Electric and magnetic field sensing for high voltage applications

Electric and magnetic fields can be measured optically, either directly via Pockels and Faraday effect or indirectly via Piezo effect. In high Voltage applications fiber optic sensors are especially attractive for their ability of easy potential separation. For electric fields the Pockels effect in BSO, EGO crystals is mostly read out polarimetrically. The current is mostly measured via the Faraday effect in fibres or bulk optics polarimetrically, but also by means of a Sagnac interferometer. Electrooptic Voltage and magnetooptic current sensors have quite a matured state of development and shown their benefits in a lot of field tests and installation in high Voltage switch gears.