Optical temperature sensor for high voltage applications

Abstract

An all-dielectric, electrically passive, optical temperature sensor for use in high voltage environments has been constructed and tested. It is based on the temperature dependence of the optical activity in crystalline quartz. The sensor showed excellent linearity over the 20-180 degrees C temperature range, providing temperature measurements within this range to an accuracy of +/-2 degrees C. The output indication was not affected by external magnetic or electric fields. The materials used in the construction of the device are expected to possess long-term chemical compatibility with harsh environments, including transformer insulating oil at temperatures up to 180 degrees C.