BS EN ISO 6145-11-2008 Gas analysis - Preparation of calibration gas mixtures using dynamic volumetric methods - Part 11 Electrochemical generation《气体分析 用动态容积法制备校准气体混合物 电化学发生法》.pdf

1、Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/10/2009 02:21, Uncontrolled Copy, (c) BSIg49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58m

2、ixtures using dynamic volumetric methods Part 11: Electrochemical generationICS 71.040.40Gas analysis Preparation of calibration gas BRITISH STANDARDBS EN ISO 6145-11:2008National forewordThis British Standard is the UK implementation of EN ISO 6145-11:2008. It is identical with ISO 6145-11:2005. It

3、 supersedes BS ISO 6145-11:2005 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee PTI/15, Natural gas and gas analysis.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to

4、include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.BS EN ISO 6145-11:2008Amendments/corrigenda issued since publicationDate Comments 30 June 2009 This corrigendum renum

5、bers BS ISO 6145-11:2005 as BS EN ISO 6145-11:2008This British Standard, was published under the authority of the Standards Policy and Strategy Committee on 30 January 2006 BSI 2009ISBN 978 0 580 60363 1Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/10/2009 02:21, Uncontrolled Copy, (c) B

6、SIEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 6145-11August 2008ICS 71.040.40English VersionGas analysis - Preparation of calibration gas mixtures usingdynamic volumetric methods - Part 11: Electrochemicalgeneration (ISO 6145-11:2005)Analyse des gaz - Prparation des mlanges de gaz pourtalo

7、nnage laide de mthodes volumtriquesdynamiques - Partie 11: Gnration lectrochimique (ISO6145-11:2005)Gasanalyse - Herstellung von Kalibriergasgemischen mitHilfe von dynamisch-volumetrischen Verfahren - Teil 11:Elektrochemische Herstellung (ISO 6145-11:2005)This European Standard was approved by CEN o

8、n 30 July 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be

9、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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Mana

10、gement Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norwa

11、y, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and

12、by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 6145-11:2008: ELicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/10/2009 02:21, Uncontrolled Copy, (c) BSIForeword The text of ISO 6145-11:2005 has been prepared by Technical Committee ISO/TC 158 “Analysis of gases” of t

13、he International Organization for Standardization (ISO) and has been taken over as EN ISO 6145-11:2008 by Technical Committee CEN/TC N21 “Gaseous fuels and combustible gas” the secretariat of which is held by CMC. This European Standard shall be given the status of a national standard, either by pub

14、lication of an identical text or by endorsement, at the latest by February 2009, and conflicting national standards shall be withdrawn at the latest by February 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENE

15、LEC 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, Cyprus, Czech Republic, Denma

16、rk, 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 6145-11:2005 has been appro

17、ved by CEN as a EN ISO 6145-11:2008 without any modification. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/10/2009 02:21, Uncontrolled Copy, (c) BSIReference numberISO 6145-11:2005(E)INTERNATIONAL STANDARD ISO6145-11First edition2005-10-15Gas analysis Preparation of calibration gas mixt

18、ures using dynamic volumetric methods Part 11: Electrochemical generation Analyse des gaz Prparation des mlanges de gaz pour talonnage laide de mthodes volumtriques dynamiques Partie 11: Gnration lectrochimique Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/10/2009 02:21, Uncontrolled Cop

19、y, (c) BSIii Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/10/2009 02:21, Uncontrolled Copy, (c) BSIiiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Procedure 2 3.1 Principle. 2 3.2 Complementary gas 2 3.3 Electrolytic systems for gas generation. 2 3.4

20、 Apparatus 3 3.4.1 Cell construction. 3 3.4.2 Current supply and gas flow control 3 3.5 Gas mixture preparation 3 3.5.1 Complementary gas 3 3.5.2 Voltage supply 3 3.5.3 Calculation of gas mixture content. 4 4 Uncertainty evaluation . 6 4.1 Introduction . 6 4.2 Sources of uncertainty. 6 4.2.1 Complem

21、entary gas flow . 6 4.2.2 Gas generation 6 4.2.3 Absorption of generated gas in the cell electrolyte 6 4.2.4 Effect of moisture content . 6 4.2.5 Effect of temperature 6 4.2.6 Purity of electrolytic chemicals. 6 4.2.7 Impurities in complementary gas 7 4.3 Uncertainty of volume fraction 7 5 Electroch

22、emical cell design. 7 Annex A (informative) Example of a commercial electrochemical cell 9 Annex B (informative) Schematics of electrolytic cells used for gas generation 11 Annex C (informative) Schematic of electrical supply to gas generation cell . 12 Annex D (informative) Decomposition voltages o

23、f solutions between smooth platinum electrodes . 13 Bibliography . 14 BS EN ISO 6145-11:2008 EN ISO 6145-11:2008 (E)Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/10/2009 02:21, Uncontrolled Copy, (c) BSIiv Foreword ISO (the International Organization for Standardization) is a worldwide f

24、ederation 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 co

25、mmittee. 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 accor

26、dance 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 requir

27、es 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 6145-11 was prepared by Technic

28、al Committee ISO/TC 158, Analysis of gases. ISO 6145 consists of the following parts, under the general title Gas analysis Preparation of calibration gas mixtures using dynamic volumetric methods: Part 1: Methods of calibration Part 2: Volumetric pumps Part 4: Continuous syringe injection method Par

29、t 5: Capillary calibration devices Part 6: Critical orifices Part 7: Thermal mass-flow controllers Part 8: Diffusion method Part 9: Saturation method Part 10: Permeation method Part 11: Electrochemical generation Part 3 to ISO 6145, entitled Periodic injections into a flowing gas stream, has been wi

30、thdrawn by Technical Committee ISO/TC 158, Analysis of gases. BS EN ISO 6145-11:2008 EN ISO 6145-11:2008 (E)Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/10/2009 02:21, Uncontrolled Copy, (c) BSIvIntroduction This part of ISO 6145 is one of a series of standards dealing with the various

31、dynamic volumetric methods used for the preparation of calibration gas mixtures. Electrochemical gas generation can be used to produce calibration gas mixtures containing calibration components which, because of their corrosive nature or low content, are unlikely to be stable in high-pressure cylind

32、ers. BS EN ISO 6145-11:2008 EN ISO 6145-11:2008 (E)Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/10/2009 02:21, Uncontrolled Copy, (c) BSIblankBS EN ISO 6145-11:2008 EN ISO 6145-11:2008 (E)Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/10/2009 02:21, Uncontrolled Copy, (c) BSI

33、1Gas analysis Preparation of calibration gas mixtures using dynamic volumetric methods Part 11: Electrochemical generation 1 Scope This part of ISO 6145 specifies a method for the preparation of calibration gas mixtures by using electrochemical generation of a calibration component and introduction

34、into a complementary gas flow. By alteration of the gas flow or the charge passed through the cell electrolyte, it is possible to change the composition of the gas mixture. The relative expanded uncertainty of the calibration gas content, U, obtained by multiplying the relative combined standard unc

35、ertainties by a coverage factor, k = 2, is not greater than 5 %. The method described in this part of ISO 6145 is intended to be applied to the preparation of calibration gas mixtures in the volume fraction ranges (0,1 to 250) 106. NOTE 1 Gases that can be produced by electrochemical generation are

36、oxygen (O2), hydrogen (H2), hydrogen cyanide (HCN), hydrogen sulfide (H2S), chlorine (Cl2), bromine (Br2), chlorine dioxide (ClO2), ammonia (NH3), nitric oxide (NO), nitrogen (N2), carbon dioxide (CO2), phosphine (PH3), arsine (AsH3) and ozone (O3). NOTE 2 The merits of the method are that a stable

37、calibration gas mixture can be quickly prepared within minutes. NOTE 3 Gas blending systems based on electrochemical generation and thermal mass flow controllers, with the facility of computerization and automatic control, are commercially available. An example is given in Annex A. 2 Normative refer

38、ences 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) applies. ISO 6143, Gas analysis Comparison methods f

39、or determining and checking the composition of calibration gas mixtures ISO 6145-1, Gas analysis Preparation of calibration gas mixtures using dynamic volumetric methods Part 1: Methods of calibration ISO 6145-7:2001, Gas analysis Preparation of calibration gas mixtures using dynamic volumetric meth

40、ods Part 7: Thermal mass-flow controllers BS EN ISO 6145-11:2008 EN ISO 6145-11:2008 (E)Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/10/2009 02:21, Uncontrolled Copy, (c) BSI2 3 Procedure 3.1 Principle Electrochemical gas generation is a fundamental method in which the quantity of the c

41、alibration gas component generated is proportional to the charge passed. The proportionality factor is the reciprocal of the Faraday constant the electrical charge carried by one mole of electrons (or singly charged ions), which is equal to the product of the Avogadro constant (NA) and the charge of

42、 an electron (e). F = NA e (1) where F is 96 485,341 5 C/mol with a relative uncertainty of 4,0 108(see References 1, 2 and 3). The passage of accurately determined electrical current through a cell determines the gas output provided the conditions given in Clause 5 are applied. 3.2 Complementary ga

43、s The flow rate of complementary gas shall be determined by one of the methods given in ISO 6145-1. 3.3 Electrolytic systems for gas generation Table 1 lists some examples of gases which can be prepared in quantitative yield by direct electrolysis, using platinum and other electrodes. Also included

44、is an example of the suppression of an unwanted constituent by adsorption on activated carbon surrounding the appropriate electrode. Table 1 Electrolysis systems for gas generation Gas required Electrolysis system Gas liberated at other electrode Yield mole of required gas per charge numerically equ

45、al to Faraday number O2or H2Pt, H2SO4, Pt Pt, K2SO4, Pt Pt, KOH, Pt H2or O21/4 (O2) 1/2 (H2) O2Pt, H2SO4, Hg2SO4, +C, Hg Pt, neutral solution, active C Pt, KOH, HgO, +C, Hg Pt, KOH, CdO, Cd nil 1/4 N2Pt, N2H4, H2SO4, Pt H21/4 Cl2Pt, NaCl, Pt H21/2 CO2Pt, H2C2O4, Pt H21 NO Pt, (NOH)SO4, + H2SO4, Pt a

46、O21 aThis system has also been used for the generation of nitrogen dioxide 4.BS EN ISO 6145-11:2008 EN ISO 6145-11:2008 (E)Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/10/2009 02:21, Uncontrolled Copy, (c) BSI33.4 Apparatus 3.4.1 Cell construction Cell construction shall be designed to

47、ensure that the generated calibrated component is transferred into the complementary gas stream at maximum efficiency suitable for calibration purposes. Some of the conditions that shall be fulfilled for the operation of an electrolytic cell used for this purpose are given in Clause 5. Examples of e

48、lectrolytic cells are given in Figures B.1 and B.2. 3.4.2 Current supply and gas flow control 3.4.2.1 The content of the calibration gas produced from the system is dependent on three factors: a) the current supplied through the cell which generates a volume flow rate of the calibration gas componen

49、t; b) the (volume) flow rate of the complementary gas; and c) the cell efficiency. NOTE Cell efficiency is the fraction recovery of calibration component over the calculated quantity generated by the current supplied to the cell (see 4.2.3). It depends on the design of the cell. Practical hints on design are given in Clause 5 and an example is given in Annex C. 3.4.2.2 A battery, capable of supplying voltage in the range 0,5 V to 1,0 V, and a milliamperemeter with a measurement range of 0,5 mA t