Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
  • G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
  • G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
  • G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
  • G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
  • G01D5/35306—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement
  • G01D5/35309—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using multiple waves interferometer
  • G01D5/35316—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using multiple waves interferometer using a Bragg gratings
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/02—Optical fibres with cladding with or without a coating
  • G02B6/02057—Optical fibres with cladding with or without a coating comprising gratings

Definitions

• the invention relates to devices for measuring devices with optical measuring instruments, and in particular to devices for recording signals from a set of fiber-optic Bragg sensors of the integrated non-destructive testing (WSS) system of an object.
• WSS integrated non-destructive testing
• VNK devices based on fiber-optic Bragg sensors, in particular, in RF copyright patent 2377497 "DEVICE FOR MEASURING DEFORMATIONS BASED ON QUASI-DISTRIBUTED FIBER-OPTICAL SENSORS ON BRAGGOVSK01 GRUB 16, 11 MP11. 12/27/2009.
• the analog device contains several fiber-optic measuring lines with fiber Bragg gratings, a reference (calibration) block with a reference (calibration) fiber Bragg grating for calibrating the signals of the measuring channels on a wavelength scale, an optical source tunable along the wavelength, for example, a tunable laser for generating radiation, which is separated by an optical splitter and enters the reference block and into several measuring lines with fiber Bragg gratings.
• the support unit is a calibration system on a wavelength scale, the role of the calibration system can be performed by a fiber Bragg grating, an interference filter with a fixed free spectral range, for example, a Fabry-Perot etalon, gas absorption cells, or any combination of these elements.
• the reference block determines the reference wavelength of the tunable source; for this, the output signal of the reference block is used for feedback in order to adjust and stabilize the source wavelength, which allows measurements of the absolute values of the wavelengths of the gratings of the measuring channels. For this, part of the radiation from the source is allocated by the first splitter along the chain of the splitters system to a photodetector (FPU) of the reference block.
• FPU photodetector
• One of the branches of the splitters system directs part of the radiation to the reference fiber Bragg grating with predetermined characteristics, which is under constant external conditions for high wavelength stability of the radiation reflected from it. Radiation reflected from the support grating passes through a splitter in the FPU of the support block.
• the output signals from the fiber-optic measuring lines are connected to a number of measuring blocks separately from the reference block.
• a complex system of optical splitters diverts part of the source radiation in the line of fiber Bragg gratings (sensors).
• the optical signals reflected from the fiber Bragg gratings pass back through the couplers and pass to the FPU of the measuring units.
• the number of the connected channel is determined by the FPU number the corresponding measuring unit, the signal from which is read and processed in the computer.
• the disadvantage of this device should be considered the complexity of its circuit, including, for example, the presence of a complex tunable laser source and feedback of the output signal of the reference block in order to adjust and stabilize the wavelength of the source, and a reduced dynamic range of the measuring signals of the circuit due to the fact that measuring channels are connected to the outputs simultaneously (and the more measuring channels, the proportionally lower the dynamic range of the measured signals will be.
• the dynamic range is ur Wen signal power in dB, which is capable of measuring the measurement system).
• the complex task of the proposed solution is the simultaneous substantial simplification of the device circuit with guaranteed reliability of identification (addressing) of the measuring channels connected to the computer, and an increase in the dynamic range of the measured optical signals.
• the technical result is achieved by using a continuous broadband radiation source in the device, for example, a superluminescent diode (SLD), an optical switch, and integrating into each measuring channel one reference fiber Bragg grating with a known wavelength of reflected radiation that is not repeated in other channels, moreover, all support grids are placed in a separate housing with a thermal stabilization system and possible isolation from other external disturbing conditions.
• a continuous broadband radiation source for example, a superluminescent diode (SLD), an optical switch, and integrating into each measuring channel one reference fiber Bragg grating with a known wavelength of reflected radiation that is not repeated in other channels, moreover, all support grids are placed in a separate housing with a thermal stabilization system and possible isolation from other external disturbing conditions.
• the guaranteed reliability of the measuring system is ensured by the optical identification of the measuring channel connected via an optical switch to the common measuring system and then to the computer.
• the signal of the reference Bragg grating with a stable wavelength of reflected radiation will unambiguously give information about the number (address) of its measuring channel in which this reference grating is placed in series with other working measuring Bragg gratings. Since the device uses an optical switch, which, by address from a computer, connects to the measuring system via one measuring channel, In terms of simplifying the scheme, this makes it possible to use only one FPU for receiving signals, unlike many FPUs in the circuit of the closest analogue.
• the proposed device for optical identification of the measuring channels of the built-in non-destructive testing system based on fiber-optic Bragg sensors contains an optical radiation source, a three-pole optical splitter, a reference Bragg grating with a known characteristic of the reflected wavelength, several measuring channels with measuring fiber Bragg gratings located at the control object, the insulation system of the support grid from external disturbing air actions, including a thermal stabilization system; FPU and block registration and conversion of signals, which is connected to a computer.
• address support gratings with non-repeating characteristics of the reflected radiation wavelengths are one built into each measuring channel. All support grids are housed in a housing with a system of isolation from external disturbing conditions.
• a superluminescent diode (SLD) is used as a continuous broadband optical radiation source. Additionally, there is an optical isolator and an optical switch, and an optical isolator is installed between the source output and the input pole of a 1 x 2 three-pole splitter, one output pole of which is connected to a common input of the optical switch. Each connected output of the optical switch is connected to its measuring channel. The other output pole of the splitter is connected to the input of the FPU and the unit for recording and converting signals.
• SLD superluminescent diode
• FIG. 1 shows a structural block diagram of the proposed device.
• a superluminescent diode (SLD) pos. 1 Insulator pos.2, installed in series with the SLD, prevents back reflection in the SLD.
• N 16
• Each reference fiber Bragg grating 5 has known characteristics and is integrated into the housing with a thermal stabilization system 6, thereby eliminating the influence of external factors, and the wavelength of the reflected radiation from each supporting grating remains stably constant.
• the second output pole of the three-pole splitter 3 is connected to the input of the FPU and the signal recording and conversion unit 8, the output of which is connected to a computer 9, which displays and processes the measurement results.
• the device operates as follows.
• a measuring channel is connected (via an addressable electrical signal from a computer) through an optical switch
• the FPU captures the reflection spectrum of all fiber Bragg gratings located in the measuring channel, including the reference grating and determines the wavelengths of reflected radiation from all gratings in this channel, including and from the supporting Bragg grating.
• An addressable electrical signal from a computer does not have the required level of reliability, therefore, by the value of the wavelength of the reflected radiation from the reference grating, the number (address) of the connected measuring channel is uniquely determined with the guaranteed level of reliability.
• a guaranteed reliable address (number) of the channel is taken into account in the computer 9 during the subsequent reading of the measurement information from the connected measuring channel of the VNK system.
• the proposed device provides a simultaneous significant simplification of the device circuit with guaranteed reliability of identification (addressing) of the measuring channels connected to the computer, and an increase in the dynamic range of the measured optical signals.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Testing Of Optical Devices Or Fibers (AREA)
• Arrangements For Transmission Of Measured Signals (AREA)
• Length Measuring Devices By Optical Means (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)

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Citations (5)

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• 2012
  • 2012-07-27 RU RU2012132132/28A patent/RU2510609C2/ru active
  • 2012-12-21 EA EA201401315A patent/EA026181B1/ru not_active IP Right Cessation
  • 2012-12-21 WO PCT/RU2012/001096 patent/WO2014017946A1/fr not_active Ceased

Patent Citations (5)

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