Optical fiber distributed type monitoring method for long-distance conduit wiring safe monitoring and its device

Abstract

The invention relates to a fiber distributed monitoring method and device for the safety monitoring of a long-distance pipeline. By using a fiber Sagner interferometer fiber consisting of a laser, a 2 is multiplied by 2 coupler and two optical fibers arranged in parallel to the long-distance pipeline, the invasion or leakage events are detected based on the interference signal caused by oscillation phenomenon. An optical fiber delay line is preset at the emergence end of either of the two optical fibers under the condition that the two optical fibers oscillate at the same time. An optical fiber delay line is preset at the farthest end under the condition that either of the two optical fibers oscillates. The interference factor is compensated by means of periodic narrow pulses, record light source fluctuation and equilibrium demodulation, thereby realizing the long-distance pipeline safety detection with high sensitivity. The invention also uses a computer database to store and sort data, analyze the event type and give alarms of different levels. The invention utilizes low-cost mobile modules to combine a plurality of independent devices distributed along the long-distance pipeline and thus to form the long-distance wireless monitoring system, and realizes the roll call measurement, periodic measurement and data upload.

Description

Technical field [0001] The invention belongs to the safety monitoring in the field of resource and information transmission, such as the safety monitoring of oil, water, gas and other transmission pipelines and communication optical cables, and specifically relates to a method for safety monitoring of long-distance pipelines using the optical fiber Sagnac interference principle device. Background technique [0002] Security risks in the field of resource and information transmission are common. Such as natural gas pipelines due to corrosion leakage due to sulfur and other reasons or external man-made, sudden natural disasters (such as earthquakes, landslides, etc.) damage, leakage or damage and other accidents. In recent years, the absolute security of optical fiber information transmission has been broken, and eavesdropping incidents on terrestrial optical cable lines have been reported frequently, and the U.S. Central Intelligence Agency’s submarine optical cable eavesdro...

AI Technical Summary

Problems solved by technology

However, the two interfering lights of the Sagnac interferometer experience an absolutely equal distance, and there is no requirement for the line width of the light source. Therefore, a Sagnac interferometer that meets certain conditions may constitute a long-distance safety monitoring system.

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