Fiber-optic arc flash sensor based on plastic optical fibers for simultaneous measurements of arc flash event position

We present an arc flash sensor that can trace the arc event position as well as intensity by utilizing conventional plastic optical fibers (POFs). In order to check the possibility as a light-receiving sensor, we experimentally confirm that the externally irradiated flash light can be coupled into the fiber core through the surface of POF without any additional treatment. After the incident light is divided in two optical paths toward opposite directions, they have the different attenuation values determined by the propagation distance. Since the optical transmission loss of a POF is constant regardless of the irradiated energy, the intensity ratio for two signals measured at both fiber ends is given as a function of position. The experimental results show that we can successfully trace the event position from this intensity ratio. In addition, it is possible to define the illuminated energy by comparing the absolute value of the intensity measured from one side. According to the experimental results, the proposed sensor has a relatively fine spatial resolution, +/- 10 cm, despite having a simple structure. (c) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)