1、 Reference number ISO 13320:2009(E) ISO 2009INTERNATIONAL STANDARD ISO 13320 First edition 2009-10-01 Particle size analysis Laser diffraction methods Analyse granulomtrique Mthodes par diffraction laser ISO 13320:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance wit
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6、postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2009 All rights reservedISO 13320:2009(E) ISO 2009 All rights reserved iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1
7、 3 Terms, definitions and symbols 1 3.1 Terms and definitions. 1 3.2 Symbols . 5 4 Principle. 6 5 Laser diffraction instrument 6 6 Operational procedures . 10 6.1 Requirements 10 6.2 Sample inspection, preparation, dispersion and concentration . 10 6.3 Measurement. 12 6.4 Precision 14 6.5 Accuracy 1
8、5 6.6 Error sources and diagnosis . 17 6.7 Resolution and sensitivity . 19 7 Reporting of results 20 Annex A (informative) Theoretical background of laser diffraction 22 Annex B (informative) Recommendations for instrument specifications 39 Annex C (informative) Dispersion liquids for the laser diff
9、raction method . 42 Annex D (informative) Refractive index, n m , for various liquids and solids 43 Annex E (informative) Recommendations to reach optimum precision in test methods. 48 Bibliography . 50 ISO 13320:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for
10、 Standardization) is a 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
11、right to be represented 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. Internatio
12、nal Standards are drafted 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 a
13、s an International Standard 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. I
14、SO 13320 was prepared by Technical Committee ISO/TC 24, Particle characterization including sieving, Subcommittee SC 4, Particle characterization. This first edition of ISO 13320 cancels and replaces ISO 13320-1:1999. ISO 13320:2009(E) ISO 2009 All rights reserved v Introduction The laser diffractio
15、n technique has evolved such that it is now a dominant method for determination of particle size distributions (PSDs). The success of the technique is based on the fact that it can be applied to various kinds of particulate systems, is fast and can be automated, and that a variety of commercial inst
16、ruments is available. Nevertheless, the proper use of the instrument and the interpretation of the results require the necessary caution. Since the publication of ISO 13320-1:1999, the understanding of light scattering by different materials and the design of instruments have advanced considerably.
17、This is especially marked in the ability to measure very fine particles. Therefore, this International Standard has been prepared to incorporate the most recent advances in understanding. INTERNATIONAL STANDARD ISO 13320:2009(E) ISO 2009 All rights reserved 1 Particle size analysis Laser diffraction
18、 methods 1 Scope This International Standard provides guidance on instrument qualification and size distribution measurement of particles in many two-phase systems (e.g. powders, sprays, aerosols, suspensions, emulsions and gas bubbles in liquids) through the analysis of their light-scattering prope
19、rties. It does not address the specific requirements of particle size measurement of specific materials. This International Standard is applicable to particle sizes ranging from approximately 0,1 m to 3 mm. With special instrumentation and conditions, the applicable size range can be extended above
20、3 mm and below 0,1 m. For non-spherical particles, a size distribution is reported, where the predicted scattering pattern for the volumetric sum of spherical particles matches the measured scattering pattern. This is because the technique assumes a spherical particle shape in its optical model. The
21、 resulting particle size distribution is different from that obtained by methods based on other physical principles (e.g. sedimentation, sieving). 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition
22、cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 9276-1, Representation of results of particle size analysis Part 1: Graphical representation ISO 9276-2, Representation of results of particle size analysis Part 2: Calculatio
23、n of average particle sizes/diameters and moments from particle size distributions ISO 9276-4, Representation of results of particle size analysis Part 4: Characterization of a classification process ISO 14488, Particulate materials Sampling and sample splitting for the determination of particulate
24、properties ISO 14887, Sample preparation Dispersing procedures for powders in liquids 3 Terms, definitions and symbols 3.1 Terms and definitions 3.1.1 absorption reduction of intensity of a light beam not due to scattering ISO 13320:2009(E) 2 ISO 2009 All rights reserved3.1.2 coefficient of variatio
25、n CV relative standard deviation (deprecated) positive random variable standard deviation divided by the mean NOTE 1 The coefficient of variation is commonly reported as a percentage. NOTE 2 Adapted from ISO 3534-1:2006 24 , 2.38. 3.1.3 complex refractive index n prefractive index of a particle, con
26、sisting of a real and an imaginary (absorption) part NOTE The complex refractive index of a particle can be expressed mathematically as n p= n p ik p where i is the square root of 1; k pis the positive imaginary (absorption) part of the refractive index of a particle; n pis the positive real part of
27、 the refractive index of a particle. In contrast to ISO 80000-7:2008 27 , item 7-5, this International Standard follows the convention of adding a minus sign to the imaginary part of the refractive index. 3.1.4 relative refractive index m relratio of the complex refractive index of a particle to the
28、 real part of the dispersion medium NOTE 1 Adapted from ISO 24235:2007 26 . NOTE 2 In most applications, the medium is transparent and, thus, its refractive index has a negligible imaginary part. NOTE 3 The relative refractive index can be expressed mathematically as m rel= n p /n mwhere n mis the r
29、eal part of the refractive index of the medium; n pis the complex refractive index of a particle. 3.1.5 deconvolution particle size analysis mathematical procedure whereby the size distribution of an ensemble of particles is inferred from measurements of their scattering pattern ISO 13320:2009(E) IS
30、O 2009 All rights reserved 3 3.1.6 diffraction particle size analysis scattering of light around the contour of a particle, observed at a substantial distance (in the far field) 3.1.7 extinction particle size analysis attenuation of a light beam traversing a medium through absorption and scattering
31、3.1.8 model matrix matrix containing vectors of the scattered light signals for unit volumes of different size classes, scaled to the detectors geometry, as derived from model computation 3.1.9 multiple scattering consecutive scattering of light by more than one particle, causing a scattering patter
32、n that is no longer the sum of the patterns from all individual particles NOTE See single scattering (3.1.20). 3.1.10 obscuration optical concentration fraction of incident light that is attenuated due to extinction (scattering and/or absorption) by particles NOTE 1 Adapted from ISO 8130-14:2004 25
33、, 2.21. NOTE 2 Obscuration can be expressed as a percentage. NOTE 3 When expressed as fractions, obscuration plus transmission (3.1.22) equal unity. 3.1.11 optical model theoretical model used for computing the model matrix for optically homogeneous and isotropic spheres with, if necessary, a specif
34、ied complex refractive index EXAMPLES Fraunhofer diffraction model, Mie scattering model. 3.1.12 reflection particle size analysis change of direction of a light wave at a surface without a change in wavelength or frequency 3.1.13 refraction process by which the direction of a radiation is changed a
35、s a result of changes in its velocity of propagation in passing through an optically non-homogeneous medium, or in crossing a surface separating different media IEC 60050-845:1987 28 NOTE The process occurs in accordance with Snells law: n m sin m= n p sin pSee 3.2 for symbol definitions. ISO 13320:
36、2009(E) 4 ISO 2009 All rights reserved3.1.14 repeatability (instrument) particle size analysis closeness of agreement between multiple measurement results of a given property in the same dispersed sample aliquot, executed by the same operator in the same instrument under identical conditions within
37、a short period of time NOTE This type of repeatability does not include variability due to sampling and dispersion. 3.1.15 repeatability (method) particle size analysis closeness of agreement between multiple measurement results of a given property in different aliquots of a sample, executed by the
38、same operator in the same instrument under identical conditions within a short period of time NOTE This type of repeatability includes variability due to sampling and dispersion. 3.1.16 reproducibility (method) particle size analysis closeness of agreement between multiple measurement results of a g
39、iven property in different aliquots of a sample, prepared and executed by different operators in similar instruments according to the same method 3.1.17 scattering particle size analysis change in propagation of light at the interface of two media having different optical properties 3.1.18 scatterin
40、g angle particle size analysis angle between the principal axis of the incident light beam and the scattered light 3.1.19 scattering pattern angular pattern of light intensity, I( ), or spatial pattern of light intensity, I(r), originating from scattering, or the related energy values taking into ac
41、count the sensitivity and the geometry of the detector elements 3.1.20 single scattering scattering whereby the contribution of a single member of a particle population to the total scattering pattern remains independent of the other members of the population 3.1.21 single shot analysis analysis, fo
42、r which the entire content of a sample container is used 3.1.22 transmission particle size analysis fraction of incident light that remains unattenuated by the particles NOTE 1 Transmission can be expressed as a percentage. NOTE 2 When expressed as fractions, obscuration (3.1.10) plus transmission e
43、qual unity. 3.1.23 width of size distribution the width of the particle size distribution (PSD), expressed as the x 90 /x 10ratio NOTE For normal (Gaussian) size distributions, often the standard deviation (absolute value), , or the coefficient of variation (CV) is used. Then, about 95 % of the popu
44、lation of particles falls within 2 from the mean value and about 99,7 % within 3 from the mean value. The difference x 90 x 10corresponds to 2,6. ISO 13320:2009(E) ISO 2009 All rights reserved 5 3.2 Symbols A iextinction efficiency of size class i C particulate concentration, volume fraction CV coef
45、ficient of variation f focal length of lens i square root of 1 i nphotocurrent of detector element, n I() angular intensity distribution of light scattered by particles (scattering pattern) I hintensity of horizontally polarized light at a given angle I(r) spatial intensity distribution of light sca
46、ttered by particles on the detector elements (measured scattering pattern by detector) I vintensity of vertically polarized light at a given angle J i first order Bessel Function k wavenumber in medium: 2n m / k pimaginary (absorption) part of the refractive index of a particle l adistance from scat
47、tering object to detector l billuminated pathlength containing particles L n vector of photocurrents (i 1 , i 2. i n ) m relrelative, complex refractive index of particle to medium M model matrix, containing calculated detector signals per unit volume of particles in all size classes n mreal part of
48、 refractive index of medium n preal part of refractive index of particle n pcomplex refractive index of particle O obscuration (1 transmission); only true for single scattering r radial distance from focal point in focal plane V vector of volume content in size classes (V 1 , V 2 V i ) V ivolume con
49、tent of size class i v velocity of particles in dry disperser x particle diameter x i geometric mean particle size of size class i x 50median particle diameter; here used on a volumetric basis, i.e. 50 % by volume of the particles are smaller than this diameter and 50 % are larger x 10particle diameter corresponding to 10 % of the cumulative undersize distribution (here by volume) x 90particle diameter corresponding to 90 % of the cumulative undersize distribution (here
