SIST EN 16568:2015
(Main)Automotive fuels - Fatty acid methyl ester (FAME) fuel and blends with diesel fuel - Determination of oxidation stability by rapidly accelerated oxidation method at 120 °C
Automotive fuels - Fatty acid methyl ester (FAME) fuel and blends with diesel fuel - Determination of oxidation stability by rapidly accelerated oxidation method at 120 °C
This European Standard specifies a test method for the determination of the oxidation stability of fuels for diesel engines, by means of measuring the induction period of the fuel up to 48 h at 120 °C. The method is applicable to fatty acid methyl esters (FAME) intended for the use as pure biofuel or as a blending component for diesel fuels, and to blends of FAME with petroleum-based diesel containing 2 % (V/V) of FAME at minimum.
NOTE 1 A similar test method for oxidation stability at 110 °C is described in EN 15751 [1], which applies to pure FAME and Diesel/FAME blends containing 2 % (V/V) of FAME at minimum. Another alternative for distillate fuels is described in EN ISO 12205 [3].
NOTE 2 For induction periods higher than 48 h the precision is not covered by the precision statement of this method. The limit values of the relevant fuel standards are well within the scope of this test method.
The presence of cetane improver can reduce the oxidation stability determined by this test method. Limited studies with 2-ethyl hexyl nitrate (EHN) indicated, however, that the stability is reduced to an extent which is within the precision range of the test method.
Kraftstoffe für Kraftfahrzeuge - Kraftstoff Fettsäure-Methylester (FAME) und Mischungen mit Dieselkraftstoff - Bestimmung der Oxidationsstabilität mittels beschleunigterem Oxidationsverfahren bei 120 °C
Diese europäische Norm legt eine Prüfmethode zur Bestimmung der Oxidationsstabilität von Kraftstoffen für Dieselmotoren fest, bei der die Induktionszeit des Kraftstoffs bei 120 °C über einen Zeitraum von bis zu 20 h gemessen wird. Die Methode ist anwendbar auf FAME-Blendkraftstoffe zur Verwendung mit Diesel auf Rohölbasis mit einem FAME-Gehalt im Bereich von 2 % (V/V) und 50 % (V/V).
ANMERKUNG 1 EN 15751 beschreibt eine nahezu identische Prüfmethode zur Bestimmung der Oxidationsstabilität bei 110 °C, anwendbar für reines FAME und Diesel/FAME-Blendkraftstoffe mit einem Mindestgehalt von 2 % (V/V) FAME. Eine weitere Alternative für Destillatkraftstoffe ist die EN ISO 12205 [3].
ANMERKUNG 2 Die Präzision dieses Verfahrens wurde anhand von Proben mit einer maximalen Induktionszeit von ~ 20h bestimmt. Höhere Induktionszeiten werden nicht von der Präzisionsangabe dieser Methode abgedeckt. Die Erfahrung aus EN 15751 lässt jedoch ausreichend Präzision bis zu 48h vermuten.
ANMERKUNG 3 Die Gegenwart eines Cetanzahlverbesserers kann die durch diese Prüfmethode bestimmte Oxidationsstabilität herabsetzen. Begrenzte Studien mit 2-Ethylhexylnitrat (EHN) zeigten allerdings auf, dass die Oxidations-stabilität nur in einem Umfang reduziert wird, der innerhalb der Präzision der Prüfmethode liegt.
ANMERKUNG 4 Für die Anwendung der vorliegenden Europäischen Norm wird der Ausdruck „% (V/V)“ verwendet, um den Volumenanteil darzustellen.
Carburants automotives - Esters méthyliques d'acides gras (EMAG) et mélanges avec gazole - Détermination de la stabilité à l'oxydation accélérée rapide à 120 °C
Goriva za motorna vozila - Metilni estri maščobnih kislin (FAME) goriv in mešanic z dizelskim gorivom - Določevanje oksidacijske stabilnosti z metodo pospešene oksidacije pri 120 °C
Ta evropski standard določa preskusno metodo za ugotavljanje oksidativne stabilnosti goriv za dizelske motorje z merjenjem indukcijskega časa goriva do 48 ur pri temperaturi 120 °C. Metoda se uporablja za metilne estre maščobnih kislin (FAME), ki so namenjeni za uporabo kot čisto biogorivo ali kot komponenta za mešanje z dizelskimi gorivi, in za mešanice metilnih estrov maščobnih kislin z dizelskim gorivom, ki vsebujejo najmanj 2 % (V/V) metilnih estrov maščobnih kislin.
OPOMBA 1 Podobna preskusna metoda za oksidativno stabilnost pri temperaturi 110 °C je opisana v standardu EN 15751 [1], ki velja za čiste metilne estre maščobnih kislin in mešanice dizelskih goriv in metilnih estrov maščobnih kislin, ki vsebujejo najmanj 2 % (V/V) metilnih estrov maščobnih kislin. Druga možnost za destilate goriv je opisana v standardu EN ISO 12205 [3].
OPOMBA 2 Izjava o natančnosti te metode ne zajema natančnosti za obdobja indukcije, daljša od 48 ur. Mejne vrednosti ustreznih standardov za gorivo sodijo v področje uporabe te preskusne metode.
S prisotnostjo aditiva za izboljšanje cetana je mogoče zmanjšati oksidativno stabilnost, ki jo določa ta preskusna metoda. Omejene študije z 2-etil heksil nitratom (EHN) nakazujejo, da je stabilnost zmanjšana do stopnje, ki je v območju natančnosti preskusne metode.
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Kraftstoffe für Kraftfahrzeuge - Kraftstoff Fettsäure-Methylester (FAME) und Mischungen mit Dieselkraftstoff - Bestimmung der Oxidationsstabilität mittels beschleunigterem Oxidationsverfahren bei 120 °CCarburants automotives - Esters méthyliques d'acides gras (EMAG) et mélanges avec gazole - Détermination de la stabilité à l'oxydation accélérée rapide à 120 °CAutomotive fuels - Fatty acid methyl ester (FAME) fuel and blends with diesel fuel - Determination of oxidation stability by rapidly accelerated oxidation method at 120 °C75.160.20Liquid fuelsICS:Ta slovenski standard je istoveten z:EN 16568:2014SIST EN 16568:2015en,fr,de01-marec-2015SIST EN 16568:2015SLOVENSKI
STANDARD
SIST EN 16568:2015
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 16568
December 2014 ICS 75.160.20 English Version
Automotive fuels - Blends of Fatty acid methyl ester (FAME) withdiesel fuel - Determination of oxidation stability by rapidly accelerated oxidation method at 120 °C
Carburants pour automobiles - Esters méthyliques d'acides gras (EMAG) et mélanges avec gazole - Détermination de la stabilité à l'oxydation par méthode d'oxydation plus accélérée à 120 °C
Kraftstoffe für Kraftfahrzeuge - Mischungen von Fettsäure-Methylestern (FAME) mit Dieselkraftstoff - Bestimmung der Oxidationsstabilität mittels beschleunigterem Oxidationsverfahren bei 120 °C This European Standard was approved by CEN on 9 November 2014.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16568:2014 ESIST EN 16568:2015
EN 16568:2014 (E) 2 Contents Page Foreword .3 Introduction .4 1 Scope .5 2 Normative references .5 3 Terms and definitions .5 4 Principle .5 5 Reagents and materials .6 6 Apparatus .6 7 Sampling .8 8 Preparation of measurement .8 8.1 Preparation of test sample .8 8.2 Preparation of the apparatus .8 8.2.1 Cleaning procedure .8 8.2.2 Temperature correction .9 9 Measurement . 10 10 Calculation and evaluation . 12 10.1 Automatic evaluation . 12 10.2 Manual evaluation . 13 11 Expression of results . 13 12 Precision . 13 12.1 General . 13 12.2 Repeatability, r . 14 12.3 Reproducibility, R . 14 13 Test report . 14 Annex A (informative)
Background of the method . 15 Bibliography . 16
SIST EN 16568:2015
EN 16568:2014 (E) 3 Foreword This document (EN 16568:2014) has been prepared by Technical Committee CEN/TC 19 “Gaseous and liquid fuels, lubricants and related products of petroleum, synthetic and biological origin”, the secretariat of which is held by NEN. 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 2015 and conflicting national standards shall be withdrawn at the latest by June 2015. 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, 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. SIST EN 16568:2015
EN 16568:2014 (E) 4 Introduction This document is based on EN 15751 [1], which was specifically developed for the determination of oxidation stability of fatty acid methyl ester (FAME) and blended petroleum based diesel fuels. The oxidation stability is assessed by determining the induction period of the fuel. The induction period is a measure for the ageing reserve of the fuel. The first version of EN 15751 was developed under CEN/TC 19 for a test temperature of 110 °C in order to stay directly comparable to EN 14112 [2] which is used to determine the oxidation stability of pure FAME. The stability of diesel/FAME blends is generally higher compared to pure FAME thus leading to long measuring times. In order to better accommodate the needs of laboratories the idea was raised to increase the reaction temperature to 120 °C. Degradation of the ageing reserve of the fuel follows the Arrhenius law. By increasing the temperature by 10 °C, the reaction rate is doubled cutting in half the induction period. The modifications to EN 15751, as given in this document, allow the application of this test method for oxidation stability for diesel/FAME blends containing 2 % (V/V) of FAME at minimum. This test method is not applicable to pure FAME. Pure FAME was not included in the scope because of reduced ability to differentiate between different qualities when the induction period is reduced by 50 %. The temperature increase required a new validation for diesel/FAME blends. Blends with up to 50 % (V/V) of FAME were selected in order to comprise also high FAME blends which are presently discussed for automotive use. Due to concerns about a potential impact of cetane improvers, an additional study with
2-ethyl hexyl nitrate (2-EHN) at 110 °C and 120 °C was performed. SIST EN 16568:2015
EN 16568:2014 (E) 5 1 Scope This European Standard specifies a test method for the determination of the oxidation stability at 120 °C of fuels for diesel engines, by means of measuring the induction period of the fuel up to 20 h. The method is applicable to blends of FAME with petroleum-based diesel having a FAME content in the range between 2 % (V/V) and 50 % (V/V). NOTE 1 An almost identical test method for oxidation stability at 110 °C is described in EN 15751 [1], which applies to pure FAME and diesel/FAME blends containing 2 % (V/V) of FAME at minimum. Another alternative for distillate fuels is described in EN ISO 12205 [3]. NOTE 2 The precision of this method was determined using samples with a maximum induction period of approximately 20 h. Higher induction periods are not covered by the precision statement, however, the experience from EN 15751 indicates sufficient precision up to 48 h. NOTE 3 The presence of cetane improver can reduce the oxidation stability determined by this test method. Limited studies with 2-ethyl hexyl nitrate (EHN) indicated, however, that the stability is reduced to an extent which is within the precision range of the test method. NOTE 4 For the purposes of this European Standard, the term “% (V/V)” is used to represent the volume fraction (m) of a material. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 3170,
EN ISO 3171,
EN ISO 3696, tater for analytical laboratory use
3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 induction period time which passes between the moment when the measurement is started and the moment when the formation of oxidation products begins to increase rapidly 3.2 oxidation stability induction period determined according to the procedure specified in this European Standard, expressed in hours 4 Principle A stream of purified air is passed through the sample which has been heated to the specified, elevated temperature. Volatile compounds are formed during the oxidation process. They are passed together with the air into a measurement cell containing demineralised or distilled water, equipped with a conductivity electrode. The electrode is connected to a measuring and recording device. It indicates the end of the induction period by rapid increase of the conductivity due to the dissociation of volatile carboxylic acids produced during the oxidation process and absorbed in the water. For more details on the background of the method see Annex A. SIST EN 16568:2015
EN 16568:2014 (E) 6 5 Reagents and materials Use only reagents of recognized analytical grade, and distilled or demineralised water according to EN ISO 3696. 5.1 Ternary solvent mixture, consisting of methanol/toluene/acetone 1 : 1 : 1 (by volume). 5.2 Alkaline laboratory glass cleaning solution. 5.3 2-Propanol. 6 Apparatus Usual laboratory equipment and glassware, together with the following: 6.1 Device for the determination of oxidation stability, comprising the following parts (see Figure 1 and Figure 2): NOTE An instrument for determining the oxidation stability is commercially available under the trade name Rancimat®, (model 743 or higher, from Metrohm AG, Herisau, Switzerland) or OSI® Instrument (from Omnion Inc., Rockland, Massachusetts, USA). These are examples of suitable equipment which are given for the convenience of users of this document. They do not constitute an endorsement by CEN of this equipment.
Key 1 air filter (6.1.1) 5 electrode (6.1.5) 2 gas membrane pump with flow rate control (6.1.2) 6 measuring and recording apparatus (6.1.6) 3 reaction vessel (6.1.3) 7 thyristor and contact thermometer (6.1.7) 4 measurement cell (6.1.4) 8 heating block (6.1.8) Figure 1 — Apparatus 6.1.1 Air filter, comprising a tube fitted with filter paper at the ends and filled with a molecular sieve (6.6), connected to the suction end of a pump. 6.1.2 Gas membrane pump, with an adjustable flow rate of (10 ± 1,0) l/h. 6.1.3 Reaction vessels of borosilicate glass, provided with a sealing cap. SIST EN 16568:2015
EN 16568:2014 (E) 7 The length of the reaction vessel depends on the measuring equipment and shall exceed the depth of the oven by at least 130 mm, in order to reduce evaporation losses to a minimum by condensing volatile fuel components at the cold vessel walls outside the oven. EXAMPLE Total length of the test tube for the Metrohm Rancimat 743 L = 250 mm, for the Omnion OSI Instrument L = 300 mm. The sealing cap shall be fitted with an air inlet and outlet tube. 6.1.4 Closed measurement cells of approximately 150 ml capacity, with an air inlet tube extending to the bottom inside of the vessel. The cell shall have ventilation holes at the top. 6.1.5 Electrodes for measuring the conductivity within a range from 0 µS/cm to 300 µS/cm aligned with the dimensions of the measurement cell (6.1.4). 6.1.6 Measuring and recording apparatus, comprising of: a) an amplifier and b) a recorder registering the signal of e
...
SLOVENSKI STANDARD
oSIST prEN 16568:2013
01-maj-2013
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Automotive fuels - Fatty acid methyl ester (FAME) fuel and blends with diesel fuel -
Determination of oxidation stability by rapidly accelerated oxidation method at 120 °C
Kraftstoffe für Kraftfahrzeuge - Kraftstoff Fettsäure-Methylester (FAME) und Mischungen
mit Dieselkraftstoff - Bestimmung der Oxidationsstabilität mittels beschleunigterem
Oxidationsverfahren bei 120 °C
Carburants automotives - Esters méthyliques d'acides gras (EMAG) et mélanges avec
gazole - Détermination de la stabilité à l'oxydation accélérée rapide à 120 °C
Ta slovenski standard je istoveten z: prEN 16568
ICS:
75.160.20 7HNRþDJRULYD Liquid fuels
oSIST prEN 16568:2013 en,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 16568:2013
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oSIST prEN 16568:2013
EUROPEAN STANDARD
DRAFT
prEN 16568
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2013
ICS
English Version
Automotive fuels - Fatty acid methyl ester (FAME) fuel and
blends with diesel fuel - Determination of oxidation stability by
rapidly accelerated oxidation method at 120 °C
Carburants automotives - Esters méthyliques d'acides gras Kraftstoffe für Kraftfahrzeuge - Kraftstoff Fettsäure-
(EMAG) et mélanges avec gazole - Détermination de la Methylester (FAME) und Mischungen mit Dieselkraftstoff -
stabilité à l'oxydation accélérée rapide à 120 °C Bestimmung der Oxidationsstabilität mittels
beschleunigterem Oxidationsverfahren bei 120 °C
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 19.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 16568:2013: E
worldwide for CEN national Members.
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oSIST prEN 16568:2013
prEN 16568:2013 (E)
Contents Page
Foreword .3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .5
4 Principle .5
5 Reagents and materials .6
6 Apparatus .6
7 Sampling .7
8 Preparation of measurement .8
8.1 Preparation of test sample .8
8.2 Preparation of the apparatus .8
8.2.1 Cleaning procedure .8
8.2.2 Temperature correction .9
9 Measurement . 10
10 Calculation and evaluation . 12
10.1 Automatic evaluation . 12
10.2 Manual evaluation . 13
11 Expression of results . 13
12 Precision . 13
12.1 General . 13
12.2 Repeatability, r . 13
12.3 Reproducibility, R . 14
13 Test report . 14
Annex A (informative) Background of the method . 15
Bibliography . 16
2
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oSIST prEN 16568:2013
prEN 16568:2013 (E)
Foreword
This document (prEN 16568:2013) has been prepared by Technical Committee CEN/TC 19 “Gaseous and
liquid fuels, lubricants and related products of petroleum, synthetic and biological origin”, the secretariat of
which is held by NEN.
This document is currently submitted to the CEN Enquiry.
3
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oSIST prEN 16568:2013
prEN 16568:2013 (E)
Introduction
This document is based on EN 15751 [1], which was specifically developed for the determination of oxidation
stability of fatty acid methyl ester (FAME) and blended petroleum based diesel fuels. The oxidation stability is
assessed by determining the induction period of the fuel. The induction period is a measure for the ageing
reserve of the fuel.
The first version of EN 15751 was developed under CEN/TC 19 for a test temperature of 110 °C in order to
stay directly comparable to EN 14112:2003 [2] which is used to determine the oxidation stability of pure
FAME. The stability of diesel/FAME blends is generally higher compared to pure FAME thus leading to long
measuring times. In order to better accommodate the needs of laboratories the idea was raised to increase
the reaction temperature to 120 °C. Degradation of the ageing reserve of the fuel follows the Arrhenius law.
By increasing the temperature by 10 °C, the reaction rate is doubled cutting in half the induction period.
The modifications to EN 15751, as given in this document, allow the application of this test method for
oxidation stability for diesel/FAME blends containing 2 % (V/V) of FAME at minimum. This test method is not
applicable to pure FAME. Pure FAME was not included in the scope because of reduced ability to differentiate
between different qualities when the induction period is reduced by 50 %.
The temperature increase required a new validation for diesel/FAME blends. Blends with up to 50 % (V/V) of
FAME were selected in order to comprise also high FAME blends which are presently discussed for
automotive use. Due to concerns about a potential impact of cetane improvers, an additional study with
2-ethyl hexyl nitrate (EHN) at 110 °C and 120 °C was performed.
4
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oSIST prEN 16568:2013
prEN 16568:2013 (E)
1 Scope
This European Standard specifies a test method for the determination of the oxidation stability of fuels for
diesel engines, by means of measuring the induction period of the fuel up to 48 h at 120 °C. The method is applicable
to fatty acid methyl esters (FAME) intended for the use as pure biofuel or as a blending component for diesel
fuels, and to blends of FAME with petroleum-based diesel containing 2 % (V/V) of FAME at minimum.
NOTE 1 A similar test method for oxidation stability at 110 °C is described in EN 15751 [1], which applies to pure
FAME and Diesel/FAME blends containing 2 % (V/V) of FAME at minimum. Another alternative for distillate fuels is
described in EN ISO 12205 [3].
NOTE 2 For induction periods higher than 48 h the precision is not covered by the precision statement of this method.
The limit values of the relevant fuel standards are well within the scope of this test method.
The presence of cetane improver can reduce the oxidation stability determined by this test method. Limited
studies with 2-ethyl hexyl nitrate (EHN) indicated, however, that the stability is reduced to an extent which is
within the precision range of the test method.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
EN ISO 3170, Petroleum liquids — Manual sampling
EN ISO 3171, Petroleum liquids — Automatic pipeline sampling
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
induction period
time which passes between the moment when the measurement is started and the moment when the
formation of oxidation products begins to increase rapidly
3.2
oxidation stability
induction period determined according to the procedure specified in this European Standard, expressed in
hours
4 Principle
A stream of purified air is passed through the sample which has been heated to the specified, elevated
temperature. Volatile compounds are formed during the oxidation process. They are passed together with the
air into a flask containing demineralised or distilled water, equipped with a conductivity electrode. The
electrode is connected to a measuring and recording device. It indicates the end of the induction period by
rapid increase of the conductivity due to the dissociation of volatile carboxylic acids produced during the
oxidation process and absorbed in the water. For more details on the background of the method see Annex A.
5
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oSIST prEN 16568:2013
prEN 16568:2013 (E)
5 Reagents and materials
Use only reagents of recognised analytical grade, and distilled or demineralised water [4].
5.1 Ternary solvent mixture, consisting of methanol/toluene/acetone 1 : 1 : 1 (by volume).
5.2 Alkaline laboratory glass cleaning solution.
5.3 2-Propanol.
6 Apparatus
Usual laboratory equipment and glassware, together with the following:
6.1 Device for the determination of oxidation stability, comprising the following parts (see Figures 1
and 2):
NOTE An instrument for determining the oxidation stability is commercially available under the trade name
® ®
Rancimat , (model 743 or higher, from Metrohm AG, Herisau, Switzerland) or OSI Instrument (from Omnion Inc.,
Rockland, Massachusetts, USA). These are examples of suitable equipment which are given for the convenience of users
of this document. They do not constitute an endorsement by CEN of this equipment.
6.1.1 Air filter, comprising a tube fitted with filter paper at the ends and filled with a molecular sieve (6.6),
connected to the suction end of a pump.
6.1.2 Gas membrane pump, with an adjustable flow rate of (10 ± 1,0) .
6.1.3 Reaction vessels of borosilicate glass, provided with a sealing cap.
The length of the reaction vessel depends on the measuring equipment and shall exceed the depth of the
oven by at least 130 mm, in order to reduce evaporation losses to a minimum by condensing volatile fuel
components at the cold vessel walls outside the oven.
EXAMPLE Total length of the test tube for the Metrohm Rancimat 743 L = 250 mm, for the Omnion OSI Instrument
L = 300 mm.
The sealing cap shall be fitted with a gas inlet and outlet tube. A few centimetres below the top, the vessel
shall preferably have a slightly reduced inner diameter in order to break any emerging foam. An artificial foam
blocker (e.g. glass ring) may also be used for this purpose.
6.1.4 Closed measurement cells of approximately 150 ml capacity, with a gas inlet tube extending to the
bottom inside of the vessel. The cell shall have ventilation holes at the top.
6.1.5 Electrodes for measuring the conductivity within a range from 0 µS/cm to 300 µS/cm aligned with the
dimensions of the measurement cell (6.1.4).
6.1.6 Measuring and recording apparatus, comprising:
a) an amplifier and
b) a recorder registering the signal of each of the electrodes (6.1.5).
6.1.7 Thyristor and contact thermometer graduated in 0,1 °C or Pt 100 element to measure the block
temperature, with attachments for relay connection and an adjustable heating element; temperature scale
0 °C to 150 °C.
6
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oSIST prEN 16568:2013
prEN 16568:2013 (E)
6.1.8 Heating block, made of cast aluminium, adjustable to a temperature up to (150 ± 0,1) °C. The block
shall be provided with holes for the reaction vesse
...
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