Distributed optical fiber temperature measurement system

Abstract

The invention discloses a distributed optical fiber temperature measurement system, which belongs to the technical field of optical fiber temperature measurement. The distributed optical fiber temperature measurement system comprises a laser, an optical circulator, a first optical filter, a second optical filter, a photoelectric conversion circuit and an acquisition card, wherein laser emitted bythe laser enters a to-be-detected sensing optical fiber through the optical circulator; backscattered light generated during the process during which the laser is propagated in the to-be-detected sensing optical fiber is returned to the optical circulator and then enters the first optical filter and the second optical filter for filtering; the filtered backscattered light enters the photoelectricconversion circuit; and electric signals outputted by the photoelectric conversion circuit are acquired by the acquisition card and are then transmitted to a computer to be processed to temperature signals. According to the distributed optical fiber temperature measurement system disclosed in the invention, the temperature precision of the distributed optical fiber temperature measurement system can be improved effectively, the stability is enhanced, and the spatial resolution is low.

Description

Technical field [0001] The invention relates to a distributed optical fiber temperature measurement system, belonging to the technical field of optical fiber temperature measurement. Background technique [0002] After more than ten years of development, the distributed optical fiber temperature measuring device has long measuring distance, high precision, [0003] It has the advantages of no measurement blind zone and strong anti-electromagnetic interference ability. It is widely used in power cable tunnels, integrated pipe corridors, coal industry and data centers and other fields that require temperature measurement, fire alarm, energy saving and emission reduction. [0004] The distributed optical fiber temperature measuring device is made by using the spontaneous Raman scattering effect. The anti-stokes signal is sensitive to temperature, and the Stokes signal is not sensitive to temperature. It can be calculated by the ratio of light intensity The temperature value of each poi...

AI Technical Summary

Problems solved by technology

The improvement of spatial resolution is limited by the pulse width of the laser and the sampling rate of the acquisition card. To ensure a spatial resolution of 1 meter, it is necessary to ensure that the pulse width of the laser is less than 10 ns and the sampling rate of the acquisition card is greater than 100 Mb / s. The common method to improve temperature accuracy is the digital cumulative average method, which can improve the signal-to-noise ratio to a certain extent, but increases the temperature measurement time, and often deteriorates its real-time performance in order to achieve sufficient accuracy.

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