Simultaneous Measurement of Temperature and Humidity using OTDR Based on Fiber-Optic Sensor System

In this study, we developed a fiber-optic sensor system (FOSS) which can measure real-time temperature and humidity simultaneously. It is for monitoring and detecting the leak before break (LBB) easily at a coolant pipe of the nuclear power plant. By measuring the temperature and humidity simultaneously, FOSS can enhance the accuracy and minimize the error of detecting the LBB. Through the experimental results, we confirmed that the proposed FOSS for the temperature and the RH measurement works well. Especially, FOSS has high sensitivity and good linear response, when the FOTS and the FOHS are measured within the measurement range of 5 to 70℃ and 50 to 95% respectively. It is expected that the OTDR based FOSS could be efficiently used in real-time measurement for temperature and RH sensing.