ZetaPlus Principles of Operation

• Charged particles will migrate under the influence of an electric field
• The direction of migration will indicate the sign of the charge
• The velocity of the particles, per unit applied electric field, is called the electrophoretic mobility
• Zeta potential can be calculated from the electrophoretic mobility

ZetaPlus Optics

• Laser light is scattered by particles moving due to the electric field
• This scattered beam is mixed with a reference beam at the detector (a photomultiplier tube)
• The reference beam is modulated
• A frequency shift gives information from which both sign and magnitude of the electrophoretic mobility can be calculated

• Zeta potential can be derived from the electrophoretic mobility