Particle Characterization
Top 10 Dry Method Development Tips
- Design every method for maximum precision: repeatability and reproducibility.
- Study different sampling techniques to help minimize error. This is particularly important for materials with small outlier populations.
- Dry measurements fall into two approaches: measurement everything on the chute or acquire multiple measurements from the same sampling. The former must be done when the material has a sampling bias. The latter may be used when the material does not exhibit a sampling bias. Know which approach is required for your material.
- Always use feedback control on the LA-960 PowderJet.
- Increase dispersion energy by using a smaller nozzle for the PowderJet.
- Choose a refractive index by studying references (i.e. CRC Handbook), applying known information about the material, or, if no information is available, by minimizing the R-parameter.
- Refractive index (RI) affects the accuracy of the particle size distribution, but has a much smaller effect on the analyzer's ability to detect changes to that distribution. In practice, even an incorrect RI can be used to successfully monitor the quality of a material or process.
- Study the effect of air pressure on the material. Pay close attention to the coarsest and finest parts of the distribution to evaluate the extent of de-agglomeration and onset of particle breaking.
- Evaluate the method's robustness by calculating the coefficient of variation for the D10, D50, and D90 values across a minimum of three measurement results. The LA-960 automatically makes these calculations.
- Evaluate the method's suitability by confirming that "good" and "bad" lots of material show a difference in particle size distribution.
LA-960 Education & Support Resources
LA-960 Product Page
The LA-960V2 uses Mie Scattering (laser diffraction) to measure particle size of suspensions or dry powders. The speed and ease-of-use of this technique makes it the popular choice for most applications.
