CN2760526Y - Distributed optical fibre raster temperature detecting system - Google Patents
Distributed optical fibre raster temperature detecting system Download PDFInfo
- Publication number
- CN2760526Y CN2760526Y CN200420098662.9U CN200420098662U CN2760526Y CN 2760526 Y CN2760526 Y CN 2760526Y CN 200420098662 U CN200420098662 U CN 200420098662U CN 2760526 Y CN2760526 Y CN 2760526Y
- Authority
- CN
- China
- Prior art keywords
- optical fibre
- fiber grating
- optical fiber
- port
- optical
- 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.)
- Expired - Fee Related
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 68
- 230000003287 optical effect Effects 0.000 claims abstract description 26
- 238000001514 detection method Methods 0.000 claims abstract description 18
- 238000012545 processing Methods 0.000 claims abstract description 16
- 238000010183 spectrum analysis Methods 0.000 claims abstract description 10
- 239000000835 fiber Substances 0.000 claims description 56
- 238000006243 chemical reaction Methods 0.000 claims description 6
- 230000003321 amplification Effects 0.000 claims description 5
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 5
- 238000005070 sampling Methods 0.000 claims description 5
- 238000004891 communication Methods 0.000 claims description 4
- 239000004973 liquid crystal related substance Substances 0.000 claims description 4
- 239000011295 pitch Substances 0.000 claims description 4
- 238000005259 measurement Methods 0.000 abstract description 5
- 238000009529 body temperature measurement Methods 0.000 abstract description 2
- 238000000034 method Methods 0.000 description 12
- 230000007797 corrosion Effects 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 238000010292 electrical insulation Methods 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000008054 signal transmission Effects 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000005672 electromagnetic field Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012806 monitoring device Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Images
Landscapes
- Measuring Temperature Or Quantity Of Heat (AREA)
Abstract
The utility model relates to a distributed optical fibre raster temperature detection system, which belongs to the technical field of measurement. The utility model comprises a laser source, an optical fibre coupler, an outer wire optical fibre, optical fibre raster sensors, a tunable optical fibre filter and an optical detector. The utility model is characterized in that the utility model is also provided with a spectrum analysis unit and a control and data processing unit, wherein the laser source is optically connected with one shunted port of the optical fibre coupler and the other shunted port of the optical fibre coupler is optically connected with the inner port of the optical detector through the tunable optical fibre filter. The road combination port of the optical fibre coupler is connected in series with at least two optical fibre raster sensors with different central wavelengths through the outer wire optical fibre, and the laser source, the tunable optical fibre filter and the optical detector are electrically connected with the spectrum analysis unit and the control and data processing unit through a bus. Due to the adoption of the optical fibre raster sensors with different raster parameters, the utility model reaches the purposes of both temperature measurement and addressing, and can be extensively used in the field of the detection of the operation statuses of various high-voltage electric power equipment.
Description
Technical Field
The utility model belongs to the field of measuring, especially, relate to an utilize the temperature-detecting system who measures high voltage electricity equipment joint department temperature variation of change of the wavelength of detecting beam or light pulse.
Background
In the high-voltage main loop of a power system transformer, a power distribution station and a power supply device, at the joint where each transformer, a current transformer, a voltage transformer, a disconnecting switch, a circuit breaker or other high-voltage switches are connected with a power line or a high-voltage cable, due to the swing of the power line or the cable or the long-term power frequency vibration of power equipment, the looseness of a connecting bolt is often caused, the contact resistance of the connecting part is increased, the temperature at the joint is greatly changed under the influence of factors such as the oxidation degree of the metal surface of the contact part, the intensity of passing current, the pressure of a contact surface and the like, so that the actual temperature change at the joint is an important operation parameter of the transformer and power distribution equipment, and in order to ensure the safe operation of the power system, the operation temperature at the joint must be periodically detected, preferably, continuously.
Since the joints are all operated under high voltage, the actual operating temperature is usually measured indirectly, such as by early temperature change test piece, wax drop or infrared temperature detection. In recent years, various new detection methods or devices have been developed, such as wireless transmitting and receiving devices adopted in "power equipment junction temperature online monitor" of chinese patent CN2599554Y, or signal conversion and transmission by photoelectric isolation disclosed in "power high-voltage contact optical fiber online monitoring device" of chinese patent CN2599547Y, which aims to transmit the measured temperature signal by a method of indirect electrical connection, so as to solve the problem of high-voltage insulation in the signal transmission process.
The method can continuously perform on-line temperature detection, so that the temperature rise change trend at the joint can be mastered in time, the actual operation condition of the equipment can be accurately judged, hidden dangers are found in advance, the treatment is advanced, the large loss is avoided, and the method has important significance for ensuring the safe operation of the power system.
However, the above methods or devices have the disadvantages that the signals are easily interfered, only one point of temperature change can be detected, and the methods or devices are not explosion-proof in the transmission process of the signals, and the one-time acquisition cost or the use cost of the user is high in practical implementation.
The Chinese patent application publication No. CN 1363828A of the patent publication No. CN 1363828 on 8/14/2002 discloses an all-same fiber grating temperature monitoring and alarming system, which comprises a broadband light source, a Y-shaped optical splitter, an all-same fiber grating, an adjustable filter, an optical detector, and corresponding optical fibers, leads, electronic circuits and audible and visual alarming devices, wherein the broadband light source 1 is connected with one splitting port of the Y-shaped optical splitter 2 through an optical fiber 7, and the combining port of the Y-shaped optical splitter 2 is connected with a plurality of all-same fiber gratings 3 in series through the optical fiber 7; the other branch port of the Y-shaped optical splitter 2 is connected with the input port of the adjustable filter 4 through an optical fiber 7; the filtering output port of the adjustable filter 4 is connected with the optical detector 5 through an optical fiber 7, and the electrical signal output of the optical detector 5 is connected to the acousto-optic alarm device 6 through a special circuit through a lead 8; in the application document, the identical fiber grating means "a plurality of fiber gratings having the same grating constant are manufactured in the same material and standard of the optical fiber". The physical size of the optical fiber grating changes due to the temperature change, so that the wavelength of the reflection spectrum of the optical fiber grating changes, and the change condition of the temperature of the detected point is reflected. The device not only realizes the on-line continuous temperature detection of a plurality of detection points, but also solves the high-voltage insulation problem in the signal transmission process, and also avoids the anti-interference problem in the wireless transmitting and receiving processes.
However, in the technical scheme, a plurality of identical fiber gratings with the same grating constant are used as the sensor, so that the defect that which detected point generates the operation overtemperature cannot be distinguished from a plurality of fiber gratings (corresponding to a plurality of detected points) connected in series on one optical fiber exists.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the technical problem that an electrical insulation performance and good reliability are provided, anti-interference, corrosion-resistant, explosion-proof ability are strong, but direct contact arrives the surface of wanting to survey electrified object and direct detection goes out its temperature value, can detect the operating temperature of a plurality of power equipment cable joint departments simultaneously, can also distinguish specifically which is detected a distributed fiber grating temperature detection system who takes place unusual temperature rise.
The technical scheme of the utility model is that: the utility model provides a distributed fiber grating temperature detecting system, including broadband laser light source, tunable fiber filter, fiber coupler, external line optic fibre, fiber grating sensor, light detector module, characterized by: the device is also provided with a spectrum analysis unit and a control and data processing unit; wherein the broadband laser light source is optically connected to one of the branching ports of at least one fiber coupler; the other shunt port of the optical fiber coupler is optically connected with the input port of the optical detector module through the tunable optical fiber filter; the combining port of the optical fiber coupler is connected in series with at least two optical fiber grating sensors with different central wavelengths through an external optical fiber; the broadband laser light source, the tunable optical fiber filter and the optical detector module are electrically connected with the spectral analysis unit and the control and data processing unit through a bus.
The fiber grating sensor is a fiber grating sensor with different grating pitches.
The control and data processing unit is also electrically connected with the display unit and/or the communication unit.
The broadband laser light source is a broadband laser light source with the light source wavelength covering the whole C wave band; the broadband laser light source has a 3dB wavelength range of 40 nm.
The display unit is a liquid crystal display circuit; the optical detector module is a PIN type or APD type photodiode circuit; the control and data processing unit at least comprises a zero-crossing detection circuit, an amplification circuit, an analog/digital conversion circuit, a sampling circuit and a microprocessor circuit.
Compared with the prior art, the utility model has the advantages that:
1. the single-path optical fiber is connected with a plurality of grating sensors with different central wavelengths in series, so that the number of measurement points is large, the measurement range is large, and the temperatures of different measurement points can be identified;
2. because the grating sensor reflects the change of temperature through the shift of the central wavelength of the reflection spectrum, the whole detection system is not influenced by factors such as light source power, optical fiber bending and the like, and has good reliability and strong anti-interference capability.
3. The fiber grating sensor is used for detecting and transmitting a temperature detection signal of a joint of high-voltage power equipment, can be directly contacted with the surface of a charged object to be detected and continuously and online detect the temperature value of the charged object, has the advantages of high insulating property, electromagnetic interference resistance, corrosion resistance, explosion resistance and the like, and is particularly suitable for being used in the severe environments such as inflammable, explosive and strong electromagnetic fields.
Drawings
Fig. 1 is a block diagram of the optical path and circuit structure of the present invention;
FIG. 2 is an electrical block diagram of the control and data processing unit of the present invention;
fig. 3 is a block diagram of the optical path and circuit configuration of the embodiment.
In the figure, 1 is a broadband laser light source, 2 is a tunable optical fiber filter, 3-1, 3-2 and 3-3 are optical fiber couplers, 4 is a light detector module, 5 is an external optical fiber, 6 is a fiber grating sensor, 7 is a spectrum analysis unit, 8 is a control and data processing unit, 9 is a display unit and/or a communication unit, and 10 is a bus.
Detailed Description
The present invention will be further explained with reference to the drawings and examples.
In fig. 1, a broadband laser light source 1 is optically connected to one branching port a of an optical fiber coupler 3; the other branch port b of the optical fiber coupler is optically connected with the input port of the optical detector module 4 through the tunable optical fiber filter 2, and the combining port c of the optical fiber coupler is connected in series with at least two optical fiber grating sensors 6 with different central wavelengths through the external optical fiber 5; the broadband laser light source, the tunable optical fiber filter and the optical detector module are electrically connected with the spectrum analysis unit 7 and the control and data processing unit 8 through a bus 10, and the control and data processing unit is also electrically connected with the display unit and/or the communication unit 9.
The fiber grating sensor is a fiber grating sensor with different grating pitches; the display unit is a liquid crystal display circuit; the optical detector module is a PIN type or APD type photodiode circuit
The wavelength of the broadband laser light source covers the whole C wave band (1525-1565 nm), the broadband laser light source has a 3dB wavelength range of 40nm, and more fiber bragg grating sensors (different according to the temperature range of a measured point) can be connected on a single optical fiber in series in a wide spectral range.
Tunable optical fiber filters are optical filters that use acousto-optic or electro-optic effects to change the refractive index of a medium, thereby achieving selection of optical wavelengths.
The center wavelength (also called peak wavelength) of the reflected light of the fiber grating sensor changes with the temperature, and when the temperature is increased/decreased, the peak wavelength of the fiber grating sensor is lengthened or shortened. The peak wavelength shift corresponding to the temperature change of every 1 ℃ is 10pm, and the reflectivity of the fiber grating sensor is more than 90 percent.
The central wavelength of the reflected light is different when the grating pitches of the fiber grating sensors are different in length. By correspondingly encoding the central wavelength of the reflected light of each fiber grating sensor and the address thereof, the fiber grating sensor with temperature change can be easily judged, and the high-voltage equipment with abnormal operation can be further known.
The display unit is a liquid crystal display circuit; the light detector module is a PIN type or APD type photodiode circuit.
In fig. 2, the control and data processing unit at least includes a zero-crossing detection, amplification, analog/digital conversion, sampling and microprocessor circuit, the photodiode of the optical detector module converts the received optical signal into an analog electrical signal, the amplification circuit amplifies the signal, the analog/digital conversion circuit converts the signal into a digital signal, the sampling circuit shapes and removes noise and interference signals, and the digital signal is sent to the spectrum analysis unit for signal analysis.
The above signal processing processes are all performed under the control of a microprocessor (CPU/MPU).
In FIG. 3, the optical fiber coupler 3 includes at least three optical fiber couplers 3-1, 3-2 and 3-3; wherein,
one branching port a of the first optical fiber coupler 3-1 is optically connected to the broadband laser light source 1, the other branching port b thereof is optically connected to one branching port a ″ of the third optical fiber coupler 3-3, and the combined port c of the first optical fiber coupler is optically connected to one branching port a' of the second optical fiber coupler 3-2.
The other branch port b 'of the second optical fiber coupler is optically connected with the input port of the optical detector module 4 through the tunable optical fiber filter 2, and the combined port c' of the second optical fiber coupler is connected in series with at least two optical fiber grating sensors 6 with different central wavelengths through the external optical fiber 5.
Similarly, the other branch port b "of the third fiber coupler 3-3 is optically connected to the input port of the optical detector module 4 via the tunable fiber filter 2, and the combining port c" is connected in series to at least two fiber grating sensors with different center wavelengths via the external fiber.
The rest is the same as fig. 1 or fig. 2.
According to the requirement of users, the fiber couplers with more channels can be arranged according to the method so as to drive more paths (or called channels) of external optical fibers and fiber grating sensors.
The utility model discloses the working process brief notes:
the microprocessor controls the broadband laser light source to emit broadband laser, and the laser is transmitted to the external optical fiber by the optical fiber coupler and transmitted to each of the serially connected fiber grating sensors by the external optical fiber. Each fiber grating sensor can reflect laser with central wavelength, the reflected laser is transmitted to a tunable fiber filter through an external fiber and a fiber coupler, the laser with certain wavelength (the same as the central wavelength of the fiber grating sensor) is selected to be transmitted to a light detector module under the control of a microprocessor, the light detector module converts light signals into electric signals, the electric signals are subjected to zero-crossing detection, amplification, analog-to-digital conversion and sampling, the microprocessor controls a spectrum analysis unit to process sampled data, temperature values of monitoring points are analyzed, and temperature rise change of the measured points is obtained by analyzing the change amplitude of the central wavelength of reflected light of each fiber grating. The address of the measured point can be known according to the central wavelength of the measured point, and the address of the measured point and the temperature or temperature rise change condition of the measured point are displayed.
Because the central wavelength ranges of the reflected light signals returned by the sensors are different, the sensors can be connected in series and networked to realize multipoint simultaneous measurement.
Because the utility model discloses a fiber grating sensor with different grating parameters has reached the operating temperature who detects a plurality of power equipment cable joint departments simultaneously, can also distinguish specifically which is detected the invention purpose that the unusual temperature rise takes place for a little. The optical fiber grating sensor is adopted to detect the temperature of the high-voltage power equipment joint, so that the optical fiber grating sensor can directly contact the surface of a charged object to be detected and directly detect the temperature value of the charged object, the requirements of continuous online direct temperature measurement, high reliability, interference resistance, corrosion resistance, strong explosion-proof capability and the like of a high-voltage power equipment joint temperature detection system are met, and the electrical insulation performance of a high-voltage system and a temperature detection/display system is ensured.
The utility model discloses can extensively be used for the operation condition of various high voltage power equipment to detect the field.
Claims (8)
1. The utility model provides a distributed fiber grating temperature detecting system, includes broadband laser light source, tunable fiber filter, fiber coupler, external line optic fibre, fiber grating sensor, light detector module, characterized by:
the device is also provided with a spectrum analysis unit and a control and data processing unit; wherein,
the broadband laser light source is optically connected with one branching port of at least one optical fiber coupler;
the other shunt port of the optical fiber coupler is optically connected with the input port of the optical detector module through the tunable optical fiber filter;
the combining port of the optical fiber coupler is connected in series with at least two optical fiber grating sensors with different central wavelengths through an external optical fiber;
the broadband laser light source, the tunable optical fiber filter and the optical detector module are electrically connected with the spectral analysis unit and the control and data processing unit through a bus.
2. A distributed fiber grating temperature sensing system as defined in claim 1 wherein said fiber grating sensors are fiber grating sensors having different grating pitches.
3. A distributed fiber grating temperature sensing system as in claim 1 wherein said control and data processing unit is further electrically connected to a display unit and/or a communication unit.
4. A distributed fiber grating temperature sensing system as defined in claim 3 wherein said display unit is a liquid crystal display circuit.
5. The distributed fiber grating temperature sensing system of claim 1, wherein said broadband laser source is a broadband laser source having a source wavelength covering the entire C-band.
6. A distributed fiber grating temperature sensing system as defined in claim 1 wherein said broadband laser light source has a 3dB wavelength range of 40 nm.
7. The distributed fiber grating temperature sensing system of claim 1, wherein said photodetector module is a PIN or APD type photodiode circuit.
8. A distributed fiber grating temperature sensing system as in claim 1 wherein said control and data processing unit includes at least zero crossing detection, amplification, analog to digital conversion, sampling and microprocessor circuitry.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200420098662.9U CN2760526Y (en) | 2004-12-10 | 2004-12-10 | Distributed optical fibre raster temperature detecting system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200420098662.9U CN2760526Y (en) | 2004-12-10 | 2004-12-10 | Distributed optical fibre raster temperature detecting system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2760526Y true CN2760526Y (en) | 2006-02-22 |
Family
ID=36082729
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200420098662.9U Expired - Fee Related CN2760526Y (en) | 2004-12-10 | 2004-12-10 | Distributed optical fibre raster temperature detecting system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2760526Y (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100417962C (en) * | 2006-09-04 | 2008-09-10 | 天津爱天光电子科技有限公司 | Linear responsive optical fiber, optical grating temperature test system capable of collecting and demodulating signal |
| CN101949744A (en) * | 2010-09-06 | 2011-01-19 | 国网电力科学研究院武汉南瑞有限责任公司 | Fiber grating-based transformer internal temperature detection system |
| CN101975625A (en) * | 2010-09-27 | 2011-02-16 | 苏州光格设备有限公司 | Distributed optical fiber temperature sensing system and measurement method thereof |
| CN102062649A (en) * | 2010-11-26 | 2011-05-18 | 中国计量学院 | Dual wavelength light source self-correcting distributed optical fiber Raman temperature sensor for optical fiber Raman frequency shifter |
| CN102322888A (en) * | 2011-08-30 | 2012-01-18 | 杭州布里特威光电技术有限公司 | High-precision optical fiber grating sensing detection structure based on radio frequency optical modulation |
| CN102353524A (en) * | 2011-06-27 | 2012-02-15 | 北京理工大学 | Method and apparatus for testing dynamic spectrum of semiconductor laser |
| CN104236752A (en) * | 2014-09-17 | 2014-12-24 | 国家电网公司 | Oil-immersed transformer temperature measuring system |
| CN102322888B (en) * | 2011-08-30 | 2016-12-14 | 武汉康特圣思光电技术有限公司 | A kind of high precision optical fiber grating sensing detection structure based on radio frequency optical modulation |
| CN108680200A (en) * | 2018-05-15 | 2018-10-19 | 山东省科学院激光研究所 | environmental monitoring system, method and device |
| WO2024103700A1 (en) * | 2022-11-15 | 2024-05-23 | 深圳技术大学 | Detection method and detection system for surface temperature abnormal area |
-
2004
- 2004-12-10 CN CN200420098662.9U patent/CN2760526Y/en not_active Expired - Fee Related
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100417962C (en) * | 2006-09-04 | 2008-09-10 | 天津爱天光电子科技有限公司 | Linear responsive optical fiber, optical grating temperature test system capable of collecting and demodulating signal |
| CN101949744A (en) * | 2010-09-06 | 2011-01-19 | 国网电力科学研究院武汉南瑞有限责任公司 | Fiber grating-based transformer internal temperature detection system |
| CN101949744B (en) * | 2010-09-06 | 2012-08-08 | 国网电力科学研究院武汉南瑞有限责任公司 | Fiber grating-based transformer internal temperature detection system |
| CN101975625B (en) * | 2010-09-27 | 2012-02-29 | 苏州光格设备有限公司 | Distributed optical fiber temperature sensing system and measurement method thereof |
| CN101975625A (en) * | 2010-09-27 | 2011-02-16 | 苏州光格设备有限公司 | Distributed optical fiber temperature sensing system and measurement method thereof |
| CN102062649A (en) * | 2010-11-26 | 2011-05-18 | 中国计量学院 | Dual wavelength light source self-correcting distributed optical fiber Raman temperature sensor for optical fiber Raman frequency shifter |
| CN102062649B (en) * | 2010-11-26 | 2012-11-21 | 中国计量学院 | Dual wavelength light source self-correcting distributed optical fiber Raman temperature sensor for optical fiber Raman frequency shifter |
| CN102353524A (en) * | 2011-06-27 | 2012-02-15 | 北京理工大学 | Method and apparatus for testing dynamic spectrum of semiconductor laser |
| CN102353524B (en) * | 2011-06-27 | 2014-04-16 | 北京理工大学 | Method and apparatus for testing dynamic spectrum of semiconductor laser |
| CN102322888A (en) * | 2011-08-30 | 2012-01-18 | 杭州布里特威光电技术有限公司 | High-precision optical fiber grating sensing detection structure based on radio frequency optical modulation |
| CN102322888B (en) * | 2011-08-30 | 2016-12-14 | 武汉康特圣思光电技术有限公司 | A kind of high precision optical fiber grating sensing detection structure based on radio frequency optical modulation |
| CN104236752A (en) * | 2014-09-17 | 2014-12-24 | 国家电网公司 | Oil-immersed transformer temperature measuring system |
| CN108680200A (en) * | 2018-05-15 | 2018-10-19 | 山东省科学院激光研究所 | environmental monitoring system, method and device |
| WO2024103700A1 (en) * | 2022-11-15 | 2024-05-23 | 深圳技术大学 | Detection method and detection system for surface temperature abnormal area |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1632485A (en) | Distributed optical fiber grating temperature detection system for high voltage electric power equipment | |
| CN103245369B (en) | Novel fiber bragg grating demodulation method and system thereof based on multi-longitudinal mode F-P laser device | |
| CN107560644B (en) | Distributed optical fiber sensing device based on signal multiplexing perception and demodulation | |
| TW201315170A (en) | Light frequency domain reflective optical network test method | |
| CN103063242A (en) | Real-time monitoring system and method based on optical time domain reflection and fiber grating distributed type | |
| CN101000267A (en) | Parallel distribution optical fibre raster temp. sensing method and its system | |
| CN104535529A (en) | Distributed gas sensing system and control method thereof | |
| CN106352905A (en) | Fiber bragg grating demodulating system and demodulator | |
| CN103604446A (en) | Multi-channel fiber bragg grating absolute wavelength demodulation system based on single detector and method thereof | |
| CN2760526Y (en) | Distributed optical fibre raster temperature detecting system | |
| CN105572551A (en) | Insulation state on-line integrated monitoring system for switchgear | |
| CN105157589A (en) | On-line monitoring system for deformation of transformer winding | |
| CN108196107A (en) | A kind of distributed full photovoltage measuring system and its measuring method | |
| CN207232005U (en) | Multiplexing fiber-optic gas sensing system based on weak optical fiber Bragg grating and optical time domain reflectometer | |
| CN110967124B (en) | Dual-wavelength multichannel distributed optical fiber temperature measurement system | |
| CN201903411U (en) | Power equipment temperature online monitoring system based on fiber bragg grating temperature sensor | |
| CN114062275B (en) | Spatial domain multiplexing demodulation instrument and method for optical fiber photoacoustic sensor | |
| CN1818616A (en) | Gas differential absorbing monitoring system with fibre-optical and multi-point in mine | |
| CN114674463A (en) | Distributed optical fiber temperature sensing calibration unit, sensing device and detection method | |
| CN1888834B (en) | Optical fiber grating sensor wave length measuring system | |
| CN206930377U (en) | Based on narrow band laser demodulating fiber bragg grating temp measuring system | |
| CN1904658A (en) | Coherent multiplexing method for optical fiber Bragg raster sensor and apparatus thereof | |
| CN110608813A (en) | Distribution cable joint temperature detection system based on optical fiber transmission | |
| CN113624363B (en) | Optical fiber temperature monitoring device | |
| CN103217182B (en) | Multi-channel fiber grating demodulating device based on color filters |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |