1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 6145-5:2010Gas analysis Preparation of calibration gas mixtures using dynamic volumetric methodsPart 5: Capillary calibration devices (ISO 6145-5:2009)BS EN ISO 6145-5:
2、2010 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO6145-5:2010. It is identical to ISO 6145-5:2009. It supersedes BS ISO6145-5:2009 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PTI/15, Natural Gas and Gas An
3、alysis.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 2011 ISBN 978 0 580 72204 2 ICS 71.040.40Compliance wi
4、th a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 28 February 2011. Amendments issued since publicationDate T e x t a f f e c t e dEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NO
5、RM EN ISO 6145-5 December 2010 ICS 71.040.40 English Version Gas analysis - Preparation of calibration gas mixtures using dynamic volumetric methods - Part 5: Capillary calibration devices (ISO 6145-5:2009) Analyse des gaz - Prparation des mlanges de gaz pour talonnage laide de mthodes volumtriques
6、dynamiques - Partie 5: Dispositifs dtalonnage par capillaires (ISO 6145-5:2009) Gasanalyse - Herstellung von Kalibriergasgemischen mit Hilfe von dynamisch-volumetrischen Verfahren - Teil 5: Kapillardosierer (ISO 6145-5:2009) This European Standard was approved by CEN on 11 December 2010. CEN members
7、 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
8、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
9、 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, Malta, Netherlands,
10、 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 exploitation in any
11、form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 6145-5:2010: EBS EN ISO 6145-5:2010 EN ISO 6145-5:2010 (E) 3 Foreword The text of ISO 6145-5:2009 has been prepared by Technical Committee ISO/TC 158 “Analysis of gases” of the International Organization for Standardi
12、zation (ISO) and has been taken over as EN ISO 6145-5:2010. 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 2011, and conflicting national standards shall be withdrawn at the latest by June 2
13、011. 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 organiz
14、ations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portu
15、gal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 6145-5:2009 has been approved by CEN as a EN ISO 6145-5:2010 without any modification. BS EN ISO 6145-5:2010ISO 6145-5:2009(E) ISO 2009 All rights reserved iiiContents Page Forewor
16、d iv 1 Scope1 2 Normative references1 3 Principle1 4 Apparatus.2 4.1 Two-capillary blending system 2 4.1.1 Set-up2 4.1.2 Apparatus.2 4.1.3 Procedure.3 4.2 Multiple capillary devices using gas dividers 4 4.2.1 Set-up of a gas divider4 4.2.2 Gas dividers with a combination of non-identical capillaries
17、.4 4.2.3 Gas dividers with a combination of identical capillaries 5 4.2.4 Operation of a gas divider with identical capillaries .6 4.2.5 Determination of the flow rates6 5 Expression of results7 5.1 Volume fraction .7 5.2 Sources of uncertainties.7 5.2.1 Temperature.7 5.2.2 Viscosity.7 5.2.3 Pressur
18、e .8 5.2.4 Geometry of the capillary tubes.8 5.3 Verification of the blending system/gas divider.8 5.4 Determination of uncertainties 8 Annex A (informative) Numerical example.10 Annex B (informative) Derivation of the formula for combined uncertainty in K .13 Bibliography14 BS EN ISO 6145-5:2010 IS
19、O 6145-5:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each m
20、ember 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 ISO, also take part in the work. ISO collaborates closely with the International
21、Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance 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 a
22、dopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires 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 p
23、atent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 6145-5 was prepared by Technical Committee ISO/TC 158, Analysis of gases. This second edition cancels and replaces the first edition (ISO 6145-5:2001), which has been technically revised. Some subclaus
24、es (such as Procedure and Calculations) have been detached from other closely related clauses and readability has been improved by bringing these subclauses closer together. The principle and verification parts have been clarified and separated, the uncertainty section has been checked and slightly
25、updated and Annex A has been revised. An informative derivation of the relative combined standard uncertainty calculation has been added as Annex B. ISO 6145 consists of the following parts, under the general title Gas analysis Preparation of calibration gas mixtures using dynamic volumetric methods
26、: Part 1: Methods of calibration Part 2: Volumetric pumps Part 4: Continuous syringe injection method Part 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: Electroch
27、emical generation ISO 6145-3, entitled Periodic injections into a flowing gas stream, has been withdrawn. BS EN ISO 6145-5:2010INTERNATIONAL STANDARD ISO 6145-5:2009(E) ISO 2009 All rights reserved 1Gas analysis Preparation of calibration gas mixtures using dynamic volumetric methods Partie 5: Capil
28、lary calibration devices 1 Scope This part of ISO 6145 is one of a series of International Standards dealing with the various dynamic volumetric techniques used for the preparation of calibration gas mixtures. This part specifies a method for the continuous production of calibration gas mixtures fro
29、m pure gases or gas mixtures using capillary calibration devices in single or multiple combinations (gas dividers). Single capillary systems can be used to provide gas mixtures where the minor component is in the range of volume fractions from 108to 0,5. The relative expanded uncertainty of this tec
30、hnique is less than 2 % (k = 2) relative. This application is used in industrial gas mixing panels for the production of specific gas atmospheres. Gas dividers can be used to divide gas mixtures prepared from gases or gas mixtures into controlled proportions by volume. These devices are capable of d
31、ilutions in the range of volume fractions from 0,000 5 to 0,9 of the primary gas concentration with a relative repeatability of better than 0,5 %. Traceability of the gas mixtures produced by a gas divider is achieved by comparison of a mixture with gas mixtures related to national or international
32、gas standards. An example is given in Annex A. 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
33、amendments) applies. ISO 6143, Gas analysis Comparison methods for 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 3 Principle A constant flow of gas
34、from a capillary tube under conditions of constant pressure drop is added to a controlled flow of complementary gas. The complementary gas flow may also be derived from another capillary tube. The appropriate capillaries are selected to give the required flows of gases into the mixing manifold. If a
35、n appropriate capillary is selected, the required flow is obtained by adjusting the pressure drop across the capillary. BS EN ISO 6145-5:2010ISO 6145-5:2009(E) 2 ISO 2009 All rights reservedCommercially available units consisting of several capillary tubes are called gas dividers. Such gas dividers
36、containing combinations of capillaries may be used to dilute pure gases or further dilute calibration gas mixtures with complementary gas, thus generating further calibration standards. 4 Apparatus 4.1 Two-capillary blending system 4.1.1 Set-up Figure 1 shows a possible set-up of a gas mixing system
37、 using two capillary tubes, i.e. a two-capillary system. Key 1 two-stage pressure regulator 2 fine adjustment valve 3 pressure differential manometer 4 capillary 5 mixing manifold aGas A. bComplementary gas. cGas mixture. Figure 1 Two-capillary blending system 4.1.2 Apparatus 4.1.2.1 Capillaries, ea
38、ch supplied with gas from a cylinder fitted with a two-stage pressure regulator, gas filter and a fine adjustment valve. 4.1.2.2 Two-stage pressure regulator, equipped with fine adjustment valves. 4.1.2.3 Differential manometer, capable of measuring the pressure drop across the capillary. BS EN ISO
39、6145-5:2010ISO 6145-5:2009(E) ISO 2009 All rights reserved 34.1.2.4 Gas manifold, fed by the flow from each capillary where mixing occurs to produce the calibration gas mixture at the outlet. 4.1.2.5 Gas filters, to filter the component gases, so as to prevent blockage of the capillaries. 4.1.2.6 Th
40、ermostatic controller (optional), to maintain the temperature of the capillaries constant. Variations in temperature can cause a significant change in the viscosity of the component gas passing through the capillary. For high accuracy, it is necessary to provide thermostatic control of the capillari
41、es. With thermostatic control of a water-jacket to 1 C, the volume fraction of the final mixture will not vary by more than 2 %. 4.1.3 Procedure 4.1.3.1 Operation Open the gas supply cylinders and adjust the two-stage pressure regulators to approximately 200 kPa gauge outlet pressure. Open the fine
42、adjustment valves to give the pressure drop across the capillaries required for the desired flows. The required pressure drop can be estimated using a modification of Equation (1), given in 4.1.3.2. The accuracy of the mixture produced at any moment is principally affected by the constancy of the fl
43、ow rates of each component. These can be estimated by observations of the variation in the pressure differential manometers applied across each capillary. 4.1.3.2 Determination of the capillary flow rate The volume flow rate qAof a gas A emerging from a capillary is approximately expressed as: ()412
44、A8p pr= qL(1) where r is the radius of the capillary tube; p1is the inlet pressure to the capillary; p2is the outlet pressure of the capillary; is the dynamic viscosity of the gas at the temperature of usage; L is the length of the capillary tube. For a given capillary, Equation (1) can be simplifie
45、d by the use of an individual calibration factor. For its determination, the gas flow from one capillary is passed into a flowmeter with known accuracy. Additionally, readings are taken of the differential pressures required to provide a range of flows. A calibration curve is constructed by plotting
46、 pressure differences (p1 p2) against flow rates. The gradient of this line will be the individual calibration factor K for the specified gas. ()AA12AAAAqKppqKp=(2) where KAis an individual factor for gas A; pAis equal to (p1 p2) across the capillary. In practice, the determination of the flow by th
47、e use of a calibration factor is advisable because several influences, for example, viscosity of the gases and temperature changes, can be recognized. BS EN ISO 6145-5:2010ISO 6145-5:2009(E) 4 ISO 2009 All rights reserved4.2 Multiple capillary devices using gas dividers 4.2.1 Set-up of a gas divider
48、 For gas dividers, multiple capillary tubes are combined. Such combinations shall be realized according to the system in Figure 1 or according to the systems in Figures 2 and 3. While, in the first set-up, the pressure difference is controlled individually for each capillary, the pressure difference
49、s in the latter realizations are equal for all capillaries. Gas dividers in the context of this part of ISO 6145 are systems with an equal pressure difference for all included capillary tubes. Generally, such gas dividers can be divided into two groups: a) gas dividers with a combination of non-identical capillaries (4.2.2); b) gas dividers with a combination of identical capillaries (4.2.3). 4.2.2 Gas dividers with a combination of non-identical capillaries The gas dividers with non-identical cap
