1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 15938:2010BS 2000-586:2010Automotive fuels Ethanol blending component and ethanol (E85) automotive fuel Determination of electrical conductivityLicensed Copy: Wang Bin, ISO
2、/EXCHANGE CHINA STANDARDS, 17/01/2011 08:17, Uncontrolled Copy, (c) BSIBS EN 15938:2010 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 15938:2010.The UK participation in its preparation was entrusted to TechnicalCommittee PTI/13, Petroleum Testing and Terminolo
3、gy.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2010ISBN 978 0 580 67064 0ICS 75.160.20Compliance with a B
4、ritish Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 October 2010.Amendments issued since publicationDate Text affectedLicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 17/01/2011
5、 08:17, Uncontrolled Copy, (c) BSIBS EN 15938:2010EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15938 September 2010 ICS 75.160.20 English Version Automotive fuels - Ethanol blending component and ethanol (E85) automotive fuel - Determination of electrical conductivity Carburants pour automob
6、iles - thanol comme base de mlange lessence et carburant thanol (E85) pour automobiles - Dtermination de la conductivit lectrique Kraftstoffe fr Kraftfahrzeuge - Ethanol als Blendkomponente und Ethanolkraftstoff (E85) - Bestimmung der elektrischen Leitfhigkeit This European Standard was approved by
7、CEN on 7 August 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 standard
8、s 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 t
9、he 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, Ma
10、lta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exp
11、loitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15938:2010: ELicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 17/01/2011 08:17, Uncontrolled Copy, (c) BSIBS EN 15938:2010EN 15938:2010 (E) 2 Contents Page Foreword 31 Scope 42 Normative references
12、43 Terms and definitions .44 Principle 55 Reagents .66 Apparatus .67 Sampling .68 Procedure .78.1 Preparation of the measuring device.78.1.1 General 78.1.2 Cleaning of the sample vessel .78.1.3 Cleaning of the measuring cell .78.1.4 Filling the sample into the sample vessel .78.2 Calibration 78.2.1
13、Interferences 78.2.2 Checking the cell constant .88.3 Measurement procedure .89 Expression of results 810 Precision .810.1 General 810.2 Repeatability, r .810.3 Reproducibility, R.911 Test report 9Bibliography . 10Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 17/01/2011 08:17, Uncontrolled
14、Copy, (c) BSIBS EN 15938:2010EN 15938:2010 (E) 3 Foreword This document (EN 15983:2010) 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
15、 Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2011, and conflicting national standards shall be withdrawn at the latest by March 2011. This document was prepared by CEN/TC 19 Ethanol Task Force under r
16、esponsibility of its Working Group 21 and is based on DIN 51627-4 1. 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,
17、 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. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 17/01/2011
18、 08:17, Uncontrolled Copy, (c) BSIBS EN 15938:2010EN 15938:2010 (E) 4 1 Scope This European Standard specifies a test method for the determination of the electrical conductivity in ethanol and ethanol (E85) automotive fuel in the range from approximately (0,3 to 5) S/cm at a temperature of 25 C (see
19、 Clause 4). The electrical conductivity is determined from the measured electrical conductance. The electrical conductivity is an important analytical criterion for the ascertainment and control of anionic and cationic components in ethanol and ethanol (E85) automotive fuel. Some of these components
20、 can exhibit corrosive properties. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments)
21、applies. EN ISO 3170, Petroleum liquids Manual sampling (ISO 3170:2004) EN ISO 3171, Petroleum liquids Automatic pipeline sampling (ISO 3171:1988) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 electrical conductance G reciprocal value of th
22、e electrical resistance NOTE The electrical conductance is expressed in siemens (S) or 1. 3.2 electrical resistance R measurement value of a sample, directly determined by means of the conductivity meter, which increases with the sample length l and decreases with the sample cross-section A NOTE The
23、 electrical resistance of a sample is expressed in ohms (). The relation between R and the electrical conductance (3.1) is shown in Equation (1). RG1= (1) 3.3 electrical conductivity Tmaterial-dependent measure of the electrical current conducted in an electrical field by the ions present in the sol
24、ution NOTE 1 The material-dependent electrical conductivity of a solution is related to the electrical current which is achieved by moving ions of the solution in an electrical field. It is therefore applicable as a method to limit ionic contamination in alcohols and alcohol based fuels. The electri
25、cal conductivity Tis determined in accordance with Equation (2) from the determined electrical conductance G (3.1) and the geometrical dimensions of the measuring cell (length and effective cross-section) which are added to form the cell constant K (3.4): Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA
26、STANDARDS, 17/01/2011 08:17, Uncontrolled Copy, (c) BSIBS EN 15938:2010EN 15938:2010 (E) 5 KGAlG =T (2) where: Tis the electrical conductivity of the sample, in S cm-1(1 S m-1= 104S cm-1), at the measurement temperature T, in C; l is the length of the measured section (geometrical electrode gap), in
27、 m or, following the respective unit conversion, in cm, with 1 m = 100 cm; A is the effective cross-section of the measuring cell, in m2 or, following the respective unit conversion, in cm2, with 1 m2= 104cm2; K is the cell constant of the measuring cell in m1or, following the respective unit conver
28、sion, in cm1, with 1 m1= 0,01 cm1. NOTE 2 The electrical conductivity of a solution depends on the temperature; therefore the temperature is given together with the measurement value. Hence, the electrical conductivity, which is mostly determined at 25 C, is designated as 25. NOTE 3 The electrical c
29、onductivity depends on ion concentration, ion type, temperature and viscosity of the solution. Therefore its measurement range can be large. “Ultrapure“ (deionized and demineralised) water for example, due to its self-dissociation at 25 C, has an electrical conductivity of 0,054 83 S cm-1(5,483 S m-
30、1). 3.4 cell constant K geometrical dimension of the measuring cell used to form one value NOTE The electrical conductivity (3.3) cannot be calculated simply from the electrical resistance R (3.2) and the geometrical cell dimensions because its functional relationship to the cell dimensions is very
31、complex, especially in cases where the geometry is not cubical. Therefore, the measuring cell is calibrated by means of a calibration solution of known electrical conductivity *. The cell constant K is determined in accordance with Equation (3) from the measured electrical conductance G* caused by t
32、he calibration solution and its known electrical conductivity *. *25*25GK= (3) where: K is the cell constant of the measuring cell in m1or, following the respective unit conversion, in cm1(1 m-1= 0,01 cm1); *25G is the measured electrical conductance at 25 C in the measuring cell filled with the cal
33、ibration solution, expressed in S; *25 is the electrical conductivity of the calibration solution at 25 C, in S m-1or S cm-1(1 S m-1= 104S cm-1). 4 Principle The determination of the electrical conductivity in ethanol or ethanol fuel is carried out by means of a direct conductometer (6.1) measuremen
34、t, using a measuring cell (6.2) suitable for a measurement range of approximately (0,01 to 5) S cm-1. The measurement is carried out at a sample temperature of (25 0,1) C. As electrical conductivity is strongly depending on temperature, selection of another measurement Licensed Copy: Wang Bin, ISO/E
35、XCHANGE CHINA STANDARDS, 17/01/2011 08:17, Uncontrolled Copy, (c) BSIBS EN 15938:2010EN 15938:2010 (E) 6 temperature and the subsequent conversion of the electrical conductance to a target temperature of 25 C is not allowed. 5 Reagents 5.1 Ethanol, absolute, of analytical grade or a similar quality,
36、 for cleaning and rinsing the measuring cell (6.2), the sample vessel (6.4) and all the other vessels/containers with which the sample can come into contact. 5.2 Calibration solution, KCl solution having a conductivity 25of max.100 S cm-1. 5.3 Water, deionized or distilled with a maximum conductivit
37、y of 1 S cm-1, for cleaning and rinsing the sample vessel (6.4) and the measuring cell (6.2). 6 Apparatus 6.1 Conductometer, suitable of being operated with measuring cells (6.2) having a cell constant of approximately (0,1 to 1) cm1, with an alternating voltage of a frequency between 50 Hz and 500
38、Hz in the measuring cell (6.2), directly displaying the measured conductivity to the nearest 0,01 S cm-1 at least. A single-point calibration using a single KCl calibration solution (5.2) is sufficient. 6.2 Measuring cell, manufactured from a material inert to ethanol or ethanol fuel, for example hi
39、gh-grade steel. The cell constant should be in the range (0,1 and 1) cm1, preferably close to 0,1 cm1. The measuring cell is introduced from above into the sample vessel (6.4), through a cover, and fixed in a way it is completely immersed in the solution to be measured. 6.3 Temperature sensor, with
40、an accuracy of 0,1 C or better, suitable for recording the temperature of the solution subjected to measurement at approximately 25 C. This sensor can also be integrated in the measuring cell (6.2). The temperature signal is indicated on a display to the nearest 0,1 C. 6.4 Thermostatable glass sampl
41、e vessel, having a capacity of 20 ml to 500 ml, into which the sample to be measured is filled. The sample vessel may be designed as a double-walled glass vessel, for example, which is thermostated by means of a circulating liquid. Alternatively, a thermostatable flow-through vessel may be used, pro
42、vided it is ensured that the substance to be measured can be maintained at a temperature of (25 0,1) C, the measuring cell (6.2) is completely immersed, and all requirements for cleaning are also complied with. 6.5 Thermostat with thermometer, suitable for thermostating the sample vessel (6.4) to (2
43、5 0,1) C . 6.6 Stirrer for ensuring a homogeneous temperature in the sample by stirring it with a magnetic stirrer and a polytetrafluorethylene-coated stirring magnet. 7 Sampling Unless specified otherwise, samples shall be taken in accordance with EN ISO 3170 or EN ISO 3171 and/or the requirements
44、of national standards regarding the sampling of fuels. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 17/01/2011 08:17, Uncontrolled Copy, (c) BSIBS EN 15938:2010EN 15938:2010 (E) 7 Only glass bottles shall be used for samples. The glass bottles shall be cleaned very thoroughly and rinsed at
45、 least twice using the product to be sampled prior to the actual sampling. Avoid a stopper made up of aluminium, brass, copper, lead, plated steel, zinc, natural rubber, leather, cork, polyurethane, PVC and polyamides. For any other handling of the samples particular attention shall be paid to avoid
46、 any risk of further contamination. 8 Procedure 8.1 Preparation of the measuring device 8.1.1 General The device manufacturers instructions shall be followed for the preparation and operation of the conductometer (6.1) and the measuring cell (6.2). The thermostat (6.5) is connected with the sample v
47、essel (6.4) and set to achieve a temperature of (25 0,1) C in the sample vessel. 8.1.2 Cleaning of the sample vessel Before the measurement, the sample vessel (6.4) is rinsed several times with ethanol (5.1). The rest of the ethanol used for rinsing shall be dripped off. If the sample vessel (6.4) h
48、as been used before for saline samples, it shall additionally be cleaned thoroughly with water (5.3) prior to using it for ethanol or ethanol fuel. Subsequently, it is dried in the drying oven at min. 80 C. Afterwards it is rinsed once more using ethanol (5.1). If there are any visible contamination
49、s (e.g. stains) on the inner glass surface of the sample vessel (6.4), the vessel shall not be used. 8.1.3 Cleaning of the measuring cell The measuring cell (6.2) is also cleaned by rinsing it thoroughly with ethanol (5.1). If the measuring cell (6.2) had been used before for saline samples, it shall be cleaned thoroughly with water (5.3) prior to using it for ethanol or ethanol fuel. Subsequently, it
