1、Workplace exposure - Characterization of ultrafine aerosols/nanoaerosols - Determination of number concentration using condensation particle countersBS EN 16897:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1
2、6897 June 2017 ICS 13.040.30 English Version Workplace exposure - Characterization of ultrafine aerosols/nanoaerosols - Determination of number concentration using condensation particle counters Exposition sur les lieux de travail - Caractrisation des arosols ultrafins/nanoarosols - Dtermination de
3、la concentration en nombre laide de compteurs de particules condensation Exposition am Arbeitsplatz - Charakterisierung ultrafeiner Aerosole/Nanoaerosole - Bestimmung der Anzahlkonzentration mit Kondensationspartikelzhlern This European Standard was approved by CEN on 10 April 2017. CEN members are
4、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 to th
5、e 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 Cent
6、re 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuani
7、a, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 1
8、7, B-1000 Brussels 2017 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16897:2017 ENational forewordThis British Standard is the UK implementation of EN 16897:2017.The UK participation in its preparation was entrusted to Technical
9、 Committee EH/2/2, Work place atmospheres.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standard
10、s Institution 2017 Published by BSI Standards Limited 2017ISBN 978 0 580 89025 3ICS 13.040.30Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2017.Am
11、endments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 16897:2017EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16897 June 2017 ICS 13.040.30 English Version Workplace exposure - Characterization of ultrafine aerosols/nanoaerosols - Determination of number concentr
12、ation using condensation particle counters Exposition sur les lieux de travail - Caractrisation des arosols ultrafins/nanoarosols - Dtermination de la concentration en nombre laide de compteurs de particules condensation Exposition am Arbeitsplatz - Charakterisierung ultrafeiner Aerosole/Nanoaerosol
13、e - Bestimmung der Anzahlkonzentration mit Kondensationspartikelzhlern This European Standard was approved by CEN on 10 April 2017. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national stan
14、dard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application 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 a
15、ny other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Rep
16、ublic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
17、 EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16897:2017
18、EBS EN 16897:2017EN 16897:2017 (E) 2 Contents Page European foreword . 3 Introduction 4 1 Scope 5 2 Normative references 5 3 Terms and definitions . 5 4 Abbreviations . 6 5 Principle . 6 6 Measurement methods . 8 6.1 General 8 6.2 Exposure measurement 9 6.3 Emission measurement 9 6.4 Background meas
19、urement 9 7 Measurement procedure . 10 7.1 Selection of suitable instrument . 10 7.2 Preparation 10 7.3 Monitoring 10 7.4 Sampling line . 10 7.5 Use of a diluter 10 8 Presentation and evaluation of data . 11 9 Check of CPC performance 11 10 Problems and uncertainties . 12 10.1 CPC counting efficienc
20、y 12 10.2 Sampling losses . 13 10.2.1 General . 13 10.2.2 Diffusion losses in a sampling tube . 13 10.2.3 Internal CPC losses 14 10.3 Uncertainties . 15 10.4 Maintenance . 15 Annex A (informative) Results of pre-normative research Laboratory comparisons of CPCs . 16 Annex B (informative) List of CPC
21、 instruments 17 Bibliography . 23 BS EN 16897:2017EN 16897:2017 (E) 3 European foreword This document (EN 16897:2017) has been prepared by Technical Committee CEN/TC 137 “Assessment of workplace exposure to chemical and biological agents”, the secretariat of which is held by DIN. This European Stand
22、ard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by December 2017, and conflicting national standards shall be withdrawn at the latest by December 2017. Attention is drawn to the possibility that some of the elements of
23、 this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. According to the CEN-CENELEC Internal
24、Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Irelan
25、d, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 16897:2017EN 16897:2017 (E) 4 Introduction Within occupational hygiene, aerosol concentrations have been tradit
26、ionally measured in terms of mass concentrations. For ultrafine aerosols and nanoaerosols, other exposure metrics such as the number and surface area concentrations could become important for predicting health effects with some aerosols, depending on their chemical and physical properties. Even if a
27、ctual occupational exposure metrics have not been established, this European Standard can be used by occupational hygienists and researchers to measure airborne particle concentrations in workplaces. Recommendations on how to perform an assessment of inhalation exposure to nano-objects and their agg
28、lomerates and aggregates (NOAA), including which measurement strategy to adopt, will be provided in prEN 17058:2016 16. BS EN 16897:2017EN 16897:2017 (E) 5 1 Scope This European Standard gives guidelines on the measurement of the fine particle fraction of the aerosol, especially for the determinatio
29、n of the number concentration of ultrafine aerosols and nanoaerosols at workplaces by use of condensation particle counters (CPC). This European Standard deals with the CPCs principle of operation, problems of sampling in the workplace environment, aspects for selecting a suitable instrument, limits
30、 of application, use of different working fluids and technologies, calibration, equipment maintenance, measurement uncertainty, and reporting of measurement results. Potential problems and limitations which are of relevance for workplace measurements are described. 2 Normative references The followi
31、ng documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 1540, Workplace
32、 exposure - Terminology 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 1540 and the following apply. 3.1 background (particle) measurement measurement of the particle concentration, at a location or a time not affected by the activity/process under i
33、nvestigation 3.2 emission (particle) measurement measurement of the particle concentration in direct vicinity of a process or machine 3.3 (particle) (electrical) mobility (equivalent) diameter diameter of a sphere carrying one elementary electric charge with the same electrical mobility as the parti
34、cle in question 3.4 exposure (particle) measurement measurement of the particle concentration close to a worker, preferably in the breathing zone of a worker Note 1 to entry: Measurements performed outside the breathing zone give only an approximated exposure value. 3.5 nanoaerosol aerosol comprised
35、 of, or consisting of, nano-objects and nanostructured particles SOURCE: ISO/TR 27628:2007, definition 2.11 17 BS EN 16897:2017EN 16897:2017 (E) 6 3.6 nano-object material with one, two or three external dimensions in the nanoscale below 100 nm Note 1 to entry: Generic term for all discrete nanoscal
36、e objects. SOURCE: CEN ISO/TS 80004-1:2015, definition 2.5 18 3.7 particle number concentration CNnumber of particles related to the unit volume of the carrier gas Note 1 to entry: For the exact particle number concentration indication, information on the gaseous condition (temperature and pressure)
37、 is necessary. This can include a comparison of the measured number concentration with the test certificate of a CPC or a correction of the nominal flow with the actual volumetric flow. A frequent check of the instrument including its air flow and response is strongly recommended. Note 2 to entry: I
38、n many cases, depending on make and model, the CPC outputs the particle number concentration based on the assumption that its air flow rate equals the nominal air flow rate determined at a specific testing condition. Note 3 to entry: The particle number concentration is given as number per cubic cen
39、timetre cm3. 3.8 ultrafine particle particle with a nominal diameter (such as geometric, aerodynamic, mobility, projected-area or otherwise) of 100 nm or less Note 1 to entry: The term is often used in the context of particles produced as a by-product of a process (incidental particles), such as wel
40、ding fume and combustion fume. SOURCE: ISO/TR 27628:2007, definition 2.21 4 Abbreviations For the purposes of this document, the following abbreviations apply. CMMD Count Median Mobility Diameter of a particle size distribution CNC Condensation Nuclei Counter CPC Condensation Particle Counter 5 Prin
41、ciple The common principle of all different CPC types is the condensation of supersaturated vapours onto particles. Particles grow to droplets of sizes that can be detected optically 1. The counting of the droplets is performed via optical light scattering. A CPC measures, in real-time, airborne par
42、ticles ranging from few nm up to several m in size in a limited range of concentration, but does not discriminate between particles of different sizes or origin. BS EN 16897:2017EN 16897:2017 (E) 7 Aerosol particles are drawn into the instrument at the inlet. A pre-separation can be applied to avoid
43、 large particles that otherwise would have been trapped in the aerosol transfer tubes of the instrument. A part or the entire air flow is directed into a heated saturator. Commercially available CPCs employ different working fluids to generate the vapour, e.g. butanol, iso-propanol, or water. Moreov
44、er, different principles are in use to achieve the needed supersaturation in the sample air. The most common CPC uses laminar flow and diffusional heat transfer. The diffusion constant and saturation vapour pressure of the working fluid determines the needed heating or cooling steps to initiate cond
45、ensation and hence the principle design of a laminar flow CPC. The mixture of particles and supersaturated vapour reaches the condensation zone and the vapour condenses onto the particles. The size of the droplets reaches diameters of up to a few micrometres in the condenser zone. The droplet passes
46、 through a detection zone where it is illuminated by a focused light beam and a portion of the scattered light is detected with a photodetector. The frequency of this event leads, with the known volume of sampled air, to the particle number concentration. At low concentrations the CPC counts individ
47、ual particles and allows a direct determination of particle number concentration (single particle count mode). At higher concentrations some instruments include an evaluation of the total scattered light intensity without single particle counting and thus estimate the number concentration, based on
48、assumptions of final particle size and optical properties (photometric mode). NOTE Another name given to CPC is condensation nuclei counter (CNC). Figure 1 shows a schematic of the probably most common CPC type with a laminar flow through a heated saturator and a cooled condenser. BS EN 16897:2017EN
49、 16897:2017 (E) 8 Key 1 aerosol inlet 7 droplet 2 working fluid reservoir 8 light source 3 heated saturator 9 illumination optics 4 particle 10 receiving optics 5 thermoelectric cooling and heating device 11 photodetector 6 condenser 12 aerosol outlet Figure 1 Principle of the laminar flow CPC 6 Measurement methods 6.1 General The CPC measures the number concentration of an aerosol in real-time within a defined range of particle diameters and concentrations. A comparison to mass based occupational limit values of airborne hazardous
