Laser Diffraction: My Top Q&A

Dv10 is the 10^th percentile of the cumulative volume distribution. It is the size below which there is 10% of the volume of the sample, so it is used to track changes to the finest particles in population. The percentiles Dv10, Dv50 and Dv90 are reported by default in the software.

We use the obscuration, or the amount of light blocked or scattered by the particles, as a measure of the concentration of particles within the Mastersizer 3000. We recommend ranges of obscuration based on the expected particle size, which are different for wet and dry dispersions. For wet measurements, you can make an obscuration titration to determine a suitable obscuration range.

For wet dispersions:

For dry dispersions:

If the Mastersizer 2000 method has been well-developed, and the particles are not at an extreme of the size range, you should be able to achieve a very similar result on the Mastersizer 3000. It may be necessary to change some of the dispersion unit settings and some of the analysis settings as there are improvements across the Mastersizer 3000 system. If your particles are at an extreme of the Mastersizer 2000 range, you may see differences when you measure on the Mastersizer 3000 due to the extended size range and the increased resolution in the submicron range. There are tools in the software, resources at www.malvern.com and specialists available through helpdesk@malvern.com to help with method transfer. In most cases method transfer is straightforward.

[My personal favourite, quoted from my Mum]. Particles are in manufacturing processes and products everywhere: such as flour and milk in food manufacture, drugs in tablets, pigments in paints, cement and construction materials, droplets in aerosols, minerals and other feedstocks for the chemical and plastics industries, and so on. In fact it is difficult, perhaps impossible [send your suggestions in to the comments?] to name a product that is particle-free.

I’d often like to answer this question with a question. How much will you save by having the most accurate, reliable and reproducible particle sizing information? As the system comes with many affordable and scalable configurations depending on your sample and needs, I would typically refer to our sales specialist’s teams. By requesting a quote online my colleagues will get straight back in touch with best set of options to suit your organization.

I especially like this question as it often means I get to travel on site to see a variety of interesting places and organizations. Once we arrive it is very quick and easy for us to set up a demonstration and I am always amazed at everyone’s positive reactions to seeing the system start up and begin collecting the data on their own samples. Asking this question is also made easy by completing the request a demo form on the Malvern website.