A signal correction technique for Raman-scattering based temperature sensing using optical fibers

For better visualization of temperature distribution in data centers, a new signal correction technique was investigated in the temperature measurement based on Raman scattering light analysis in optical fibers. In a typical raised-floor data center, the temperature of the free access floor is almost constant and lower than the server rack area. Using this characteristic of the data centers and the impulse response of the measurement system, a correction technique was developed to improve the spatial resolution of the temperature measurement. As a result, the relative error for the temperature difference on the door of the server-rack became less than 1/10 of the original distributed temperature sensing (DTS) measurement. The new technique made us possible to visualize the temperature distribution in data centers more thoroughly and accurately.