DIN EN ISO 6145-5-2011 Gas analysis - Preparation of calibration gas mixtures using dynamic volumetric methods - Part 5 Capillary calibration devices (ISO 6145-5 2009) German versi.pdf

1、March 2011 Translation by DIN-Sprachendienst.English price group 11No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS

2、71.040.40!$n:0“1752313www.din.deDDIN EN ISO 6145-5Gas analysis Preparation of calibration gas mixtures using dynamic volumetricmethods Part 5: Capillary calibration devices (ISO 6145-5:2009)English translation of DIN EN ISO 6145-5:2011-03Gasanalyse Herstellung von Kalibriergasgemischen mit Hilfe von

3、 dynamisch-volumetrischenVerfahren Teil 5: Kapillardosierer (ISO 6145-5:2009)Englische bersetzung von DIN EN ISO 6145-5:2011-03Analyse des gaz Prparation des mlanges de gaz pour talonnage laide de mthodes volumtriquesdynamiques Partie 5: Dispositifs dtalonnage par capillaires (ISO 6145-5:2009)Traduc

4、tion anglaise de DIN EN ISO 6145-5:2011-03www.beuth.deDocument comprises 19 pagesIn case of doubt, the German-language original shall be considered authoritative.03.11 DIN EN ISO 6145-5:2011-03 2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Co

5、mmittee ISO/TC 158 “Analysis of gases” (Secretariat: NEN, Netherlands) and has been taken over as EN ISO 6145-5:2010 by Technical Committee CEN/SS N21 “Gaseous fuels and combustible gas” (Secretariat: CCMC). The responsible German body involved in its preparation was the Normenausschuss Materialprfu

6、ng (Materials Testing Standards Committee), Working Committee NA 062-05-73 AA Gasanalyse und Gas-beschaffenheit. 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 Par

7、t 2: Volumetric pumps Part 4: Continuous 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: Electrochemical generation The DIN Standards correspo

8、nding to the International Standards referred to in this document are as follows: ISO 6143 DIN EN ISO 6143 ISO 6145-1 DIN EN ISO 6145-1 ISO/IEC Guide 98-3 DIN V ENV 13005 National Annex NA (informative) Bibliography DIN V ENV 13005, Guide to the expression of uncertainty in measurement DIN EN ISO 61

9、43, Gas analysis Comparison methods for determining and checking the composition of calibration gas mixtures DIN EN ISO 6145-1, Gas analysis Preparation of calibration gas mixtures using dynamic volumetric methods Part 1: Methods of calibration syringeEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NOR

10、M 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 d

11、ynamiques - 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

12、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 t

13、o 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

14、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,

15、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 f

16、orm and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 6145-5:2010: EContents DIN EN ISO 6145-5:2011-03 EN ISO 6145-5:2010 (E) 2 Page Foreword 1 Scope 4 2 Normative references 4 3 Principle4 4 Apparatus .5 4.1 Two-capillary blending system 5 4.1.1 Set-up5 4.1.2 Apparatus .

17、5 4.1.3 Procedure .6 4.2 Multiple capillary devices using gas dividers.7 4.2.1 Set-up of a gas divider 7 4.2.2 Gas dividers with a combination of non-identical capillaries.7 4.2.3 Gas dividers with a combination of identical capillaries.8 4.2.4 Operation of a gas divider with identical capillaries9

18、4.2.5 Determination of the flow rates 9 5 Expression of results 10 5.1 Volume fraction10 5.2 Sources of uncertainties.10 5.2.1 Temperature .10 5.2.2 Viscosity .10 5.2.3 Pressure11 5.2.4 Geometry of the capillary tubes.11 5.3 Verification of the blending system/gas divider.11 5.4 Determination of unc

19、ertainties.11 Annex A (informative) Numerical example .13 Annex B (informative) Derivation of the formula for combined uncertainty in K .16 Bibliography 17 3Foreword The text of ISO 6145-5:2009 has been prepared by Technical Committee ISO/TC 158 “Analysis of gases” of the International Organization

20、for Standardization (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 lat

21、est by June 2011. 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 stan

22、dards organizations 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,

23、Poland, Portugal, 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. DIN EN ISO 6145-5:2011-03 EN ISO 6145-5:2010 (E) 3 1 Scope This part of ISO 6145

24、 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 from pure gases or gas mixtures using capillary calibrati

25、on 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 technique is less than 2 % (k = 2) relative. This applica

26、tion 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 dilutions in the range of volume fractions from 0,000 5

27、 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 gas standards. An example is given in Annex A. 2 Norma

28、tive 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) applies. ISO 6143, Gas analysis Comparison

29、 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 from a capillary tube under conditions of constant pre

30、ssure 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 an appropriate capillary is selected, the required flow

31、 is obtained by adjusting the pressure drop across the capillary. DIN EN ISO 6145-5:2011-03 EN ISO 6145-5:2010 (E) 4 Commercially available units consisting of several capillary tubes are called gas dividers. Such gas dividers containing combinations of capillaries may be used to dilute pure gases o

32、r 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 using two capillary tubes, i.e. a two-capillary system. Key 1 two-stage

33、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, each supplied with gas from a cylinder fitted with a two-stage pressure reg

34、ulator, 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. DIN EN ISO 6145-5:2011-03 EN ISO 6145-5:2010 (E) 5 4.1.2.4 Gas manifold, fed by the

35、 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 Thermostatic controller (optional), to maintain the temperature of the capillaries constant. V

36、ariations 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 capillaries. With thermostatic control of a water-jacket to 1 C, the volume fraction of the final mix

37、ture 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 adjustment valves to give the pressure drop across the capillaries required for the desired

38、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 flow rates of each component. These can be estimated by observations of the variation in the p

39、ressure 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: ()412A8p pr= qL(1) where r is the radius of the capillary tube; p1is the inlet pressure to the ca

40、pillary; 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 simplified by the use of an individual calibration factor. For its determination, the gas flow from o

41、ne 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 pressure differences (p1 p2) against flow rates. The gradient of this line will be the indi

42、vidual 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 the use of a calibration factor is advisable because several influences, for example, viscosit

43、y of the gases and temperature changes, can be recognized. DIN EN ISO 6145-5:2011-03 EN ISO 6145-5:2010 (E) 6 4.2 Multiple capillary devices using gas dividers 4.2.1 Set-up of a gas divider For gas dividers, multiple capillary tubes are combined. Such combinations shall be realized according to the

44、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 differences in the latter realizations are equal for all capillaries. Gas dividers in the context of this part of ISO 614

45、5 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 divid

46、ers with a combination of non-identical capillaries The gas dividers with non-identical capillaries are combinations of more than two capillaries of different lengths and diameters and thus provide different flow rates (see Figure 2). Usually, one capillary is used for the dilution gas (capillary tu

47、be 1 in Figure 2) while the component gas is flowing through one (capillary tube 2 in Figure 2) or a combination of the other capillaries. During operation, the gas pressures of the component and dilution gas shall be adjusted by external regulators. Key 1 dilution-gas capillaries 2-10 component-gas

48、 capillaries 11 generated gas 12 component gas, volume fraction, 013 division-switching valve 14 pressure regulator aDilution gas. bExhaust gas. Figure 2 Principle of operation DIN EN ISO 6145-5:2011-03 EN ISO 6145-5:2010 (E) 7 To increase the dilution-factor range, an additional capillary may be in

49、stalled and switched, when necessary, in parallel with the first one. By selecting the capillaries through which the component gas flows, at least 9 levels of dilution can be obtained when those capillaries are used individually. The use of their combinations can provide dilution-factor values of 10 to 2 000. These “component-gas capillaries” may be equal or different in design. The individual capillary flow rates are determined according to 4.1.3.2. To determine or to verify the respective diluti