1、January 2012 Translation by DIN-Sprachendienst.English price group 14No part of this translation 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).IC
2、S 19.120!$y,l“1860973www.din.deDDIN ISO 9276-6Representation of results of particle size analysis Part 6: Descriptive and quantitative representation of particle shape andmorphology (ISO 9276-6:2008)English translation of DIN ISO 9276-6:2012-01Darstellung der Ergebnisse von Partikelgrenanalysen Teil
3、 6: Deskriptive und quantitative Darstellung der Form und Morphologie von Partikeln(ISO 9276-6:2008)Englische bersetzung von DIN ISO 9276-6:2012-01Reprsentation de donnes obtenues par analyse granulomtrique Partie 6: Description et reprsentation quantitative de la forme et de la morphologie desparti
4、cules (ISO 9276-6:2008)Traduction anglaise de DIN ISO 9276-6:2012-01www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.2701.12 A comma is used as the decimal marker. Contents Page National foreword .3 National Annex NA (informative) B
5、ibliography .3 Introduction .4 1 Scope 5 2 Normative references 5 3 Symbols and abbreviated terms .6 4 Criteria for the evaluation of shape description methods .7 5 Classification of methods and descriptors .8 5.1 General classification 8 5.2 Levels of shape 8 5.3 Principles for deriving shape descr
6、iptors .10 6 Errors which can occur in the analysis of a single image .11 6.1 Generation of shape descriptors11 6.2 Image resolution 11 6.3 Binarization 12 6.4 Algorithms for calculating shape descriptors 12 7 Size parameters for normalization of shape descriptors .13 8 Shape descriptors 14 8.1 Macr
7、oshape descriptors .14 8.2 Mesoshape descriptors .16 8.3 Combination of shape descriptors 17 8.4 Roughness descriptor .18 Annex A (normative) Some computation equations 19 Annex B (informative) Examples of methods of presentation of shape and size distribution data 20 Bibliography 26 2 DIN ISO 9276-
8、6:2012-01 National foreword This standard has been prepared by Technical Committee ISO/TC 24 “Particle characterization including sieving”, Subcommittee SC 4 “Sizing by methods other than sieving” with ANSI (USA) holding the secretariat. The secretariat is currently held by BSI (UK). The responsible
9、 German body involved in its preparation was the Normenausschuss Bauwesen (Building and Civil Engineering Standards Committee), Working Committee NA 005-11-42 AA Partikelmesstechnik (Sp ISO/TC 24/SC 4). The DIN Standard corresponding to the International Standard referred to in this document is as f
10、ollows: ISO 9276-1 DIN ISO 9276-1 National Annex NA (informative) Bibliography DIN ISO 9276-1, Representation of results of particle size analysis Part 1: Graphical representation DIN ISO 9276-2, Representation of results of particle size analysis Part 2: Calculation of average particle sizes/diamet
11、ers and moments from particle size distributions DIN ISO 9276-4, Representation of results of particle size analysis Part 4: Characterization of a classification process DIN ISO 9276-6, Representation of results of particle size analysis Part 6: Descriptive and quantitative representation of particl
12、e shape and morphology 3 DIN ISO 9276-6:2012-01 Introduction A variety of different methods for the descriptive and quantitative representation of particle shape and morphology are known. Even for the term particle size, there is no single definition. Different methods of size analysis are based on
13、the measurement of different physical properties. In ISO 9276-1, the particle size is defined as the diameter of a sphere having the same physical property. This is known as the equivalent spherical diameter. So-called property functions help to correlate it with the property of primary interest, wh
14、ich may, for instance, be flowability, taste or dissolution time. Broad application of sizing methods in particle characterization shows that particle size is often an important factor. But particle size alone is not sufficient to allow particle phenomena such as powder flow, mixing, abrasion or bio
15、logical response to be understood. Particle shape and morphology play an important role in particle systems and therefore it is also necessary to characterize and describe these characteristics quantitatively. Including additional shape parameters in property functions is supposed to give a better c
16、orrelation with the particular property of the particle system. For instance, knowledge of the size of grinding particles and of the sharpness of their edges will make it possible not only to distinguish between fresh and used grinding particles but also to predict their abrasive effect quantitative
17、ly by means of a property function. ISO 13322-1 and ISO 13322-2 give guidance on the measurement, description and validation methodologies used when determining particle sizes by static and dynamic image analysis, respectively. Broad industrial use of image analysis techniques requires standardized
18、methods of measurement for the characterization of the size, geometrical shape and morphology of particles. A particles shape is the envelope formed by all the points on the surface of the particle. Particle morphology represents the extension of a simple shape description of this kind to more compl
19、ex descriptions including characteristics such as porosity, roughness and texture. Various glossaries of terms giving descriptions, in words, of particle shape and morphology already exist (see Clause 5). These descriptions may be useful for the classification or identification of particles but, at
20、the moment, there is insufficient consensus on the definition of particle shape and morphology in the quantitative terms necessary for them to be implemented in software routines. A future revision of this part of ISO 9276 may cover this. Representation of results of particle size analysis Part 6: D
21、escriptive and quantitative representation of particle shape and morphology 4 DIN ISO 9276-6:2012-01 IMPORTANT The electronic file of this document contains colours which are considered to be useful for the correct understanding of the document. Users should therefore consider printing this document
22、 using a colour printer. 1 Scope This part of ISO 9276 specifies rules and nomenclature for the description and quantitative representation of particle shape and morphology. To achieve a more comprehensive description of a particle or particle system, particle size information can be used together w
23、ith other information but, in most cases, the particle size information cannot be replaced. The averaging of shape over all particles in a sample has been shown to be an ineffective approach. Distributions of other particle characteristics are required in addition to particle size distributions (see
24、 ISO 9276-1). The relevance, to technological applications, of any method of representing particle shape is the deciding factor in its use. Therefore this part of ISO 9276 is restricted to methods which can be correlated with physical properties in industrial applications. The aim of particle analys
25、is is to determine the most appropriate characterization method for a particular application. This implies a profound understanding of the relationship between particle characteristics and macroscopic product and process properties (or at least a database of broad empirical data). Problems of shape
26、and morphology would normally be three-dimensional problems, but most definitions in this part of ISO 9276 are in fact given for two dimensions because of the widespread use of image analysis methods. With the help of the evaluation criteria given in Clause 4, a minimum set of shape descriptors is d
27、erived in Clause 8 from the various descriptors and methods in Clause 5, enabling a direct comparison of different shape analysis equipment or methods to be made within the limits discussed in Clause 6. 2 Normative references The following referenced documents are indispensable for the application o
28、f this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 9276-1:1998, Representation of results of particle size analysis Part 1: Graphical representation (and its Technical Co
29、rrigendum ISO 9276-1:1998/Cor.1:2004) ISO 13322-1:2004, Particle size analysis Image analysis methods Part 1: Static image analysis methods 5 DIN ISO 9276-6:2012-01 3 Symbols and abbreviated terms For the purposes of this document, the symbols given in ISO 13322-1 and ISO 9276-1 and the following ap
30、ply. In ISO 9276-1, the symbol x is used to denote the particle size or the diameter of a sphere. However, it is recognized that the symbol d is also widely used to designate these values. Therefore, in this part of ISO 9276, the symbol x may be replaced by d wherever it appears. Symbols for the par
31、ticle size other than x or d shall not be used. A projection area AboxFeret box area Acarea of the convex hull (envelope) bounding the particle b intercept on graph for fractal dimension C circularity CI global surface concavity index DFfractal dimension dcmindiameter of the minimum circumscribed ci
32、rcle dimaxdiameter of the maximum inscribed circle dLspacing of a series of parallel lines for use in the Cauchy-Crofton formula (see Clause A.1) E thickness Inumber of intercepts for use in the Cauchy-Crofton formula (see Clause A.1) LGgeodesic length N number P length of perimeter PClength of the
33、perimeter of the convex hull (envelope) bounding the particle Rn roundness S surface area V volume xAarea-equivalent diameter of particle xEthickness of a very long particle xFmaxmaximum Feret diameter xFminminimum Feret diameter xLFFeret diameter perpendicular to the minimum Feret diameter, normall
34、y known as “length” xLGgeodesic length of a very long particle 6 DIN ISO 9276-6:2012-01 xLmaxlength of major axis of Lengendre ellipse of inertia xLminlength of minor axis of Lengendre ellipse xPperimeter-equivalent diameter of particle xSsurface-equivalent diameter of particle xVvolume-equivalent d
35、iameter of particle angle or direction 1robustness 2largest concavity index 3concavity/robustness ratio number of erosions Wadells sphericity FPaverage concavity 4 Criteria for the evaluation of shape description methods A common problem in shape description is how to judge the quality of a shape de
36、scription method. Not all methods are suitable for every kind of shape and application. Until now, consistent evaluation criteria have not existed for shape description methods. Criteria for the evaluation of shape description methods: accessibility, which describes how easy it is to compute a shape
37、 descriptor in terms of memory requirements and computation time; scope, which refers to the classes of shape that can be described by the method; uniqueness, which describes whether a one-to-one mapping relationship exists between shapes and shape descriptors; stability and sensitivity, which descr
38、ibe how sensitive a shape description is to “small” changes in shape. Each method shall use descriptors with a specific degree of complexity. In general, descriptors can be described as sets of numbers that are produced to describe a given shape. The shape may not be entirely reconstructable from th
39、ese descriptors, but the descriptors for different shapes shall be sufficiently different to make it possible to discriminate between the shapes. Criteria for shape descriptors: invariance with respect to rotation and reflection for a given shape, the values of the descriptors shall be the same irre
40、spective of the orientation of the particle; invariance with respect to scale for a given shape, the values of the descriptors shall be the same irrespective of the size of the particle; independence if the elements of the descriptors are independent, some can be discarded without the need to recalc
41、ulate the others; 7 DIN ISO 9276-6:2012-01 economy it is desirable that the descriptors be economical in the number of terms used to describe a shape. The above three invariance conditions (concerning rotation, reflection and scale) guarantee that the result of a shape analysis is not affected by th
42、e parameters of the analysis and is independent of the particle size. It should, however, be stressed that the particle size at which certain shape information is obtained may be of practical relevance, as in the case of surface roughness, and size shall therefore be included in the shape analysis.
43、The robustness of shape descriptors with respect to the density, translation and rotation of the sampling grid can indicate whether it is acceptable to compare measurement results from different algorithms or different image analysers1. 5 Classification of methods and descriptors 5.1 General classif
44、ication Methods of shape description, as well as the various shape descriptors, can be classified according to different criteria. An obvious way of classifying shape descriptors is to determine whether they are qualitative or quantitative in nature: a) Qualitative description, i.e. in words: expres
45、sions such as “needlelike particles” and “oblate shape”. Examples of this type of shape characterization are given in the US Pharmacopoeial Convention2, in ASTM F 18773and in the glossary made available by the NIST Center for Analytical Chemistry4. b) Quantitative description: in the following text,
46、 shape descriptors will be understood as numbers that can be calculated from particle images or physical particle properties via mathematical or numerical operations. 5.2 Levels of shape For a better understanding of shape description, it is important to establish definitions regarding the basic cha
47、racteristics of an arbitrary object. The shape of an arbitrary object can be defined in many ways. One such definition describes shape as a binary image representing the extent of the particle. This can be understood as the silhouette of the particle. Barrett5recognizes three potentially independent
48、 particle shape properties (see Figure 1): form, which reflects the geometrical proportions of a particle; roundness, which expresses the radius of curvature at the particle corners; surface texture, which is taken as defining local roughness features at corners and at edges between corners only. These particle shape properties may not suffice for a complete description of the shape of a particular particle and may be defined differently by different authors. But they give us a good idea
