Steel and iron - Determination of total carbon and sulfur content - Infrared absorption method after combustion in an induction furnace (routine method) (ISO 15350:2000)

This International Standard specifies an infrared absorption method, after combustion in an induction furnace, for the determination of the total carbon and sulfur content in steel and iron. The method is applicable to carbon contents of mass fraction between 0,005 % and 4,3 % and to sulfur contents of mass fraction between 0,000 5 % and 0,33 %. This method is intended to be used in normal production operations and is intended to meet all generally accepted, good laboratory practices of the type expected by recognized laboratory accreditation agencies. It uses commercially available equipment, is calibrated and calibration verified using steel and iron certified reference materials, and its performance is controlled using normal statistical process control (SPC) practices. This method can be used in the single element mode, i.e., determination of carbon and sulfur independently or in the simultaneous mode, i.e., determination of carbon and sulfur concurrently.

Stahl und Eisen - Bestimmung der Gesamtgehalte an Kohlenstoff und Schwefel - Infrarotabsorptionsverfahren nach Verbrennung in einem Induktionsofen (Standardverfahren) (ISO 15350:2000)

Diese Internationale Norm legt ein Verfahren mit Infrarotabsorption nach Verbrennung im Induktionsofen zur Bestimmung des gesamten Kohlenstoff- und Schwefelgehalts in Stahl und Eisen fest.
Das Verfahren ist anwendbar auf Kohlenstoff, der in Massenanteilen zwischen 0,005 % (m/m) und 4,3 % (m/m) vorliegt sowie auf Schwefel, der in Massenanteilen zwischen 0,000 5 % (m/m) und 0,33 % (m/m) vorliegt.
Es ist vorgesehen, dass dieses Verfahren im Rahmen der üblichen Produktionsabläufe angewendet wird und dass es allen allgemein üblichen Laborpraktiken entspricht, die von anerkannten Laborakkreditierungs-institutionen erwartet werden. Bei diesem Verfahren werden handelsüblich verfügbare Geräte sowie eine Kalibrierung und eine Verifizierung der Kalibrierung mit Hilfe zertifizierter Referenzmaterialien für Stahl und Eisen angewendet, und die Durchführung des Verfahrens wird unter Anwendung der üblichen Praktiken zur statistische Prozesskontrolle (SPC) überprüft.
Das Verfahren kann im Einelementmodus oder im Simultanmodus angewendet werden, d. h. Kohlenstoff oder Schwefel können unabhängig voneinander oder gleichzeitig bestimmt werden.

Aciers et fontes - Dosage du carbone et du soufre totaux - Méthode par absorption dans l'infrarouge après combustion dans un four à induction (méthode pratique) (ISO 15350:2000)

La présente Norme internationale spécifie une méthode pour le dosage du carbone et du soufre totaux dans les
aciers et les fontes, par absorption dans l'infrarouge après combustion dans un four à induction.
La méthode est applicable aux aciers et fontes avec des fractions massiques de carbone comprises entre 0,005 %
et 4,3 % et avec des fractions massiques de soufre comprises entre 0,000 5 % et 0,33 %.
La présente méthode est destinée à être utilisée lors d'opérations normales de production et à satisfaire toutes les
bonnes pratiques de laboratoire prévues et acceptées par les organismes reconnus d'accréditation de laboratoires.
Elle fait appel à tout appareillage disponible dans le commerce, est étalonnée et l'étalonnage est vérifié en utilisant
des matériaux de référence certifiés en acier et en fonte. Ses performances sont contrôlées au moyen de
procédures de maîtrise statistique des procédés (MSP).
La présente méthode peut être utilisée de manière séquentielle, c'est-à-dire pour doser individuellement le carbone
et le soufre, ou de manière simultanée, c'est-à-dire pour doser simultanément le carbone et le soufre.

Jeklo in železo - Določevanje celotnega ogljika in žvepla - Metoda z infrardečo absorpcijo po zgorevanju v indukcijski peči (rutinska metoda) (ISO 15350:2000)

Ta mednarodni standard opredeljuje metodo z infrardečo absorpcijo po zgorevanju v indukcijski peči za določevanje celotnega ogljika in žvepla v jeklu in železu. Metoda se uporablja za vsebnost ogljika z masno frakcijo od 0.005 do 4.3 % ter za vsebnost žvepla z masno frakcijo med 0.0005 in 0.33 %. Ta metoda je namenjena uporabi pri običajnih proizvodnih operacijah ter temu, da izpolnjuje vse splošno sprejete dobre laboratorijske prakse tipa, ki ga pričakujejo priznane akreditacijske agencije za laboratorije. Uporablja opremo, ki je na voljo na tržišču, je kalibrirana, kalibriranje pa potrjeno z uporabo jeklenih in železnih certificiranih referenčnih materialov, njena zmogljivost pa se nadzoruje z uporabo običajnih praks statističnega obvladovanja procesov (SOP). Ta metoda se lahko uporablja na način, ki vključuje en element, tj. ločeno določevanje ogljika in žvepla ali na istočasni način, tj. hkratno določevanje ogljika in žvepla.

General Information

Status
Published
Publication Date
03-Jun-2010
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
19-May-2010
Due Date
24-Jul-2010
Completion Date
04-Jun-2010

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Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 15350:2010
01-julij-2010
-HNORLQåHOH]R'RORþHYDQMHFHORWQHJDRJOMLNDLQåYHSOD0HWRGD]LQIUDUGHþR
DEVRUSFLMRSR]JRUHYDQMXYLQGXNFLMVNLSHþL UXWLQVNDPHWRGD  ,62
Steel and iron - Determination of total carbon and sulfur content - Infrared absorption
method after combustion in an induction furnace (routine method) (ISO 15350:2000)
Stahl und Eisen - Bestimmung der Gesamtgehalte an Kohlenstoff und Schwefel -
Infrarotabsorptionsverfahren nach Verbrennung in einem Induktionsofen
(Standardverfahren) (ISO 15350:2000)
Aciers et fontes - Dosage du carbone et du soufre totaux - Méthode par absorption dans
l'infrarouge après combustion dans un four à induction (méthode pratique) (ISO
15350:2000)
Ta slovenski standard je istoveten z: EN ISO 15350:2010
ICS:
77.080.01 Železne kovine na splošno Ferrous metals in general
SIST EN ISO 15350:2010 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 15350:2010

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SIST EN ISO 15350:2010


EUROPEAN STANDARD
EN ISO 15350

NORME EUROPÉENNE

EUROPÄISCHE NORM
April 2010
ICS 77.080.01
English Version
Steel and iron - Determination of total carbon and sulfur content
- Infrared absorption method after combustion in an induction
furnace (routine method) (ISO 15350:2000)
Aciers et fontes - Dosage du carbone et du soufre totaux - Stahl und Eisen - Bestimmung der Gesamtgehalte an
Méthode par absorption dans l'infrarouge après combustion Kohlenstoff und Schwefel - Infrarotabsorptionsverfahren
dans un four à induction (méthode pratique) (ISO nach Verbrennung in einem Induktionsofen
15350:2000) (Standardverfahren) (ISO 15350:2000)
This European Standard was approved by CEN on 18 March 2010.

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 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 Management Centre has the same status as the
official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.






EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2010 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15350:2010: E
worldwide for CEN national Members.

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SIST EN ISO 15350:2010
EN ISO 15350:2010 (E)
Contents Page
Foreword .3

2

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SIST EN ISO 15350:2010
EN ISO 15350:2010 (E)
Foreword
The text of ISO 15350:2000 has been prepared by Technical Committee ISO/TC 17 “Steel” of the International
Organization for Standardization (ISO) and has been taken over as EN ISO 15350:2010 by Technical
Committee ECISS/TC 102 “Methods of chemical analysis for iron and steel” the secretariat of which is held by
SIS.
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 October 2010, and conflicting national standards shall be withdrawn at
the latest by October 2010.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 15350:2000 has been approved by CEN as a EN ISO 15350:2010 without any modification.

3

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SIST EN ISO 15350:2010

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SIST EN ISO 15350:2010
INTERNATIONAL ISO
STANDARD 15350
First edition
2000-12-15
Steel and iron — Determination of total
carbon and sulfur content — Infrared
absorption method after combustion in an
induction furnace (routine method)
Aciers et fontes — Dosage du carbone et du soufre totaux — Méthode par
absorption dans l'infrarouge après combustion dans un four à induction
(méthode pratique)
Reference number
ISO 15350:2000(E)
©
ISO 2000

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SIST EN ISO 15350:2010
ISO 15350:2000(E)
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ii © ISO 2000 – All rights reserved

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SIST EN ISO 15350:2010
ISO 15350:2000(E)
Contents Page
Foreword.iv
1 Scope .1
2 Normative references .1
3 Principle.2
4 Reagents.2
5 Apparatus .3
6 Test method.3
7 Sampling.4
8 Procedure .4
9 Expression of results .10
10 Test report .11
Annex A (informative) Examples of diagram for analytical principles .13
Annex B (informative) Example calculation of a linearity check.19
Annex C (informative) Additional information on international cooperative tests.20
Annex D (informative) Graphical representation of precision data .24
© ISO 2000 – All rights reserved iii

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SIST EN ISO 15350:2010
ISO 15350:2000(E)
Foreword
SO (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 3.
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 International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 15350 was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 1,
Methods of determination of chemical composition.
Annexes A to D of this International Standard are for information only.
iv © ISO 2000 – All rights reserved

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SIST EN ISO 15350:2010
INTERNATIONAL STANDARD ISO 15350:2000(E)
Steel and iron — Determination of total carbon and sulfur
content — Infrared absorption method after combustion in an
induction furnace (routine method)
1 Scope
This International Standard specifies an infrared absorption method, after combustion in an induction furnace, for
the determination of the total carbon and sulfur content in steel and iron.
The method is applicable to carbon contents of mass fraction between 0,005 % and 4,3 % and to sulfur contents of
mass fraction between 0,000 5 % and 0,33 %.
This method is intended to be used in normal production operations and is intended to meet all generally accepted,
good laboratory practices of the type expected by recognized laboratory accreditation agencies. It uses
commercially available equipment, is calibrated and calibration verified using steel and iron certified reference
materials, and its performance is controlled using normal statistical process control (SPC) practices.
This method can be used in the single element mode, i.e., determination of carbon and sulfur independently or in
the simultaneous mode, i.e., determination of carbon and sulfur concurrently.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 437:1982, Steel and cast iron — Determination of total carbon content — Combustion gravimetric method.
ISO 4934:1980, Steel and cast iron — Determination of sulfur content — Gravimetric method.
ISO 4935:1989, Steel and iron — Determination of sulfur content — Infrared absorption method after combustion in
an induction furnace.
ISO 5725-1:1994, Accuracy (trueness and precision) of measurement methods and results — Part 1: General
principles and definitions.
ISO 5725-2:1994, Accuracy (trueness and precision) of measurement methods and results — Part 2: Basic method
for the determination of repeatability and reproducibility of a standard measurement method.
ISO 5725-3:1994, Accuracy (trueness and precision) of measurement methods and results — Part 3: Intermediate
measures of the precision of a standard measurement method.
ISO 9556:1989, Steel and Iron — Determination of total carbon content — Infrared absorption method after
combustion in an induction furnace.
ISO 10701:1994, Steel and iron — Determination of sulfur content — Methylene blue spectrophotometric method.
© ISO 2000 – All rights reserved 1

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SIST EN ISO 15350:2010
ISO 15350:2000(E)
ISO 13902:1997, Steel and iron — Determination of high sulfur content — Infrared absorption method after
combustion in an induction furnace.
ISO 14284:1996, Steel and iron — Sampling and preparation of samples for the determination of chemical
composition.
3Principle
3.1 Carbon
The carbon is converted to carbon monoxide and/or carbon dioxide by combustion in a stream of oxygen.
Measurement is by infrared absorption of the carbon monoxide and carbon dioxide carried by a current of oxygen.
3.2 Sulfur
The sulfur is converted to sulfur dioxide by combustion in a stream of oxygen. Measurement is by infrared
absorption of the sulfur dioxide carried by a current of oxygen.
4 Reagents
4.1 Acetone, the residue after evaporation shall have a mass fraction less than 0,000 5 %.
4.2 Cyclohexane, the residue after evaporation shall have a mass fraction less than 0,000 5 %.
4.3 Inert ceramic, attapulques clay impregnated with sodium hydroxide and having particle sizes from 0,7 mm
to 1,2 mm for absorption of carbon dioxide.
4.4 Pure iron, used as an accelerator, 0,4 mm to 0,8 mm size with carbon and sulfur contents with a mass
fraction of less than 0,001 % respectively.
4.5 Magnesium perchlorate, reagent grade, having particle size from 0,7 mm to 1,2 mm for absorption of
moisture.
4.6 Oxygen, ultra high purity (mass fraction minimum 99,5 % )
An oxidation catalyst [copper(II) oxide or platinum] tube heated to 600�C followed by suitable carbon dioxide and
water absorbents shall be used when the presence of organic contaminants is suspected in the oxygen.
4.7 Platinum or platinized silica, heated to 350�C for the conversion of carbon monoxide to carbon dioxide.
4.8 Accelerator, copper, tungsten-tin or tungsten for carbon determination and tungsten for sulfur determination,
0,4 mm to 0,8 mm size with carbon and sulfur contents of mass fraction less than 0,001 % and 0,000 5 %
respectively.
4.9 Cellulose cotton, for the collection of sulfur trioxide
4.10 Steel and iron certified reference materials (CRMs), all reference materials used for calibration and
calibration verification shall be certified by internationally-recognized bodies and validated by adequate
performance on one or more national or international interlaboratory test programmes. Preference shall be given to
materials that were certified using referee methods, e.g. ISO 437 and ISO 9556 for carbon, and ISO 4934,
ISO 4935, ISO 10701 and ISO 13902 for sulfur, traceable to SI units as opposed to those based on other certified
reference materials.
4.11 Steel and iron reference materials (RMs), those used for statistical process control of the method need not
be certified, but adequate homogeneity data shall be available, either from the certifying body or from the laboratory
that uses the material, in order to ensure the validity of the control data generated.
2 © ISO 2000 – All rights reserved

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SIST EN ISO 15350:2010
ISO 15350:2000(E)
5 Apparatus
Ordinary laboratory equipment plus the following shall be used.
5.1 C and/or S determinator, consisting of an IR energy source, a separate measuring chamber and reference
chamber, and a diaphragm acting as one plate of a parallel plate capacitor.
5.2 Ceramic crucible, as specified by the manufacturer of the instrumentation used and capable of withstanding
combustion in an induction furnace without evolving carbon- and sulfur-containing chemicals so that achieving and
maintaining blank values within specification is possible.
NOTE Carbon and sulfur contamination can usually be removed by igniting the crucibles in an electric furnace in air for not
less than 40 min at 1 000 �C or not less than 15 min at 1 350 �C. After treatment, remove them from the heat, allow them to cool
for 2 min to 3 min on an appropriate clean heat-resistant tray and then store them in a desiccator.
5.3 Crucible tongs, capable of handling recommended crucibles (5.2).
6 Test method
This test method is written for use with commercial analysers, equipped to carry out the included operations
automatically and calibrated using steels and irons of known carbon and sulfur contents.
The analyser used will be satisfactory if it meets the criteria listed in clause 8.
6.1 Infrared (IR) absorption for carbon — Method A
The amount of carbon dioxide is measured by infrared absorption. Carbon dioxide (CO ) absorbs IR energy at a
2
precise wavelength within the IR spectrum. Energy of this wavelength is absorbed as the gas passes through a cell
body in which the IR energy is transmitted. All other IR energy is prevented from reaching the detector by use of a
precise wavelength filter. Thus, the absorption of IR energy can only be attributed to CO and its concentration is
2
measured as changes in energy at the detector. One cell is used as both a reference and a measuring chamber.
Total carbon, as CO , is monitored and measured over a period of time. See Figure A.1.
2
6.2 Infrared (IR) absorption for carbon — Method B
During specimen combustion, the flow of CO with its oxygen gas carrier is routed through the measuring chamber
2
(see 5.1) while oxygen alone passes through the reference chamber. Energy from the IR source passes through
both chambers, simultaneously arriving at the diaphragm (capacitor plate). Part of the IR energy is absorbed by the
CO present in the measuring chamber while none is absorbed passing through the reference chamber. This
2
creates an IR energy imbalance reaching the diaphragm, thus distorting it. This distortion alters the fixed
capacitance creating an electric signal change that is amplified for measurement as CO . Total carbon, as CO ,is
2 2
monitored and measured over a period of time. See Figure A.2.
6.3 Infrared (IR) absorption for carbon — Method C, closed loop
The combustion is performed in a closed loop, where CO and CO are detected in the same infrared cell. Each gas
2
is measured using a solid state energy detector. Filters are used to pass the appropriate IR wavelength to each
detector. In the absence of CO and CO , the energy received by each detector is maximum. During combustion,
2
the IR absorption properties of CO and CO gases in the chamber cause a loss of energy; therefore a loss in signal
2
results which is proportional to concentrations of each gas in the closed loop. Total carbon, as CO plus CO, is
2
monitored and measured over a period of time. See Figure A.3.
6.4 Infrared absorption for sulfur — Method A
Sulfur dioxide (SO ) absorbs infrared (IR) energy at a precise wavelength within the IR spectrum. Energy of this
2
wavelength is absorbed as the gas passes through a cell body in which the IR energy is transmitted. All other IR
energy is prevented from reaching the detector by use of a precise wavelength filter. Therefore, the absorption of
© ISO 2000 – All rights reserved 3

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SIST EN ISO 15350:2010
ISO 15350:2000(E)
IR energy can only be attributed to SO and its concentration is measured as changes in energy at the detector.
2
One cell is used as both a reference and a measure chamber. Total sulfur, as SO , is monitored and measured
2
over a period of time. See Figure A.4.
6.5 Infrared absorption for sulfur — Method B
During specimen combustion, the flow of SO with its oxygen gas carrier is routed through the measuring chamber
2
(see 5.1) while oxygen alone passes through the reference chamber. Energy from the IR source passes through
both chambers, simultaneously arriving at the diaphragm (capacitor plate). Part of the IR energy is absorbed by the
SO present in the measuring chamber while none is absorbed passing through the reference chamber. This
2
creates an IR energy imbalance reaching the diaphragm, thus distorting it. This distortion alters the fixed
capacitance creating an electric signal change that is amplified for measurement as SO . Total SO is monitored
2 2
and measured over a period of time. See Figure A.5.
6.6 Infrared absorption for sulfur — Method C, closed loop
The combustion is performed in a closed loop where SO is detected in an infrared cell. The SO is measured
2 2
using a solid state energy detector, and filters are used to pass the appropriate IR wavelength to the detector.
During combustion, the IR absorption properties of the SO gas in the chamber causes a loss of energy, therefore
2
a loss in signal results which is proportional to the concentration of the gas in the closed loop. Total sulfur, as SO ,
2
is monitored and measured over a period of time. See Figure A.6.
7 Sampling
Carry out sampling in accordance with ISO 14284 or appropriate national standards for iron and steel.
8 Procedure
WARNING — The risks related to combustion analysis are mainly burns in pre-igniting the ceramic
crucibles and in effecting fusion. Use crucible tongs at all times and suitable containers for the used
crucibles. Normal precautions for handling oxygen cylinders shall be taken. Oxygen from the combustion
process shall be effectively removed from the apparatus since a high concentration of oxygen in a
confined space can present a fire hazard.
8.1 Preparation of apparatus
Assemble the apparatus and prepare it for operation according to the manufacturer's instructions. Test the furnace
and analyser to ensure the absence of leaks. Make a minimum of five determinations using a specimen with
measurable concentrations of carbon and sulfur and accelerator as directed in 8.3 before attempting to calibrate
the system or determine the blank.
8.2 Test portion
8.2.1 The sample shall be uniform in size, but not finer than 0,4 mm. It shall also be free of oil, grease and other
contaminants, particularly those that could augment the carbon and sulfur contents of the sample. The same size of
portion of test material shall be taken for both calibration and analysis and shall be in accordance with the
manufacturer's instructions.
Wash contaminated samples and those which contain a mass fraction of less than 0,02 % carbon in acetone,
cyclohexane or other suitable solvent, and dry at 70�C to 100�C.
Weigh, to the nearest 1 mg, a suitable amount of test sample depending on the capability of induction furnace and
analyte content.
4 © ISO 2000 – All rights reserved

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SIST EN ISO 15350:2010
ISO 15350:2000(E)
8.2.2 The laboratory should ensure that its samples are not contaminated with carbon- and/or sulfur-containing
materials. Specific sample preparation methods are not included in this International Standard. It is recommended
that from time to time the laboratory conduct controlled, replicate determinations on portions of analysis-ready and
analysis-ready/solvent-cleaned samples at different concentrations in order to detect contamination. If there are
statistically significant differences between the analysis-ready and the analysis-ready/solvent-cleaned portions,
sample preparation procedures should be reviewed and revised, as appropriate.
8.3 Calibration
8.3.1 Carbon
8.3.1.1 Establishing calibration ranges and selecting CRMs
Establish the total range of carbon contents to be analysed in the laboratory using this method and then divide it
into sub-parts as given in the Table 1.
Table 1 — Calibration range of carbon
Instrument range designation Calibration range
mass fraction
%
I 0,005 to 0,120
II 0,10 to 1,25
III 1,0 to 4,3
The instrument ranges given in Table 1 were selected to achieve optimum instrument performance and to set
parameters for interlaboratory testing. They overlap slightly to provide operating flexibility. It is important to note
that carbon contents with a mass fraction below 0,005 % or above 5 % are outside the tested range and therefore
such results cannot be claimed to have been determined in compliance with this standard method. In like manner,
laboratories are not obliged to calibrate over all three ranges if these are not required to meet the workload
requirements.
Finally, reasonable deviations from these ranges may be made to accommodate to workload requirements the
need for flexibility in matching the calibration ranges for both carbon and sulfur in simultaneous determinators.
Select a set of CRMs (4.10) for calibration and verification which, at a minimum, fall at the bottom, top, and quartile
points of each operational operating range. In addition, select a CRM very low in carbon content for use in
establishing the blank.
8.3.1.2 Adjust response of measurement system
If the instrument has more than one carbon detector (measurement system) perform the adjustment described in
this sectiononeachone.
NOTE 1 The sole purpose of this section is to provide a calibration of sufficient accuracy to establish the blank.
Establish all experimental parameters for all ranges of carbon. If simultaneous carbon and sulfur determinations are
to be made, make sure that all parameters for the corresponding channels are the same. Parameters to be
specified include:
� crucible: to pre-burn or not;
� accelerator: type and mass;
� sample size: mass.
© ISO 2000 – All rights reserved 5

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SIST EN ISO 15350:2010
ISO 15350:2000(E)
It is highly recommended that crucibles be pre-burned to minimize the magnitude and variability of the blank.
Transfer the selected mass of an RM (4.11) containing about 0,05 % carbon by mass fraction, weighed to the
nearest 1 mg and the selected mass of accelerator, weighed to the nearest 5 mg, to a crucible (5.2). Place the
crucible on the furnace pedestal and raise the pedestal into position. Use crucible tongs (5.3) to handle pre-burned
crucibles.
Start the analysis cycle; referring to the manufacturer's recommended procedure regarding entry of specimen
weight and blank value.
Repeat the analysis of the RM (4.11) until the absence of drift is indicated. Following the manufacturer's
instructions adjust the signal to provide a reading within 0,003 % mass fraction carbon value for the RM.
8.3.1.3 Determination of blank reading
For each instrument range, transfer the selected mass of accelerator, to the nearest 0,005 g, into a crucible. Add
the selected mass of the CRM (4.10) to be used to measure the carbon blank. Enter the mass of the CRM into the
instrument's weight compensator. Place the crucible on the furnace pedestal and analyse. Repeat the
determination three more times. Average the results. Subtract the carbon content of the CRM from the average to
determine the blank value. If the blank is greater than 0,002 % by mass fraction and the standard deviation is
greater than 0,000 5 % by mass fraction, find the cause of the problem, fix it, and repeat the experiment. Enter the
average blank value into the analyser in accordance with the manufacturer's instructions.
The mass of accelerator taken should be adjusted, if necessary, to match the amount specified in 8.3.1.2. If the
analyser does not have automatic blank correction, the blank value should be subtracted from the total result prior
to any calculation.
8.3.1.4 Establish calibration curves
Using CRMs (4.10) selected appropriately from the list created in 8.3.1.1, calibrate the instrument for the ranges
indicated in 8.3.1.1, using the blank values determined in 8.3.1.3 in accordance with the manufacturer's
instructions. If the software supplied with the instrument does not allow curve-fitting with multiple calibrants,
calibrate it as instructed by the manufacturer and then immediately analyse all the calibrants as unknowns.
Evaluate the results against the manufacturer’s requirements. Correct any non-compliant conditions before
continuing to the next step.
8.3.2 Sulfur
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