The Zetasizer Nano ZSP, an older model from the series Zetasizer range uses the Dynamic Light Scattering (DLS) and Electrophoretic Light Scattering (ELS) technique to determine the particle or molecule size and to determine the electrokinetic potential, Zeta. The instrument is equipped with a He laser of 633 nm and with the Non-Invasive Back-Scatter (NIBS) technique at an angle of 173°. The measurement ranges in size from 1 nm to 10 µm and the molecular weight ranges from 980 Da to 20 MDa.