BS EN 13274-7-2008 Respiratory protective ndevices — Methods of ntest — nPart 7 Determination of particle filter npenetration《呼吸保护装置 试验方法 粒子过滤器渗透性的测定》.pdf

《BS EN 13274-7-2008 Respiratory protective ndevices — Methods of ntest — nPart 7 Determination of particle filter npenetration《呼吸保护装置 试验方法 粒子过滤器渗透性的测定》.pdf》由会员分享，可在线阅读，更多相关《BS EN 13274-7-2008 Respiratory protective ndevices — Methods of ntest — nPart 7 Determination of particle filter npenetration《呼吸保护装置 试验方法 粒子过滤器渗透性的测定》.pdf（22页珍藏版）》请在麦多课文档分享上搜索。

1、BRITISH STANDARDBS EN 13274-7:2008Respiratory protective devices Methods of test Part 7: Determination of particle filter penetrationICS 13.340.30g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3

2、g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 13274-7:2008This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2008 BSI 2008ISBN 978 0 580 58578 4National forewordThis British Standard is the UK implementation of EN 13274-7:2008. It

3、 supersedes BS EN 13274-7:2002 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee PH/4, Respiratory protection.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include a

4、ll the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments/corrigenda issued since publicationDate CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 13274-7January 20

5、08ICS 13.340.30 Supersedes EN 13274-7:2002 English VersionRespiratory protective devices - Methods of test - Part 7:Determination of particle filter penetrationAppareils de protection respiratoire - Methode dessai -Partie 7 : Dtermination de la pntration de filtres particulesAtemschutzgerte - Prfver

6、fahren - Teil 7: Bestimmung desDurchlasses von PartikelfilternThis European Standard was approved by CEN on 5 December 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard with

7、out 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 (English, French, German). A version in any other language m

8、ade 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, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France

9、, 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 STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMU

10、NGManagement 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 13274-7:2008: EEN 13274-7:2008 (E) 2 Contents Page Foreword3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms and

11、 definitions .5 4 Pre-requisites.5 5 Test requirements6 5.1 General6 5.2 Penetration test6 5.3 Exposure test .6 5.4 Storage test 7 6 Sodium chloride test method .7 6.1 Principle7 6.2 Test equipment 7 6.3 Test conditions 8 6.4 Procedure .8 6.5 Calculation of the penetration9 7 Paraffin oil test metho

12、d.9 7.1 Principle9 7.2 Test equipment 9 7.3 Test conditions at filter .10 7.4 Procedure .10 7.5 Calculation of the penetration11 Annex A (normative) Test results - Uncertainty of measurements17 Annex ZA (informative) Relationship between this European Standard and the Essential Requirements of EU Di

13、rectives 18 BS EN 13274-7:2008EN 13274-7:2008 (E) 3 Foreword This document (EN 13274-7:2008) has been prepared by Technical Committee CEN/TC 79 “Respiratory protective devices”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either b

14、y publication of an identical text or by endorsement, at the latest by July 2008, and conflicting national standards shall be withdrawn at the latest by July 2008. 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

15、 shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 13274-7:2002. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive

16、 89/106/EEC. For relationship with EU Directive 89/106/EEC, see informative Annex ZA, which is an integral part of this document. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria,

17、 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 Kingdom. BS EN 13274-7

18、:2008EN 13274-7:2008 (E) 4 Introduction This European Standard is intended as a supplement to the specific device standards for respiratory protective devices. Test methods are specified for complete or parts of devices. If deviations from the test method given in this standard are necessary, these

19、deviations will be specified in the relevant device standard. BS EN 13274-7:2008EN 13274-7:2008 (E) 5 1 Scope This European Standard specifies the procedure for testing particle filter penetration for respiratory protective devices. 2 Normative references The following referenced documents are indis

20、pensable 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. EN 132:1998, Respiratory protective devices Definitions of terms and pictograms EN 13274-5, R

21、espiratory protective devices Methods of test Part 5: Climatic conditions 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 132:1998 apply. 4 Pre-requisites In order to implement this part of EN 13274, at least the following parameters need to be specif

22、ied in the appropriate device standard: items to be tested; number of samples; test method(s); flow rate through the filter; sequence of conditioning phases, where more than one is required; specification of any observations to be carried out; sample preparation and orientation; sample holding; in t

23、he case of the exposure test, the specified mass of test aerosol; pass/fail criteria; any deviations from this method. BS EN 13274-7:2008EN 13274-7:2008 (E) 6 5 Test requirements 5.1 General Unless otherwise specified, the values stated in this European Standard are expressed as nominal values. Exce

24、pt for temperature limits, values which are not stated as maxima or minima shall be subject to a tolerance of 5 %. Unless otherwise specified the ambient temperature for testing shall be in the range between 16 C and 32 C and the temperature limits shall be subject to an accuracy of 1 C. Two test ae

25、rosols are used for measurement of filter penetration: a) Sodium Chloride, using the equipment described in Clause 6: b) Paraffin Oil, using the equipment described in Clause 7. NOTE Laboratories should give consideration to the following factors: Test chamber should be designed to minimise air velo

26、city variations across the surface of the filter under test. Localised high air velocity (“jets”), may result inartificially high filter penetration. Paraffin oil used for testing should not have been exposed to heating and compressed air for a long period of time, as this may alter the composition

27、of the oil, possibly causing inaccurate results. Replacement of paraffin oil in the test rig should be done every 3 months. The test aerosol is fed into the test chamber, where the particle filtering device under test is mounted under a leaktight manner on a suitable adaptor. Aerosol is passed throu

28、gh the device and the aerosol concentration is measured immediately before and after the particle filtering device by the photometer. 5.2 Penetration test The measurement of penetration, according to 5.1, shall be taken as the average over a time of (30 + 3) s, beginning 3 min after the start of the

29、 aerosol test. 5.3 Exposure test Penetration shall be recorded throughout the test at sample intervals not exceeding 5 min. NOTE Continuous recording of penetration is recommended. For particle filtering devices being tested using paraffin oil, continue the test until the particle filtering device h

30、as been exposed to the specified mass of the test aerosol as defined in the appropriate device standard. For particle filtering devices being tested using sodium chloride, continue the test until the particle filtering device has been exposed to the specified mass of the test aerosol as defined in t

31、he appropriate device standard, unless: a) for single shift use particle filtering devices, the penetration shows continued decline for 5 min or 5 sample intervals, whichever is the greater; b) for re-useable particle filtering devices, the penetration shows continued decline for 5 min or 5 sample i

32、ntervals, whichever is the greater, and the maximum penetration is lower than when tested using paraffin oil test aerosol. If these conditions are met, the exposure test may be terminated early. Report the maximum penetration during exposure. BS EN 13274-7:2008EN 13274-7:2008 (E) 7 5.4 Storage test

33、For re-useable particle filtering devices the storage test shall be performed immediately after the completion of the exposure test. Remove the particle filtering device from the penetration test chamber and store the particle filtering device in accordance with EN 13274-5, for duration of (24 1) h

34、under ambient conditions as described in 3.1 of EN 13274-5:2001, ensuring that particle filtering devices are not in contact with each other. The particle filtering device shall not be removed from the suitable adaptor if this may result in damage to the device. After storage, immediately repeat the

35、 penetration test according to 5.2. 6 Sodium chloride test method 6.1 Principle An aerosol of sodium chloride particles is generated by atomising an aqueous solution of the salt and evaporating the water. The concentration of this aerosol is measured before and after the filter under test by means o

36、f flame photometry. Accurate determinations are possible in the range 0,001 % to 100 % filter penetration. When an alternative design of test equipment to that given in 6.2 is used, it shall be correlated directly with this reference method and shall be shown to be equivalent over the whole of the o

37、perational range. 6.2 Test equipment The apparatus is shown schematically in Figure 1. The aerosol is generated by using a Collison atomizer filled with a 1 % solution of sodium chloride. The atomizer, an example of which is shown in Figure 2, consists of a glass reservoir into which is sealed an at

38、omizer head having three spray nozzles. Air is supplied to the atomizer at a pressure of 3,45 bar and the resulting liquid spray impinges on a baffle which removes the large particles. The particles which do not impact are removed in the air flow and, on mixing with dry air the water evaporates leav

39、ing a dry sodium chloride aerosol. The aerosol produced by this method is polydisperse with a mass median particle diameter of approximately 0,6 m. The particle size distribution is given in Figure 3. It has been found that the aerosol remains constant, within acceptable limits, with respect to part

40、icle size and concentration provided that the supply pressure is in the range from 3,3 bar to 3,6 bar and the flow rate of air to the three nozzles is from 12,5 I/min to 13,0 I/min. The output is mixed with 82 I/min of dry air in a chamber with a minimum volume of 1 750 cm3giving a total flow rate o

41、f 95 l/min. NOTE 1 The sodium chloride solution in the atomizer is consumed at a rate of approximately 15 ml/h. This loss is due in part to the atomization of the solution and in part to evaporation of water from the reservoir. The volume of the reservoir is such that the change in concentration and

42、 loss in volume of the solution during an 8 h period will not cause an appreciable change in the characteristics of the test aerosol. The sodium chloride aerosol is analysed before and after the filtering device under test by flame photometry. The photometer used for this analysis can be any suitabl

43、e instrument having the required sensitivity, however, a photometer specially designed to meet these requirements is available. NOTE 2 Information concerning the supplier of the photometer and the aerosol generator can be obtained from the secretariat of CEN/TC 79. In the photometer, the hydrogen bu

44、rner is housed in a vertical flame tube through which the aerosol to be analysed flows. The hydrogen burner, which gives a flame symmetrical about the vertical axis, is surrounded BS EN 13274-7:2008EN 13274-7:2008 (E) 8 by a heat proof glass tube. This tube shall be optically homogeneous to minimize

45、 the effect on the light emitted by the flame. Sodium chloride particles in air passing through the flame tube are vaporized giving the characteristic sodium emission at 589 nm. The intensity of this emission is proportional to the concentration of sodium in the air flow. The intensity of the light

46、emitted by the flame is measured by using a photomultiplier tube. To separate the sodium emission from background light of other wavelengths, a narrow band interference filter with appropriate sideband filters is used. This filter should preferably have a half-peak band width of no more than 5 nm. A

47、s the photomultiplier output is only proportional to the incident light over a relatively small range, high light intensities are attenuated by neutral density filters. These filters are accurately calibrated in conjunction with the interference filter in use and so the actual light intensity can be

48、 calculated from the output of the photomultiplier. The signal from the photomultiplier is amplified and recorded. 6.3 Test conditions Particle size distribution of the test aerosol at the test chamber see Figure 3 Test aerosol concentration at the test chamber (4 to 12) mg/m3 Relative humidity of t

49、he test aerosol at the test chamber less than 60 % Flow rate of test aerosol from the generator 95 l/min Air pressure to atomizer (3,3 to 3,6) bar Flow rate to atomizer (12,5 to 13,0) l/min Flow rate of diluting air 82 l/min NOTE Flow rate of hydrogen to photometer, 450 ml/min to 500 ml/min (typical). 6.4 Procedure The test aerosol is fed into the test chamber, where the filter under test is fixed. The specified flow is passed through the filter and the aerosol concentration is measured immediately before and after the filter by