WO2018141501A1 - Dispositif de détection à fibre optique et procédé pour faire fonctionner un dispositif de détection à fibre optique - Google Patents

Dispositif de détection à fibre optique et procédé pour faire fonctionner un dispositif de détection à fibre optique Download PDF

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Publication number
WO2018141501A1
WO2018141501A1 PCT/EP2018/050308 EP2018050308W WO2018141501A1 WO 2018141501 A1 WO2018141501 A1 WO 2018141501A1 EP 2018050308 W EP2018050308 W EP 2018050308W WO 2018141501 A1 WO2018141501 A1 WO 2018141501A1
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WIPO (PCT)
Prior art keywords
fiber
detection device
fiber optic
adhesive
optic detection
Prior art date
Application number
PCT/EP2018/050308
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German (de)
English (en)
Inventor
Johannes Roths
Barbara Hopf
Thomas Bosselmann
Michael Willsch
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Siemens Aktiengesellschaft
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Publication of WO2018141501A1 publication Critical patent/WO2018141501A1/fr

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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
    • 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
    • G01D5/12—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 using electric or magnetic means
    • G01D5/14—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 using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/18—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 using electric or magnetic means influencing the magnitude of a current or voltage by varying effective impedance of discharge tubes or semiconductor devices
    • G01D5/183—Sensing rotation or linear movement using strain, force or pressure sensors
    • 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
    • G01D5/3537—Optical fibre sensor using a particular arrangement of the optical fibre itself
    • G01D5/35374—Particular layout of the fiber
    • 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
    • G01D5/36—Forming the light into pulses
    • G01D5/38—Forming the light into pulses by diffraction gratings

Definitions

  • the invention relates to a fiber optic detection device and a method for operating such a fiber optic detection device.
  • Fiber-optic sensors based on fiber Bragg gratings Fiber-optic sensors based on fiber Bragg gratings
  • FBG Fluorescence Activated Biharmonic Sensor
  • an FBG is sensitive to both temperature and strain, temperature changes should be detected and taken into account when using such a fiber optic sensor under real environmental conditions.
  • an additional, free reference FBG is usually used, which is arranged to protect against mechanical stresses in a protective tube, which is also referred to as a capillary. This brings the number of Einzelsenso ⁇ reindeer, the cabling effort and the space requirements increase.
  • the temperature of the reference FBG used as the calibration sensor corresponds exactly to the temperature at the location at which the strain is detected, that is, measured.
  • Object of the present invention is therefore to provide a fiber optic detection device and a method for operating such a fiber optic detection device, so that a particularly precise measurement can be realized in a particularly simple manner.
  • a first aspect of the invention relates to a fiber optic detection device, which is also referred to as a fiber optic sensor.
  • the fiber optic detection device has at least one fiber designed as a fiber, which is thus formed for guiding or guiding light from ⁇ .
  • the fiber has at least a first Faserele ⁇ ment with a first slow polarization axis and we ⁇ antes a second fiber element having a second slow axis of polarization, wherein the second fiber element in the longitudinal direction of the fiber, in particular directly adjoins the first fiber element.
  • the respective slow Po ⁇ larisationsachse is usually referred to as a slow axis or slow axis.
  • the second slow polarization axis is arranged offset in the circumferential direction of the fiber relative to the first slow polarization axis.
  • respective projections of the slow polarization axes are on a common plane rather than de ⁇ congruent or coincide, but the projections include a different of 0 degree or 180 degree angle, so that the projections in the plane oblique or perpendicular to each other.
  • the plane is perpendicular to the longitudinal direction Rich ⁇ tion or to the axial direction of the fiber.
  • the fiber optic detection device has at least one sensor tandem, which has at least one first fiber Bragg grating (first FBG) inscribed in the first fiber element and at least one second fiber Bragg grating (second FBG) inscribed in the second fiber element.
  • the sensor tandem is designed to detect at a corresponding measuring point at least one temperature prevailing at the measuring point and at least one load acting on the fiber at the measuring point.
  • the detection of at least one acting on the fiber Load means in particular that the sensor Tandem is adapted to detect at least one measurement or characteristic quantities ⁇ SSE, which characterizes at least a load acting on the fiber.
  • the load is, for example, a load acting on the fiber and thus on it, in particular a force.
  • the load is for example egg ⁇ ne stretching of the fiber, so that the sensor tandem, for example, is designed to detect an elongation of the fiber.
  • the measuring point is a measuring point or a measuring range in which the temperature and the load mentioned can be detected by means of the sensor tandem.
  • the inventive fiber optic measuring device to compensate for undesirable influences on the measurement of a ge ⁇ desired measurement or characteristic.
  • the desired measured quantity to be detected is, for example, the load, wherein the measurement of the load influences affecting temperature can be compensated.
  • it may be for example at the desired to be detected measured variable is temperature, WO, for example at pressures such forces, particularly cross ⁇ forces that may affect the detection or measurement of Tempe ⁇ temperature, can be compensated.
  • Fiber Bragg gratings or optical sensors based on FBG are known for the measurement of stress, strains and / or temperatures and, because of their advantages, are used in systems which are difficult to access. These optical see, in particular fiber optic sensors are insensitive to electro-magnetic fields and are therefore suitable for measurements in industrial power plants or medical applications in which, for example, high field strengths prohibit the use of conventional thermocouples or electrical strain gauges.
  • Another major advantage of FBG-based sensors is the possibility to integrate several measuring points in one fiber. Thus, temperature and strain measurements can be performed flexibly with little effort, low space consumption and low cabling.
  • the fiber optic sensing ⁇ means comprises a plurality of successive in the longitudinal direction of the fiber and in particular spaced apart sensor tandem and / or other corresponding fiber elements, the previous and following explanations of the first fiber elements and the first sensor tandem readily on the other, further fiber elements and sensor tandems can be transmitted and vice versa.
  • the fiber Bragg gratings of the respective sensor tandems differ from one another, in particular in their respective Bragg wavelengths, with the Bragg wavelengths of the fiber Bragg gratings of the respective sensor tether differing by at least five nanometers from one another, for example.
  • an FBG is a periodic refractive index variation in the ⁇ formed for example as a fiber optic fiber, in particular in its core, with a grating period of, for example, approximately 530 nanometers.
  • This Bre ⁇ chung index modulation acts as a dielectric mirror such that in the example as a glass fiber formed Fa ⁇ ser led light ⁇ is rich reflects the so-called Bragg wavelength in a very narrow Wellendorfnbe, while all other wavelengths the grating unaffected happen.
  • the Bragg wavelength depends only on the grating period and the effective modal refractive index. Both quantities are temperature, strain and voltage dependent.
  • a sensor assembly which measures with a simple handling, for example with an adhesive bonding of the fiber to a surface of a to be checked Bezie ⁇ hung as to be examined component, temperature and strain in at least one measuring point, in particular at different ⁇ union points of the component provides a challenge is, especially when sensor system on the advantages of Fasersen-, for example, to their small size and / or the Mög ⁇ friendliness to integrate multiple measurement points in a fiber, or by means of a fiber to be measured, ⁇ is not intended to be dispensed ver.
  • This challenge can now be mastered in a simple manner by means of the fiber optic detection device according to the invention.
  • Methods for the separation of strain and temperature influences are, for example, the use of the signals of fast and slow axis of a polarization-maintaining fiber, the use of two gratings with significantly different Bragg wavelengths, use of fibers with different doping, use of type I and type Ila grating, combination of standard SMF28 fiber and photonic crystal fibers or the use of FBG fibers with different fiber diameters.
  • these methods are not suitable for decoupling strain and temperature with bonded fibers or in applications in which lateral forces on the fiber can not be reliably excluded.
  • bonding or embedding the fiber in this ⁇ be brought transverse forces which act on the fiber, and in particular the respective FBG, birefringence can produce in the fiber.
  • an FBG-based optical sensor for measuring three-axis strain states.
  • This concept is based ⁇ example, in two FBG Bragg wavelengths around 1300 nanometers and 1550 nanometers, which at the same location in a PM fiber (polarization maintaining fiber) are enrolled.
  • PM fiber polarization maintaining fiber
  • the determination of the transverse strain should also be possible if the fiber is aligned along the principal stress directions.
  • this requires two integration systems for the evaluation, and the determination of the transverse forces is extremely critical because of the very similar sensitivities of all four measurement signals.
  • a further embodiment of the invention is of a construction partly ⁇ held on a surface of the fiber, and in particular indirectly or directly.
  • the component is to be checked or monitored or examined by means of the sensor tandem.
  • the by means of the sensor tether detectable temperature is a tempera ⁇ ture of the component, in particular its surface is. It is thus provided in this embodiment that the component to be examined or checked belongs to the detection device.
  • one of the slow polarization axes is parallel to the surface, with the other slow polarization axis perpendicular to the surface. This can be realized in a particularly simple manner a particularly precise Mes ⁇ solution.
  • the fiber is retained on the surface by means of an adhesive, which contacts the Faserele ⁇ elements.
  • the fiber is bonded by means of said adhesive to the surface and thus to the component, wherein the fiber is provided with the adhesive such that, for example, a first part of the adhesive at least in a first portion of the first fiber element and a second Part of the adhesive is arranged at least in a second portion of the second fiber element.
  • the adhesive contacts, for example, depending ⁇ ips subregions particular directly.
  • the sensor tandem or the fiber optic sensing device can thus be designed as, in particular completely, devisvidverknacher FBG sensor, the simultaneous, quantitati ⁇ ve and more precise measurements of stresses, particularly longitudinal elongations, and temperatures or temperature-ratur 64 on at least one defined measuring point, in particular to allows more defined measurement points while correcting unknown, acting on the fiber transverse forces which are so far unknown, as an origin be ⁇ relationship as a cause of transverse forces is unknown.
  • sensor fiber fiber is aligned along its existing elongation main axes and fixed for example by means of at least one SYMMETRI ⁇ rule adhesive connection, in particular by means of symmetrical adhesive connections, and in particular over the entire FBG length of the test surface.
  • a extending in the longitudinal direction of the fiber length of the Klebstof ⁇ fes at least over the whole in the longitudinal direction or in the axial direction of the fiber extending length of the sensor tandems extends.
  • strains along the fiber can be measured, and transverse forces occurring perpendicular to the fiber can be compensated.
  • the measuring ⁇ target can thereby be extended in the same way to other symmetrical structure forms, for example in a bonding in a groove, on embedding the fiber in a material etc. or transmitted.
  • an FBG strain sensor is bonded at two points at a point of interest for strain measurement.
  • the sensor fiber with the FBG is freely supported between the two points, also referred to as fixation or adhesive points.
  • Accurate strain measurements require complete strain transfer from the designated as a measuring surface finish to the fiber, in particular throughout the tempera ⁇ tur Scheme. This is not always given to a transition from the fiber to the respective, also called splice adhesive designated point, and between ei ⁇ ner primary coating of the fiber and a fiber cladding, which may lead to systematic errors in the strain measurement. This can be avoided by means of the optical fiber detection device according to the invention.
  • sensor fibers are glued directly onto the surface of the structure to be examined.
  • optical fiber may thus be designed as a bonded multi-point sensor point temperature and Packaging Machine ⁇ solutions allows at different locations on the surface and can compensate caused by the adhesive error in the measurement.
  • the Faserelemen- are te as separately produced from each other and connected with each other at a junction devices wholesomeswei ⁇ se individual components formed.
  • the slow polarization axes can be aligned in a particularly simple and cost-effective manner as well as precisely aligned with each other and thus arranged offset from one another.
  • the adhesive has a running in the longitudinal direction of the fiber length, wherein the connection point is arranged in the middle of the length.
  • a symmetrical adhesive bond is created example ⁇ example, which for example has two opposite free ends in the longitudinal direction of the fiber.
  • the length of the adhesive or of the adhesive bond is at least three centimeters.
  • a further embodiment is characterized in that the fiber elements are ver ⁇ spliced together at the connection point, so that the connection point is formed as a splice. As a result, a particularly precise measurement can be ensured.
  • the respective fiber element is formed as a polarization-maintaining fiber, which is also referred to as PM fiber. This benefits a particularly precise measurement.
  • a second aspect of the invention relates to a method for operating a fiber optic detection device, in particular in particular a fiber optic device according to the invention.
  • the fiber optic sensing device according to the second aspect of the invention comprises at least one fiber formed as a light guide from ⁇ which at least a first fiber element having a first slow polarization axis and we ⁇ antes a lengthwise extending direction of the fiber, in particular directly, to the first fiber element subsequent second fiber element having a second slow polarization ⁇ onsachse comprises.
  • the second slow polarization axis is arranged offset in the circumferential direction of the fiber to the first slow polarization axis.
  • the schwop ⁇ diagram detecting means comprises at least one sensor tandem, which comprises at least one introduced cried ⁇ surrounded in the first fiber element first fiber Bragg grating and at least one inscribed in the second fiber element second fiber Bragg grating.
  • Ver ⁇ ride on a corresponding measuring point at least one prevailing at the measuring point temperature and at least one load acting on the measuring point on the fiber, and in particular strain detected.
  • Advantages and advantageous Ausgestal ⁇ tions of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention and vice versa. Further advantages, features and details of the invention ⁇ be apparent from the following description of preferred embodiments and with reference to the drawing.
  • the drawing shows in: 1 shows a detail of a schematic and perspektivi ⁇ cal side view of a first embodiment of a fiber optic detection device according to the invention
  • Fig. 2 shows a detail of a schematic explosion
  • FIG 3 shows a detail of a schematic Perspektivan ⁇ view of a second embodiment of the fiber optic detection device.
  • Fig. 1 shows a detail in a schematic and perspective side view of a fiber optic detection ⁇ device 10 according to a first embodiment.
  • the fiber optic sensing device comprises at least a recess formed as a light guide fiber 12, which is thus adapted to Füh ⁇ ren or passing light.
  • the Fa ⁇ ser 12 comprises here a first fiber element 14 having a first slow polarization axis 16 and a first fast polarization axis 18 which is orthogonal to the first polarization axis slow sixteenth
  • the fiber 12 comprises at least a second fiber element 20 having a second slow polarization axis 22 and a second fast polarization axis 24 which is orthogonal Bezie ⁇ hung perpendicularly to the second slow polarization axis 22nd
  • the respective fiber element 14 or 20 per se is formed as a light-conducting fiber and in particular as a polarization-maintaining fiber, which is also referred to as PM fiber. It is in the respective
  • Fiber element 14 or 20 two in the longitudinal direction of the fiber 12 and the respective fiber element 14 and 20 extending stress elements 26th and 28 and 30 and 32, respectively.
  • the respective stress elements 26 and 28 or 30 and 32 of jewei ⁇ time the fiber element 14 and 20 are arranged along the respective slow polarization axis 16 and 22 and thus in the radial direction of the respective fiber element 14 and 20 and hence the fiber 12 products next to each other.
  • the respective Faserele ⁇ ment 14 or 20 is formed per se as a so-called panda fiber or panda type.
  • the fibrous elements 14 and 20 are respective individual ⁇ components, which are joined together in completely prepared state of the fa ⁇ seroptician detecting means 10 at a junction V.
  • the fiber elements 14 and 20 as separately from each other Herge ⁇ presented and formed at the junction V interconnected components.
  • the fiber elements 14 and 20 are connected to one another by splicing, with the result that the fiber elements 14 and 20 are spliced to one another and thereby connected to one another.
  • the connection point V is formed as a splice.
  • Fig. 1 and 2 is particularly easy to see that the long ⁇ polarization axes 16 and 22 are rotated in the circumferential direction of the fiber 12 to each other or offset from each other.
  • the aforementioned longitudinal direction of the fiber 12 is illustrated in FIGS. 1 and 2 by a double arrow 34.
  • the fiber elements 14 and 20 are arranged coaxially to each other and in their respective circumferential direction such twisted or offset to ⁇ each other that the slow polarization axes 16 and 22 in the circumferential direction of the fiber 12 offset by an angle or twisted to each other, in a Range of including 89 degrees to and including 91 degrees and is in particular 90 degrees.
  • the slow polarization axes 16 and 22 extend in a common, perpendicular to the longitudinal direction or to the axial direction of the fiber 12 extending plane obliquely or preferably perpendicular to each other and include the said angle.
  • the fiber optic sensing means at least one in Fig. 1 and 2 particularly schematically Darge ⁇ notified sensor Tandem 36, comprising at least one inscribed in the first fiber element 14 first fiber Bragg grating 38 (first FBG) and at least one in the second Fa ⁇ serelement 20 inscribed second fiber Bragg grating 40 (second FBG) comprises.
  • first FBG first fiber Bragg grating 38
  • second FBG second fiber Bragg grating 40
  • the fiber Bragg gratings 38 and 40 preferably differ in their respective
  • the Un ⁇ difference between the Bragg wavelengths of the fiber Bragg gratings 38 and 40 is at least five (5) nanometers.
  • the sensor Tandem 36 is adapted recognizable on a, for example, Fig. 3, korrespondie ⁇ in power measuring point M is at least one at the measuring point M Messrs sighted temperature and at least one of the Measuring point M on the fiber 12, in particular in the fiber 12, acting Be ⁇ load, in particular an elongation such as a longitudinal extension of the fiber 12 to detect.
  • Fig. 3 shows a second embodiment of the fiber optic
  • the fiber optic sensing device 10 comprises at least one member 42, which investigated by means of the sensor 36 under ⁇ tandem, can be monitored or checked.
  • the temperature which can be detected by means of the sensor tether 36 is a temperature of the component 42, in particular a surface 44 of the component 42.
  • the fiber 12 is aligned relative to the component 42, in particular to the surface 44, and aligned with the component 42, in particular.
  • the first slow polarization axis 16 of the fiber element 14 extends at least substantially ⁇ parallel to the surface 44, while the second slow polarization axis 22 of the fiber element 20 at least substantially perpendicular to the surface 44 ver ⁇ runs.
  • three spatial directions x, y and z are illustrated, which extend in pairs perpendicular to each other. In this case, the spatial directions x and z span an xz plane in which the surface 44 extends.
  • the first slow polarization axis 16 extends at least Wesentli ⁇ surfaces parallel to the spatial direction x, thus parallel to, or in the xz plane.
  • the second slow polarization axis 22 extends at least substantially parallel to the spatial direction y and thus perpendicular to the xz plane. It can thus be seen from FIG. 3 that the fiber elements 14 and 20 are spliced to one another at at least substantially 90 degrees and thus form a fiber tandem with the sensor tandem 36.
  • the fiber elements 14 and 20 are glued with their main optical axes ⁇ parallel and perpendicular to the surface 44.
  • the respective slow polarization axis is 16 or 22, a respective optical principal axis of each fiber element 14 or 20, wherein the slow polarization axis 16 of the fiber element 14 at least substantially parallel to the surface 44 and the slow polarization axis 22 of the fiber element 20 at least in the We ⁇ sentlichen perpendicular to the surface 44 extends.
  • the fiber 12 is held by means of an adhesive 46 on the surface 44.
  • the fiber 12 is bonded by means of the adhesive 46 to the surface 44 and thereby held on the surface 44, wherein the fiber 12, in particular an outer peripheral side surface 48 of the fiber 12, the surface 44, in particular directly touches.
  • the adhesive 46 touches the fiber 12, particularly theRICSsei ⁇ term lateral surface 48, in particular directly, at least in a length portion of the fiber 12. Further, the adhesive 46 contacts the surface 44, in particular directly. In particular, the adhesive 46 touches both at least a first portion of the fiber element 14 and at least a second portion of the fiber. rich of the fiber element 20, in particular each directly.
  • Fer ⁇ ner it is preferably provided that an arrangement of the adhesive 46 in the radial direction of the fiber 12 between this and the surface 44 is omitted, so that the adhesive 46 is not disposed between the fiber 12 and the surface 44.
  • stresses or transverse forces can be induced in the fiber 12. These voltages induced by the adhesive 46 are also used as adhesive-induced voltages.
  • the adhesive-induced stresses amplify the initial birefringence in the fiber element 14, whose slow polarization axis 16, also referred to as a slow axis, runs parallel to the surface 44.
  • the birefringence is by approximately the same amount by which the birefringence is amplified in the fiber element 14 is reduced.
  • the influence of the adhesive 46 also known as adhesive to the Doppelbre ⁇ chung or the peak distance of the respective FBG can be compensated by simple averaging. Temperature and strain are determined from this corrected peak distance and a Bragg wavelength.
  • the peak spacing is obtained, for example, by subtracting the wavelength of the fast polarization axis 18 or 24, which is also referred to as fast axis, from the wavelength of the respectively associated slow polarization axis 16 or 22, also referred to as slow axis.
  • the not yet connected to one another each formed as a Panda fiber and fiber elements which are provided 14 and 20, whereupon at ⁇ game as the fiber element 14 with their slow of polarization ⁇ tion axis 16 at 90 degrees to the slow polarization ⁇ axis 22 of the fiber element 20 spliced.
  • a primary coating as described ⁇ designated primary coating of the respective fiber members 14 and 20 in the region of a few centimeters away the designed as a splice junction V around.
  • splice parameters are chosen so that a mechanical stability of the splice is guaranteed up to elongation values of 2000 Microstrain and deformation of the stress elements 26 and 28 or 30 and 32 is avoided as possible.
  • the respective FBGs of the respective sensor tether 36 are arranged or written as close as possible to the splice point.
  • the production of the respective FBG takes place for example by exposure of the respective fiber element 14 or 20, in particular its core, in the sinusoidal ⁇ shaped interference pattern of a UV laser behind a suitable phase mask.
  • the orientation of the sensor tandems 36 or the Po ⁇ larisa tion axes 16 and 22, 12 to each other in the circumferential direction of the fiber for example, by evaluation of the inten- sticians Kunststoffes a laterally-rayed PM fiber (fiber element 14 and 20, respectively) in the light microscope.
  • the fiber elements 14 and 20 are for this purpose laterally clamped in rotatable holders, so that an azimuthal alignment can be ensured.
  • the described alignment or described offset arrangement of the Pola ⁇ risationsachsen 16 and 22 relative to each other can be done with an accuracy of + - 1 degree.
  • thermosetting epoxy adhesive for example, is used as the adhesive 46.
  • the adhesive 46 is applied, for example, in an initially liquid form to at least a portion of the fiber 12 and at least a portion of the surface 44.
  • the adhesive 46 as beispiels- extending in the longitudinal direction of the fiber 12 length which carries ⁇ centimeter be at least three (3).
  • the adhesive 46 is first applied to the upper surface ⁇ 44th Subsequently, for example, the fiber 12 is placed centrally in the adhesive 46, so that in ⁇ example, the joint V with respect to the longitudinal extension direction of the fiber 12 in the middle of said
  • Length of the adhesive 46 is arranged.
  • the fiber elements 14 and 20 be ⁇ drawing, the fiber 12 for example by means of a suitable adhesive such as by means of a tempe ⁇ raturstabilen UV-cure adhesive on at least two spaced- spaced points next to the actual adhesive 46 and thus next to an actual splice to which the fiber 12 is glued by means of the adhesive 46 with the surface 44, prefixed.
  • the adhesive 46 is cured, for example, at 150 degrees Celsius for one hour in a climatic chamber, so that a firm connection of the Fa ⁇ ser 12 can be ensured to the surface 44.
  • the measuring principle of the fiber optic detection device 10 is based on the assumption that in the immediate vicinity of the
  • the respective FBG provides, for example, at least one Sen ⁇ sorsignal ready characterizing the detected pressures and the detected temperature.
  • the adhesive effect can be corrected in the peak intervals from both Sensorsigna ⁇ len of FBG.
  • the Bragg wavelength of the respective fast axis of the respective FBG for example, in the fiber element 14 and the voltage-corrected peak distance can be used.
  • surface-bonded FBGs can be used by means of the fiber optic detection device 10.
  • the adhesive bond protects since ⁇ with the fiber 12 so that de-coated fibers, that is fibers can be used without cladding. While UN account for collateral by temperature and aging-related Variegated ⁇ conclusions of the so-called fiber coatings. It is not necessary to dispense with multiplexing capability of the sensors for temperature-elongation decoupling, with high accuracy of the temperature measurement.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Length Measuring Devices By Optical Means (AREA)
  • Optical Transform (AREA)

Abstract

La présente invention concerne un dispositif de détection à fibre optique (10) comprenant : au moins une fibre (12) qui se présente sous la forme d'un guide d'ondes optiques et qui présente au moins un premier élément de fibre (14) ayant un premier axe de polarisation lent (16) et au moins un second élément de fibre (20), qui se raccorde au premier élément de fibre (14) dans la direction longitudinale (34) de la fibre (12), et qui présente un second axe de polarisation lent (22) qui est décalé par rapport au premier axe de polarisation lent (16) dans la direction circonférentielle de la fibre (12) ; et au moins un tandem de détection (36) qui présente au moins un premier réseau de Bragg sur fibre optique (38) inscrit dans le premier élément de fibre (14) et au moins un second réseau de Bragg sur fibre optique (40) inscrit dans le second élément de fibre (20), et qui est conçu pour déterminer au niveau d'un emplacement de mesure (M) correspondant, une température régnant à l'emplacement de mesure (M) et au moins une contrainte sollicitant la fibre (12) à l'emplacement de mesure (M).
PCT/EP2018/050308 2017-01-31 2018-01-08 Dispositif de détection à fibre optique et procédé pour faire fonctionner un dispositif de détection à fibre optique WO2018141501A1 (fr)

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Application Number Priority Date Filing Date Title
DE102017201523.3 2017-01-31
DE102017201523.3A DE102017201523A1 (de) 2017-01-31 2017-01-31 Faseroptische Erfassungseinrichtung sowie Verfahren zum Betreiben einer solchen faseroptischen Erfassungseinrichtung

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WO2018141501A1 true WO2018141501A1 (fr) 2018-08-09

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CN115900579A (zh) * 2023-01-06 2023-04-04 山东大学 一种自校正可拼接式光纤位移场传感系统及其校正方法
CN116046061A (zh) * 2022-12-30 2023-05-02 水利部交通运输部国家能源局南京水利科学研究院 水工程保偏光纤背向Rayleigh散射多参量智慧感测装置及方法

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EP2166314A1 (fr) * 2008-02-29 2010-03-24 Fujikura, Ltd. Dispositif de mesure d'une quantité physique par mesure de la réflexion de la gamme de fréquence optique et procédé de mesure de la température et des contraintes à l'aide dudit dispositif
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DE102008035996A1 (de) 2008-08-01 2010-02-04 Technische Universität München Faseroptischer Drehwinkelsensor
CN105051551B (zh) 2013-03-28 2018-07-17 Abb研究有限公司 具有旋制光纤和温度补偿的光纤电流传感器

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DE10352590A1 (de) * 2002-11-12 2004-05-27 Toptica Photonics Ag Verfahren zum Herstellen einer optischen Faser mit einer Auskoppelstelle für Streulicht, Verwendung einer optischen Faser und Vorrichtung zum Überwachen von in einer optischen Faser geführter Lichtleistung
EP2166314A1 (fr) * 2008-02-29 2010-03-24 Fujikura, Ltd. Dispositif de mesure d'une quantité physique par mesure de la réflexion de la gamme de fréquence optique et procédé de mesure de la température et des contraintes à l'aide dudit dispositif
US20140054451A1 (en) * 2010-12-02 2014-02-27 Ofs Fitel, Llc Dbf fiber laser bend sensor and optical heterodyne microphone
WO2015067293A1 (fr) * 2013-11-05 2015-05-14 Omnisens Sa Dispositif de détection optique distribué et méthode de mesures simultanées de température et de contrainte
US20160258743A1 (en) * 2015-03-05 2016-09-08 General Photonics Corporation Measurements of strain, stress and temperature by using 1-dimensional and 2-dimensional distributed fiber-optic sensors based on sensing by polarization maintaining fiber of distributed polarization crosstalk distribution

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116046061A (zh) * 2022-12-30 2023-05-02 水利部交通运输部国家能源局南京水利科学研究院 水工程保偏光纤背向Rayleigh散射多参量智慧感测装置及方法
CN116046061B (zh) * 2022-12-30 2023-06-30 水利部交通运输部国家能源局南京水利科学研究院 水工程保偏光纤背向Rayleigh散射多参量智慧感测装置及方法
CN115900579A (zh) * 2023-01-06 2023-04-04 山东大学 一种自校正可拼接式光纤位移场传感系统及其校正方法

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