1、 Reference number ISO 24235:2007(E) ISO 2007INTERNATIONAL STANDARD ISO 24235 First edition 2007-04-01 Fine ceramics (advanced ceramics, advanced technical ceramics) Determination of particle size distribution of ceramic powders by laser diffraction method Cramiques techniques Dtermination de la rpar
2、tition granulomtrique des poudres cramiques au moyen dune mthode par diffraction laser ISO 24235:2007(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 typefaces which are
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6、rofilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case 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
7、2007 All rights reservedISO 24235:2007(E) ISO 2007 All rights reserved iii Contents Page Foreword iv 1 Scope. 1 2 Normative references. 1 3 Terms and definitions. 1 4 Principle of measurement 2 5 Equipment. 2 6 Dispersion medium. 4 7 Sample preparation 4 8 Measuring procedure. 4 9 Report of result .
8、 5 ISO 24235:2007(E) iv ISO 2007 All rights reservedForeword ISO (the International Organization for 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. Ea
9、ch member body interested in a subject for which a technical committee has been established has the 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 Internatio
10、nal Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International 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 Standar
11、ds adopted by the technical committees are circulated to the member bodies for voting. Publication as 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
12、of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 24235 was prepared by Technical Committee ISO/TC 206, Fine ceramics. INTERNATIONAL STANDARD ISO 24235:2007(E) ISO 2007 All rights reserved 1 Fine ceramics (advanced ceramics, advanced technical cer
13、amics) Determination of particle size distribution of ceramic powders by laser diffraction method 1 Scope This International Standard specifies a laser diffraction method for measuring particle size distributions, by means of the detection of angular distributions of the intensity of light scattered
14、 by fine-ceramic raw powders dispersed in a liquid phase irradiated by a laser beam. A typical size range is 0,1 m to 50 m. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For unda
15、ted references, the latest edition of the referenced document (including any amendments) applies. ISO 3082:2000, Iron ores Sampling and sample preparation procedures ISO 13320-1:1999, Particle size analysis Laser diffraction methods Part 1: General principles ISO 14703:2000, Fine ceramics (advanced
16、ceramics, advanced technical ceramics) Sample preparation for the determination of particle size distribution of ceramic powders ISO 14887:2000, Sample preparation Dispersing procedures for powders in liquids. 3 Terms and definitions For the purposes of this document, the terms and definitions given
17、 in ISO 13320-1 apply, together with the following. 3.1 angular distribution of intensity of light scattered intensity of light scattered as a function of scattering angle 3.2 scattering angle angle between the directions of the transmitted laser beam and the scattered light detected 3.3 relative re
18、fractive index ratio of the absolute refractive index of the sample to the real part of the dispersion medium ISO 24235:2007(E) 2 ISO 2007 All rights reserved4 Principle of measurement A particle illuminated by a collimated light beam of a known wavelength from a laser presents a scattering signatur
19、e that is a function of the size, shape and relative refractive index of the particle. When particles dispersed in a liquid are irradiated by a laser beam, the scattering signature is supposed to be the summation of the signatures of each particle. In the basic optical system shown in Figure 1, the
20、light scattered by the particles in the laser beam is collected by a Fourier lens on the detector placed on the focal plane of the lens, to detect the angular distribution of the scattered intensity. The size distribution of the particles is mathematically reduced from the measured angular distribut
21、ion of the scattered intensity, so that it can be best-fitted with that predicted, based on the Mie scattering theory, Fraunhofer diffraction theory or the like. NOTE 1 A detailed description of the principle of laser diffraction method is found in ISO 13320-1:1999, Annex D. NOTE 2 For particles of
22、smaller diameters, light scattering at angles in the side and back lobes may also be utilized for the determination of the size distribution of particles. Key 1 fourier lens 2 laser beam 3 scattered-light detector Figure 1 Schematic drawing of an optical system used for size-distribution measurement
23、s of particles by the laser diffraction method 5 Equipment 5.1 Equipment for determination of particle size distribution The fundamental constitution of measuring equipment shall be that shown in Figure 2. 5.1.1 The suspension in the dispersion tank, equipped with stirring blades, shall be circulate
24、d by a pump. A laser is used as the radiation light source. NOTE A He-Ne gas laser or semiconductor laser is used. 5.1.2 The laser beam is expanded into a parallel beam by the beam expander/collimator unit to illuminate a group of particles in the flow cell. NOTE A stirrer-type batch cell is also us
25、ed. ISO 24235:2007(E) ISO 2007 All rights reserved 3Key 1 stirring blade 2 dispersion tank 3 exhaust liquid 4 ultrasonic vibrator 5 laser 6 pin hole 7 beam-enlarging apparatus 8 back-scattering light detector 9 side-scattered light detector 10 Fourier lens 11 forward-scattered light detector 12 circ
26、ulation pump 13 flow cell 14 flow of suspension 15 operational processor 16 printer Figure 2 Typical example of particle-size-distribution measuring equipment for laser diffraction method 5.1.3 The scattered light from the illuminated particles is collected by a Fourier lens on the detector consisti
27、ng of photoelectric elements positioned at the focal plane of the lens. Some models have additional detectors in the side and back in order to detect the light scatted at larger scattering angles. 5.1.4 The electric signal from each element of the detector is A/D-converted and then sent to the opera
28、tional processor. The size distributions of the particles are derived from the signals from all detectors. 5.1.5 The equipment for the determination of particle size distribution used for making measurements in accordance with this International Standard is subject to a regular verification procedur
29、e. 5.1.6 The operators of the equipment shall have received adequate training to ensure they are competent for conducting the measurements to be reported. 5.2 Equipment for preparation of sample An ultrasonic dispersing device shall be used. A built-in ultrasonic disperser may be used. ISO 24235:200
30、7(E) 4 ISO 2007 All rights reserved6 Dispersion medium The type of dispersion medium and the method for evaluating the scattering conditions shall be as specified in ISO 14703 and ISO 14887. 7 Sample preparation 7.1 Sampling Sampling shall be carried out in accordance with ISO 3082. 7.2 Preparation
31、of sample suspensions The preparation of sample suspensions shall be carried out in accordance with ISO 14703. 8 Measuring procedure The measuring procedure shall be as follows. 8.1 Turn on the power supply to the measuring equipment 30 min or more before the start of measurement. 8.2 Select an appr
32、opriate dispersion medium (Clause 6) and conduct sampling in accordance with 7.1, and prepare a suspension of the sample. 8.3 Input the refractive index (indices) of the particles and dispersion medium if the equipment accepts their input. NOTE Care must be taken to specify whether the requested ref
33、ractive index is absolute or relative. Refractive indices of some isotropic materials are listed in Table D.2 in ISO 13320-1:1999, Annex D. Other values can be used when agreed between the supplier and the user of data, provided that they are reported. It should be noted that the refractive indices
34、of the materials and dispersion medium are of crucial importance, especially when the particles are in the sub-micron range. 8.4 Establish the number of times that scattering-intensity data is taken, and the measuring conditions. 8.5 After supplying the dispersion tank with the dispersion medium, fi
35、ll the circulation line with the dispersion medium. 8.6 Confirm that the laser beam has been aligned with the centre of the detector. 8.7 Allow the dispersion medium to circulate. 8.8 Carry out the background measurements. 8.9 Drip the suspension prepared in 8.2 into the dispersion tank, by using a
36、squirt or the like, until a concentration appropriate for the high signal/noise ratio detection of the scattered light intensity is reached. NOTE The value of obscuration or transmittance of the laser beam is a good index to judge whether multiple scattering is incurred. 8.10 Carry out the particle-
37、size-distribution measurements, and record the results. ISO 24235:2007(E) ISO 2007 All rights reserved 5 9 Report of result 9.1 Conditions of sample preparation and measurement 9.1.1 Conditions of sample preparation The conditions of sample preparation and the like shall be indicated in accordance w
38、ith ISO 14703. 9.1.2 Measuring conditions The measuring conditions shall be indicated in accordance with the entry format of Table 1. 9.2 Measured results The measured results shall be stated as follows: 9.2.1 Size distributions in cumulative volume percentages shall be presented by means of graphs
39、and tables. 9.2.2 Diameters at 10 %, 50 % and 90 % cumulative percentages in distribution shall be indicated in accordance with the entry format of Table 1. 9.2.3 Particle size distributions, other than cumulative volume percentages, shall be made with the parameter on the abscissa clearly mentioned
40、. ISO 24235:2007(E) 6 ISO 2007 All rights reservedTable 1 Example of records of measuring conditions and particle sizes Date Operator NAME Supplier/Customer Particle Particle Shape Sphere Plate Needle Liquid Dispersion Medium Dispersant Weight % Beaker Capacity ml Suspension Volume ml Suspension Con
41、centration Weight % Ultrasonic bath Ultrasonic Homogenizer Model / Type Dispersion Power W at Hz Device Stirrer Tip Diameter mm /Material Position of Tip Head below Suspension Level mm Agitation Time min Particle Size Model /Type No. Sampling Device Model /Type No. Refraction Indices Powder /Dispers
42、ion Medium Circulation Batch Operating Conditions of Built-in Dispersion Devices Sonicator W at Hz Concentration Weight % Optical Transmittance % Extinction % Obscuration % Other Run No. X 10 X 50 X 90 Particle Size 1 m 2 3 Average ISO 24235:2007(E) ICS 81.060.30 Price based on 6 pages ISO 2007 All rights reserved
