CN112629702A - Novel fiber grating high-precision temperature detection system - Google Patents
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- 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
- G01K11/3206—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 at discrete locations in the fibre, e.g. using Bragg scattering
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Abstract
The invention discloses a novel fiber grating high-precision temperature detection system which comprises a light source unit, wherein the light source unit is connected with the input end of an edge filtering unit, the output end of the edge filtering unit is connected with the input end of a 1: N splitter, N output ends of the 1: N splitter unit are respectively connected with the input end of a remote optical fiber, the output end of the remote optical fiber is connected with the input end of a 1:2 splitter, the output end of a first splitter of the 1:2 splitter is sequentially connected with a first fiber grating, a first return optical fiber and a first photoelectric detector, the output end of a second splitter of the 1:2 splitter is sequentially connected with a second fiber grating, a second return optical fiber and a second photoelectric detector through optical fibers, the first photoelectric detector and the second photoelectric detector are respectively connected with the input end of a data processing module, and the output end of the data processing module is electrically connected with a display unit, the invention has low cost, simple and stable structure and realizes the temperature measurement with the precision of 0.02 ℃.
Description
Technical Field
The invention relates to the field of optical fiber sensing temperature measurement, in particular to a novel optical fiber grating high-precision temperature detection system.
Background
Sensing is an important branch of fiber gratings, and has been studied in foreign countries since 110106, and gradually applied after 2000. The traditional temperature sensing is generally realized by using an electric chip, but the requirements of using under the environments such as electromagnetic interference, humid environment, flammability and explosiveness, high-precision detection and the like are difficult to meet. The fiber grating has the advantages of electromagnetic interference resistance, corrosion resistance, no power supply at the probe, remote monitoring and the like. In recent years, a large amount of research in the aspect of fiber grating sensing appears at home and abroad. Temperature sensing is an important branch of fiber grating sensing.
Through inquiring the existing patents, Chinese patent numbers: CN115021311B, published 2015, 11, month 4, discloses a multi-channel high-precision fiber grating temperature sensing system. The device uses a tunable laser with narrow line width (the line width is less than 1 Mhz), an optical fiber resonant cavity and a standard gas absorption chamber for reference, and the temperature measurement with the precision of 0.0004K is realized by processing a data acquisition card, a computer and the like at a terminal, but the method has high requirements on a light source (the narrow line width), needs a standard gas chamber, has complex realization process and high cost, and is inconvenient to implement; chinese patent No.: CN112252704A, a high-speed high-precision multi-channel bragg grating demodulator, similar to CN1150213B, needs to use a DFB laser with an extremely narrow line width as a light source, and the wavelength of the light source needs to be continuously adjustable in a small range. In the patent, the relative realization of the light source and the control end is complex, and the cost is high; chinese patent No.: CN207662536U, a temperature sensing system based on a double fiber Bragg grating, 2 gratings used, a matched grating and an induction grating, wherein the matched grating and the induction grating are in cascade connection.
Disclosure of Invention
The invention provides a novel fiber grating high-precision temperature detection system, which can provide higher precision compared with the traditional detection method by using fiber gratings.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a novel fiber grating high-precision temperature detection system comprises a light source unit, wherein the light source unit is connected with the input end of an edge filtering unit through an optical fiber, the output end of the edge filtering unit is connected with the input end of a 1: N splitter through an optical fiber, N output ends of the 1: N splitter unit are respectively connected with the input end of a remote optical fiber through optical fibers, the output end of the remote optical fiber is connected with the input end of a 1:2 splitter through an optical fiber, the 1:2 splitter is provided with a first splitter output end and a second splitter output end, the first splitter output end is sequentially connected with a first fiber grating, a first return optical fiber and a first photoelectric detector through optical fibers, the second splitter output end is sequentially connected with a second fiber grating, a second return optical fiber and a second photoelectric detector through optical fibers, and the first photoelectric detector and the second photoelectric detector are respectively and electrically connected with the input end of a data processing module, the output end of the data processing module is electrically connected with the display unit.
The technical scheme of the invention is further improved as follows: the light source unit adopts a common wide spectrum unit and the spectrum width is more than 20 nm.
The technical scheme of the invention is further improved as follows: the edge filtering unit adopts any one of a dielectric film filter, a long-period grating filter, a birefringent optical fiber filter and an edge filter.
The technical scheme of the invention is further improved as follows: the first fiber grating and the second fiber grating both adopt long-period fiber gratings.
The technical scheme of the invention is further improved as follows: the first fiber bragg grating and the second fiber bragg grating both adopt bragg gratings, the output end of the first optical splitter is connected with the port A of the first circulator through an optical fiber, the port B of the first circulator is connected with the first fiber bragg grating through an optical fiber, the port C of the first circulator is connected with the first return fiber through an optical fiber, the output end of the second optical splitter is connected with the port A of the second circulator through an optical fiber, the port B of the second circulator is connected with the second fiber bragg grating through an optical fiber, and the port C of the second circulator is connected with the second return fiber through an optical fiber.
The technical scheme of the invention is further improved as follows: the temperature range of the installation positions of the first fiber bragg grating and the second fiber bragg grating is 25-60 ℃.
The technical scheme of the invention is further improved as follows: the characteristic wavelength of the first fiber grating is lambda1And lambda1On the rising curve of V-shaped characteristic spectrum waveform of the edge filter unit, the characteristic wavelength of the second fiber grating is lambda2And lambda2On the descending curve of V-shaped characteristic spectrum waveform of the edge filter unit, the lambda value1And λ2And changes direction when the temperature changes.
The technical scheme of the invention is further improved as follows: the remote optical fiber, the first return optical fiber and the second return optical fiber are simultaneously laid in a multi-optical-fiber mode of an optical cable or a multi-core mode of an optical fiber.
The technical scheme of the invention is further improved as follows: the data processing module is internally provided with a 16-bit AD conversion chip, a micro control unit MCU and an FPGA, and the first photoelectric detector and the second photoelectric detector are respectively and electrically connected with the data processing module and then carry out temperature calibration.
Due to the adoption of the technical scheme, the invention has the technical progress that:
1. the invention uses the edge filter unit to superpose two-path fiber grating sensing signals, and converts the wavelength change caused by temperature into power change so as to facilitate the simpler and more convenient detection of a photoelectric detector, and the characteristic wavelength lambda of the first fiber grating1And the characteristic wavelength lambda of the second fiber grating2The change trends in temperature change are opposite, the change directions are the same, differential processing is used, the change intensity of temperature signals is enhanced, and the influence of environmental change is filtered;
2. if the first fiber grating and the second fiber grating are Bragg gratings simultaneously, because the Bragg gratings are reflective gratings, the light source has a certain width, the light transmitted after passing through the Bragg gratings can have a certain recess, the reflected light is narrow-band light with a specific wavelength, namely a peak, therefore, the experimental device in the invention needs to use the reflected light of the bragg grating, so the circulators are respectively arranged in front of the first fiber grating and the second fiber grating, the incident light of the light source enters from the port A of the circulator and is output to the bragg grating through the port B of the circulator, the reflected light after passing through the bragg grating is reflected into the port B and is output to the return fiber through the port C of the circulator, and the characteristic wavelength of the light output by the first fiber grating and the second fiber grating is ensured to be overlapped with the wavelength range of the V-shaped edge filtering unit;
if the first fiber grating and the second fiber grating simultaneously select the long-period fiber grating, the long-period fiber grating is a transmissive grating, a forward-transmitted fiber core fundamental mode is coupled into a forward-transmitted cladding mode, and the cladding mode is lost quickly, so the long-period fiber grating basically has no back reflection, an absorption peak with a specific wavelength is arranged in a transmission spectrum of the long-period fiber grating, the central wavelength of the absorption peak is related to the period of the long-period fiber grating, and by selecting a proper grating period, the narrow-band light, namely a peak, required by the device can be realized by using the cascaded long-period fiber grating, and the central wavelength is overlapped with the wavelength range of the V-shaped edge filtering unit;
3. the invention improves the sensitivity of sensing change at the photoelectric detector end, facilitates the simpler and more convenient detection of the photoelectric detector, has relatively low cost, relatively simple structure, relatively stability and higher precision, and realizes the temperature measurement with the precision of 0.02 ℃.
Drawings
FIG. 1 is a flow chart of a system in which a first fiber grating and a second fiber grating are long-period fiber gratings according to the present invention;
FIG. 2 is a flow chart of a system in which the first fiber grating and the second fiber grating are Bragg gratings according to the present invention;
FIG. 3 is a characteristic curve of the V-shaped edge filter unit of the present invention;
FIG. 4 is a graph showing the waveform output from the V-shaped edge filter unit according to the present invention after superimposing the fiber gratings;
the optical fiber remote sensing device comprises a light source unit 1, a light source unit 2, a V-shaped edge filtering unit 3, a 1: N splitter 4, a remote optical fiber 5, a 1:2 splitter 6-1, a first circulator 6-2, a second circulator 7-1, a first optical fiber grating 7-2, a second optical fiber grating 8-1, a first return optical fiber 8-2, a second return optical fiber 9-1, a first photoelectric detector 9-2, a second photoelectric detector 10, a data processing module 11 and a display unit.
Detailed Description
The present invention will be described in further detail with reference to the following examples:
as shown in the system flow diagrams of fig. 1 and 2; the utility model provides a novel fiber grating high accuracy temperature detecting system, includes light source unit 1, light source unit 1 adopts ordinary wide spectrum unit and spectral width to be greater than 20nm, ordinary wide spectrum unit adopts ASE broadband light source, wavelength range be 1528 ~ 1563nm, output optical power value is 15.3 dBm. The light source unit 1 is connected with the input end of the V-shaped edge filtering unit 2 through an optical fiber, the V-shaped edge filtering unit 2 adopts any one of a dielectric film filter, a long-period grating filter, a birefringent optical fiber filter and an edge filter, and the characteristic curve of the V-shaped edge filtering unit 2 is shown in figure 2. The output end of the V-shaped edge filtering unit 2 is connected with the input end of a 1: N splitter 3 through an optical fiber, the 1: N splitter 3 is a power branching device with a 1 port entering an N port, N output ends of the 1: N splitter 3 are respectively connected with the input end of a remote optical fiber 4 through optical fibers, the length of the remote optical fiber 4 is selected to be proper according to the distance, the distance can be as short as several meters when the distance is close, and the distance is not more than 11 kilometers when the distance is far as the current optical power condition, so that the monitoring of a temperature area to be measured in a long distance or a relatively dangerous area can be realized. The optical power of N output ends is uniformly distributed, each output end is connected with a sensing probe unit, each sensing probe unit is composed of a first fiber bragg grating 7-1 and a second fiber bragg grating 7-2, one sensing probe unit realizes the measurement of a temperature to be measured, only one output end of the N output ends is taken as an example in the figures 1 and 2, the output end of a remote optical fiber 4 is connected with the input end of a 1:2 optical splitter 5 through an optical fiber, the 1:2 optical splitter 5 is provided with a first optical splitter output end 5-1 and a second optical splitter output end 5-2, as shown in the figure 1, the first fiber bragg grating 7-1 and the second fiber bragg grating 7-2 both adopt long-period fiber bragg gratings, the long-period fiber bragg gratings are transmissive gratings, and a forward-transmitted fiber core fundamental mode is coupled into a forward-transmitted cladding mode, the cladding mode is lost very fast, so the long-period fiber grating basically has no back reflection, an absorption peak with specific wavelength exists in the transmission spectrum of the long-period fiber grating, the central wavelength of the absorption peak is related to the period of the long-period fiber grating, and by selecting a proper grating period, the narrow-band light, namely a peak, required by the device can be realized by using the cascaded long-period fiber grating, and the central wavelength is overlapped with the wavelength range of the V-shaped edge filtering unit 2. The output end 5-1 of the first optical splitter is sequentially connected with a first fiber grating 7-1, a first return fiber 8-1 and a first photoelectric detector 9-1 through optical fiber connection, and the output end 5-2 of the second optical splitter is sequentially connected with a second fiber grating 7-2, a second return fiber 8-2 and a second photoelectric detector 9-2 through optical fibers.
As shown in fig. 2: the first fiber grating 7-1 and the second fiber grating 7-2 both adopt Bragg gratings, and the light source has a certain width, and the light transmitted through the first fiber grating 7-1 and the second fiber grating 7-2 will have a certain depression, and the reflected light is narrow-band light with a specific wavelength, i.e. a peak, so the experimental device in the invention needs to use the reflected light of the first fiber grating 7-1 and the second fiber grating 7-2, therefore, circulators need to be respectively arranged before the first fiber grating 7-1 and the second fiber grating 7-2, the output end 5-1 of the first optical splitter is connected with the A port of the first circulator 6-1 through optical fibers, the B port of the first circulator 6-1 is connected with the first fiber grating 7-1 through optical fibers, and the C port of the first circulator 6-1 is sequentially connected with the first return optical fiber 8 through optical fibers 1 and a first photodetector 9-1, wherein the output end 5-2 of the second optical splitter is connected to the port a of the second circulator 6-2 through an optical fiber, the port B of the second circulator 6-2 is connected to the second fiber grating 7-2 through an optical fiber, and the port C of the second circulator 6-2 is connected to the second return fiber 8-2 and the second photodetector 9-2 through an optical fiber, so as to ensure that the characteristic wavelength of the output light of the first fiber grating 7-1 and the second fiber grating 7-2 overlaps with the wavelength range of the V-shaped edge filtering unit 2.
The 1:2 optical splitter 5 provides two paths of similar light for the first fiber grating 7-1 and the second fiber grating 7-2, the two paths of light output by the 1:2 optical splitter 5 are almost the same, the first fiber grating 7-1 and the second fiber grating 7-2 both adopt Bragg gratings or long-period fiber gratings, and the Bragg gratings or the long-period fiber gratings are characterized in that the gratings with specific periods cause characteristic wavelength changes to external temperature changes.
As shown in FIG. 3, the first fiber grating 7-1 has a characteristic wavelength λ1And lambda1On the rising curve of the V-shaped characteristic spectrum waveform of the V-shaped edge filtering unit 2, the characteristic wavelength of the second fiber grating 7-2 is lambda2And lambda2Is positioned on the descending curve of the V-shaped characteristic spectrum waveform of the V-shaped edge filtering unit 2. After the superposition of the edge filtering unit, the change of the wavelength is converted into the change of the optical power, so that the change of the optical power can be conveniently detected by directly using the first photoelectric detector 9-1 and the second photoelectric detector 9-2, the optical power obtained by the first photoelectric detector 9-1 is the optical power obtained by the second photoelectric detector 9-2, the optical signals are converted into current signals by the first photoelectric detector 9-1 and the second photoelectric detector 9-2 and are sent to the data processing unit 10, the current signals are converted into voltage signals by the data processing unit 10 and are collected and output to obtain the sum of the voltage values of the first photoelectric detector 9-1 and the second photoelectric detector 9-2, and the characteristic wavelength lambda on the rising curve of the V-shaped characteristic spectrum waveform of the V-shaped edge filtering unit 2 is equal to the sum of the characteristic wavelength lambda when the temperature changes1And lambda on the falling curve of the V-shaped characteristic spectrum waveform of the V-shaped edge filter unit 22When one of the signals is increased and the other one is decreased, the relative difference Δ p between the optical power obtained by the first photodetector 9-1 and the optical power obtained by the second photodetector 9-2 is increased, and the increased signal intensity facilitates the direct reading of the voltage value by the AD conversion in the data processing module 10. When the fiber bragg grating is actually used and installed, the first fiber bragg grating 7-1 and the second fiber bragg grating 7-2 are installed at the positions with the temperature range of 25-60 ℃. The first backhaul fiber 8-1 and the second backhaul fiber 8-2 correspond to the remote fiber 4, the first backhaul fiber 8-1 and the second backhaul fiber 8-2 are used for signal backhaul, and actually, during the laying process, the first backhaul fiber 8-1 and the second backhaul fiber 8-2 and the remote fiber 4 can be laid simultaneously, and the laying and applying can be reduced by using a multi-fiber optical cable or a multi-fiber optical cable mannerThe workload of workers.
The first photoelectric detector 9-1 and the second photoelectric detector 9-2 are respectively electrically connected with an input end of the data processing module 10, a 16-bit AD conversion chip, a micro control unit MCU and an FPGA are arranged in the data processing module 10, the main processing is differential power value calculation, AD conversion, corresponding filtering denoising processing and the like, and the temperature value is obtained through calculation.
Since the temperature change and the voltage change approximately show a linear relationship, but there is a certain deviation, which is called a non-linear error, and since the first photodetector 9-1 and the second photodetector 9-2 have a non-linear error, the first photodetector 9-1 and the second photodetector 9-2 are electrically connected to the data processing module 10 respectively and then are subjected to temperature calibration, so as to reduce the non-linear error and make the temperature measurement more accurate. The calibration method is to obtain an error value after the output result is obtained from the actual temperature measurement when the first photodetector 9-1 and the second photodetector 9-2 are produced, and to add or subtract the error value when in use, so as to make the temperature more accurate.
The output end of the data processing module 10 is electrically connected with the display unit 11, and the display unit 11 displays the temperature value obtained after the data processing module 10 processes the temperature value. The display unit 11 can be directly displayed by the MCU through the liquid crystal display panel, or can be accessed to the server by expanding the wireless chip in the data processing unit, so that data is uploaded in the server, and the display and query access of the temperature value are realized through a computer or mobile phone app.
Example 1: the light source unit 1 adopts an ASE broadband light source, the wavelength range is 1528-1563 nm, and the typical value of the output light power is 15.3 dBm; the V-shaped edge filtering unit 2 adopts a dielectric film filter, wherein the V-shaped concave range of the filter is 1530-1560 nm approximately; the 1: N splitter 3 adopts a 1:8 splitter, and the insertion loss of 8 output ends is about 11.8 dB; the remote optical fiber 4, the first return optical fiber 8-1 and the second return optical fiber 8-2 are all built by SMF-28 common single-mode optical fibers with the length of 110m, and yellow loose sleeves are arranged outside the optical fibers for protection; the 1:2 optical splitter 5 adopts a 1:2 equally distributedThe insertion loss of the two output ends of the optical splitter is about 4.3 DB; the first fiber grating 7-1 is Bragg grating with characteristic wavelength lambda11538nm, the second fiber grating 7-2 is Bragg grating with characteristic wavelength λ21554nm, because the first fiber grating 7-1 and the second fiber grating 7-2 are reflective gratings, incident light enters from the port A of the first circulator 6-1, passes through the port B of the first circulator 6-1 and is output to the first fiber grating 7-1, and passes through the port A of the first fiber grating 7-1 to form a lambda1The reflected light is output to the first return fiber 8-1 from the port C of the first circulator 6-1, and similarly, the incident light enters from the port A of the second circulator 6-2, passes through the port B of the second circulator 6-2 and is output to the second fiber grating 7-2, and passes through the port λ of the second fiber grating 7-22The reflected light is output to a second return optical fiber 8-2 from a port C of a second circulator 6-2, common InGaAs PIN photodiodes are used for a first photodetector 9-1 and a second photodetector 9-2, the spectral width is 800-1700 nm, the responsivity is 0.85mA/mw, and the dark current is 0.15pA, the first photodetector 9-1 and the second photodetector 9-2 convert optical signals into current signals, the current signals are sent to a data processing unit 10, the data processing unit 10 converts the current signals into voltage signals, the voltage signals are collected and output, the voltage values of the first photodetector 9-1 and the second photodetector 9-2 are respectively the sum, and when the temperature changes, the characteristic wavelength lambda on a rising curve of a V-shaped characteristic spectrum waveform of the V-shaped edge filtering unit 2 is obtained1And lambda on the falling curve of the V-shaped characteristic spectrum waveform of the V-shaped edge filter unit 22When one of the signals is increased and the other one is decreased, the relative difference Δ p between the optical power obtained by the first photodetector 9-1 and the optical power obtained by the second photodetector 9-2 is increased, and the increased signal intensity facilitates the direct reading of the voltage value by the AD conversion in the data processing module 10. Actually, through a test environment arranged on site, the temperature is adjusted to change from 25 degrees to 60 degrees, the corresponding output voltage value is measured after the temperature is changed by 5 degrees each time, the obtained data is subjected to linear fitting to obtain the actually measured temperature, and the actually measured temperature is displayed through the display unit 11 and obtained after the data is processed by the data processing module 10The temperature value can be found through a plurality of tests: temperature T measured by the temperature measurement system of the invention1Temperature T measured by instrument with higher precision2The temperature error delta T between the two temperature measurement systems is less than or equal to 0.02 ℃, namely the temperature precision of the temperature measurement system is 0.02 ℃.
Claims (10)
1. The utility model provides a novel fiber grating high accuracy temperature measuring system which characterized in that: the optical fiber detection device comprises a light source unit (1), wherein the light source unit (1) is connected with the input end of a V-shaped edge filtering unit (2) through an optical fiber, the output end of the V-shaped edge filtering unit (2) is connected with the input end of a 1: N splitter (3) through an optical fiber, N output ends of the 1: N splitter (3) are respectively connected with the input end of a remote optical fiber (4) through an optical fiber, the output end of the remote optical fiber (4) is connected with the input end of a 1:2 optical splitter (5) through an optical fiber, the 1:2 optical splitter (5) is provided with a first optical splitter output end (5-1) and a second optical splitter output end (5-2), the first optical splitter output end (5-1) is sequentially connected with a first optical fiber grating (7-1), a first return optical fiber (8-1) and a first photoelectric detector (9-1) through optical fiber connections, the output end (5-2) of the second optical splitter is sequentially connected with a second fiber grating (7-2), a second return fiber (8-2) and a second photoelectric detector (9-2) through optical fibers, the first photoelectric detector (9-1) and the second photoelectric detector (9-2) are respectively and electrically connected with the input end of a data processing module (10), and the output end of the data processing module (10) is electrically connected with a display unit (11).
2. The novel fiber grating high-precision temperature detection system according to claim 1, characterized in that: the light source unit (1) adopts a common wide spectrum unit, and the spectrum width is more than 20 nm.
3. The novel fiber grating high-precision temperature detection system according to claim 2, characterized in that: the common wide spectrum unit adopts an ASE broadband light source, the wavelength range is 1528-1563 nm, and the output light power value is 15.3 dBm.
4. The novel fiber grating high-precision temperature detection system according to claim 1, characterized in that: the V-shaped edge filtering unit (2) adopts any one of a dielectric film filter, a long-period grating filter, a birefringent fiber filter and an edge filter.
5. The novel fiber grating high-precision temperature detection system according to claim 4, characterized in that: the first fiber grating (7-1) and the second fiber grating (7-2) both adopt long-period fiber gratings.
6. The novel fiber grating high-precision temperature detection system according to claim 4, characterized in that: the first fiber grating (7-1) and the second fiber grating (7-2) both adopt Bragg gratings at the same time, the output end (5-1) of the first optical splitter is connected with the port A of the first circulator (6-1) through an optical fiber, the port B of the first circulator (6-1) is connected with a first fiber grating (7-1) through an optical fiber, the C port of the first circulator (6-1) is connected with a first return optical fiber (8-1) through an optical fiber, the output end (5-2) of the second optical splitter is connected with the port A of the second circulator (6-2) through an optical fiber, the port B of the second circulator (6-2) is connected with a second fiber grating (7-2) through an optical fiber, and the C port of the second circulator (6-2) is connected with a second back transmission optical fiber (8-2) through an optical fiber.
7. The novel fiber grating high-precision temperature detection system according to any one of claims 5 or 6, characterized in that: the temperature range of the installation positions of the first fiber bragg grating (7-1) and the second fiber bragg grating (7-2) is 25-60 ℃.
8. The novel fiber grating high-precision temperature detection system according to any one of claims 5 or 6, characterized in that: the characteristic wavelength of the first fiber grating (7-1) is lambda1And lambda1The filtering unit (2) is positioned at the V-shaped edge and is V-shapedOn the rising curve of the characteristic spectrum waveform, the characteristic wavelength of the second fiber grating (7-2) is lambda2And lambda2Is positioned on a descending curve of a V-shaped characteristic spectrum waveform of the V-shaped edge filtering unit (2), and the lambda is1And λ2And changes direction when the temperature changes.
9. The novel fiber grating high-precision temperature detection system according to claim 1, characterized in that: the remote optical fiber (4), the first return optical fiber (8-1) and the second return optical fiber (8-2) are simultaneously laid in a mode of one optical cable and multiple optical fibers or a mode of one optical fiber and multiple cores.
10. The novel fiber grating high-precision temperature detection system according to claim 1, characterized in that: the data processing module (10) is internally provided with a 16-bit AD conversion chip, a Micro Control Unit (MCU) and an FPGA, and the first photoelectric detector (9-1) and the second photoelectric detector (9-2) are respectively and electrically connected with the data processing module (10) and then carry out temperature calibration.
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| CN102889903A (en) * | 2011-07-21 | 2013-01-23 | 桂林优西科学仪器有限责任公司 | OFS (optical fiber sensor) measuring system for tunable laser sources and application method thereof |
| CN104535090A (en) * | 2014-12-16 | 2015-04-22 | 三峡大学 | Wavelength-matched double FBG demodulation systems based on cascaded long period grating |
| CN105628065A (en) * | 2015-12-22 | 2016-06-01 | 南京工程学院 | Fiber grating signal demodulation device and demodulation method |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102889903A (en) * | 2011-07-21 | 2013-01-23 | 桂林优西科学仪器有限责任公司 | OFS (optical fiber sensor) measuring system for tunable laser sources and application method thereof |
| CN104535090A (en) * | 2014-12-16 | 2015-04-22 | 三峡大学 | Wavelength-matched double FBG demodulation systems based on cascaded long period grating |
| CN105628065A (en) * | 2015-12-22 | 2016-06-01 | 南京工程学院 | Fiber grating signal demodulation device and demodulation method |
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Application publication date: 20210409 |