A FIRE DETECTION SYSTEM USING OPTICAL FIBERS FOR UTILITY TUNNELS

In this paper we examine a fire detection system for utility tunnels o n the basis of the fact that temperature distribution along an optical fibre can be determined through measurement of the Raman back scatter ing of the Stokes and anti-Stokes lines. This system can measure tempe rature distribution by scanning, with an accuracy of 5 degrees C and 5 m, an optical fibre 2 km long in 30s. We discuss how to locate the fi re source and calculate its thermal energy from the temperature distri bution data obtained, and consider whether the system can be applied t o fire detection in utility tunnels. (C) 1997 Elsevier Science Ltd.