Standards Development

Scope

The ISO series 13317 covers methods for determining sedimentation velocity and particle size distribution of particulate materials by gravitation-induced particle migration in liquids. The direction of this motion depends on the density difference (also: density contrast) between dispersed and continuous phase. During the measurement, particles should not undergo any physical or chemical change in the continuous phase (liquid).

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 amounts to 200 nm – 100 m for aqueous samples, whereas sedimentation velocity can be quantified for the range 0.6 μm/s – 10 mm/s. Sedimentation analysis is conducted for low analyte concentrations. The permissible range of particle concentration depends on measurement technique and theory of analysis, yet it is typically not above 1 vol%.

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 and representation of results.

This standard does neither cover 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).

NOTE. This part of ISO 13317 may involve hazardous materials, operations and equipment. This part of ISO 13317 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. It is the responsibility of the user of this part of ISO 13317 to establish appropriate safety and health practices and to determine the applicability of the regulatory limitations prior to its use. 

Purpose

ISO series 13317 covers currently 4 standards. Part 1 to part 3 were published 2001/2002 and part 4 in 2014. Especially Part 1 and 3 are used in many industrial fields and serve as basics for educational purposes. Since then, sciences have developed and also the technological level of sensor techniques, electronics and software have progressed a lot and novel sophisticated analysers entered the market. Due to these developments, particle size distribution determination based on sedimentation velocity as a first principle method (no analysis theory, no material parameters) awakes again more interest for sedimentation measurement techniques. In addition, this fractionating technique facilitates to distinguish between close fractions of the dispersity property (i.e. the sedimentation velocity and its corresponding equivalent diameter). Accordingly, particle size distributions can be very finely resolved, which is an advantage compared to spectroscopic ensemble techniques. Especially emerging new applications of submicron particles and products made of them, which appear (nanomedicine, functionalized inks, innovative paints, cosmetics etc.), need very precise particle size distributions. Therefore, it is needed to upgrade these (old) standards to the state of art and by this serve the numerous users of gravity sedimentation and separation techniques in an adequate way.

ISO series 13317 covers currently 4 standards. Part 1 to part 3 were published 2001/2002 and part 4 in 2014. Especially Part 1 and 3 are used in many industrial fields and serve as basics for educational purposes. Since then, sciences have developed and also the technological level of sensor techniques, electronics and software have progressed a lot and novel sophisticated analysers entered the market. Due to these developments, particle size distribution determination based on sedimentation velocity as a first principle method (no analysis theory, no material parameters) awakes again more interest for sedimentation measurement techniques. In addition, this fractionating technique facilitates to distinguish between close fractions of the dispersity property (i.e. the sedimentation velocity and its corresponding equivalent diameter). Accordingly, particle size distributions can be very finely resolved, which is an advantage compared to spectroscopic ensemble techniques. Especially emerging new applications of submicron particles and products made of them, which appear (nanomedicine, functionalized inks, innovative paints, cosmetics etc.), need very precise particle size distributions. Therefore, it is needed to upgrade these (old) standards to the state of art and by this serve the numerous users of gravity sedimentation and separation techniques in an adequate way.

Consider the following: Is there a verified market need for the proposal? What problem does this standard solve? What value will the document bring to end-users? See Annex C of the ISO/IEC Directives part 1 for more information. See the following guidance on justification statements on ISO Connect: https://connect.iso.org/pages/viewpage.action?pageId=27590861