GB/T 29022-2021Particle size analysis - Dynamic light scattering (DLS) (English PDF)

1 Scope

This document specifies the use of Dynamic Light Scattering (DLS) for the measurement of submicron particles, emulsions or fine air bubbles dispersed in a liquid:

The mean hydrodynamic particle size and particle size distribution method: DLS is also known as "Quasi-Elastic Light Scattering (QELS)" and "Photon Correlation Spectroscopy" method (PCS)", although Photon Correlation Spectroscopy is actually one of the measurement techniques:

This document applies to the measurement of diluted and concentrated suspensions over a wide concentration range: When measuring high and low concentration samples, DLS uses the same

However, high-concentration samples have special requirements on instrument structure and sample preparation: At high concentrations, particle-to-particle interactions

The dominant effect of multi-scattering and high-concentration samples appears, which can lead to significant differences in particle size measurement results between high and low concentration samples:

2 Normative references

The contents of the following documents constitute essential provisions of this document through normative references in the text: Among them, dated citations documents, only the version corresponding to that date applies to this document; for undated references, the latest edition (including all amendments) applies to this document:

ISO 9276-1 Representation of particle size analysis results - Part 1: Graphical characterization (Representationofresultsofparticlesize analysis-Part 1:Graphicalrepresentation)

Note: GB/T 15445:1-2008 Representation of Particle Size Analysis Results Part 1: Graphical Characterization (ISO 9276-1:1998, IDT)

ISO 9276-2 Representation of the results of particle size analysis - Part 2: Calculation of mean particle size/diameter and individual moments (Repre- sentationofresultsofparticlesizeanalysis-Part 2:Calculationofaverageparticlesizes/diameters andmomentsfromparticlesizedistributions)

Note: GB/T 15445:2-2006 Representation of the results of particle size analysis Part 2: Calculate the average particle size/diameter and the moments of each order from the particle size distribution (ISO 9276-

2:2001, IDT)

3 Terms and Definitions

The following terms and definitions apply to this document:

3:1 particle

Tiny matter with well-defined physical boundaries:

Note 1: Physical boundaries can also be described as interfaces:

Note 2: Particles can move as a whole:

Note 3: Also known as particles:

[Source: ISO 26824:2013, 1:1, with modifications]

3:2 average hydrodynamic diameter xDLS

The hydrodynamic diameter reflecting the median of the particle size distribution:

Note 1: The average particle size is directly determined, either without calculating the particle size distribution, or from the intensity-weighted distribution, volume-weighted distribution or number-weighted distribution, and the

Calculated from the combined (transformed) density function: The exact meaning of the mean particle size of the particles depends on the calculation method:

GB/T 19077 | GB/T 39990 | GB/T 39193 | GB/T 29024.3 | GB/T 29024.2 | […]