Compensation methods of the temperature dependence of glass ring type optical current sensors

Optical current sensors or so called optical current transformers (OCT) based on the Faraday effect have an intrinsic temperature dependency of the current sensitivity caused by the natural drift of the Verdet constant as well as birefringence in the sensing medium. In order to reach high class accuracy of up to 0.2%, comparable to inductive current transformers, these effects have to be compensated.