Optical, electrical, and electro-mechanical measurement methodologies of electric field, charge, and polarization in dielectrics

A selective review is presented of the use of optical, electrical, and electro-mechanical measurement methodologies of the electric field, charge, conductivity, and permittivity in dielectrics. Kerr electro-optic measurements are presented to demonstrate how volume charge distributions can significantly distort the electric field distribution and how the field and charge distributions depend on dielectric and electrode materials and geometry and on voltage magnitude, polarity, and time duration. A new class of interdigitated dielectrometry sensors is reviewed which from one side can measure profiles in dielectric permittivity and conductivity and related physical properties such as moisture content. Electromechanical devices such as the Absolute Charge Sensor and the Couette Charger with a rotating cylindrical electrode are reviewed for their applications in liquid flow electrification measurements