Particle analysis

Researchers aiming at analyzing suspended particle size distribution will typically gravitate to one of four methods:

• Sieve analysis – this is the most traditional, and still most common method to assess particle size. The sieve stack is actually several sieves stacked on top of each other, each with a larger aperture than the previous one, with the sample being placed in the uppermost (and largest aperture) sieve. A sieve shaker shakes the sample until the particles in it pass through the smallest aperture they can fit – in other words, the aperture larger than their largest dimension, generally their width in a diagonal orientation. The resolution of this method is naturally limited by the number and range of the aperture sizes on the sieve stack.

You can see why this method is tried and true, and many labs still make due with it – but other than the propensity to errors stemming from overloading, worn out apertures and errors in data transfer, weighing, sieving, back weighing and cleaning the sieves is extremely time consuming and wearisome.

• Dynamic light scattering (DLS) – in Dynamic Image Analysis (DIA), millions of particles per minute flow past a camera, which acquires several hundred frames every second. unlike sieve analysis particle size is determined in a completely random orientation.
• Static laser light scattering (SLS, also known as laser diffraction) – here, indirect measurement of particle size is performed via analysis of laser light intensity distributions following scattering by particles at different angles. Large particles scatter the light to small angles while small particles scatter the light in large angels.

Each of these systems has its own advantages and disadvantages, and, depending on the specific device, is better suited for particles of a particular size. Merkel is prepared not only to offer you the best particle analysis devices at affordable prices, but also advise you on which devices are truly best for your particular needs.