FIBRE-OPTIC PIPELINE MONITORING DEVICE Russian patent published in 2017 - IPC G01H9/00 G01N21/00 

FIELD: physics.

SUBSTANCE: claimed fibre-optic pipeline monitoring device contains two independent reflectometers united into one system, each of which is connected to a variety of optical fibres of the fibre-optic line. The reflectometer contains a laser continuous radiation source connected with the optical radiation intensity modulator, a circulator, one of the outputs of which is connected to the fibre-optic line, the first and the second erbium amplifiers, a generator of rectangular electrical pulses, a photodetector made in the form of a balanced detector with a differential amplifier, a fibre-optic interferometer of Mach-Zehnder. The reflectometer contains a phase modulator, a clock generator, a generator of rectangular electrical pulses. The control input of the optical radiation intensity modulator is connected to the generator output of the rectangular electrical pulses, which is connected to the clock generator, also the control input of the optical radiation intensity modulator is connected to the fibre-optic interferometer of Mach-Zehnder with an arm difference of ΔL=V_g Δt⋅, where V_g - the group radiation velocity in optical fibre, Δt - the delay time of the fibre-optic interferometer of Maha-Zehnder. The fibre-optic interferometer of Mach-Zehnder is connected to the first erbium amplifier, and the phase modulator is mounted on one of the arms of the fibre-optic interferometer of Mach-Zehnder. The input of the phase modulator is connected to the output of the generator of rectangular electrical pulses connected to the clock generator, the output of the first erbium amplifier is connected to the input of the circulator, the second output of which is connected with the second erbium amplifier. The second erbium amplifier is also connected to the photodetector, the output of which is connected to the input of the signal processing.

EFFECT: decreasing the probability of fading the reflectometer signal, without degrading the spatial resolution.

2 dwg