1、BS ISO21501-1:2009ICS 19.120NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDDeterminationof particle sizedistribution Single particle lightinteraction methodsPart 1: Light scattering aerosolspectrometerThis British Standard was published under the authority of t
2、he Standards Policy and Strategy Committee on 30 June 2009. BSI 2009ISBN 978 0 580 59623 0Amendments/corrigenda issued since publicationDate CommentsBS ISO 21501-1:2009National forewordThis British Standard is the UK implementation of ISO 21501-1:2009. Together with BS ISO 13323-1:2000 (subsequently
3、 withdrawn and replaced by BS ISO 21501-2:2007, BS ISO 21501-3 and BS ISO 21501-4:2007), it supersedes BS 3406-7:1988 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee LBI/37, Particle characterization including sieving.A list of organizations represented
4、 on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunityfrom legal obligations.BS ISO 21501-1:2009
5、Reference numberISO 21501-1:2009(E)ISO 2009INTERNATIONAL STANDARD ISO21501-1First edition2009-06-01Determination of particle size distribution Single particle light interaction methods Part 1: Light scattering aerosol spectrometer Dtermination de la distribution granulomtrique Mthodes dinteraction l
6、umineuse de particules uniques Partie 1: Spectromtre darosol en lumire disperse BS ISO 21501-1:2009ISO 21501-1:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefa
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11、ww.iso.org Published in Switzerland ii ISO 2009 All rights reservedBS ISO 21501-1:2009ISO 21501-1:2009(E) ISO 2009 All rights reserved iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Terms and definitions. 1 3 Requirements 3 3.1 Size range 3 3.2 Counting efficiency. 3 3.2.1 General. 3 3.2.
12、2 Lower size limit . 4 3.2.3 Upper size limit . 4 3.3 Size resolution 4 3.4 Sizing accuracy. 5 3.5 Sampling flow rate 5 3.6 Effective detection flow rate 5 3.7 Maximum particle number concentration 5 4 Test method. 5 4.1 Size calibration 5 4.2 Effective detection flow rate 6 4.3 Maximum particle num
13、ber concentration 7 4.4 Size resolution 8 4.5 Counting efficiency. 9 Annex A (informative) Principle of the instruments . 11 Annex B (informative) Particle size standards 18 Annex C (informative) Effects of the LSAS parameters on the particle size and particle number concentration determination . 21
14、 Annex D (informative) Representative sampling 22 Annex E (informative) Example of an LSAS calibration with DEMS-classified PSL particles 24 Bibliography . 26 BS ISO 21501-1:2009ISO 21501-1:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for Standardization) is a
15、worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented
16、 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 Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are draft
17、ed 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 adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Stan
18、dard 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 patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 21501-1 was prepared
19、 by Technical Committee ISO/TC 24, Particle characterization including sieving, Subcommittee SC 4, Particle characterization. ISO 21501 consists of the following parts, under the general title Determination of particle size distribution Single particle light interaction methods: Part 1: Light scatte
20、ring aerosol spectrometer Part 2: Light scattering liquid-borne particle counter Part 3: Light extinction liquid-borne particle counter Part 4: Light scattering airborne particle counter for clean spaces BS ISO 21501-1:2009ISO 21501-1:2009(E) ISO 2009 All rights reserved vIntroduction Monitoring par
21、ticle size distributions and particle number concentrations is required in various fields, e.g. in filter manufacturing, in the electronic industry, in the pharmaceutical industry, in the chemical industry, in the manufacture of precision machines and in medical operations. The aerosol spectrometer
22、is a useful instrument for the determination of the size distribution and number concentration of particles suspended in a gas. The purpose of this part of ISO 21501 is to provide the calibration procedure and the validation method for aerosol spectrometers, so as to improve the accuracy of the meas
23、urement result by aerosol spectrometers in general, and to minimize the difference in the results measured by different instruments. BS ISO 21501-1:2009BS ISO 21501-1:2009INTERNATIONAL STANDARD ISO 21501-1:2009(E) ISO 2009 All rights reserved 1Determination of particle size distribution Single parti
24、cle light interaction methods Part 1: Light scattering aerosol spectrometer 1 Scope This part of ISO 21501 specifies characteristics of a light scattering aerosol spectrometer (LSAS) which is used for measuring the size, number concentration and number/size distribution of particles suspended in a g
25、as. The light scattering technique described in this part of ISO 21501 is based upon single particle measurements. The size range of particles measured by this method is between approximately 0,06 m to 45 m in diameter. Instruments that conform to this part pf ISO 21501 are used for the determinatio
26、n of the particle size distribution and particle number concentration at relatively high concentrations of up to 1011particles/m3. Application fields include: characterization of metered dose inhalers (MDI), dry powder inhalers (DPI) and nebulizers in pharmacy; production control of active agents; c
27、ut-off determination: impactors, cyclones and impingers; atmospheric aerosols: bio-aerosols, stables/composting facilities, nebulized droplets, measurements in street tunnels; fractional separation efficiency determination of filters. For the above-mentioned applications, aerosol spectrometers shoul
28、d determine the particle size distribution, particle number concentration, size resolution and sizing accuracy as accurately as possible. These aerosol spectrometers are not suitable for the classification of clean rooms. 2 Terms and definitions For the purposes of this document, the following terms
29、 and definitions apply. 2.1 particle discrete element of the material regardless of size ISO 2395:1990 BS ISO 21501-1:2009ISO 21501-1:2009(E) 2 ISO 2009 All rights reserved2.2 aerosol suspension in a gaseous medium of solid particles, liquid particles or solid and liquid particles having a negligibl
30、e falling velocity ISO 4225:1994 NOTE In general, one divides the atmospheric aerosol into three size categories: the superfine range x 1 m, where x is the particle diameter. 2.3 particle size size of a sphere having the same physical properties in the method of analysis as the particle being descri
31、bed NOTE 1 See also equivalent particle diameter (2.4). NOTE 2 There is no single definition of particle size. Different methods of analysis are based on the measurement of different physical properties. The physical property to which the equivalent diameter refers shall be indicated using a suitabl
32、e subscript or reference to the documentary measurement standard according to which the particle size was measured. In ISO 9276 the symbol x is used to denote the particle size or the diameter of a sphere. However, it is recognized there that the symbol d is also widely used to designate these value
33、s. Therefore the symbol x may be replaced by d where it appears. 2.4 equivalent particle diameter diameter of the sphere with defined characteristics which behaves under defined conditions in exactly the same way as the particle being described 2.5 light scattering equivalent particle diameter xscae
34、quivalent diameter of a homogeneous sphere of a reference substance (e.g. latex) which scatters defined incident light with the same radiation efficiency into a defined solid angle element 2.6 number concentration density distribution density (frequency) distribution of the particle number concentra
35、tion represented as a function of the particle size 2.7 particle concentration indication of, e.g. particle numbers, particle mass, particle surface related to the unit volume of the carrier gas NOTE For the exact concentration indication, information on the gaseous condition (temperature and pressu
36、re) or the reference to a standard volume indication is necessary. 2.8 coincidence error probability of the presence of more than one particle inside the sensing zone simultaneously NOTE Coincidence error is related to particle number concentration and size of sensing zone. 2.9 counting efficiency r
37、elation of the concentration determined from the counting rate of the measuring instrument and the real concentration of the aerosol at the inlet of the instrument BS ISO 21501-1:2009ISO 21501-1:2009(E) ISO 2009 All rights reserved 32.10 border zone error particle sizing error that occurs when parti
38、cles pass through the optical border of the sensing zone 3 Requirements 3.1 Size range The measuring size range is defined by the lower and upper size limit of quantification. 3.2 Counting efficiency 3.2.1 General The counting efficiency is the relation of the particle number concentration ,measured
39、NC determined from the counting rate of a device and corrected for possible coincidence errors to the real particle number concentration ,actualNC of the aerosol at the inlet of the device. The counting efficiency ( )x is a function of the particle size and is expressed as the ratio: ()( )(),measure
40、d, actualNNCxxCx = (1) The counting efficiency is also a function of signal processing, the homogeneous illumination of the measuring volume and the extent to which the particles enter the measuring volume and flow rate. Figure 1 shows a graphical representation of counting efficiency. In an ideal c
41、ase, the counting efficiency in the middle of the measuring range as represented here has the value one. If an experimental examination results in a value deviating from one, then this is to be accounted for as a correction to the measurement result. Usually, one defines the lower and/or upper size
42、limit of the measuring range for the particle size with the particle diameters for which the counting efficiency shows the value 0,5. For a proper evaluation of a measuring instrument, it is useful to determine the complete counting efficiency curve, or to indicate the particle diameters correspondi
43、ng to values of the counting efficiency (e.g. at 0,1 and 0,9) besides those corresponding to a counting efficiency value of 0,5. The counting efficiency can be determined according to 4.5. BS ISO 21501-1:2009ISO 21501-1:2009(E) 4 ISO 2009 All rights reservedKey X particle size Y counting efficiency
44、(x) 1 lower size limit 2 upper size limit 3 size range Figure 1 Graphical representation of the counting efficiency 53.2.2 Lower size limit The lower size limit for the particle size is defined by convention to be the smallest diameter with which the counting efficiency shall be 0,5 0,15 (50 % 15 %;
45、 lower size limit of the measuring range). 3.2.3 Upper size limit The upper size limit for the particle size is defined by convention to be the largest diameter with which the counting efficiency shall be 0,5 0,15 (50 % 15 %; upper size limit of measuring range). This is of particular interest if th
46、e aerosol inlet is situated horizontally in the LSAS, as particle losses can occur in the LSAS through impact and sedimentation. 3.3 Size resolution The size resolution indicates which neighbouring particle sizes a particle measuring instrument can still differentiate between and record separately.
47、Aerosol spectrometers should determine the particle size distribution and the particle number concentration as accurately as possible with high size resolution and good sizing accuracy. The size resolution depends on particle size. Almost all measuring instruments determine the particle number conce
48、ntration in a limited number of size classes which are firmly specified by the instrument design (e.g. instrument geometry, evaluation electronics, evaluation software). In practical operation, the size resolution of an LSAS cannot be better than the width of its size classes. The size resolution ca
49、n be determined according to 4.4. BS ISO 21501-1:2009ISO 21501-1:2009(E) ISO 2009 All rights reserved 53.4 Sizing accuracy The sizing accuracy depends on the particle size. Therefore, the sizing accuracy can be evaluated for any particle size as follows srr( ) 100xxxx= (2) where ()x is the ratio of particle size difference, in %; xris the particle size of the certified reference material, in m; xsis the particle size indicated by the LSAS, in m. The sizing accuracy o
