometer systems used in uniaxial
testing
Matériaux métalliques — Étalonnage des chaînes extensométriques
utilisées lors d’essais uniaxiaux
Reference number
ISO 9513:2012(E)
ISO 2012
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SIST EN ISO 9513:2013
ISO 9513:2012(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2012

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,

electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s

member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved
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SIST EN ISO 9513:2013
ISO 9513:2012(E)
Contents Page

Foreword ............................................................................................................................................................................iv

Introduction ........................................................................................................................................................................ v

1 Scope ...................................................................................................................................................................... 1

2 Terms and definitions ......................................................................................................................................... 1

3 Symbols and designations ............................................................................................................................... 1

4 Principle ................................................................................................................................................................. 2

5 Calibration equipment ........................................................................................................................................ 2

5.1 Calibration apparatus ......................................................................................................................................... 2

5.2 Calibration traceability ....................................................................................................................................... 2

6 Pre-calibration inspection ................................................................................................................................. 2

6.1 Objective ................................................................................................................................................................ 2

6.2 Records of the inspection ................................................................................................................................. 3

6.3 Identification of extensometer system elements ........................................................................................ 3

7 Measurement of extensometer gauge length .............................................................................................. 3

7.1 Fixed gauge length extensometry .................................................................................................................. 3

7.2 Variable gauge length extensometry ............................................................................................................. 3

7.3 Non-contacting extensometry ......................................................................................................................... 4

7.4 Extensometer gauge lengths established using setting gauges ........................................................... 4

8 Calibration process ............................................................................................................................................. 4

8.1 Environmental considerations ......................................................................................................................... 4

8.2 Position of the extensometer ........................................................................................................................... 4

8.3 Calibration increments ....................................................................................................................................... 4

8.4 Calibration process ............................................................................................................................................. 6

8.5 Determination of the characteristics of the extensometer system ........................................................ 6

9 Classification of the extensometer system .................................................................................................. 7

9.1 Input data ............................................................................................................................................................... 7

9.2 Analysis of the data ............................................................................................................................................ 7

9.3 Classification criteria ......................................................................................................................................... 7

9.4 Assessment of the results ................................................................................................................................ 7

10 Uncertainty determination ................................................................................................................................ 8

10.1 Uncertainty of the calibration ........................................................................................................................... 8

10.2 Uncertainty budget determination .................................................................................................................. 8

11 Extensometer system calibration intervals .................................................................................................. 8

12 Calibration certificate ......................................................................................................................................... 8

12.1 Mandatory information ....................................................................................................................................... 8

12.2 Data presentation ................................................................................................................................................ 9

Annex A (informative) Uncertainty of measurement ...............................................................................................10

Annex B (informative) Calibration of the calibration apparatus ..........................................................................15

Annex C (informative) Example of a report of the calibration of calibration apparatus ................................17

Annex D (informative) Examples of extensometer system configurations ......................................................20

Annex E (informative) Laser extensometry ...............................................................................................................29

Annex F (informative) Video extensometry ...............................................................................................................37

Annex G (informative) Full field strain measurement video extensometry ......................................................41

Annex H (informative) Calibration of a cross-head measurement system .......................................................43

Bibliography .....................................................................................................................................................................44

© ISO 2012 – All rights reserved iii
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SIST EN ISO 9513:2013
ISO 9513:2012(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 9513 was prepared by Technical Committee ISO/TC 164, Mechanical testing of metals, Subcommittee

SC 1, Uniaxial testing.

This third edition cancels and replaces the second edition (ISO 9513:1999), which has been technically revised.

It also incorporates the Technical Corrigendum ISO 9513:1999/Cor.1:2000.
iv © ISO 2012 – All rights reserved
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SIST EN ISO 9513:2013
ISO 9513:2012(E)
Introduction

This International Standard sets out criteria for the calibration of extensometer systems, covering general

principles, the calibration equipment to be used, pre-calibration inspection and the measurement of

gaugelength for various types of extensometer systems. Aspects of the calibration process are addressed,

as are the assessment of the results, uncertainties, calibration intervals and reporting. Criteria for calibration

apparatus, their calibration and grading are addressed, complemented by a Bibliography covering a number of

[1] to [10]

important papers related to extensometer systems and their application . Work is in progress to develop

processes for dynamic extensometer calibration, however these have not reached, at the time of writing of this

International Standard, the level of development appropriate for inclusion within this International Standard. For

further information, refer to Reference [6].

Informative annexes address calculation of uncertainties of measurement for an extensometer system

calibration (Annex A), calibration of calibration apparatus (Annex B) and an example of a calibration report

(Annex C). Subsequent annexes address examples of extensometer system configurations (Annex D), laser

extensometry (Annex E), video extensometry (Annex F), full field extensometry (Annex G) and calibration of a

crosshead measurement system (Annex H).
© ISO 2012 – All rights reserved v
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SIST EN ISO 9513:2013
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SIST EN ISO 9513:2013
INTERNATIONAL STANDARD ISO 9513:2012(E)
Metallic materials — Calibration of extensometer systems used
in uniaxial testing
1 Scope

This International Standard specifies a method for the static calibration of extensometer systems used in

uniaxial testing, including axial and diametral extensometer systems, both contacting and non-contacting.

2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
extensometer system
equipment used to measure displacement or strain on the surface of a test piece

NOTE For the purpose of this International Standard, the term “extensometer system” includes the indicator.

Some extensometers indicate strain directly (e.g. laser extensometers or digital image correlation techniques). Other

extensometers indicate the change in gauge length of a test piece; this is converted into strain by dividing by the relevant

gauge length.
2.2
gauge length
portion of a test piece where extension is measured
3 Symbols and designations

Symbols used throughout this International Standard are given in Table 1 together with their designation.

Table 1 — Symbols and designations
Symbol Designation Unit
L Nominal gauge length of extensometer mm
L’ Measured gauge length of extensometer mm
l Maximum limit of calibration range mm
max
l Minimum limit of calibration range mm
min
l Displacement indicated by extensometer µm
l Displacement given by calibration apparatus µm
Relative gauge length error of the extensometer system
L %
q Relative bias error of the extensometer system %
q Absolute bias error of the extensometer system µm
r Resolution of the extensometer system µm
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SIST EN ISO 9513:2013
ISO 9513:2012(E)
4 Principle

The calibration of extensometer systems involves a comparison of the readings given by the extensometer with

known variations in length provided by a calibration apparatus.

NOTE 1 The user can define the displacement range(s) over which the calibration is to be performed. In this way, the

performance of the extensometer system can be optimized. For example, for strain-controlled low cycle fatigue, only a

small portion of the operating range of the extensometer is typically used. Hence, it would be appropriate, in this case, to

concentrate the calibration on the centre portion of the operating range.

The calibration process compares the known displacement from the calibration device with the output of

the extensometer system. This output can range from manual readings of high precision dial gauges to the

displacement indication of a transducer/electronics/data-logging system. In the latter case, the extensometer

system output would include any data curve fitting applied by the electronics/data-logging system.

NOTE 2 For certain types of extensometer systems, the calibration and classification will also be dependent upon the

ability of the extensometer system to define the gauge length.
5 Calibration equipment
5.1 Calibration apparatus

The calibration apparatus, which allows a known displacement l to be applied to the extensometer, may consist

of a rigid frame with suitable coaxial spindles or other fixtures to which the extensometer can be attached. The

calibration apparatus shall comprise a mechanism for moving at least one of the axial spindles together with a

device for accurately measuring the change in length produced. These variations in length can be measured by,

for example, an interferometer, a linear incremental encoder or gauge blocks and a comparator, or a micrometer.

NOTE Special attachments to the calibration apparatus spindles are utilized for the calibration of diametral

extensometers.

The calibration apparatus should be calibrated in accordance with Annex B and should meet the performance

requirements given in Table B.1.

Annex B gives a recommended calibration procedure for the calibration apparatus and details performance

criteria that indicate that the apparatus is suitable for calibrating extensometer systems in accordance with this

International Standard.
5.2 Calibration traceability

The calibration apparatus and the supporting equipment (such as micrometers, callipers, optical projection

microscopes) shall be calibrated using standards that are traceable to the International System of Units (SI).

The uncertainty associated with any measurements made by the supporting equipment shall not exceed one

third of the permissible error of the extensometer system being calibrated (see Table 2). The temperature

measurement instrument shall have a resolution of 0,1 °C.
6 Pre-calibration inspection
6.1 Objective

Prior to the calibration of the extensometer system it shall be inspected. This shall comprise, but not be limited to,

inspection of the mechanical components for, for example, free movement, damaged parts, worn knife edges,

and worn gauge length setting pins/fixtures. For extensometer systems incorporating electronic transducers,

the cabling and connectors shall be examined for damage, wear, etc.

The extensometer system shall be calibrated in the as-found condition if at all possible. The results shall be assessed

and, if necessary, the system shall be adjusted and re-calibrated. In this case, both data sets shall be reported.

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SIST EN ISO 9513:2013
ISO 9513:2012(E)
6.2 Records of the inspection

Records of the pre-calibration inspection shall be kept, identifying the “as-found” condition of the extensometer

system, when the inspection was performed and who performed it. These pre-calibration inspection records

can take the form of either a written report or a completed “pro-forma” checklist.

6.3 Identification of extensometer system elements

The extensometer shall be uniquely identified. Parts that may be changed by the user during normal use of the

extensometer that affect the calibration of the extensometer shall also be uniquely identified where possible.

However, this requirement does not extend to clamping devices used to attach the extensometer to the test

piece. These unique identifications form part of the records for the extensometer system.

7 Measurement of extensometer gauge length
7.1 Fixed gauge length extensometry

7.1.1 The measured gauge length, L′ , of a fixed gauge length extensometer shall be determined by either

direct or indirect means. In both cases, the extensometer setting pin or gauge fixture is used to set the

extensometer contact points to their pre-set displacement.

NOTE Variability of the measured gauge length might be experienced due to excessive play/wear in the gauge length

setting mechanism.

7.1.1.1 Direct measurement of the gauge length, L , is performed between the extensometer contact points,

using a calibrated measuring instrument such as a caliper or a shadowgraph/projection microscope.

7.1.1.2 Indirect measurement of the gauge length, L′ , is performed by placing the extensometer on a soft

metal test piece in such a way that the blades or points of the extensometer leave their marks. Once the

extensometer is removed, the distance between the marks on the test piece shall be measured, using equipment

with an accuracy consistent with the required class of extensometer.

7.1.2 The relative error on the gauge length, q , calculated from Formula (1) shall meet the requirements

given in Table 2.
LL−
q = ×100 (1)
7.2 Variable gauge length extensometry

7.2.1 The gauge length of a variable gauge length extensometer shall be measured either directly, or indirectly.

7.2.1.1 Direct measurement of the gauge length is performed by setting the extensometer to the required

gauge length using jigs, fixtures or other tools, followed by measurement between the extensometer contact

points, using a calibrated measuring instrument such as a calliper or a shadowgraph/projection microscope.

7.2.1.2 Indirect measurement of the gauge length, L is performed by attaching the extensometer to a soft

metal test piece in such a way that the blades or points of the extensometer leave their marks. Once the

extensometer is removed, the distance between the marks on the test piece is measured, using equipment with

an accuracy consistent with the required class of extensometer.

7.2.2 Extensometers commonly used in creep, elevated temperature tensile or stress relaxation testing have

their gauge length defined by small ridges machined on the parallel length of the test piece, to which the

© ISO 2012 – All rights reserved 3
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SIST EN ISO 9513:2013
ISO 9513:2012(E)

extensometer is clamped. The gauge length for such extensometers shall be determined directly from the test

piece and shall be to an accuracy consistent with the required class of extensometer.

7.2.3 The relative error on the gauge length, q , calculated from Formula (1), shall meet the requirements

given in Table 2.

7.2.4 Where an extensometer sets or measures the gauge length, the relative error on the gauge length shall

be determined. If features on the test piece define the gauge length, the relative error on the gauge length does

not need to be determined.

7.2.5 Where an extensometer automatically sets the gauge length, the maximum and minimum gauge lengths

used, plus three more gauge lengths between the minimum and maximum, shall be measured. Where fewer

than five gauge lengths are used, all gauge lengths shall be measured.
7.3 Non-contacting extensometry

The gauge length for non-contacting extensometry is established in accordance with the manufacturer’s

instructions.
7.4 Extensometer gauge lengths established using setting gauges

Where an extensometer gauge length is set using a removable gauge, the relative error on the gauge length,

q , calculated from Formula (1) shall not exceed the values given in Table 2.

The uncertainty of measuring the gauge length shall be three times better than the allowable error in gauge length.

8 Calibration process
8.1 Environmental considerations

8.1.1 The ambient temperature during the calibration of the extensometer system shall be recorded.

In general, the calibration of the extensometer system should be carried out at a temperature stable to within

± 2 °C, the target temperature being within the range 18 °C to 28 °C. Temperature changes during the calibration

process may add to the uncertainty of the calibration and in some cases may affect the ability to properly

calibrate the extensometer.

8.1.2 For extensometers used for uniaxial testing at temperatures outside the range 10 °C to 35 °C, the

calibration should be carried out at or near the test temperature, if facilities exist.

8.1.3 The extensometer shall be placed near the calibration apparatus, or be mounted on it, for a sufficient

length of time prior to its calibration so that the parts of the extensometer system and of the calibration apparatus

which are in contact stabilize at the calibration temperature.
8.2 Position of the extensometer

The extensometer shall be placed, wherever feasible, in the calibration apparatus in a similar orientation to that

in which it will be used during uniaxial testing to avoid errors due to loss of equilibrium or to deformation of any

part of the extensometer.
The extensometer shall be attached in a similar way as during uniaxial testing.
8.3 Calibration increments

8.3.1 The user shall establish the range of displacements over which the extensometer system shall be calibrated.

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SIST EN ISO 9513:2013
ISO 9513:2012(E)

8.3.2 The number of calibration points, and the number of ranges over which calibration is performed, shall

be based upon the relationship between the minimum displacement at which a property is determined, l , and

min
the maximum displacement at which a property is determined, l .
max
8.3.3 For monotonic tests, the following series of readings shall be made.

a) If (l /l ) is less than or equal to 10, one range of at least five increments shall be recorded.

max min

b) If (l /l ) is greater than 10 but less than or equal to 100, two ranges (l to 10l and 10l to l ),

max min min min min max

or (l to 0,1l and 0,1l to l ), each of at least five increments, shall be recorded.

min max max max

c) If (l /l ) is greater than 100, three ranges (l to 10l , 10l to 100l , 100l to l ), or (l to

max min min min min min min max min

0,01l , 0,01l to 0,1l , 0,1 l to l ), each of at least five increments, shall be recorded.

max max max max max

For each of the three categories [a), b), c) above], the increment between any two adjacent points shall not

exceed one third of the range. Examples of these increments are shown in Figure 1.

Key
1 calibration points
Figure 1 — Schematic diagram showing calibration point distribution

NOTE 1 A tensile test measuring, from the extensometer, the modulus and proof stresses only, would fall into category

a). A tensile test, establishing proof stresses and elongation at failure from the extensometer, or a creep to rupture test,

would fall into category b) or category c).

NOTE 2 For fatigue tests, a range of at least five increments (with the increment between any two adjacent p

...

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