Prøving

Komité: ISO/TC 24/SC 4 (Particle characterization)
Opprinnelse: ISO
Sluttdato: 2. nov 2021
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<p>The ISO series 13317 covers methods for determining the distributions of sedimentation velocities and particle size of particulate materials by gravitation-induced particle migration in liquids. The direction of this motion depends on the density difference (<italic>density contrast</italic>) between dispersed and continuous phase. During the measurement, particles should not undergo any physical or chemical change in the continuous phase (liquid).</p><p>The primary measurand is the particle velocity distribution, which is converted into size distribution based on established sedimentation theory. The measurement techniques described in this ISO series are applicable to liquid dispersions, like suspensions and emulsions. The measurable particle size range depends on materials properties and typically reaches from 200 nm to 100 μm for aqueous samples, whereas sedimentation velocity can be quantified in the range from 0,6 µm/s to 10 mm/s. Sedimentation analysis is conducted for low particle concentrations. The maximum permissible value depends on measurement technique and theory of analysis. In general, the volume fraction of particle should not exceed 1 %.</p><p>This part of ISO series 13317 addresses the principles of particle size analysis by gravitational sedimentation, the principal types of measurement techniques as well as general rules for conducting measurements, method validation, determination of the uncertainty budget and representation of results.</p><p>This standard covers neither particle migration by centrifugal, electric or magnetic forces nor sedimentation at high particle concentrations (e.g. zone sedimentation). Moreover, it does not deal with the determination of properties other than sedimentation velocity and particle size (i.e. neither particle concentration, particle shape, particle density, zeta-potential nor apparent viscosity).</p><non-normative-note><label>NOTE</label><p>This part of <std std-id="iso:std:iso:13317:en" type="undated"><std-ref>ISO 13317</std-ref></std> can involve hazardous materials, operations and equipment. This part of <std std-id="iso:std:iso:13317:en" type="undated"><std-ref>ISO 13317</std-ref></std> does not purport to address all the safety problems associated with its use. Explosion proof analysers are required when examining volatile liquids with a low flash point.</p></non-normative-note><p>It is the responsibility of the user of this part of <std std-id="iso:std:iso:13317:en" type="undated"><std-ref>ISO 13317</std-ref></std> to establish appropriate safety and health practices and to determine the applicability of the regulatory limitations prior to its use.</p>