Breakdown monitor and its supervisory manner null of

摘要

PURPOSE:To enhance the detecting sensitivity to an emission generated from an electric apparatus by removing a noise generated from a photoelectric converter in a device for detecting a partial discharge and a spark by a fluorescent fiber. CONSTITUTION:An optical branch unit 14 for branching an optical signal delivered from the end part drawn to the outside of an electric apparatus of a fluorescent fiber 3 into two light guide fibers 5 is provided, and first and second photoelectric converters are connected to the light guiding fibers, respectively. A noise removing circuit which receives electric signals outputted by the two photoelectric converters and passes the electric signals only when the electric signals are simultaneously inputted is provided. According to this constitution, noises from the photoelectric converters can be removed, and a faint emission of a partial discharge can be detected.