For convenient DLS and SLS measurements along with determination of electrophoretic mobility (or zetapotential) in both aqueous and non-aqueous dispersions, a Zetasizer Nano ZS from Malvern Instruments Ltd, Worshestershire, UK, is available. The instrument measures DLS and SLS at a set angle of 173° using the NIBS technology. The accessible particle-diameter range is 0.3 nm – 10 μm in concentrations up to 40 % (w/v) depending on sample and the molecular weight range is 980–2•10⁷ g/mol. The zetapotential measurements in the conductivity range of 0-200 mS/cm are performed at 13° using M3-PALS technology (particle diameters from 3.8 nm to 100 μm). The instrument is equipped with a 4 mW He-Ne laser (wavelength of 632.8 nm) with an automatic laser attenuator that allows for measurements at sample transmissions ranging from 100 % to 0.0003 %. The detection unit comprises an avalanche photodiode. The temperature range of the instrument is 2-90°C. (Sponsored by The Crafoord Foundation.)