1、BRITISH STANDARD BS EN ISO 14111:1999 BS 3156-11.0.3: 1999 Incorporating Amendment No.1 to BS3156-11.0.3:1997 (renumbers the BS as BS EN ISO14111:1999) Natural gas Guidelines to traceability in analysis The European Standard EN ISO14111:1999 has the status of a BritishStandard ICS 75.060BSENISO14111
2、:1999 This BritishStandard, having been prepared under the directionof the Sector Board forMaterials and Chemicals, waspublished under the authorityof the Standards Boardand comes into effect on 15September 1997 BSI 04-2000 ISBN 0 580 27567 1 National foreword This BritishStandard is the English lan
3、guage version of EN ISO14111:1999. The UK participation in its preparation was entrusted to Technical Committee PTI/15, Natural gas and gas analysis, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on th
4、e interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The BritishStandar
5、ds which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard doe
6、s not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an insi
7、de front cover, pagesi andii, theEN ISO title page, page2, theISOtitle page, pagesiitoiv, pages1 to24 anda back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments iss
8、ued since publication Amd. No. Date Comments 10655 December 1999 Implementation of the European StandardBSENISO14111:1999 BSI 04-2000 i Contents Page National foreword Inside front cover Foreword 2 Foreword iii Text of ISO14111 1ii blankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO14111 M
9、arch 1999 ICS 75.060 English version Natural gas Guidelines to traceability in analysis (ISO14111:1997) Gaz naturel Lignes directrices pour la traabilit en analyse (ISO14111:1997) Erdgas Leitlinien fr die Rckfhrbarkeit in der Analytik (ISO14111:1997) This European Standard was approved by CEN on 3 M
10、arch 1999. 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 ob
11、tained on application to the Central Secretariat 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 Central Se
12、cretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN
13、European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1999 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref.No.ENISO14111:1999EENISO1411
14、1:1999 BSI 04-2000 2 Foreword The text of the International Standard from Technical Committee ISO/TC193, Natural gas, of the International Organization for Standardization (ISO) has been taken over as a European Standard by CEN/CS. This European Standard shall be given the status of a national stand
15、ard, either by publication of an identical text or by endorsement, at the latest by September 1999, and conflicting national standards shall be withdrawn at the latest by September 1999. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countrie
16、s are bound to implement this European Standard: Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and theUnitedKingdom. Endorsement notice The text of the International Standard
17、ISO14111:1997 has been approved by CEN as a European Standard without any modification. NOTENormative references to International Standards are listed in Annex ZA (normative).BS 3156-11.0.3:1997 ii BSI 04-2000 Contents Page Foreword iii Introduction 1 1 Scope 1 2 Normative references 1 3 Definitions
18、 2 4 Fundamental principles of metrological traceability 3 5 Elaboration of the traceability concept 5 6 Chemical composition and the SI system 6 7 Traceability in natural-gas analysis 9 8 Hierarchy of reference gas mixtures 12 9 Role of traceability in uncertainty assessment 15 10 Implementation of
19、 traceability in International Standards for natural-gas analysis 16 11 Examples 18 12 Summary 20 Annex A (informative) Supplementary terms and definitions 21 Annex B (informative) Example of typical interlaboratory test results 22 Annex C (informative) Bibliography 23 Annex ZA (normative) Normative
20、 references to international publicationswiththeir relevant European publications 24 Figure 1 Conceptual traceability hierarchy 4 Figure 2 Hierarchy of reference gas mixtures 12 Figure 3 Traceability network for a field measurement design 20 Figure B.1 Summary of results 22 Table 1 Adaptation of sta
21、ndard terminology 12 Descriptors: Natural gas, gas analysis, traceability, general conditions.BS 3156-11.0.3:1997 BSI 04-2000 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing Intern
22、ational 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
23、 ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an
24、International Standard requires approval by at least75% of the member bodies casting a vote. International Standard ISO14111 was prepared by Technical Committee ISO/TC193, Natural gas, Subcommittee SC1, Analysis of natural gas. Annex A to Annex C of this International Standard are for information on
25、ly.iv blankBS 3156-11.0.3:1997 BSI 04-2000 1 Introduction At a time when assurances of measurement accuracy in natural-gas analyses are increasingly being sought, every analytical chemist responsible for the design and operation of systems used in such analyses needs to be aware of, and adopt, suita
26、ble means by which he or she will be able to provide these assurances. This implies that the analyst must employ validated methods in which each result is securely linked, through a series of reference materials (reference gas mixtures), to accepted metrological standards. The formal structure which
27、 the analyst creates in doing this constitutes what is called a traceability chain. Only by this means will the analyst be able to secure and support a proper estimate of measurement accuracy (uncertainty). This seemingly simple concept is elaborated in considerable detail in this International Stan
28、dard. The practical considerations involved in the establishment of a satisfactory traceability chain give rise to challenging problems, particularly in natural-gas analysis, but relevant and useful advice is provided. At present, traceability of measurement is universally defined through the existe
29、nce of unbroken calibration chains ending at the level of international or national measurement standards realizing appropriate SI units. This concept originates from the field of physical metrology, where it has been implemented with apparent success. Transfer of the metrological scheme to chemical
30、 analysis and other domains in the field of testing is, however, a highly difficult task, for which standard methods are not yet available. Therefore it is not possible, at present, to standardize the implementation of measurement traceability in natural-gas analysis, or in other areas of chemical a
31、nalysis. For the reasons indicated above, this International Standard does not give any specific traceability protocols. Instead, its purpose is to clarify fundamental concepts involved in chemical traceability; identify basic problems in the application of metrology in chemistry; indicate feasible
32、solutions on a reference material basis; assist in the design of practical implementations using reference gas mixtures; serve as a reference document for the application of the traceability concept in other International Standards for natural-gas analysis. 1 Scope This International Standard provid
33、es general guidelines on the implementation and application of traceability concepts in the analysis of natural gas. Its purpose is to lay down the foundations for the development of specific traceability protocols in other International Standards for natural-gas analysis. NOTEBesides the field of n
34、atural-gas analysis, this International Standard could also be useful as a guidance document in other areas of gas analysis and in related fields such as air quality measurement, vehicle emission monitoring and reference-gas mixture preparation. 2 Normative references The following standards contain
35、 provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate
36、the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO3534-1:1993, Statistics Vocabulary and symbols Part1:Probability and general statistical terms. ISO5168:, Measurement of flu
37、id flow Evaluation of uncertainties 1) . ISO5725-1:1994, Accuracy (trueness and precision) of measurement methods and results Part1:General principles and definitions. ISO5725-2:1994, Accuracy (trueness and precision) of measurement methods and results Part2:Basic method for the determination of rep
38、eatability and reproducibility of a standard measurement method. ISO5725-3:1994, Accuracy (trueness and precision) of measurement methods and results Part3:Intermediate measures of the precision of a measurement method. ISO5725-4:1994, Accuracy (trueness and precision) of measurement methods and res
39、ults Part4:Basic methods for the determination of the trueness of a standard measurement method. ISO5725-6:1994, Accuracy (trueness and precision) of measurement methods and results Part6:Use in practice of accuracy values. ISO6142:1981, Gas analysis Preparation of calibration gas mixtures Weighing
40、methods (including addendum1). 1) To be published. (Revision of ISO5168:1978)BS 3156-11.0.3:1997 2 BSI 04-2000 ISO6143:1981, Gas analysis Determination of composition of calibration gas mixtures Comparison methods. ISO6711:1981, Gas analysis Checking of calibration gas mixtures by a comparison metho
41、d. ISO6974-1:, Natural gas Determination of composition with defined uncertainty by gas chromatography Part1:Guidelines for tailored analysis 2) . ISO6974-2:, Natural gas Determination of composition with defined uncertainty by gas chromatography Part2:Measuring-system characteristics and statistics
42、 for data processing 2) . ISO6976:1995, Natural gas Calculation of calorific values, density, relative density and Wobbe index from composition. ISO9001:1994, Quality systems Model for quality assurance in design, development, production, installation and servicing. ISO10012-1:1992, Quality assuranc
43、e requirements for measuring equipment Part1:Metrological confirmation system for measuring equipment. ISO10723:1995, Natural gas Performance requirements for on-line analytical systems. ISO Guide30:1992, Terms and definitions used in connection with reference materials. ISO Guide33:1989, Uses of ce
44、rtified reference materials. ISO Guide35:1989, Certification of reference materials General and statistical principles. BIPM/IEC/ISO/OIML/IFCC/IUPAC. International vocabulary of basic and general terms in metrology (VIM), second edition, 1993. 3 Definitions For the purposes of this International Sta
45、ndard, the following definitions apply. 3.1 traceability a property of the result of a measurement or the value of a standard whereby it can be related to stated references, usually national or International Standards, through an unbroken chain of comparisons all having stated uncertainties NOTE 1Th
46、e concept is often expressed by the adjective “traceable”. NOTE 2The unbroken chain of comparisons is called a “traceability chain”. VIM 3.2 (measurement) standard, etalon a material measure, measuring instrument, reference material or measuring system intended to define, realize, conserve or reprod
47、uce a unit or one or more values of a quantity to serve as a reference EXAMPLES a) 1kg mass standard; b) 1007 standard resistor; c) standard ammeter; d) caesium frequency standard; e) standard hydrogen electrode; f) reference solution of cortisol in human serum having a certified concentration. VIM
48、3.3 reference material a material or substance one or more of whose property values are sufficiently homogeneous and well established to be used for the calibration of an apparatus, the assessment of a measurement method or for assigning values to materials NOTEA reference material may be in the for
49、m of a pure or mixed gas, liquid or solid. Examples are water for the calibration of viscometers, sapphire as a heat-capacity calibrant in calorimetry, and solutions used for calibration in chemical analysis. ISO Guide30 3.4 Terms related to accuracy and uncertainty NOTESince traceability essentially serves the purpose of assessment and control of accuracy, viz the uncertainty of measurement, the following terms relating to accuracy and uncertainty are also key terms of this document. The definitions, taken
