Raman optical fiber temperature measuring device and temperature measuring method

Abstract

The invention discloses a Raman optical fiber temperature measuring device. The pulse signal laser emitted by the pulse laser module is sent to the input end of the circulator, and one of the output ends of the circulator is connected to the first data acquisition module through the first sensing optical fiber. The other output end is connected to the second data acquisition module via the sensing fiber, the sensing fiber is provided with a fiber Bragg grating, and the first data acquisition module and the second data acquisition module transmit the collected data to the data acquisition module. processing module. By collecting the Raman scattered light at both ends of the optical fiber, the device improves the energy utilization rate of the pulse signal laser and can balance the signal intensity collected at both ends of the optical fiber. Furthermore, firing one laser pulse allows two sets of Raman scattering data to be collected for averaging, reducing measurement time.

Description

technical field [0001] The invention relates to the field of temperature measuring devices, in particular to a temperature measuring device for collecting Raman scattering at both ends of an optical fiber. Background technique [0002] The research on the distributed optical fiber temperature measurement system based on the principle of spontaneous Raman scattering began in the 1970s. Compared with the traditional temperature sensing system, the distributed optical fiber Raman temperature measurement system has the advantages of strong anti-electromagnetic interference, wide measurement area, good stability, low cost and easy wiring. At present, the distributed optical fiber Raman temperature measurement system has been widely used in national defense, industry, public security and other fields due to its unique advantages. [0003] The working principle of the existing Raman temperature measurement system is: the laser continuously emits pulsed light into the sensing fiber...

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Problems solved by technology

[0004] Since the existing method only collects scattered light in one direction in the optical fiber, and requires a large amount of data for average calculation, the existing method has the following defects and deficiencies: 1. There is loss in the light propagating in the optical fiber, so the collected scattering curve Exponential attenuation, the intensity of the signal at the end of the fiber is significantly lower than that at the front end of the fiber, and the temperature curve at the end changes very little, which will increase the error of the measurement result; 2. Only collect the scattered light in one direction of the fiber, and the pulse signal laser The energy utilization rate is not high; 3. The average calculation requires a large amount of collected data, and only collects scattered light in one direction, which has low efficiency and takes a long time for temperature measurement

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