This instrument is capable of measuring both particle size and zeta potential in solution. Zeta potential is described as the electrokinetic potential in colloidal systems. The effective range for particle sizing is 2nm - 3um. Measurements can be made in a variety of media (water, salt solutions, non-aqueous solutions, etc.). Users will be required to provide their own quartz cuvettes for all non-aqueous work. In addition to the standard ELS (electrophoretic light scattering) used to measure zeta potential, this instrument has the more sensitive PALS (phase analysis light scattering) option. PALS can measure velocities that are as little as 1000 times smaller than conventional ELS. The instrument is also equipped with a sample compartment heater, for taking measurements from room temperature up to 75 C. There are two calculation models available (Smoluchowsky or Huckel), depending whether the sample is aqueous or non-aqueous.