The real-time safety monitoring of railway condition by FBG sensor

The safety and reliability is very important for railway industry. In this paper we propose a fiber Bragg grating monitoring system on line to realize real-time, fast, distributed measurement of physical quantities such as temperature, strains and vibration of the railway. The fiber Bragg grating sensor can be able to bear high pressure, resistant to corrosion and resist the electromagnetism disturbance, using safety in harmful environment. Furthermore, it can directly measured multiplex physical quantities at various locations using a single unit of FBG by using the technology of wavelength division multiplexing (WDM).