Raman Optical Fiber Distributed Temperature Sensor

A Distributed Temperature Sensing (DTS) system is ideal for fire detection and monitoring long-distance temperature profiles. DTS is a linear system capable of detecting temperature over the entire length of an optical fiber cable.

When a light source (laser) propagates down an optical fiber, it exchanges molecules with lattice vibration. On application of heat, it is scattered back by the glass fiber molecules to the transmitted end where it is analyzed. Nearly all the scattered light has a wavelength identical to incident light, small amount of light has a different wavelength due to Raman Effect. On Raman scattering, stokes and anti-stokes signals generate, the intensity ratio of which is dependent on temperature. The arrival time of backscattered signals is used to determine the position of temperature readings, a principle known as Optical Time Domain Reflectometry (OTDR).

Applications

• Linear temperature sensing along pipelines and tunnels.
• Fire detection inside tunnels.
• Oil and gas leakage along pipelines.
• Conveyor Belt Monitoring.
• Reactor Skin Temperature Monitoring.