 NTA also measures the hydrodynamic size of particles from the diffusion coefficient but is capable of overcoming some of the limitations posed by DLS.While the above-mentioned techniques are best suited for measuring particles typically in the submicron region, particle size analyzers (PSAs) based on static light scattering or laser diffraction (LD) have become the most popular and widely used instruments for measuring particles from hundreds of nanometres to several millimeters.Similar scattering theory is also utilized in systems based on non-electromagnetic wave propagation, such as ultrasonic analysers.