CN1333244C - Optical raster temp senser and its mfg. method - Google Patents
Optical raster temp senser and its mfg. method Download PDFInfo
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- CN1333244C CN1333244C CNB2004100187654A CN200410018765A CN1333244C CN 1333244 C CN1333244 C CN 1333244C CN B2004100187654 A CNB2004100187654 A CN B2004100187654A CN 200410018765 A CN200410018765 A CN 200410018765A CN 1333244 C CN1333244 C CN 1333244C
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- fiber
- optical fiber
- grating
- cavity
- fiber grating
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Abstract
The present invention discloses an optical fiber raster temperature sensor and a manufacturing method thereof, particularly an optical fiber raster temperature sensor insensitive to external stress or strain and a manufacturing method thereof, which belongs to the optical fiber sensing field. The sensor comprises a metal cavity, an optical fiber raster in the cavity or an optical fiber raster pasted on a metal bar or a metal pipe, an optical fiber elicitation end and heat-conduction powder or ointment, wherein the heat-conduction powder or ointment is filled in the space between the cavity and the optical fiber raster. In the manufacturing method, the optical fiber raster is inserted into the metal cavity; both ends of the optical fiber raster are fixed at both ends of the cavity; then, the heat-conduction fluid powder or ointment is filled into the space between the cavity and the optical fiber raster or the space between the metal cavity and the metal rod or the metal pipe. The present invention has the advantages that the problem that the existing optical fiber raster temperature sensor generates interactive sensitivity to external strain is fundamentally solved, and the present invention has high temperature test precision.
Description
Technical field
The present invention relates to a kind of fiber-optical grating temperature sensor and manufacture method thereof, particularly a kind of stress to external world or strain insensitive optical fiber optical grating temperature sensor and manufacture method thereof belong to sensory field of optic fibre.
Background technology
As a kind of full optical fibre device, Bragg grating (being called for short FBG) is used for fields such as optical fiber communication and Fibre Optical Sensor more and more widely.The FBG sensor has anti-electromagnetic interference (EMI), and is corrosion-resistant, long service life, and volume is little, can the optical wavelength multiplexing mode realize significant advantages such as multiple spot distribution measuring, thereby bring into play huge effect in the occasion that can't use traditional sensors.In recent years, along with the continuous development of FBG sensing technology, its range of application is also enlarging day by day, and beginning replaces traditional sensor-based system in some field.
The FBG sensing is by determining to be reflected by fiber grating or the bragg wavelength of transmission is realized absolute measurement to the measurand value.Although it is multiple that the measurable physical quantity of FBG sensor has, the FBG directly amount of induction mainly is two kinds of temperature and strains.We know, bragg wavelengths
BEffective refractive index n by grating periods lambda and reverse coupled mould
EffDecision, i.e. λ
B=2 Λ n
EffWhen FBG is subjected to time spent of doing of axial stress, not only the grating periods lambda can change because of geometry deformation, and effective refractive index n
EffAlso can change because of the elasto-optical effect of optical fiber.The bragg wavelengths that causes by axial stress or strain variation Δ ε
BVariation can be expressed as Δ λ
B=λ
B(1-P
e) Δ ε, wherein P
eElasto-optical coefficient for optical fiber.Thermal expansion and thermo-optic effect make Λ and n
EffBe again the function of temperature simultaneously.The bragg wavelengths that causes by temperature variation Δ T
BVariation can be expressed as Δ λ
B=λ
B(the Δ T of α+ξ), wherein α is the thermal expansivity of optical fiber, ξ is the thermo-optical coeffecient of optical fiber.When strain and temperature variation exist simultaneously, λ
BVariation then be Δ λ
B=λ
B(1-P
e) Δ ε+λ
B(the Δ T=K of α+ξ)
εΔ+K
TΔ T, wherein K
ε=λ
B(1-P
e), K
T=λ
B(α+ξ) is respectively the sensitivity coefficient of fiber grating to strain and temperature.By following formula as can be known, bragg wavelengths
BMutual responsive to strain and temperature, promptly when strain and temperature variation exist simultaneously, bragg wavelengths only from recording
BIn can't offer an explanation strain and temperature contribution.
Because the fiber grating of un-encapsulated very easily damages, so the fiber grating that uses as sensor all will pass through the encapsulation of certain form, to reach the purpose of protection fiber grating.Fiber-optic grating sensor after the encapsulation will have the to external world strain different with fiber grating itself and the sensitivity coefficient of temperature.For describing the influence of encapsulation, can introduce strain transfer coefficient x
εWith temperature transfer coefficient x
T, this moment bragg wavelengths
BBe changed to Δ λ
B=x
εK
εΔ ε+x
TK
TΔ T.This shows, make FBG sensor strain and temperature variation enhanced sensitivity or subtract quick effect to external world by using different materials and adopting different encapsulating structures to reach.
Existing fiber-optical grating temperature sensor adopts bonding agent that fiber grating is fixed in the metal tube, the characteristics of this packaged type are simple in structure, because the thermal expansivity of metal material is higher than the thermal expansivity of fiber optic materials, metal tube has played the sensitization to temperature variation simultaneously.But, because grating and metal bond together, so in the time of in sensor and testee are fixed together or are embedded in as structures such as concrete, the strain that testee produced will be delivered to fiber grating by the bonding agent of metal and curing, make it strain to external world and produce mutual sensitivity, thereby temperature survey is impacted.
Summary of the invention
Purpose of the present invention just provides a kind of fiber-optical grating temperature sensor, and this temperature sensor can be got rid of extraneous stress or the strain influence to temperature measurement accuracy effectively, thereby has the high characteristics of probe temperature precision.
For overcoming the deficiencies in the prior art, the present invention is realized by following technical proposals.Comprise metallic cavity 3, fiber grating 4 in the cavity, perhaps be pasted on the fiber grating 4 of metal bar or metal tube 6, and the fiber-optical grating temperature sensor of optical fiber exit 1 formation, it is characterized in that, the two ends of fiber grating 4 are fixed on the two ends 2 of metallic cavity, and the length that is fixed in the optical fiber in the cavity is greater than the distance between two point of fixity 2; Space between metallic cavity 3 and fiber grating 4, or, fill the powder or the lotion 5 of heat conduction flowability in metallic cavity 3 and the metal bar of stickup fiber grating 4 or the space between the metal tube 6.
The powder of above-mentioned heat conduction flowability is a silver powder, a kind of in copper powder and the dag.
The lotion of above-mentioned heat conduction flowability is a heat conductive silica gel.
Above-mentioned fiber-optical grating temperature sensor manufacture method is characterized in that comprising the following steps:
1. with fiber grating 4, perhaps stick on the metal bar or metal tube 6 in fiber gratings 4 insert in the metallic cavity 3, with the hardening agent that comprises epoxy resin with the two ends of fiber grating 4 with the two ends 2 of adhesive securement a metallic cavity;
2. the space between fiber grating 4 and metallic cavity 3, perhaps the powder or the lotion 5 of heat conduction flowability filled in the space between the metal bar that is pasted with fiber grating 4 or metal tube 6 and metallic cavity 3.
Packing material with mobile and thermal conductive resin has played the supporting role to the fiber grating of pressured state simultaneously, and buffer action has been played in the vibration of environment to external world.Fiber-optical grating temperature sensor provided by the present invention fundamentally solved the existing fiber grating temperature sensor to external world strain produce mutual tender subject.
Description of drawings
Fig. 1 does not add metal bar or the metal tube structural representation of the present invention fixedly the time for fiber grating.Fig. 2 is fixed on the metal bar for fiber grating or the structural representation of the present invention in the metal tube time.
Among Fig. 1,1 is the optical fiber exit, and 2 is the fixed connection point of optical fiber exit and metallic cavity, and 3 is metallic cavity, and 4 is fiber grating; 5 is the mobile filling material of thermal conductivity, and 6 is the metal bar or the metal tube of fixed fiber grating.
Embodiment
Below in conjunction with accompanying drawing the specific embodiment of the present invention is elaborated.As shown in Figure 1, remove and use mask or interferometric method that fiber grating 4 is write on the fiber coating layer a section of the optical fiber 1 with photosensitivity.For annealing or other burin-in process to fiber grating 4 serviceable life that makes fiber grating 4 have good temperature stability and length.The metal such as the stainless steel that will have thermal conductive resin and mechanical property are processed into the shape that there is cavity inside, the optical fiber exit of fiber grating 4 is bonded in securely the two ends of metallic cavity 3 with bonding agent, the part that should make when bonding in cavity and comprise fiber grating 4 is not subjected to axial tensile force, or produce the light axial compression, make in cavity but the optical fiber that do not comprise fiber grating 4 produces slight bending.Be firmly bonded behind the two ends of metallic cavity 3 at fiber grating 4, fill the Heat Conduction Material 5 with flowability between metal cavitg and fiber grating, described Heat Conduction Material can be powder or the colloid with good heat conductive effect.Described powder can be for by good conductor metal (as silver, copper etc.), the particulate powders that nonmetal (as graphite) or oxide are made.Described have good heat conductive effect colloid and can be commercially available heat conductive silica gel.For obtaining big coefficient of heat conductivity, particulate powders and the organic reagent that metal or oxide can be made are mixed into glue or paste.As can be made into the heat-conducting cream of coefficient of heat conductivity greater than 7.5W/mK with the fine silver powder (content of silver is 62% to 65%) that uses 99.8%.Heat-conducting cream is in flow state under air-proof condition.
Be subjected to the time spent of doing of extraneous axial force when metallic cavity 3, metallic cavity 3 will produce corresponding strain, make it to stretch or compression, but because the optical fiber at fiber grating 4 two ends in metallic cavity 3 is in the slight bending state, so no matter metallic cavity 3 is tension or pressurized, all there is not Stress Transfer vertically to arrive fiber grating 4.Have the temperature variation that the existence of mobile heat conduction packing material experiences metallic cavity 3 and be delivered to fiber grating 4, make fiber grating 4 can respond the fiber-optical grating temperature sensor ambient temperature fast and change.In addition, have mobile heat conduction packing material and also played simultaneously being in the supporting role of slight bending state optical fiber, and buffering and absorption are played in the vibration in the issuable external world.
As previously mentioned, to the fiber-optical grating temperature sensor after the encapsulation, bragg wavelengths
BBe changed to Δ λ
B=x
εK
εΔ ε+x
TK
TΔ T.The fiber-optical grating temperature sensor that adopts method provided by the present invention to make, the strain transfer coefficient x in the above-mentioned equation
εTo equal zero, and temperature transfer coefficient x
TTo equal 1.
Be to guarantee the shape that fiber grating 4 is maintained fixed in metallic cavity 3, can be earlier that fiber grating 4 and a tubulose or clava 6 is bonding, as shown in Figure 2.Under kind of situation, the strain transfer coefficient x in the above-mentioned equation
εTo equal zero, and temperature transfer coefficient x
TTo be not equal to 1.When tubulose or clava 6 thermal expansivity are higher than the thermal expansivity of fiber optic materials, transfer coefficient x
TTo equal 1 greatly, tubulose or clava 6 will play the temperature sensitizing effect to fiber grating 4 this moment.
Those skilled in the art are clear, and thought of the present invention can adopt the alternate manner beyond the above-named embodiment to realize.The present invention simultaneously also is applicable to fiber Bragg grating strain sensor, and the passive temperature compensation of fiber grating when being used for optic communication device.
Claims (4)
1. fiber-optical grating temperature sensor, comprise metallic cavity (3), fiber grating (4) in the cavity, perhaps be pasted on the fiber grating (4) of metal bar or metal tube (6), and optical fiber exit (1), it is characterized in that the fiber lengths of the fiber grating (4) that is provided with is greater than distance between two fixed connection points (2) between two fixed connection points (2) of optical fiber exit and metallic cavity; Space between metallic cavity (3) and fiber grating (4), or, fill the powder or the lotion (5) of heat conduction flowability in metallic cavity (3) and the metal bar of stickup fiber grating (4) or the space between the metal tube (6).
2. by the described fiber-optical grating temperature sensor of claim 1, it is characterized in that the powder of heat conduction flowability is a silver powder, a kind of in copper powder and the dag.
3. by the described fiber-optical grating temperature sensor of claim 1, it is characterized in that the lotion of heat conduction flowability is a heat conductive silica gel.
4. press the described fiber-optical grating temperature sensor manufacture method of claim 1 for one kind, it is characterized in that comprising the following steps: with fiber grating (4), perhaps stick on the metal bar or metal tube (6) in fiber grating (4) insert in the metallic cavity (3), the two ends of fiber grating (4) are fixed on the two ends (2) of a metallic cavity with bonding agent; Space between fiber grating (4) and metallic cavity (3), perhaps the powder or the lotion (5) of heat conduction flowability filled in the space between the metal bar that is pasted with fiber grating (4) or metal tube (6) and metallic cavity (3).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100187654A CN1333244C (en) | 2004-03-19 | 2004-03-19 | Optical raster temp senser and its mfg. method |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100187654A CN1333244C (en) | 2004-03-19 | 2004-03-19 | Optical raster temp senser and its mfg. method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1563916A CN1563916A (en) | 2005-01-12 |
| CN1333244C true CN1333244C (en) | 2007-08-22 |
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ID=34479515
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2004100187654A Expired - Fee Related CN1333244C (en) | 2004-03-19 | 2004-03-19 | Optical raster temp senser and its mfg. method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109209501A (en) * | 2018-10-18 | 2019-01-15 | 北京科技大学 | A kind of Underground filler Temperature Distribution formula monitoring system |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102564641A (en) * | 2012-01-04 | 2012-07-11 | 中国计量学院 | Suspended-type high temperature sensing device based on LPFG (Long Period Fiber Grating) |
| CN103267590A (en) * | 2013-04-23 | 2013-08-28 | 天津市东方龙光电测控技术有限公司 | Locating temperature measuring device combining fiber gratings and distributed optical fibers |
| CN103344193B (en) * | 2013-07-08 | 2016-01-13 | 大连理工大学 | Optical fiber concrete freeze thawing expansion strain monitoring sensor |
| CN104567710B (en) * | 2015-01-23 | 2017-11-28 | 浙江大学城市学院 | Immersed tube tunnel deformation monitoring and force analysis system and its application method and purposes |
| CN108593137A (en) * | 2018-06-01 | 2018-09-28 | 南京梦联桥传感科技有限公司 | A kind of high-precision sensitizing type fiber-optical grating temperature sensor |
| CN113125041B (en) * | 2021-04-15 | 2022-01-11 | 武汉理工大学 | Dual-sensitivity high-sensitivity FBG temperature sensor and manufacturing method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6462329B1 (en) * | 1999-11-23 | 2002-10-08 | Cidra Corporation | Fiber bragg grating reference sensor for precise reference temperature measurement |
| CN1384341A (en) * | 2002-06-14 | 2002-12-11 | 清华大学 | Optical-fiber grating sensor detecting pressure temperature simultaneously |
| JP2003254838A (en) * | 2002-03-04 | 2003-09-10 | Furukawa Electric Co Ltd:The | Optical temperature sensor |
| JP2003344183A (en) * | 2002-05-27 | 2003-12-03 | Ntt Advanced Technology Corp | Fiber grating temperature sensor and temperature measurement system |
| US6659640B2 (en) * | 2001-04-26 | 2003-12-09 | The United States Of America As Represented By The Secretary Of The Navy | Fiber optic temperature measurement system and method |
-
2004
- 2004-03-19 CN CNB2004100187654A patent/CN1333244C/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6462329B1 (en) * | 1999-11-23 | 2002-10-08 | Cidra Corporation | Fiber bragg grating reference sensor for precise reference temperature measurement |
| US6659640B2 (en) * | 2001-04-26 | 2003-12-09 | The United States Of America As Represented By The Secretary Of The Navy | Fiber optic temperature measurement system and method |
| JP2003254838A (en) * | 2002-03-04 | 2003-09-10 | Furukawa Electric Co Ltd:The | Optical temperature sensor |
| JP2003344183A (en) * | 2002-05-27 | 2003-12-03 | Ntt Advanced Technology Corp | Fiber grating temperature sensor and temperature measurement system |
| CN1384341A (en) * | 2002-06-14 | 2002-12-11 | 清华大学 | Optical-fiber grating sensor detecting pressure temperature simultaneously |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109209501A (en) * | 2018-10-18 | 2019-01-15 | 北京科技大学 | A kind of Underground filler Temperature Distribution formula monitoring system |
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| Publication number | Publication date |
|---|---|
| CN1563916A (en) | 2005-01-12 |
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