Distributed optical fiber temperature sensor and temperature measuring method

摘要

PURPOSE:To improve SN ratio equal to or exceeding the improving rate of the SN ratio of an averager by constituting a sensor of a light source part, an optical directional coupler, a filter, a photoelectric conversion part, the averager, a memory and a signal processing part, etc. CONSTITUTION:A laser pulser 1 being the light source part makes a laser pulse enter an optical fiber to be measured 3. The optical directional coupler 2 conducts Raman scattered light from the optical fiber 3 to a measuring device. The filter 4 separates Stokes light from anti-Stokes light in the Raman scattered light. The photoelectric conversion parts 5 and 5' photoelectrically converts the Stokes light and the anti-Stokes light into electrical signals in proportion to the intensity respectively. The averager 7 averages the electrical signals from the photoelectric conversion parts 5 and 5' specified times. The memory 8 stores (n) ((n) is an integer=2) pieces of data obtained by performing the average processing specified times. The signal processing part 9 performs weighted moving average processing by using the (n) pieces of data.