DIN EN ISO 6145-4-2008 Gas analysis - Preparation of calibration gas mixtures using dynamic volumetric methods - Part 4 Continuous syringe injection method (ISO 6145-4 2004) Englis.pdf

1、November 2008DEUTSCHE NORM English price group 12No part of this standard 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 71.040.40!$Rx(“147850

2、5www.din.deDDIN EN ISO 6145-4Gas analysis Preparation of calibration gas mixtures using dynamic volumetricmethods Part 4: Continuous syringe injection method (ISO 6145-4:2004)English version of DIN EN ISO 6145-4:2008-11Gasanalyse Herstellung von Kalibriergasgemischen mit Hilfe von dynamisch-volumetr

3、ischenVerfahren Teil 4: Kontinuierliches Spritzen-Injektionsverfahren (ISO 6145-4:2004)Englische Fassung DIN EN ISO 6145-4:2008-11www.beuth.deDocument comprises 21 pagesDIN EN ISO 6145-4:2008-11 2 National foreword This standard has been prepared by Technical Committee ISO/TC 158 “Analysis of gases”

4、 (Secretariat: NEN, Netherlands) and has been taken over as EN ISO 6145-4:2008 by Technical Committee CEN/SS N21 “Gaseous fuels and combustible gas” (Secretariat: CMC). The responsible German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committ

5、ee), Technical 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 Part 2: Volumetric pumps Part 4: Continu

6、ous 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 corresponding to the International Standards

7、referred to in this document are as follows: ISO 6143 DIN EN ISO 6143 ISO 6145-1 DIN EN ISO 6145-1 ISO 7504 DIN V 51897 In addition, it should be noted that the “Guide to the expression of uncertainty in measurement (GUM)” has been published as DIN V ENV 13005. National Annex NA (informative) Biblio

8、graphy DIN V 51897, Gas analysis Definitions and explanations DIN V ENV 13005, Guide to the expression of uncertainty in measurement DIN EN ISO 6143, Gas analysis Comparison methods for determining and checking the composition of calibration gas mixtures DIN EN ISO 6145-1, Gas analysis Preparation o

9、f calibration gas mixtures using dynamic volumetric methods Part 1: Methods of calibration EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 6145-4 August 2008 ICS 71.040.40 English Version Gas analysis - Preparation of calibration gas mixtures using dynamic volumetric methods - Part 4: Conti

10、nuous syringe injection method (ISO 6145-4:2004) Analyse des gaz - Prparation des mlanges de gaz pour talonnage laide de mthodes volumtriques dynamiques - Partie 4: Mthode continue par seringue dinjection (ISO 6145-4:2004) Gasanalyse - Herstellung von Kalibriergasgemischen mit Hilfe von dynamisch-vo

11、lumetrischen Verfahren - Teil 4: Kontinuierliches Spritzen-Injektionsverfahren (ISO 6145-4:2004) 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 this European Standard the

12、status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German

13、). 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 Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Rep

14、ublic, 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 STANDARDIZATION COMIT EUROPEN DE

15、 NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 6145-4:2008: EContents Page2 Foreword .3 Introduction.4 1 Scope .5 2 Norm

16、ative references .5 3 Principle 5 4 Application to preparation of gas mixtures .6 4.1 Description of the experimental procedure .6 4.2 Area of validity 7 4.3 Operating conditions .8 5 Expression of results .8 5.1 Volume fraction 8 5.2 Sources of uncertainty .8 5.3 Uncertainty of volume fraction .9 A

17、nnex A (informative) Pre-mixed gases for preparation of mixtures of high dilution 10 Annex B (informative) Example of apparatus for preparation of calibration gas mixtures .11 Annex C (informative) Practical hints 13 Annex D (informative) Example of the determination of the uncertainty in the concen

18、tration of a calibration gas mixture prepared by the continuous injection method 16 Bibliography .19 DIN EN ISO 6145-4:2008-11 EN ISO 6145-4:2008 (E) Foreword3 EN ISO 6145-4:2008 (E) :DIN EN ISO 6145-4:2008-11 The text of ISO 6145-4:2004 has been prepared by Technical Committee ISO/TC 158 “Analysis

19、of gases” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 6145-4:2008 by Technical Committee CEN/SS 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,

20、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 this document may be the subject of patent rights. CE

21、N 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 Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Re

22、public, 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 Kingdom. Endorsement notice The text of ISO 6145-4:2004 ha

23、s been approved by CEN as a EN ISO 6145-4:2008 without any modification. IntroductionThis part of ISO 6145 is one of a series of standards dealing with various dynamic volumetric methods used forthe preparation of calibration gas mixtures.4 DIN EN ISO 6145-4:2008-11 EN ISO 6145-4:2008 (E) 1ScopeThis

24、 part of ISO 6145 specifies a method for continuous production of calibration gas mixtures, containing twoor more components, from pure gases or other gas mixtures by continuous injection of the calibrationcomponent(s) into a complementary gas stream by means of a syringe.If pre-mixed gases are used

25、 instead of pure gases (see Annex A), much lower volume fractions can beobtained. The volume flow rates, from which the volume fractions are determined, can be calculated from theindividual flow rates and can be independently measured by a suitable method given in ISO 6145-1.The merits of the method

26、 are that a substantial quantity of the gas mixture can be prepared on a continuousbasis and that multi-component mixtures can be prepared almost as readily as binary mixtures if theappropriate number of syringes is utilized, or if the syringe already contains a multi-component mixture ofknown compo

27、sition. This method also provides a convenient means for increasing the volume fraction of thecalibration component in the mixture in small steps. It is therefore a useful method for evaluation of othercharacteristics of gas analysers, such as minimum detection limit and dead zone, as well as accura

28、cy. Therelative expanded uncertainty in the volume fraction obtainable for a binary mixture (at a coverage factor of 2) isand the range of applicability is to .2 Normative referencesThe following referenced documents are indispensable for the application of this document. For datedreferences, only t

29、he edition cited applies. For undated references, the latest edition of the referenced document(including any amendments) applies.ISO 6143, Gas analysis Comparison methods for determining and checking the composition of calibrationgas mixturesISO 6145-1, Gas analysis Preparation of calibration gas m

30、ixtures using dynamic volumetric methods Part 1: Methods of calibration3 PrincipleThe calibration component, either in the gaseous or liquid phase, is displaced from a syringe, through acapillary which may be the needle of the syringe, the plunger of which is continuously driven by a suitablevariabl

31、e-speed motor, into a complementary gas stream.The volume fraction, of calibration component, , in a mixture with complementary gas, , is given byEquation (1):(1)5% 105102AABA= qA/(qA+ qB)5 EN ISO 6145-4:2008 (E) DIN EN ISO 6145-4:2008-11 whereis the volume flow rate of the calibration component, ;i

32、s the volume flow rate of the complementary gas, .If the calibration component is injected in the liquid phase, the flow rate in the gaseous phase on evaporation isgiven by Equation (2):(2)whereis the volume flow rate of the injected liquid, in the same units as ;is the density of the liquid compone

33、nt at the temperature at which the mixture is prepared;is the density of the component in the gaseous phase, expressed in the same units and at the sametemperature as .Substitution of Equation (2) in Equation (1) then provides the value of in terms of the parameters listedabove.4 Application to prep

34、aration of gas mixtures4.1 Description of the experimental procedure4.1.1 ApparatusSchematic diagrams of examples of apparatus for preparation of binary mixtures are shown in Annex B;Figure B.1 presents the apparatus for filling a syringe with a gaseous calibration component and Figure B.2shows a mi

35、xing system for preparation of the calibration gas mixture.4.1.2 Selection and calibration of syringe for the calibration componentThe flow rate of the calibration component is determined by parallel selection of the cross-sectional area of thesyringe barrel and the linear velocity of the plunger. S

36、ometimes, for preparation of a mixture of given volumefraction of the calibration component, it may be preferable to use a syringe of larger cross-section (largercapacity) in combination with a lower plunger velocity, and in other cases a smaller cross-section with higherplunger velocity may provide

37、 the better combination (refer for practical hints to Annex C).Select a suitable combination of linear speed of the syringe drive mechanism and metering syringe of volumeappropriate to the volume fraction, and the uncertainty in that volume fraction, of the calibration gas mixture tobe prepared.In o

38、rder to validate the uniformity of the syringe barrel, since this is a dynamic method, determine the volume ofthe gas or liquid delivered by the syringe at several graduation marks, and at the temperature at which the gasmixture is prepared. It is necessary, therefore, to allow time for the syringe

39、to return to ambient temperatureafter it has been warmed, for example by handling, before any measurements are made at any stage. Thisvolume calibration shall be derived from traceable mass measurements of a suitable liquid of known density inthe syringe. Since the calibration is to be carried out a

40、t several points, i.e. with the syringe partially filled,precautions shall be taken to ensure that the meniscus of the liquid is horizontal when observations of itsposition are made.An example of the methodology is presented in Annex C.qAAqBBqA=(qA,lA,l) /A,gqA,lqAA,lA,gA,lA6 DIN EN ISO 6145-4:2008-

41、11 EN ISO 6145-4:2008 (E) 4.1.3 Calibration of the syringe driverCalibrate the syringe driver at the temperature at which the gas mixture is prepared, and against referenceequipment which is traceable to international length and time standards. A recommended method for calibrationagainst a digital m

42、icrometer and a digital timer is also presented in Annex C.4.1.4 Preparation of the calibration gas mixtureWhen the calibration component is in the gaseous phase apparatus, an example of which is shown inFigure B.1, for evacuating, purging and filling the reservoir and filling the syringe shall be u

43、sed. The procedureis then as follows.a) Close the shut-off valve on the cylinder of calibration component.b) Evacuate the entire apparatus until the pressure has been reduced to a value which is sufficiently low, suchthat any residual gas in the reservoir makes no significant contribution to the vol

44、ume fraction and has noeffect on the stability of the final calibration gas mixture.A residual pressure of approximately ( ) has been found to be suitable. However, theultimate vacuum required will depend in practice on the nature and composition of the final gas mixture. Dueconsideration should the

45、refore be given to the partial pressure of the residual gas when the uncertainty inthe volume fraction of the calibration gas mixture is evaluated.c) Close the shut-off valve between the vacuum pump and the reservoir and fill the reservoir with thecalibration component, to a pressure of approximatel

46、y ( ). Re-evacuate and refill thereservoir in the same manner. In the final filling operation, adjust the pressure of the calibration componentin the reservoir so that the over-pressure is sufficient for the syringe to be filled.Make appropriate provision to ensure that hazardous gaseous components

47、are vented safely from theworking area.d) With the plunger pushed fully home, insert the needle of the empty metering syringe through the septum(see Figure B.1) into the reservoir. Raise and lower the plunger several times to ensure that the syringe isthoroughly flushed with the calibration componen

48、t without any significant contamination.e) Fill the syringe by fully withdrawing the plunger, then remove the syringe from the septum of the reservoir.With the needle retained in position on the syringe, set the plunger to the first graduation mark and connectthe syringe to the mixing system (Figure

49、 B.2).NOTE A convenient way by which to make the connection is again to use a septum.In some cases, it is convenient to introduce the calibration component into the syringe in the liquid phase,then allow it to evaporate after it has issued from the nozzle. The filling procedure is then straightforward butprecautions are still required to ensure that no significant amount of air or other contaminants areintroduced into the syringe with the liquid.f) Pass the complementary gas through a pressure regulator and a shut-off v