Electric Field Measurement in Liquid Dielectrics Using a Combination of AC Voltage Modulation and a Small Retardation Angle

A modified Kerr electro-optic effect technique has been applied to the direct measurement of electric field intensity in dielectric liquids such as nitrobenzene, tricresylphosphate, benzene, transformer oil and silicone oil. In particular, by utilizing the incident elliptically polarized light with retardation angle α = 1 degree and modulating applied alternating voltage, it was possible to measure the electric field using short electrode lengths of 6 cm for low Kerr constant liquids such as transformer oil and silicone oil.