CN101620003A - Fiber grating Fabry-Perot cavity vibration sensor and vibration measurement system thereof - Google Patents
Fiber grating Fabry-Perot cavity vibration sensor and vibration measurement system thereof Download PDFInfo
- Publication number
- CN101620003A CN101620003A CN200910023528A CN200910023528A CN101620003A CN 101620003 A CN101620003 A CN 101620003A CN 200910023528 A CN200910023528 A CN 200910023528A CN 200910023528 A CN200910023528 A CN 200910023528A CN 101620003 A CN101620003 A CN 101620003A
- Authority
- CN
- China
- Prior art keywords
- fiber
- optical
- vibration
- vibration sensor
- girder
- 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.)
- Pending
Links
Images
Landscapes
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
The invention relates to a fiber grating Fabry-Perot (F-P) cavity vibration sensor and a vibration measurement system thereof. The invention is technically characterized in that a fiber grating F-P cavity is stuck to the middle position of a cantilever beam; and one end of the cantilever beam is fixed on a support, and the other end thereof is connected with a mass block. The measurement system using the vibration sensor is characterized in that one side of the intensity-demodulation type fiber grating F-P cavity vibration sensor is extended into a fiber index-matching liquid, and the other side thereof is connected with the port of a terminal B of a fiber circulator via single-mode fiber; a terminal A of the fiber circulator is connected with a narrow-band light source; and a terminal C of the fiber circulator is connected with a photoelectric detector. By adopting the fiber grating F-P cavity, optical signals can resonate in the F-P cavity to form interference peaks, so that the accuracy of the detection can be greatly increased; meanwhile, by adopting the intensity-demodulation manner of narrow-band light source irradiation, the detection frequency of the vibration sensor can be increased from a few hertz to hundreds of hertz; and the invention can measure the frequency and amplitude of weak vibration signals at the same time, and improve the measurement accuracy.
Description
Technical field
The present invention relates to a kind of optical fiber optical grating Fabry-Perot cavity vibration sensor and Vibration-Measuring System thereof, be used for the frequency and the amplitude of Measuring Object weak vibration, belong to technical field of optical fiber sensing.
Background technology
The measurement of weak vibration all is widely used in fields such as MEMS (micro electro mechanical system), civil construction, highway bridge, power equipment, pacemaker control, seismic event, the detections of accurate vibration isolation platform.For example, the real-time monitoring of the weak vibration that produces by to equipment work the time judges whether its duty is unusual, in time fixes a breakdown, and avoids the generation of accident.
Conventional vibration sensor generally adopts electrical quantities to carry out sensing, and this class sensor functional reliability in outdoor environment is poor, is subjected to electromagnetic interference (EMI) easily, and signal can not carry out long-distance transmissions.Optical fibre vibration sensor has good solenoid isolation than traditional vibration transducer, and structure is small and exquisite, and light weight has favorable durability and chemical resistance of concrete ability simultaneously, thereby is subjected to common concern.
Optical fiber optical grating Fabry-Perot (F-P) chamber is to carry at hydrogen to use ultraviolet photoetching in the optical fiber, and two places separated by a distance write two space phase gratings (claiming Bragg grating again) that parameter is identical in fibre core.Like this, when the light signal incident of certain specific wavelength (being called as bragg wavelength) that satisfies the optical grating reflection condition, can be coupled into reflection and transmitted light wave, thereby make light wave between two grid, form vibration.The ultimate principle of utilizing the fiber Bragg grating F-P chamber to carry out the physical quantity perception is: the variation of physical quantitys such as temperature, strain can cause the long variation in the chamber in the F-P chamber that is constituted between two gratings, thereby causes moving of F-P chamber output light signal interference peaks.When throwing light on,, just can obtain the information of corresponding temperature and strain by detection of reflected light intensity variations with narrow-band light source.
In the optical fibre vibration sensor, in the majority with the form of Fiber Bragg Grating FBG (FBG) vibration transducer, the vibration transducer of the type is because of advantage such as simple in structure, with low cost, easy to make receives an acclaim.But it is limited that the disadvantage of single FBG vibration transducer is exactly a measuring accuracy, for the detectivity deficiency of weak vibration signal.Simultaneously, most FBG vibration transducers all are that wavelength is carried out demodulation, and for most wavelength demodulation device, its the highest response frequency only is several hertz, can't measure the vibration information of upper frequency, and the price of Wavelength demodulation equipment is generally relatively more expensive, thereby has limited its development.
Summary of the invention
The technical matters that solves
For fear of the deficiencies in the prior art part, the present invention proposes a kind of optical fiber optical grating Fabry-Perot cavity vibration sensor and Vibration-Measuring System thereof, optical signal amplitude and the frequency of frequency and tested weak vibration signal and the corresponding relation of amplitude that can return by the fiber Bragg grating F-P cavity reflection reach the purpose to vibration signal perception and measurement.
Technical scheme
Technological thought of the present invention is: utilize the fiber Bragg grating F-P chamber that sticks on the cantilever beam structure, by surveying the cyclical variation information of the fiber Bragg grating F-P cavity reflection light intensity that causes owing to vibration, the weak vibration information of coming object sensing.During measurement, the sensor stand of cantilever mounted beam is placed on the testee, when testee generation microvibration, semi-girder is done forced vibration with testee, and an end of semi-girder quality of connection piece because of being subjected to the effect of inertial force, causes the flexible strain of semi-girder surface generating period, the feasible chamber long hair that is pasted on the fiber Bragg grating F-P chamber on semi-girder surface is given birth to cyclical variation, thereby causes F-P cavity reflection light signal interference peaks generation corresponding mobile.Like this, when adopting narrow-band light source, can the generating period variation through the intensity of the light signal of fiber Bragg grating F-P cavity reflection, utilize the frequency and the amplitude of Electro-Optical Sensor Set and demodulating system measuring light change in signal strength, can determine the frequency and the amplitude of testee vibration, and the light signal strength amplitude and the object under test Oscillation Amplitude that detect are linear, and optical signal frequency equates with the object vibration frequency is strict.
A kind of optical fiber optical grating Fabry-Perot cavity vibration sensor, technical characterictic are to comprise fiber Bragg grating F-P chamber 1, semi-girder 2, mass 3 and support 4; Fiber Bragg grating F-P chamber 1 sticks on semi-girder 2 medium positions; Semi-girder 2 one ends are fixed on the support 4, other end quality of connection piece 3; Described semi-girder 2 is an equi intensity cantilever.
A kind of measuring system of utilizing above-mentioned vibration transducer measuring vibrations signal is characterized in that comprising intensity demodulation type optical fiber optical grating Fabry-Perot cavity vibration sensor, single-mode fiber 8, optical fiber circulator 5, optical fibre refractivity matching fluid 7, narrow-band light source 9 and Electro-Optical Sensor Set 6; One side of intensity demodulation type optical fiber optical grating Fabry-Perot cavity vibration sensor stretches in the optical fibre refractivity matching fluid 7, opposite side links to each other with the B port of optical fiber circulator 5 by single-mode fiber 8, the A end of circulator 5 connects narrow-band light source 9, and the C end of circulator 5 connects Electro-Optical Sensor Set 6.
Described narrow-band light source 9 adopts distributed feed-back formula (claiming Distributed Feedback Laser again) semiconductor laser, its-three dB bandwidth＜10MHz.
Beneficial effect
Optical fiber optical grating Fabry-Perot cavity vibration sensor of the present invention and Vibration-Measuring System thereof, owing to adopted the fiber Bragg grating F-P chamber, and light signal resonates in the F-P chamber and form interference peaks, can make the precision of surveying improve greatly.Adopt the intensity demodulation mode of narrow-band light source irradiation simultaneously, the frequency that can make the sensor detection is from extremely hundreds of hertz of several hertz of continuation.Can realize measurement simultaneously to weak vibration signal frequency and amplitude, improved measuring accuracy, increased investigative range, and, can change the sensitivity and the range of this vibration transducer by the parameter in adjustment fiber Bragg grating F-P chamber and the paste position in F-P chamber to vibration frequency.This sensor adopts light signal strength demodulation simultaneously, the precision height, response is fast, and is with low cost, and simple in structure, easy for installation, solenoid isolation is good etc.
Description of drawings
Fig. 1 is the side view of the fiber Bragg grating F-P cavity vibration sensor structure of the present invention's proposition;
Fig. 2 is the vertical view of the fiber Bragg grating F-P cavity vibration sensor structure of the present invention's proposition;
Fig. 3 is the measuring system schematic diagram that utilizes fiber Bragg grating F-P cavity vibration sensor measuring vibrations signal of the present invention;
Wherein: 1-fiber Bragg grating F-P chamber, 2-semi-girder, 3-mass, 4-support, 5-optical fiber circulator (or fiber coupler), 6-Electro-Optical Sensor Set, 7-optical fibre refractivity matching fluid, 8-single-mode fiber, 9-narrow-band light source, a, location for paste, b-F-P chamber.
Embodiment
Now in conjunction with the embodiments, accompanying drawing is further described the present invention:
The fiber Bragg grating F-P cavity vibration sensor of the embodiment of the invention is consulted accompanying drawing 1 and accompanying drawing 2.
The two ends in fiber Bragg grating F-P chamber 1 are sticked on equi intensity cantilever 2 medium positions, and an end of semi-girder 2 is fixed on the support 4, and the other end is fixed a mass 3.Wherein the reflectivity in fiber Bragg grating F-P chamber is less than 5%.It is 60mm that semi-girder adopts length, and an end width fixing with support is 25mm, and thickness is the isosceles triangle spring steel plate of 2mm.Mass adopts the aluminium block that is of a size of 5 * 5 * 5mm.
The measuring system of the embodiment of the invention is seen accompanying drawing 3.
Optical fiber connector in the fiber Bragg grating F-P cavity vibration sensor stretches in the optical fibre refractivity matching fluid 7, and opposite side links to each other with the B end of optical fiber circulator 5 by single-mode fiber 8; Two port: A ends of optical fiber circulator 5 connect narrow-band light source 9, and the B end links to each other with Electro-Optical Sensor Set 6 by single-mode fiber 8.Narrow-band light source 9 adopts Distributed Feedback Laser, its-three dB bandwidth＜10MHz.Electro-Optical Sensor Set adopts photodiode to link to each other with computing machine with oscillograph or data collecting card.
When sensor places vibration environment, mass 3 has produced the motion with respect to support 4 under the inertial force effect, promptly produced opplied moment at an end that fixes with semi-girder 2, semi-girder 2 produces deflection under above-mentioned moment loading, and then in the corresponding strain of its surface generation, make and stick on synchronous stretching or the compression of its surperficial fiber Bragg grating F-P chamber 1 generation, caused moving of fiber Bragg grating F-P chamber 1 reflected light signal interference peaks, after narrowband optical signal that light source 9 sends entered fiber Bragg grating F-P chamber 1, the light signal strength that obtains through its reflection will be subjected to the modulation of vibration signal.
If the Oscillation Amplitude of object under test is A
0, vibration frequency is ω, then the vibration displacement expression formula of object is
A(t)＝A
0sinωt
Disregard the influence of semi-girder deadweight, ignore the phase delay of forced vibration simultaneously, then the forced vibration displacement equation of mass 3 is
In the formula, τ=ω/ω
0Be testee vibration frequency ω and semi-girder resonant frequency ω
0Ratio, B
0=A
0/ K is the testee amplitude A
0With the ratio of semi-girder equivalent stiffness COEFFICIENT K, B
0/ 1-τ
2The amplitude of expression forced vibration.
By mechanical knowledge, the pass of the displacement x of the flexible strain stress on semi-girder 2 surfaces and mass 3 anomaly weighing apparatus position is
Wherein, N is the thickness of semi-girder, and L is the length of semi-girder.
When the variation of the long h in chamber be limited in less than 1/10th wavelength more among a small circle the time, the reflected light signal intensity I in fiber Bragg grating F-P chamber 1
RCan be reduced to following linear approximate relationship with the relation of chamber long variable quantity ε h:
Wherein, I
0Incident optical signal intensity during for 9 irradiations of employing narrow-band light source, R
gBe the reflectivity of fiber grating, n
EffBe the effective refractive index of optical fiber, α=4 π n
EffR
g/ λ is the linear parameter in fiber Bragg grating F-P chamber 1.
Then during measuring vibrations, Electro-Optical Sensor Set 6 received light intensity expressions are
Can obtain light intensity I
RWith the testee amplitude A
0, and the relation of light intensity change frequency ω ' and vibration frequency ω
ω’＝ω
Wherein, β=(α I
0Nh)/[K (1-τ) L
2] be a linear scale factor, I
RmaxThe largest light intensity signal that obtains for Electro-Optical Sensor Set.
The demarcation by experiment of one linear scale factor β obtains: before actual measurement, measuring system of the present invention is loaded a known vibration signal, and the amplitude of known vibration signal and Electro-Optical Sensor Set 6 received light intensity maximal values are divided by obtains linear scale factor β value.
By the Oscillation Amplitude A that can obtain object under test with co-relation
0The largest light intensity signal I that obtains with Electro-Optical Sensor Set 6
RmaxLinear, vibration frequency ω is consistent with the optical signal frequency ω ' that detects.
To sum up, in the actual measurement process, this sensor is placed or is fixed on the object under test, and the light signal that narrow-band light source (as Distributed Feedback Laser) is sent enters in the fiber Bragg grating F-P chamber by optical fiber circulator, arrives in the Electro-Optical Sensor Set through optical fiber circulator through the light signal of its reflection again.When there was not vibration in object under test, the light signal strength of sensor output was stable; When there is weak vibration in object under test, the light signal that Electro-Optical Sensor Set obtains will be subjected to the modulation of object vibration frequency and amplitude, the light intensity signal that detects the most at last is converted into electric signal, send in computing machine or the dsp processor, after linear scale factor β conversion, directly demonstrate the frequency and the amplitude information of testee weak vibration.
Claims (3)
1. an optical fiber optical grating Fabry-Perot cavity vibration sensor is characterized in that comprising fiber Bragg grating F-P chamber (1), semi-girder (2), mass (3) and support (4); Fiber Bragg grating F-P chamber (1) sticks on semi-girder (2) medium position; Semi-girder (2) one ends are fixed on the support (4), other end quality of connection piece (3); Described semi-girder (2) is an equi intensity cantilever.
2. a measuring system of utilizing the described vibration transducer measuring vibrations of claim 1 signal is characterized in that comprising intensity demodulation type optical fiber optical grating Fabry-Perot cavity vibration sensor, single-mode fiber (8), optical fiber circulator (5), optical fibre refractivity matching fluid (7), narrow-band light source (9) and Electro-Optical Sensor Set (6); One side of intensity demodulation type optical fiber optical grating Fabry-Perot cavity vibration sensor stretches in the optical fibre refractivity matching fluid (7), opposite side links to each other with the B port of optical fiber circulator (5) by single-mode fiber (8), the A end of circulator (5) connects narrow-band light source (9), and the C end of circulator (5) connects Electro-Optical Sensor Set (6).
3. the measuring system of measuring vibrations signal according to claim 2 is characterized in that: described narrow-band light source (9) adopts distributed feedback type semiconductor laser, its-three dB bandwidth＜10MHz.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910023528A CN101620003A (en) | 2009-08-07 | 2009-08-07 | Fiber grating Fabry-Perot cavity vibration sensor and vibration measurement system thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910023528A CN101620003A (en) | 2009-08-07 | 2009-08-07 | Fiber grating Fabry-Perot cavity vibration sensor and vibration measurement system thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101620003A true CN101620003A (en) | 2010-01-06 |
Family
ID=41513354
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200910023528A Pending CN101620003A (en) | 2009-08-07 | 2009-08-07 | Fiber grating Fabry-Perot cavity vibration sensor and vibration measurement system thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101620003A (en) |
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101900576A (en) * | 2010-07-08 | 2010-12-01 | 北京交通大学 | Method for manufacturing fiber bragg grating Fabry-Perot sensor |
| CN101750399B (en) * | 2010-01-08 | 2012-01-04 | 上海交通大学 | Refractive index measuring device |
| CN102607691A (en) * | 2012-03-23 | 2012-07-25 | 哈尔滨理工大学 | Intrinsic fiber Fabry-Perot vibration sensor for liquid media and using method thereof |
| CN102879357A (en) * | 2012-10-11 | 2013-01-16 | 西安石油大学 | Micro-nano fiber bragg grating refractive index sensor and manufacturing method thereof |
| CN102914356A (en) * | 2012-09-19 | 2013-02-06 | 武汉理工光科股份有限公司 | Light intensity demodulating system and method based on non-uniform spectrum |
| CN103217632A (en) * | 2013-02-27 | 2013-07-24 | 上海大学 | Point contact type optical fiber ultrasonic sensor |
| CN103364070A (en) * | 2013-07-20 | 2013-10-23 | 北京航空航天大学 | Fiber bragg grating vibration sensing system based on volume phase grating demodulation |
| CN104613988A (en) * | 2015-02-06 | 2015-05-13 | 哈尔滨工业大学 | FBG optical fiber based central wavelength stabilizing device and method |
| CN105158508A (en) * | 2015-10-09 | 2015-12-16 | 华北电力大学（保定） | Novel fiber vibration acceleration sensor with simple structure |
| CN106872015A (en) * | 2017-02-22 | 2017-06-20 | 重庆邮电大学 | A kind of optical-fiber type vibrating sensing measuring system |
| CN107942215A (en) * | 2017-12-20 | 2018-04-20 | 哈尔滨理工大学 | The extrinsic fabry perot fiber optic sensor of external attaching type and test platform |
| CN109186821A (en) * | 2018-07-25 | 2019-01-11 | 孝感锐创机械科技有限公司 | A kind of contactless micro-vibration and device for pressure measurement |
| CN109520610A (en) * | 2018-12-27 | 2019-03-26 | 国网宁夏电力有限公司电力科学研究院 | A kind of adjustable optical fiber raster vibration sensor of frequency |
| CN110045149A (en) * | 2019-01-31 | 2019-07-23 | 哈工大机器人义乌人工智能研究院 | A kind of optical fibre grating acceleration sensor and acceleration detection method |
| CN110160629A (en) * | 2019-06-26 | 2019-08-23 | 电子科技大学 | A kind of scaling method and device of sensing system of fiber strain |
| CN111076803A (en) * | 2019-11-28 | 2020-04-28 | 上海电力大学 | High-sensitivity two-dimensional vibration monitoring sensing head |
| WO2021143742A1 (en) * | 2020-01-13 | 2021-07-22 | 奥动新能源汽车科技有限公司 | Swing sensor |
| CN114894095A (en) * | 2022-03-04 | 2022-08-12 | 中国科学院合肥物质科学研究院 | Cantilever beam displacement measuring device and measuring method |
-
2009
- 2009-08-07 CN CN200910023528A patent/CN101620003A/en active Pending
Cited By (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101750399B (en) * | 2010-01-08 | 2012-01-04 | 上海交通大学 | Refractive index measuring device |
| CN101900576B (en) * | 2010-07-08 | 2011-07-20 | 北京交通大学 | Method for manufacturing fiber bragg grating Fabry-Perot sensor |
| CN101900576A (en) * | 2010-07-08 | 2010-12-01 | 北京交通大学 | Method for manufacturing fiber bragg grating Fabry-Perot sensor |
| CN102607691A (en) * | 2012-03-23 | 2012-07-25 | 哈尔滨理工大学 | Intrinsic fiber Fabry-Perot vibration sensor for liquid media and using method thereof |
| CN102607691B (en) * | 2012-03-23 | 2014-04-16 | 哈尔滨理工大学 | Using method of intrinsic fiber Fabry-Perot vibration sensor for liquid media |
| CN102914356A (en) * | 2012-09-19 | 2013-02-06 | 武汉理工光科股份有限公司 | Light intensity demodulating system and method based on non-uniform spectrum |
| CN102879357A (en) * | 2012-10-11 | 2013-01-16 | 西安石油大学 | Micro-nano fiber bragg grating refractive index sensor and manufacturing method thereof |
| CN103217632A (en) * | 2013-02-27 | 2013-07-24 | 上海大学 | Point contact type optical fiber ultrasonic sensor |
| CN103364070B (en) * | 2013-07-20 | 2015-07-15 | 北京航空航天大学 | Fiber bragg grating vibration sensing system based on volume phase grating demodulation |
| CN103364070A (en) * | 2013-07-20 | 2013-10-23 | 北京航空航天大学 | Fiber bragg grating vibration sensing system based on volume phase grating demodulation |
| CN104613988B (en) * | 2015-02-06 | 2016-09-07 | 哈尔滨工业大学 | A kind of sufficient center wavelength accuracy apparatus and method based on FBG optical fiber |
| CN104613988A (en) * | 2015-02-06 | 2015-05-13 | 哈尔滨工业大学 | FBG optical fiber based central wavelength stabilizing device and method |
| CN105158508B (en) * | 2015-10-09 | 2018-07-27 | 华北电力大学（保定） | A kind of novel optical fiber vibration acceleration sensor simple in structure |
| CN105158508A (en) * | 2015-10-09 | 2015-12-16 | 华北电力大学（保定） | Novel fiber vibration acceleration sensor with simple structure |
| CN106872015B (en) * | 2017-02-22 | 2019-04-09 | 重庆邮电大学 | A kind of optical-fiber type vibrating sensing measuring system |
| CN106872015A (en) * | 2017-02-22 | 2017-06-20 | 重庆邮电大学 | A kind of optical-fiber type vibrating sensing measuring system |
| CN107942215A (en) * | 2017-12-20 | 2018-04-20 | 哈尔滨理工大学 | The extrinsic fabry perot fiber optic sensor of external attaching type and test platform |
| CN109186821A (en) * | 2018-07-25 | 2019-01-11 | 孝感锐创机械科技有限公司 | A kind of contactless micro-vibration and device for pressure measurement |
| CN109520610A (en) * | 2018-12-27 | 2019-03-26 | 国网宁夏电力有限公司电力科学研究院 | A kind of adjustable optical fiber raster vibration sensor of frequency |
| CN110045149A (en) * | 2019-01-31 | 2019-07-23 | 哈工大机器人义乌人工智能研究院 | A kind of optical fibre grating acceleration sensor and acceleration detection method |
| CN110160629A (en) * | 2019-06-26 | 2019-08-23 | 电子科技大学 | A kind of scaling method and device of sensing system of fiber strain |
| CN111076803A (en) * | 2019-11-28 | 2020-04-28 | 上海电力大学 | High-sensitivity two-dimensional vibration monitoring sensing head |
| WO2021143742A1 (en) * | 2020-01-13 | 2021-07-22 | 奥动新能源汽车科技有限公司 | Swing sensor |
| CN114894095A (en) * | 2022-03-04 | 2022-08-12 | 中国科学院合肥物质科学研究院 | Cantilever beam displacement measuring device and measuring method |
| CN114894095B (en) * | 2022-03-04 | 2023-08-29 | 中国科学院合肥物质科学研究院 | Cantilever beam displacement measuring device and measuring method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101620003A (en) | Fiber grating Fabry-Perot cavity vibration sensor and vibration measurement system thereof | |
| CN201155991Y (en) | Optical fibre grating acceleration sensor | |
| CN201449289U (en) | Intensity demodulation-type vibration sensor based on fiber grating Fabry-Perot cavity | |
| CN101982740B (en) | Optical fiber grating vibration sensor comprising double cantilever beams with equal strength | |
| CN102636250B (en) | Optical fiber vector vibration sensor | |
| CN101701859B (en) | Fiber grating monitoring system for power transmission line | |
| Jin et al. | A fibre-optic grating sensor for the study of flow-induced vibrations | |
| CN203432538U (en) | Fiber grating crack sensor | |
| CN101261281A (en) | Optical fibre acceleration sensor based on ultra- short cavity optical fibre laser | |
| CN101598748B (en) | Thermo-compensation current sensing head as well as alternate current measurement method and system | |
| CN102778242A (en) | Demodulation method for Bragg grating | |
| CN104390694A (en) | Cladded optical fiber grating vibration sensor | |
| CN102156016B (en) | Fast-response passive silica optical fiber pressure sensor measurement system for shock wave test | |
| CN203177817U (en) | Temperature compensating fiber-containing angle sensor for measuring level angle of tower | |
| CN104360254A (en) | Ultrasonic detection system and method for fiber bragg grating for local discharge detection on electrical equipment in power grid | |
| CN204359896U (en) | For the Fiber Bragg Grating ultrasonic wave detecting system that electrical network local discharge of electrical equipment detects | |
| CN100516787C (en) | Girder type dynamic weighing system | |
| De Vries et al. | Performance of embedded short-gage-length optical fiber sensors in a fatigue-loaded reinforced concrete specimen | |
| CN114137450A (en) | Magnetofluid-filled fiber optic magnetic field and displacement sensor | |
| Guozhen et al. | A novel fiber Bragg grating acceleration sensor for measurement of vibration | |
| CN201237522Y (en) | Optical grating weighting transducer | |
| CN107504988B (en) | Fiber bragg grating sensing experiment system based on composite beam structure | |
| CN103245304A (en) | Angle sensor provided with temperature compensation optical fibers and used for measuring level angle of pole tower | |
| CN2935132Y (en) | Biosensor based on long-period fiber grating | |
| CN202582504U (en) | Reflective grating strainometer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Open date: 20100106 |