The Brookhaven Instruments 90 Plus NanoBrook Zeta is an advanced analyzer that combines Dynamic Light Scattering (DLS) for particle sizing with Electrophoretic Light Scattering (ELS) for zeta potential determination. It is designed for the analysis of nanoparticles and colloidal-sized materials in various liquid media. The instrument provides rapid and accurate measurements of particle size (ranging from 0.3 nm to 6 µm) and zeta potential (from 1 nm to 100 µm), including the ability to resolve multimodal size and surface charge distributions. It features precise temperature control from -5 °C to 110 °C and is particularly well-suited for aqueous suspensions and low salt environments. The system employs a 40 mW 640 nm temperature-controlled red semiconductor laser for its measurements.