A 2-DIMENSIONAL KERR-EFFECT TECHNIQUE FOR ELECTRIC-FIELD DISTRIBUTIONIN LIQUID DIELECTRICS

Based on the electro-optical Kerr effect, an attempt is made to develo p a measurement technique for the two-dimensional distribution of the electrical field in dielectric liquids. For rapid, two-dimensional mea surements, it is convenient to introduce a computer-controlled electro nic camera for optical detection. However, because of the two-dimensio nal non-uniformity resulting from the system components, the measureme nt principle needs a two-dimensional analysis. To simplify the mathema tical analysis, square pulsed modulations are employed. The influence of the system non-uniformity is eliminated by use of both optical and electrical modulations. To improve the system sensitivity, an optimum system setup is analyzed. To decrease the effect of the noise componen t resulting from the EHD (electrohydrodynamic) motion of the dielectri c liquid, a diagnostic image lock-in technique is proposed. The validi ty of the two-dimensional measurement principle and the effectiveness of the diagnostic image lock-in processing are examined by the measure ment of an electrical field distribution in a nitrobenzene specimen be tween two parallel plate electrodes.