CN107179142B - A kind of quick temperature measurement method for determining frequency changed power based on Brillouin spectrum - Google Patents
A kind of quick temperature measurement method for determining frequency changed power based on Brillouin spectrum Download PDFInfo
- Publication number
- CN107179142B CN107179142B CN201710422852.3A CN201710422852A CN107179142B CN 107179142 B CN107179142 B CN 107179142B CN 201710422852 A CN201710422852 A CN 201710422852A CN 107179142 B CN107179142 B CN 107179142B
- Authority
- CN
- China
- Prior art keywords
- frequency
- power
- brillouin spectrum
- measurement
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
- G01K11/32—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
- G01K11/32—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres
- G01K11/322—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres using Brillouin scattering
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Temperature Or Quantity Of Heat (AREA)
Abstract
The invention discloses a kind of quick temperature measurement method for determining frequency changed power based on Brillouin spectrum, the present invention passes through Brillouin spectrum specific frequency f when measurement ambient temperature variationTThe variation of power calculates analysis and obtains the temperature change along sensor fibre according to the linear relationship of the power variation and ambient temperature；The present invention is not necessarily to frequency sweeping process, need to only measure some specific frequency fTPower, time of complete measurement is 1/the tens of traditional frequency sweep method.
Description
Technical field
The present invention relates to sensory field of optic fibre, especially a kind of quick temperature measurement side that frequency changed power is determined based on Brillouin spectrum
Method.
Background technique
It is the transmitting main matchmaker of information with optical fiber with the rapid development of social economy with the increase at full speed of various information capacities
The Fibre Optical Communication Technology of matter and using the guided wave principle in optical fiber be the optical fiber sensing technology of theoretical basis the mankind in the past few decades
Life and many other fields in be more and more widely used and paid attention to, attracted the great research interest of people.
Compared with traditional electric sensor, sensitivity that distributed fiberoptic sensor not only has fibre optical sensor intrinsic
Height, electromagnetism interference, it is corrosion-resistant, durability is good, small in size, light-weight the advantages that, but also have following essential characteristic: (1)
Optical fiber integrates sensing and transmission, is both sensing unit the information of other sensing units transmission again is led to for any one section on optical fiber
Road can carry out continuous detection spatially；(2) the one-dimensional distribution being measured in the available entire fiber area of one-shot measurement
Figure, if fiber deployment reticulated, so that it may obtain measured two and three dimensions distribution situation, can obtain simultaneously measured
Spatial distribution state and the information that changes over time.Wherein, the distributed sensing fiber technology based on brillouin effect
(BEOFS) have and can measure multiple physical quantitys (such as temperature, strain and loss), spatial resolution height, distance sensing length, measurement
The advantages that precision is high has received widespread attention in recent years.Wherein again with single-ended measurement, system structure simple Brillouin light when
Domain reflectometer (BOTDR) is representative.
BOTDR measuring system, according to after optical fiber to the frequency shift amount of spontaneous brillouin scattering and sensor fibre temperature variation
There are linear relationships, measure sensor fibre temperature change by measurement brillouin frequency in-migration.Due to spontaneous brillouin scattering signal
Frequency spectrum is in Lorentz lorentz's shape, has certain spectrum width, so, BOTDR system is all made of frequency sweep method and obtains Brillouin spectrum, i.e., logical
It crosses in certain frequency range with certain frequency interval, successively obtains Brillouin spectrum, then to the Brillouin measured
Frequency spectrum carries out Lorentz curve and is fitted to obtain the Brillouin shift curve on entire sensor fibre.Then, the variation of frequency displacement is utilized
Go the temperature change on reflection sensor fibre.In Brillouin spectrum test, detection range is longer, swept frequency range is wider,
Sweep interval is smaller, and required time of measuring is longer.Such as the NJUB-1200 of Nanjing University, 10 km of sensor fibre, average time
5000 times, frequency sweep 50 times, time of measuring takes around 3 minutes.In particular, to improve measurement accuracy, it is necessary to reduce between frequency sweep
Every with increase average time, it is longer that this will lead to time of measuring.
Summary of the invention
It is a kind of fixed based on Brillouin spectrum to provide the technical problem to be solved by the present invention is to overcome the deficiencies in the prior art
The quick temperature measurement method of frequency changed power calculates analysis and obtains sense light by measuring the power of Brillouin spectrum specific frequency
Temperature distribution information along fibre, this method have subtracted frequency sweep process time-consuming in conventional method, time of measuring are reduced to the second
Grade, is saved greatly time of measuring.
The present invention uses following technical scheme to solve above-mentioned technical problem:
A kind of quick temperature measurement method that frequency changed power is determined based on Brillouin spectrum proposed according to the present invention, including following step
It is rapid:
Step 1: calibration obtains the Brillouin shift and Brillouin spectrum of each measurement point on sensor fibre, surveyed at i-th
It measures in the Brillouin spectrum of point and chooses one section of linear frequency scale, the Linear Quasi of power and frequency is carried out in the linear frequency scale
It closes, obtains the relationship of power and frequency: Pi=ki*fi+bi；Wherein, kiFor i-th of coefficient, biFor i-th of constant, fiIt is i-th
Frequency in the Brillouin spectrum of measurement point, PiFor f in the Brillouin spectrum of ith measurement pointiCorresponding power, i=1,2,3,
... N, N are the sum of measurement point；The linear frequency scale refers to frequency and power frequency range in a linear relationship；
Step 2: in the Brillouin spectrum of real-time measurement ith measurement point a certain frequency power, the frequency is in step 1
In the linear frequency scale of the Brillouin spectrum of selected ith measurement point, according to the variable quantity and sensing of the power of the frequency
The linear relationship of the temperature variation of optical fiber: Δ Pi=-ki*CT*ΔTi, calculate the temperature for obtaining sensor fibre ith measurement point
Change size, to obtain the temperature change size of all measurement points on sensor fibre；Wherein, Δ PiFor in ith measurement point
The variable quantity of the power of frequency, Δ TiFor the temperature variation of ith measurement point, CTFor known temperature coefficient.
It is advanced optimized as a kind of quick temperature measurement method for determining frequency changed power based on Brillouin spectrum of the present invention
Scheme, the variable quantity of the power of the frequency refer to the power of a certain frequency in the Brillouin spectrum of real-time measurement ith measurement point
With the power difference of the frequency in the Brillouin spectrum for the ith measurement point demarcated in step 1.
It is advanced optimized as a kind of quick temperature measurement method for determining frequency changed power based on Brillouin spectrum of the present invention
Scheme, calibration, which obtains the Brillouin shift of each measurement point on sensor fibre with Brillouin spectrum, in step 1 is passed by optical fiber
Feel what equipment obtained.
It is advanced optimized as a kind of quick temperature measurement method for determining frequency changed power based on Brillouin spectrum of the present invention
Scheme, Brillouin spectrum is in Lorentz shape in step 1.
It is advanced optimized as a kind of quick temperature measurement method for determining frequency changed power based on Brillouin spectrum of the present invention
Scheme indicates the temperature point of sensor fibre according to the temperature change size of all measurement points on the sensor fibre of step 2 acquisition
Cloth information.
It is advanced optimized as a kind of quick temperature measurement method for determining frequency changed power based on Brillouin spectrum of the present invention
Scheme, sensor fibre ambient temperature causes optical fiber Brillouin to compose integral translation, so that measurement frequency in linear frequency scale
Point fTPower occur corresponding linear variation.
The invention adopts the above technical scheme compared with prior art, has following technical effect that
(1) present invention passes through the variation of measurement Brillouin spectrum specific frequency power, according to the power variation and the external world
The linear relationship of temperature calculates analysis and obtains temperature change；
(2) other than demarcating acquisition for the first time, subsequent measurement is not necessarily to frequency sweeping process, need to only measure some specific frequency
Power, time of complete measurement is 1/the tens of traditional frequency sweep method；
(3) since time of measuring is greatly shortened, present invention may apply to measure the low-frequency vibration of sensor fibre.
Detailed description of the invention
Fig. 1 is Lorentz curve.
Fig. 2 is the schematic diagram of the method for the present invention.
Fig. 3 is system construction drawing of the invention.
Specific embodiment
Technical solution of the present invention is described in further detail with reference to the accompanying drawing:
Spontaneous brillouin scattering spectrum is that Lorentz composes shape, as shown in Figure 1.It can be seen that the curved portion in box has in figure
There is good linear relationship, this is the basis of the method for the present invention.
The method of the present invention principle is as shown in Figure 2.Plot1 is that ambient temperature is T1When sensor fibre spontaneous brillouin scattering
Spectrum, centre frequency f0, plot2 be ambient temperature be T2 when sensor fibre spontaneous brillouin scattering spectrum, centre frequency f0'；
At this point, temperature variation are as follows:
Δ T=T2-T1
Corresponding Brillouin spectrum centre frequency shift variable quantity are as follows:
Δ f=f0'-f0=CT*ΔT
Curve 2 can regard that curve 1 obtains after translation Δ f to the right as.As described above, there is good line to curve 1
The part of sexual intercourse carries out linear fit, obtained linear representation are as follows:
Y=k*x+b
Corresponding linear fit partial expression in curve 2 are as follows:
Y=k* (x- Δ f)+b
May therefore specify that the specific frequency point f of the range of linearityT, corresponding power is P in curve 11, in curve 2
In corresponding power be P2, have:
P1=k*fT+b
P2=k* (fT-Δf)+b
Then:
Δ P=P2-P1=-k* Δ f=-k*CT*ΔT
It can see that the power variation of some Frequency point in the range of linearity and the temperature of sensor fibre from formula above
Linear relationship is presented in variable quantity.Wherein linear coefficient-k*CTFor it is known that some frequency in the measurement range of linearity therefore can be passed through
The power variation of point obtains the temperature variation in the optical fiber external world.
The present invention is based on the above method, by measure the power variation of the linear part range frequency of Brillouin spectrum come
To the temperature distribution information of sensor fibre.
The specific operation process that the present invention uses is as follows:
(1) hardware connects: sensor fibre is correctly accessed hardware platform；
(2) hardware connecting test: opening software kit, clicks " test connection " key, whether test hardware platform
It is ready, including detection hardware platform microwave source, EDFA, the connection of capture card three and the support of USB interface；
(3) parameter setting: after hardware successful connection, can operation button lift a ban automatically.Parameter is first carried out before data acquisition to set
It sets, including capture card parameter and microwave source parameter, the quality of parameter setting will have a direct impact on measurement result；
(4) calibration acquisition: measurement answers advanced rower to measure surely for the first time, clicks main interface " calibration acquisition ", calibration is adopted
Collection needs a period of time, can check acquisition progress from acquisition progress bar；
(5) measure: after nominal data has acquired, so far preparation is had completely prepared for, and can be measured.System
System provides single measurement and continuous measurement interface, and single measurement only carries out one-shot measurement, is continuously measured as continuous uninterrupted measurement,
Click on " single acquisition " key and " continuous acquisition " key；
(6) measurement terminates, and logs off.
The work flow diagram of whole system determines frequency power based on Brillouin spectrum as shown in figure 3, this example provides one kind
The quick temperature measurement system of variation, including sensor fibre, data acquisition module, parameter management module, data disaply moudle, control mould
Block and temperature alarming module.The system can acquire the power of assigned frequency point in the Brillouin spectrum along sensor fibre in real time,
Specific frequency point f is handled by analysisTThe relation data of changed power and sensor fibre environment temperature variation is realized to sense light
Temperature distribution information carries out quick positioning measurement along fibre, can carry out Realtime Alerts beyond preset threshold temperature.
What has been described above is only a preferred embodiment of the present invention, it should be noted that for those of ordinary skill in the art
For, without departing from the concept of the premise of the invention, various modifications and improvements can be made, these belong to the present invention
Protection scope.
Claims (5)
1. a kind of quick temperature measurement method for determining frequency changed power based on Brillouin spectrum, which comprises the following steps:
Step 1: calibration obtains the Brillouin shift and Brillouin spectrum of each measurement point on sensor fibre, in ith measurement point
Brillouin spectrum in choose one section of linear frequency scale, in the linear frequency scale carry out power and frequency linear fit,
Obtain the relationship of power and frequency: Pi=ki*fi+bi；Wherein, kiFor i-th of coefficient, biFor i-th of constant, fiIt is surveyed for i-th
Measure the frequency in the Brillouin spectrum of point, PiFor f in the Brillouin spectrum of ith measurement pointiCorresponding power, i=1,2,3 ... N, N
For the sum of measurement point；The linear frequency scale refers to frequency and power frequency range in a linear relationship；
Step 2: in the Brillouin spectrum of real-time measurement ith measurement point a certain frequency power, the frequency is selected in step 1
In the linear frequency scale of the Brillouin spectrum of the ith measurement point taken, according to the variable quantity and sensor fibre of the power of the frequency
Temperature variation linear relationship: Δ Pi=-ki*CT*ΔTi, calculate the temperature change for obtaining sensor fibre ith measurement point
Size, to obtain the temperature change size of all measurement points on sensor fibre；Wherein, Δ PiFor frequency in ith measurement point
Power variable quantity, Δ TiFor the temperature variation of ith measurement point, CTFor known temperature coefficient；
The temperature change size of all measurement points is according to Δ P on the sensor fibrei=-ki*CT*ΔTiSuccessively calculate i-th=
1,2,3 ... the temperature change size of N number of measurement point, the temperature change of each point collectively form the temperature change point of all measurement points
Cloth；
The variable quantity of the power of the frequency refer in the Brillouin spectrum of real-time measurement ith measurement point the power of a certain frequency with
The power difference of the frequency in the Brillouin spectrum for the ith measurement point demarcated in step 1.
2. a kind of quick temperature measurement method for being determined frequency changed power based on Brillouin spectrum according to claim 1, feature are existed
In it is to pass through Fibre Optical Sensor that calibration, which obtains the Brillouin shift of each measurement point and Brillouin spectrum on sensor fibre, in step 1
What equipment obtained.
3. a kind of quick temperature measurement method for being determined frequency changed power based on Brillouin spectrum according to claim 1, feature are existed
In Brillouin spectrum is in Lorentz shape in step 1.
4. a kind of quick temperature measurement method for being determined frequency changed power based on Brillouin spectrum according to claim 1, feature are existed
In the temperature change size of all measurement points indicates the Temperature Distribution of sensor fibre on the sensor fibre obtained according to step 2
Information.
5. a kind of quick temperature measurement method for being determined frequency changed power based on Brillouin spectrum according to claim 1, feature are existed
In sensor fibre ambient temperature causes optical fiber Brillouin to compose integral translation, so that measurement frequency point in linear frequency scale
fTPower occur corresponding linear variation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710422852.3A CN107179142B (en) | 2017-06-07 | 2017-06-07 | A kind of quick temperature measurement method for determining frequency changed power based on Brillouin spectrum |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710422852.3A CN107179142B (en) | 2017-06-07 | 2017-06-07 | A kind of quick temperature measurement method for determining frequency changed power based on Brillouin spectrum |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107179142A CN107179142A (en) | 2017-09-19 |
| CN107179142B true CN107179142B (en) | 2019-05-24 |
Family
ID=59835256
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710422852.3A Active CN107179142B (en) | 2017-06-07 | 2017-06-07 | A kind of quick temperature measurement method for determining frequency changed power based on Brillouin spectrum |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107179142B (en) |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB9315231D0 (en) * | 1993-07-22 | 1993-09-08 | York Ltd | Optical time domain reflextometry |
| CN100494911C (en) * | 2007-10-15 | 2009-06-03 | 北京航空航天大学 | Detecting method suitable for optical fiber distributed temperature and stress sensing device |
| CN101476948B (en) * | 2008-12-19 | 2010-06-30 | 南京大学 | Long-distance optical fiber sensing method based on Hadamard matrix self-correlated characteristic |
| CN101762290A (en) * | 2010-02-03 | 2010-06-30 | 电子科技大学 | Distributed Raman amplification-based Brillouin optical time domain analysis system |
| WO2013185810A1 (en) * | 2012-06-13 | 2013-12-19 | Omnisens Sa | A sensing system and method for distributed brillouin sensing |
| CN103033285A (en) * | 2012-12-21 | 2013-04-10 | 华北电力大学（保定） | Simultaneous measurement method of temperature and strain of laid photoelectric composite cable |
| US10031043B2 (en) * | 2013-12-02 | 2018-07-24 | Omnisens Sa | Method and apparatus for detecting a structural fault in a structure using a brillouin gain spectrum obtained at a point along a sensing optical fiber |
| US9885619B2 (en) * | 2014-01-02 | 2018-02-06 | Ramot At Tel-Aviv University Ltd. | Pump-power-independent double slope-assisted distributed and fast brillouin fiber-optic sensor |
| CN103968864B (en) * | 2014-04-23 | 2016-04-06 | 南京大学 | For the maximal phase seemingly Match Analysis of the frequency displacement of Measurement accuracy Brillouin spectrum |
-
2017
- 2017-06-07 CN CN201710422852.3A patent/CN107179142B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN107179142A (en) | 2017-09-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102052930B (en) | Fiber bragg grating distributed strain sensor and strain monitoring method thereof | |
| CN110686626B (en) | OPGW (optical fiber composite overhead ground wire) icing monitoring system and method based on phase-sensitive optical time domain reflection system | |
| US8428902B2 (en) | System and method for measuring fiber temperatures using OTDR measurements | |
| CN103591971B (en) | A kind of localization method of fiber grating | |
| CN111442788B (en) | Health monitoring method and system for overhead transmission line | |
| CN111323060B (en) | Optical detection system based on Brillouin scattering | |
| CN104568019A (en) | Multimode fiber-based method and multimode fiber-based system for simultaneously measuring temperature and strain | |
| CN103968864B (en) | For the maximal phase seemingly Match Analysis of the frequency displacement of Measurement accuracy Brillouin spectrum | |
| CN103033285A (en) | Simultaneous measurement method of temperature and strain of laid photoelectric composite cable | |
| CN106643842A (en) | Distributed sensor and sensing method | |
| CN102445285B (en) | Peak searching method of Brillouin optical time domain reflectometer (BOTDR) system | |
| CN204555926U (en) | A kind of distributive fiber optic strain measuring system based on the long adjustable F-P white light interference demodulating equipment in chamber | |
| CN107179142B (en) | A kind of quick temperature measurement method for determining frequency changed power based on Brillouin spectrum | |
| CN211452794U (en) | Device for positioning fault point of optical cable | |
| CN210533574U (en) | Device for testing surface temperature uniformity of bottom plate of wind tunnel test section | |
| CN106646670A (en) | Distributed micrometeorological monitoring method for transmission lines | |
| CN114674454B (en) | Concrete temperature monitoring system and method based on fiber bragg grating array sensing | |
| CN114034327B (en) | Brillouin scattering signal measurement method based on sparse sampling and artificial neural network | |
| CN204854809U (en) | Water pump monitoring devices | |
| CN106123796B (en) | A kind of fiber grating measuring device that precision and stability can be improved | |
| CN107631814A (en) | Light senses light channel structure, frequency displacement change detecting method and sensing device from relevant | |
| CN109141487A (en) | A kind of distributed fiberoptic sensor | |
| CN210513373U (en) | Vehicle weighing monitoring system based on linear type interference type optical fiber sensing | |
| CN105527001B (en) | Vehicle dynamic measurement sensing device and method based on fiber annular cavity attenuation and vibration technique | |
| CN206420564U (en) | A kind of intensity of illumination measuring system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |