Particle Size Resolution Tests Using Control Samples

To assess the ability of a laser diffraction particle size analyser to distinguish between particles of different size, the instrument can be tested using multimodal control samples. This method can be used not only to give buyers a comparison between products but also, in the longer term, to check that the reliability of the data they produce is being maintained.

New control material

A new control sample, containing a mixture of sieved materials with three particle size peaks, has been released by Meritics for this purpose.

Testing on the LS 13 320 laser diffraction particle size analyser from Beckman Coulter, using the new control material, confirmed the instrument’s ability to measure and resolve very small differences in particle size distribution.

This is achieved using a custom-designed, X-shaped array containing a large number of individual detectors. The system is also highly sensitive to the presence of contaminant and aggregate particles, which it does not allow to cause confusion in the distribution data.

The new control sample material’s peaks are in the 120/220/420 µm range. This makes it ideal for assessing the ability of an instrument to suspend and analyse large particles, assuring users that even their largest particles are being suspended in the method they are using.

Submicron resolution testing

For resolution testing of laser diffraction particle size analysis instruments in the sub-micron region (below 1µm), a control material with peaks at 80/200/500 nm is already available independently and commercially.

Again, testing of the Beckman Coulter LS 13 320, using the sub-micron control sample, has proven the instrument’s remarkable resolution. The LS 13 320, which incorporates Beckman Coulter’s own Polarisation Intensity Differential Scattering (PIDS) technology, maximises information collection using 4 wavelengths of light and a number of different light polarisations, as well as additional wide angle detectors. In fact, it takes as many as 36 detection measurements in the submicron region.

Beckman Coulter LS 13 320 scores highly

In addition to the resolution, accuracy and reliability of its results, Meritics is impressed by the speed and user-friendliness of Beckman Coulter’s LS 13 320. Suitable for analysis of dry, aqueous and non-aqueous samples, this versatile laser diffraction particle size analyser is widely relied upon to meet all particle sizing needs in a wide range of R&D, quality control and manufacturing environments.


Date added: 2013-01-22 20:38:47