1、BRITISH STANDARDBS EN ISO 16664:2008Gas analysis Handling of calibration gases and gas mixtures GuidelinesICS 71.040.40g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g
2、42g43g55g3g47g36g58This British Standard was published under the authority of the Standards Policy and Strategy Committee on National forewordThe UK participation in its preparation was entrusted to Technical Committee A list of organizations represented on this committee can be obtained on request
3、to its secretary.from legal obligations.Amendments/corrigenda issued since publicationBS EN ISO 16664:2008This British Standard is the UK implementation of EN ISO 16664:2008. It is identical with ISO 16664:2004. It supersedes BS ISO 16664:2004 which is withdrawn.PTI/15, Natural gas and gas analysis.
4、 Compliance with a British Standard cannot confer immunity ISBN 978 0 580 60364 8Date Comments 30 June 2009 This corrigendum renumbers BS ISO 16664:2004 as BS EN ISO 16664:200817 August 2004 BSI 2009 This publication does not purport to include all the necessary provisions of a contract. Users are r
5、esponsible for its correct application.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 16664August 2008ICS 71.040.40English VersionGas analysis - Handling of calibration gases and gas mixtures -Guidelines (ISO 16664:2004)Analyse des gaz - Manutention des gaz et des mlangesde gaz pour talonnage
6、 - Lignes directrices (ISO16664:2004)Gasanalyse - Handhabung von Kalibriergasen undGasgemischen - Richtlinien (ISO 16664:2004)This European Standard was approved by CEN on 30 July 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving
7、 this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions
8、 (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 Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulga
9、ria, 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 STANDARDIZAT
10、IONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 16664:2008: EForeword The text of ISO 16664:2004 has been
11、prepared by Technical Committee ISO/TC 158 “Analysis of gases” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 16664:2008 by Technical Committee CEN/SS N21 “Gaseous fuels and combustible gas” the secretariat of which is held by CMC. This European Standar
12、d shall be given the status of a national standard, either by publication 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 t
13、his 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 St
14、andard: Austria, Belgium, Bulgaria, 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 Kingdo
15、m. Endorsement notice The text of ISO 16664:2004 has been approved by CEN as a EN ISO 16664:2008 without any modification. iiEN ISO 16664:2008 (E) IS:46661 O4002(E) iiiContents Page Introduction v 1 Scope 1 2 Terms and definitions. 1 3 Transport and storage 4 3.1 General remarks 4 3.2 Low temperatur
16、e . 4 3.3 High temperature 4 3.4 Water 4 3.5 Storage and handling . 4 4 Mode of withdrawal. 5 4.1 General. 5 4.2 Minimum utilization pressure 5 4.3 Temperature 5 4.4 Pressure reduction and flow 5 4.5 Replacement, change of cylinder positions. 5 5 Transfer system 6 5.1 Purging procedure 6 5.2 Conside
17、rations when designing and constructing gas transfer lines 7 6 Stability 13 Annex A (informative) Check on the stability of calibration gas mixtures by end-users . 14 Bibliography . 17 BS EN ISO 16664:2008EN ISO 16664:2008 (E)This page deliberately left blankIS:46661 O4002(E) vIntroduction This Inte
18、rnational Standard uses the terms “calibration gas” for both gas mixtures and pure gases as the limiting case of gas mixtures. The quality of calibration gases in cylinders as certified by producers is defined by a) the correct analyte content; b) a known uncertainty which is appropriate for its int
19、ended use; c) the stability; d) the homogeneity. During its utilization period, the quality of calibration gases is influenced by storage conditions at the manufacturers and users sites; transport conditions; modes of calibration gas withdrawal and transfer; the transfer system employed. BS EN ISO 1
20、6664:2008EN ISO 16664:2008 (E)blankINTENRATIONAL TSANDADR IS:46661 O4002(E)1Gas analysis Handling of calibration gases and gas mixtures Guidelines SAFETY PRECAUTIONS National and International safety regulations concerning storage, use and transportation of pure gases and gas mixtures are to be foll
21、owed in addition to this International Standard. 1 Scope This International Standard describes factors that may influence the composition of pure gases and homogeneous gas mixtures used for calibration purposes. This International Standard only applies to gases or gas mixtures that are within the “u
22、tilization period”, and it pays special attention to storage of calibration gas cylinders; calibration gas withdrawal from cylinders; transfer of calibration gas from cylinders to the point of calibration. It also outlines a method of assessing the stability for a gas mixture, and takes into account
23、 the gas composition uncertainty given on the certificate and the users measurement uncertainty. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 calibration gas pure gas or gas mixture used for calibration 2.2 calibration gas mixture gas mixt
24、ure of sufficient stability and homogeneity whose composition is properly established for use in the calibration of a measuring instrument or for the validation of a measurement or gas analytical method ISO 7504:2001 2.3 component chemical substance present in, or a material used in the preparation
25、of, a gas mixture NOTE 1 In practice, the term component is used variously to mean either: a) a distinct pure chemical substance; or b) a material such as: a pure substance mixed with small amounts of inadvertent impurities, BS EN ISO 16664:2008EN ISO 16664:2008 (E)IS:46661 O4002(E) 2 I SO 4002 All
26、irthgs ersedevr a well defined mixture, such as air, a less well defined mixture, such as natural gas. NOTE 2 In circumstances where it is required to distinguish unambiguously between the individual distinct chemical substances present in a gas mixture and the materials used in gas mixture preparat
27、ion, then the chemical substances shall be referred to as “constituents”. When a constituent is or has been the subject of quantitative analysis, it may be referred to as an “analyte”. NOTE 3 In the preparation of gas mixtures, materials such as gases, vapours and gas mixtures, including their impur
28、ities, are sometimes called “parent gases”. ISO 7504:2001 2.4 homogeneity state of a gas mixture wherein all of its components are distributed uniformly throughout the volume occupied by the gas mixture NOTE Unless any other indication is given, it is normally to be assumed that the gas mixture is h
29、omogeneous with respect to composition and properties at all points in the gas mixture. ISO 7504:2001 2.5 impurity component present, but not wanted, in a gas mixture NOTE 1 Impurities found in a gas mixture originate from the parent gases or are introduced during or after its production. NOTE 2 An
30、impurity affecting the intended use of a gas mixture is called a “critical impurity”. NOTE 3 If the fraction of a gas mixture component is close to unity, and if the other components are of no special interest, such a gas mixture is considered, in general, as a “pure gas” consisting of that predomin
31、ant component containing some impurities. NOTE 4 The “purity” of a “pure gas” is quantified usually by the difference between unity and the sum of the fractions of all specified impurities. adapted from ISO 7504:2001 2.6 leak rate volume of fluid leaking from the system per unit of time due to incom
32、plete sealing of materials 2.7 leak tightness conformity to a specified leak rate 2.8 response time time interval between the instant when a stimulus is subjected to a specified abrupt change and the instant when the response reaches and remains within specified limits around its final steady value
33、VIM BS EN ISO 16664:2008EN ISO 16664:2008 (E)IS:46661 O4002(E) 32.9 stability attribute of a gas mixture, stored or used under specified conditions, to maintain its composition within specified uncertainty limits for a specified period of time (maximum storage life) and over a specified range of pre
34、ssure and of temperature NOTE It is appropriate to specify the uncertainty limits for each component of interest. ISO 7504:2001 2.10 maximum storage life period after which the stored gas mixture shall not be used NOTE 1 This period is usually identified as that for which the producer assures that t
35、he gas mixture maintains its composition within the specified limits when it is stored in accordance with requirements based upon maximum filling pressure, minimum utilization pressure, and minimum and maximum applicable temperature. NOTE 2 The end of this period may be indicated by an “expiry date”
36、. ISO 7504:2001 2.11 transfer system gas-conducting system which begins at the cylinder valve and ends at the gas sample inlet to the measuring instrument and includes all structural elements 2.12 uncertainty measurement parameter, associated with the result of a measurement, that characterizes the
37、dispersion of the values that could reasonably be attributed to the measurand NOTE 1 The parameter may be, for example, a standard deviation or a given multiple of it, or the half-width of an interval having a stated level of confidence. NOTE 2 Uncertainty of measurement comprises, in general, many
38、components. Some of these components may be evaluated from the statistical distribution of the results of series of measurements and can be characterized by experimental standard deviations. The other components, which also can be characterized by standard deviations, are evaluated from assumed prob
39、ability distributions based on experience or other information. NOTE 3 It is understood that the result of a measurement is the best estimate of the value of a measurand, and that all components of uncertainty, including those arising from systematic effects, such as components associated with corre
40、ctions and reference standards, contribute to the dispersion. GUM; ISO 7504:2001 2.13 utilization period time between the date of certification and the expiry date 2.14 permeability property of a material of transmitting gases and liquids by passage through one surface and out at another surface by
41、diffusion and sorption processes NOTE Not to be confused with porosity. ISO 472:1999 BS EN ISO 16664:2008EN ISO 16664:2008 (E)IS:46661 O4002(E) 4 I SO 4002 All irthgs ersedevr3 Transport and storage 3.1 General remarks After preparation of the calibration gas, the gas cylinder will be transported to
42、 the user. The environment in which the cylinders are transported is not normally regulated in terms of temperature and humidity. Low temperatures may have a detrimental impact on the mixture composition, especially when condensable components are present in the mixture. As a consequence of this, en
43、vironmental conditions during transport and storage should never exceed those recommended by the manufacturer. Gas cylinders and especially cylinder valves shall be free of grease and other lubricants. During storage and transportation, cylinder valves shall be closed, sealing nuts shall be tightene
44、d and protection caps shall be attached. The gas cylinders are transported in several ways, e.g. by air, railway, road and on water. In some specific cases, the temperature restrictions may be such that not every means of transport is acceptable. 3.2 Low temperature The gas cylinder may be exposed t
45、o low temperatures during storage and transportation. For gas mixtures containing condensable components, it is important that the cylinder is not stored or transported at temperatures below those recommended by the manufacturer. If the mixture is exposed to temperatures below the stated range, some
46、 components may condense and this will change the composition of the mixture. If the mixture has been exposed to temperatures lower than those recommended by the manufacturer, the certificate from the manufacturer is no longer valid. In this case, it is very important that the mixture shall not be u
47、sed before the manufacturer is asked for further advice. He may advise homogenizing the mixture before usage. 3.3 High temperature Avoid high temperatures (heating) close to the cylinder, e.g. from welding flames, blowlamps, ovens or other intensive heat sources. High temperatures will result in hig
48、her pressures leading to potentially hazardous situations. In addition, elevated temperatures may result in decomposition of thermally unstable species. 3.4 Water Gas cylinders shall be protected from excessive humidity during transport. Transportation by boat may result in the cylinder being spraye
49、d with water; this and/or excessive humidity may cause corrosion of the cylinder valve. Always protect the cylinder from precipitation to prevent corrosion. If the cylinders are stored outdoors protected by a roof, the cylinder base should also be protected from water accumulating on the floor by raising it above the ground. 3.5 Storage and handling The best way to store calibration gas mixtures for a longer period is by laying the cylinders in a horizontal position, well protected against rolling and falling. For safety
