OPTICAL FIBER SYSTEM APPARATUS FOR MEASURING TEMPERATURE DISTRIBUTION

摘要

PURPOSE:To improve temperature measurement precision at a distant from a predetermined point. CONSTITUTION:A light pulse emitted from a high output pulse light source 1 falls into a measuring fiber 3. A spectral device 2 separates and outputs stakes light and anti-stokes light caused by Raman scattering out of back scattering light generated in the fiber 3. Each light signal is amplified by amplifiers 6A and 6C and digitized by a digital averager 8 After the transmission of a trigger signal of pulse light emission, a control circuit 8c switches terminal connection states of optical switches 4A, 4B and electric switches 7A, 7B to the reverse side in 70musec so that the signal may pass through amplifiers 6B and 6D of higher amplifications. Therefore, a signal level where temperature measurement of high precision is possible is maintained over all the regions.