Particle Size Testing
Particle Size Distribution
Particle Size Distribution, the number of particles of different sizes, is performed by laser light scattering.
The instrument utilized to perform this test combines a He-Ne laser with a Tungsten lamp to determine particle size in the range of 0.02-2000 um using the Mie Theory.
Particles are first dispersed with a fluid (Dispersion Fluid), which may/may not also include sonication. Based on a mathematical function, the relative amount and size of particles is determined. This may also be referred to as Grain Size Distribution.
The material being tested has a direct impact on the Dispersion Fluid used. Common dispersion fluids include DI Water, IPA, Sedisperse, Kerosene, and Mineral Oil. It is also common to use an aqueous mixture or a non-aqueous mixture. To determine the proper dispersion fluid, we ask that the SDS be supplied.
Results are reported as Mean Diameter (um) and Median Diameter (um). The raw data is also included with the report showing the graph associated to the testing. This graph includes the % on Diameter (Cumulative Underside Distribution) along with the Diameter on % (Differential Size Distribution).
Sample requirements for testing:
10 mg to 5 grams solid material
10-100 mL, upwards of 1 L maximum for a slurry/liquid sample
pH shall be ≥4
Test Method: ISO 13320
Particle Count Testing
Test Method: ISO 4406
Sieve analysis is commonly performed for separation, fractioning, and particle size determination. A sieve shaker, with two dimensional movement (a horizontal, circular motion and a vertical, tapping action) allows particles to stratify.
This technique is utilized for Dry Sieve analysis. The particles pass through various screens to determine the size fractions. ASTM E11 Sieves are used for sieve analysis ranging from No. 325 Sieve (45 um mesh) through No. 12 Sieve (1700 um mesh).
This measurement can be limited due to a sample’s density, tendency to agglomerate, or electrostatic charging.
Sample requirements for testing: 100 grams minimum