Application of a Packaged Fiber Bragg Grating Sensor to Outdoor Optical Fiber Cabinets for Environmental Monitoring

Outdoor optical fiber cabinets are generally installed along roadsides where environmental conditions, such as sun exposure, rain, and dust, can cause damage to the cabinets. Furthermore, high temperatures and unexpected impacts that cause cabinet deformation may damage the network equipment inside the cabinets, affecting the quality of communications. This paper developed an optical fiber sensing system for real-time monitoring of the temperature variation and external forces exerted on outdoor cabinets using fiber Bragg gratings (FBGs). This FBG sensing system was established in the network management center, and was linked to the outdoor cabinets at the remote end through optical fibers in order to monitor the impacts and temperature changes of the cabinets. Experimental results revealed that exerting an external impact force of 297 N on an outdoor cabinet severely dented the impacted cabinet surface. When the monitoring system detects external impacts exceeding 297 N or cabinet temperatures greater than 65 °C, the network management center can then immediately send maintenance personnel to check for any network impairments.