CN110057426A - Dark pit level measuring system and method based on strained layer around Bragg grating - Google Patents
Dark pit level measuring system and method based on strained layer around Bragg grating Download PDFInfo
- Publication number
- CN110057426A CN110057426A CN201910371117.3A CN201910371117A CN110057426A CN 110057426 A CN110057426 A CN 110057426A CN 201910371117 A CN201910371117 A CN 201910371117A CN 110057426 A CN110057426 A CN 110057426A
- Authority
- CN
- China
- Prior art keywords
- bragg grating
- optical fiber
- grating
- fiber
- liquid level
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title abstract description 14
- 239000013307 optical fiber Substances 0.000 claims abstract description 128
- 239000007788 liquid Substances 0.000 claims abstract description 116
- 239000000835 fiber Substances 0.000 claims abstract description 57
- 238000012545 processing Methods 0.000 claims abstract description 35
- 230000001953 sensory effect Effects 0.000 claims abstract description 27
- 238000010438 heat treatment Methods 0.000 claims description 24
- 230000003287 optical effect Effects 0.000 claims description 21
- 239000004744 fabric Substances 0.000 claims description 14
- 230000008859 change Effects 0.000 claims description 11
- 238000001514 detection method Methods 0.000 claims description 8
- 229910001220 stainless steel Inorganic materials 0.000 claims description 6
- 239000010935 stainless steel Substances 0.000 claims description 6
- 238000004458 analytical method Methods 0.000 claims description 5
- 238000000985 reflectance spectrum Methods 0.000 claims description 5
- 238000005260 corrosion Methods 0.000 claims description 4
- 230000007797 corrosion Effects 0.000 claims description 4
- 239000000463 material Substances 0.000 claims description 3
- 238000000691 measurement method Methods 0.000 claims description 3
- 239000007769 metal material Substances 0.000 claims description 3
- 238000012546 transfer Methods 0.000 claims description 3
- 230000000747 cardiac effect Effects 0.000 claims description 2
- 239000012530 fluid Substances 0.000 claims description 2
- 239000010410 layer Substances 0.000 claims 19
- 238000013459 approach Methods 0.000 claims 1
- 238000007654 immersion Methods 0.000 claims 1
- 239000013047 polymeric layer Substances 0.000 claims 1
- 230000008901 benefit Effects 0.000 abstract description 4
- 230000006641 stabilisation Effects 0.000 abstract description 3
- 238000011105 stabilization Methods 0.000 abstract description 3
- 230000007774 longterm Effects 0.000 abstract description 2
- 230000005540 biological transmission Effects 0.000 abstract 1
- 238000005516 engineering process Methods 0.000 description 9
- 238000005259 measurement Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 6
- 125000006850 spacer group Chemical group 0.000 description 6
- 238000012544 monitoring process Methods 0.000 description 5
- 238000010276 construction Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000007726 management method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000002463 transducing effect Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/28—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring the variations of parameters of electromagnetic or acoustic waves applied directly to the liquid or fluent solid material
- G01F23/284—Electromagnetic waves
- G01F23/292—Light, e.g. infrared or ultraviolet
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Thermal Sciences (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
The invention discloses a kind of dark pit level measuring system and method based on strained layer around Bragg grating, measuring system includes fiber grating liquid level sensory package, fiber Bragg grating (FBG) demodulator, terminal box, data processing system.Fiber grating liquid level sensory package is embedded in dark pond, its tail optical fiber is connected to fiber Bragg grating (FBG) demodulator by terminal box, the central wavelength data transmission that fiber Bragg grating (FBG) demodulator will test is to data processing system, it is compared with the central wavelength of corresponding Bragg grating, the Bragg grating that maximum variation occurs for wavelength is in the sensitive zones near liquid level for immersing liquid, and the liquid level of liquid in dark pond is determined according to the position between each sensitive zones.Present system is used to measure the liquid level in the dark pond of sponge City complex, have the advantages that electromagnetism interference, far measuring distance, signal stabilization are good, it is suitble to the long-term work under harsh environments, there is important value to the real-time condition for the rainwater for grasping sponge city.
Description
Technical field
The invention belongs to technical field of liquid level measurement more particularly to a kind of dark ponds based on strained layer around Bragg grating
Liquid level measuring system and method.
Background technique
Sponge city is the completely new product of technology of Internet of things and smart city development.Currently, the sponge city based on Internet of Things
City's on-line monitoring has become hot spot, it incorporates the theory of smart city in sponge city, passes through Internet of Things, sensor, cloud
The information technologies such as calculating, big data, by various concentrations or distributed water resource, green facility and sponge urban construction
Coordinated implementation, to make the construction in sponge city and manage more efficient, wisdom.In these techniques, sensing technology is most base
Plinth and important key technology.Because if transducing signal is unstable, the large amount of data information of acquisition is unreliable, then online prison
The effect that examining system can play all is not known where to begin.
Currently, the technology of many measurements or tracking liquid level has existed, the example of this technology has capacitance type sensor, base
In the sensor and differential pressure pickup of diode, every kind of technology is suitable for specific operating condition.Sponge city is as a kind of
New city storm water man- agement system, that there are anti-interferences is weak for traditional electromagnetic sensing technology, and signal stabilization is poor, remote to transmit
The drawbacks such as hardly possible, large-scale network-estabilishing inconvenience are not enough to carry out liquid to it so that the function of on-line monitoring system cannot be played effectively
Position detection.
Summary of the invention
The technical problem to be solved by the invention is to provide a kind of dark pit levels based on strained layer around Bragg grating
Measuring system and method, the system are used to measure the liquid level in the dark pond of sponge City complex, have electromagnetism interference, measurement distance
Far, the good advantage of signal stabilization is suitble to the long-term work under harsh environments, to the real-time of the rainwater for grasping sponge city
Situation has important value.
The technical solution adopted by the present invention to solve the technical problems is: providing one kind and is based on straining around Bragg grating
The dark pit level measuring system of layer, fiber grating liquid level sensory package, fiber Bragg grating (FBG) demodulator, terminal box, data processing system,
Fiber grating liquid level sensory package is placed in dark pond, and for sensing liquid level in dark pond, optical fiber pigtail is connect with optical cable, by connecing
Wire box incoming fiber optic grating demodulation instrument；Fiber Bragg grating (FBG) demodulator, for recording fiber grating liquid level sensing group at each terminal box
The central wavelength of the Bragg grating of part, and transfer data to data processing system；Data processing system reception optical fiber grating
The central wavelength for each channel grating that (FBG) demodulator sends over, original wavelength data corresponding with what is stored are analyzed
Compare, determine the sensitive zones contacted with liquid, and generates output display.
According to the above technical scheme, an optical fiber is axially fixed in capillary in fiber grating liquid level sensory package,
Tail optical fiber is connect with armored optical cable, is connected to fiber Bragg grating (FBG) demodulator by terminal box, optical fiber includes along fiber lengths interval
Multiple sensitive zones, wherein each sensitive zones include the Bragg grating and cloth loudspeaker generated to the reflectance spectrum of incident photoresponse
Strained layer around lattice grating.Wherein according to the temperature of strained layer, each strained layer is configured in corresponding cloth loudspeaker lattice
Optical fiber is caused on grating and is strained, so that the central wavelength of the reflectance spectrum of Bragg grating be made to change, wavelength occurs most
The Bragg grating changed greatly is in the sensitive zones near liquid level for immersing liquid, according to the position between each sensitive zones
Determine the liquid level of liquid in dark pond.
It according to the above technical scheme, further include an optical fiber in fiber grating liquid level sensory package, two optical fiber are along axial solid
Be scheduled in same capillary, the second optical fiber include the second Bragg grating group and surrounding strained layer, wherein the first optical fiber and
The different channels of second intelligent acess fiber Bragg grating (FBG) demodulator, the Bragg grating on two optical fiber are inclined along the length direction of optical fiber
It moves.
According to the above technical scheme, the Bragg grating of 10 5mm is carved on every optical fiber, is spaced 1.5cm, and Bragg grating is protected
There is the pre-stretching amount of 3nm, by sequence from top to bottom, the wavelength of wavelength 3nm incremented by successively, two optical fiber can be identical, can also not
Together, for wave-length coverage in 1534nm~1558nm, minimum is no more than 1532nm, and maximum wavelength is no more than 1557nm.
According to the above technical scheme, fiber grating liquid level sensory package further includes heating device, and heating device is every 4 hours
Heated that (heating device can be set at daily 6 points, and,, two o'clock timing is beaten at 10 points at ten four points at ten eight points at 22 points
Open), heating is closed after 15~25 minutes, and the heat source in heating device is connect with heating coil, is heated to capillary, to increase
Add higher than the heat differential between the part and the other parts lower than liquid level of optical fiber of liquid level in optical fiber, heating coil surrounds
Around capillary.In order to be heated to capillary.
According to the above technical scheme, fiber Bragg grating (FBG) demodulator demodulation range is 1530nm~1560nm.It is issued by ASE light source
Optical signal, the optical signal of sending through optical attenuator, filtered to the acceptable power bracket of filter by filter by power attenuation
Wave, is equally divided into 8 tunnels through optical splitter, enters optical fiber by different channels, along spread fiber；Optical detector detection fiber
Reflectance spectrum, and convert optical signals to electric signal, processor receives the detection signal from optical detector, is converted into
Central wavelength passes through interface output center wavelength.
According to the above technical scheme, data processing system includes the memory for storing nominal data, and processor is by specific cloth loudspeaker
The initial center wavelength of lattice grating is compared with the measuring center wavelength of the specific Bragg grating；Liquid is below capillary
It immerses, fluid temperature is low compared with air, and wavelength reduces, and sensitive zones where the maximum Bragg grating of wavelength change are to immerse liquid
The sensitive zones near liquid level, the liquid level of liquid in dark pond is determined according to the position between each sensitive zones.
According to the above technical scheme, the thermal expansion coefficient of strained layer and the thermal expansion coefficient of optical fiber are different, and strained layer includes poly-
Close nitride layer；Optical fiber includes multiple interval regions, the interval region settings of multiple interval regions every a pair of of neighboring sensor region it
Between, interval region does not include strained layer；Capillary selects stainless steel or other corrosion-resistant metal materials, makes fiber-optic grating sensor
Have the characteristics that anti-electromagnetism, corrosion-resistant, high sensitivity, measurement accuracy are high, heating coil outer layer covers have an insulating layer, in insulating layer
Outside is stainless steel, and centre is evacuated, and to delay to radiate, applies water-proof and anti-corrosive material in outer layer.Favorable sealing property has
Good thermal insulation property.
The present invention also provides a kind of dark pit level measurement methods of strained layer around Bragg grating, and this method includes following
Step, before installation, by the corresponding reference center wavelength storage of Bragg grating in fiber grating liquid level sensory package to data
In processing system, and determine the relative distance between each sensitive zones；Step 1 configures fiber grating liquid level sensory package
Into dark pond, the tail optical fiber of optical fiber is connect with armored optical cable, accesses (FBG) demodulator by terminal box；Step 2, fiber Bragg grating (FBG) demodulator
The central wavelength of the Bragg grating of the fiber grating liquid level sensory package at each terminal box is recorded, and is transferred data to
Data processing system；Step 3, data processing system receive the middle cardiac wave for each channel grating that the (FBG) demodulator sends over
Long, the central wavelength that analysis detection arrives identifies the corresponding central wavelength of each Bragg grating；Step 4, by specific cloth loudspeaker lattice
The initial center wavelength of grating is compared with the measuring center wavelength of the specific Bragg grating, and maximum variation occurs to determine
Central wavelength Bragg grating；Step 5, according to locating for the Bragg grating of the determining maximum variation of central wavelength generation
Sensitive zones and each sensitive zones between position determine the liquid level of liquid in dark pond；Step 6 generates an expression liquid level
Output.
According to the above technical scheme, the optical fiber of fiber grating liquid level sensory package is there are when the second optical fiber, data processing system
Locating for the Bragg grating that maximum variation occurs according to central wavelength on two optical fiber between sensitive zones and each sensitive zones
Position further more accurately determine liquid level.
The beneficial effect comprise that: it is poor to overcome traditional liquid level measuring technique anti-interference, jitter etc.
Drawback, integrates the data such as the soil moisture, water level, flow, hydraulic pressure and satisfaction is transmitted stable, anti-interference strong, precision height etc. and required.Benefit
Collected data are transferred to optical fiber and relevant network technology the database of system, the comprehensive liquid level to sponge city
It is monitored and manages, real-time perfoming tracking and monitoring, accumulation actual operating data, the longtime running effect of energy monitoring facilities, and
Shi Faxian operation risk and problem simultaneously carry out effective processing disposition, improve the operational support rate of facility, are sponge urban construction
Horizontal continuous improvement provides basic data.
Monitoring method provided by the invention, optical fiber is axially fixed in capillary, to capillary heating to increase light
Higher than the heat differential between the part and the other parts lower than liquid level of optical fiber of liquid level in fibre, and in heated capillary
Liquid level rise faster so that measurement result have more real-time, it is more accurate.
Detailed description of the invention
Present invention will be further explained below with reference to the attached drawings and examples, in attached drawing:
Fig. 1 is that the embodiment of the present invention is surveyed based on the dark pit level of the sponge City complex of strained layer around Bragg grating
The block diagram of amount system；
Fig. 2 is the structural schematic diagram of fiber grating liquid level sensory package in the embodiment of the present invention；
Fig. 3 is the specific embodiment of level sensing component；
Fig. 4 is the second specific embodiment of level sensing component；
Fig. 5 is the exemplary flow chart of method for measuring liquid level.
Specific embodiment
In order to make the objectives, technical solutions, and advantages of the present invention clearer, with reference to the accompanying drawings and embodiments, right
The present invention is further elaborated.It should be appreciated that described herein, specific examples are only used to explain the present invention, not
For limiting the present invention.
Including the use of cloth loudspeaker in dark pit level measuring system of the embodiment of the present invention based on strained layer around Bragg grating
Lattice grating has a strained layer around each Bragg grating along the fiber grating liquid level sensory package of fiber reflection light, by
Strained layer causes the strain of Bragg grating, to change the central wavelength of the reflectance spectrum of Bragg grating.Level sensing is installed
It is demarcated before component, and nominal data is stored in data processing system, when being placed in temperature change, strained layer pair
Bragg grating generates strain, and the central wavelength of Bragg grating changes.This thermal expansion coefficient with strained layer and optical fiber
Different related, strained layer includes polymer.In addition, optical fiber liquid level sensory package is due to lacking electrical component, it can be to avoid any
Electrical component is potentially short-circuit, can not also be can be used for various environment by electromagnetic interference.
Fig. 1 illustrates the specific embodiment of liquid level measuring system 100, and liquid level measuring system 100 includes fiber grating demodulation
Instrument 101, data processing system 102 and dark pond 111.Level sensing component 115 is configured in dark pond, and is fused to and is arranged in optical cable
On each connector box at, be connected to fiber Bragg grating (FBG) demodulator 101, the component Configuration is in dark pond 115.Level sensing component
115 include optical fiber 114 and heating device 119.Optical fiber 114 includes multiple between multiple sensitive zones 116 and sensitive zones 116
Interval region 117.Each sensitive zones 116 include Bragg grating 112 and are centered around one of Bragg grating 112 and answer
Change layer 113；Optical fiber 114 is axially fixed in the capillary 120 of heating device 119.Heating device 119 includes capillary 120
And the heating coil 123 being enclosed in around capillary, insulating layer 121 and heat source 122.
Dark pond 111 includes liquid 124, and level sensing component 115 may include multiple optical fiber, such as the second optical fiber 118.When another
In the presence of kind of optical fiber, another grating there is also.For example, the second optical fiber 118 includes the second grating (for example, being similar to cloth loudspeaker lattice
Grating 112) and the second strained layer (being similar to strained layer 113), they are separated by interval region (being similar to interval region 117).
Heat source 122 in heating device 119 is connect with the heating coil 123 around capillary 120, is added to capillary
Heat, it is other higher than the part (such as the first sensitive zones) of 124 liquid level of liquid and optical fiber lower than 124 liquid level of liquid in optical fiber to increase
Part (such as the second sensitive zones) between heat differential.Capillary 120 selects stainless steel or other corrosion resistant metal materials.It is described
123 outer layer covers of heating coil have insulating layer 121.121 inside and outside of insulating layer is stainless steel, and centre is evacuated, to delay
Heat dissipation applies water-proof and anti-corrosive material in outer layer.
Fiber Bragg grating (FBG) demodulator 101 measures the central wavelength 103 of Bragg grating 112, and provides it to data processing
System 102.Fiber Bragg grating (FBG) demodulator, demodulation range are 1530nm~1560nm, issue optical signal by the ASE light source,
The optical signal of sending is filtered, through light through optical attenuator, power attenuation to the acceptable power bracket of filter by filter
Splitter is equally divided into 8 tunnels, enters optical fiber by different channels, along spread fiber；The reflection of optical detector detection fiber
Spectrum, and electric signal is converted optical signals to, processor receives the detection signal from optical detector, is converted as center wave
It is long, pass through interface output center wavelength.
Data processing system 102 includes the memory 104 of storage nominal data 106, processor 105 and interface 108, processing
Device 105 is by the initial center wavelength for the specific Bragg grating being stored in memory 104, i.e. nominal data 106 and the specific cloth
The measuring center wavelength 103 of loudspeaker lattice grating compares.It is measured along the maximum Bragg grating of optical fiber axial direction wavelength change
Place sensitive zones are the sensitive zones near liquid level for immersing liquid, determine dark pond according to the position between each sensitive zones
The liquid level of interior liquid.Data processing system 102 compares grating central wavelength on the first optical fiber and the second optical fiber and maximum variation occurs
Bragg grating, be further accurately determined liquid level 107, and liquid level signal 109 is exported by interface 108.
Fig. 2 is the structural schematic diagram of fiber grating liquid level sensory package 200, is showing for level sensing component shown in Fig. 1 125
Example.Level sensing component 200 includes the optical fiber 201 with multiple sensitive zones 202, capillary 120, insulating layer 121 and heating
Coil 123.Sensitive zones 202 along optical fiber 201 length positioning.Each sensitive zones 202 include the cloth loudspeaker lattice in optical fiber 201
Grating and strained layer around Bragg grating, Bragg grating 112 and strained layer 113 as shown in figure 1.Therefore, 201 class of optical fiber
It is similar to optical fiber 117 shown in FIG. 1.
As shown in Fig. 2, each sensitive zones 202 include Bragg grating (such as cloth loudspeaker lattice of a different central wavelengths
Grating 112).Fiber Bragg grating (FBG) demodulator 101 can detect the central wavelength of each Bragg grating, and be output to data processing system
In system 102.
Fig. 3 illustrates the specific embodiment of level sensing component 300, which can be level sensing component shown in Fig. 1
115 example.Level sensing component 301 includes the optical fiber 301 with multiple sensitive zones, for example, sensitive zones 302,304,
306 and 308.Optical fiber 301 is similar to optical fiber 201 shown in Fig. 2, is the example of optical fiber 114 shown in Fig. 1.Although four sensing units
Domain is as shown in figure 3, but may include the sensitive zones of four above and below according to specifically configuration, level sensing component 300.
Sensitive zones 302,304,306,308 along optical fiber 301 length arrangement.Each sensitive zones include one and are surrounded by strained layer
Bragg grating.First sensitive zones 302 include the Bragg grating 313 being arranged in optical fiber 301, and in optical fiber 301
And the strained layer 309 around Bragg grating 313.Second sensitive zones 304 include 314 He of Bragg grating in optical fiber 301
Strained layer 310 around optical fiber 301 and Bragg grating 314.Third sensitive zones 306 include the cloth loudspeaker lattice light in optical fiber 301
Strained layer 311 around grid 315 and optical fiber 301 and Bragg grating 315.4th sensitive zones 308 include the cloth in optical fiber 301
Strained layer 312 around loudspeaker lattice grating 316 and optical fiber 301 and Bragg grating 316.Bragg grating 313,314,315 and 316
Initial center wavelength be set to 1541nm, 1538nm, 1535nm, 1532nm respectively.Shown in sensitive zones 202 shown in Fig. 2 or Fig. 1
Sensitive zones 116 can be configured according to sensitive zones 302,304,360 and 308.Equally, the Bragg grating 112 in Fig. 1 can also
To be configured according to Bragg grating 313,314,315 and 316.
In specific embodiment shown in Fig. 3, sensitive zones 302,304,306,308 are separated by interval region.First passes
Sensillary area 302 and the second sensing unit 304 are separated by the first spacer region 303.Second sensing unit 304 and third sensing unit 306 are by second
Spacer region 305 separates, and third sensing unit 306 and the 4th sensing unit 308 are separated by third spacer region 307.Spacer region shown in FIG. 1
Domain 117 can be configured according to spacer region 303,305,307.In the embodiment shown in fig. 3, spacer region 303,305,307 does not wrap
Include strained layer or Bragg grating.But in other embodiments, interval region 303,305,307 may include one of strained layer
Point, but do not include Bragg grating.Fig. 3 also illustrates liquid 124 and is separated with gas 318 by liquid level 317.
Data processing system 102 by corresponding nominal data 106 in the wavelength 103 received and memory 104 into
Row comparison processing show that the Bragg grating of maximum variation occurs for wavelength.The Bragg grating be in immerse liquid near
The sensitive zones of liquid level determine the liquid level of liquid in dark pond according to the position between each sensitive zones.As shown in figure 3, cloth loudspeaker lattice
Grating 315 is immersed in liquid 124, and Bragg grating 314 is not immersed in liquid 124, so, data processing system 102
Analyzing the maximum Bragg grating of wavelength change come is Bragg grating 315, it is possible thereby to determine the liquid level of liquid 124
317 liquid level is between the second sensitive zones 304 and third sensitive zones 306.According to the relative distance between each sensitive zones,
Nominal data can accurately determine the liquid level of liquid level 124 in dark pond.In the particular embodiment, according to optical fiber 301 and light source
Certain characteristics, about 200 Bragg gratings are formed in optical fiber 301, this than have the optical fiber of less Bragg grating measurement
The liquid level of liquid 124 is more accurate in dark pond.Although 308 along light in addition, sensitive zones 302,304,306 shown in fig. 3
The spacing of fibre 301 is approximately equal.But the spacing between the sensitive zones that in other embodiments, optical fiber 301 includes may be unequal.
For example, the interval between sensitive zones may be closer (i.e. closeer than the other parts in optical fiber 301 in certain parts of optical fiber 301
It spends bigger).More dense sensitive zones can provide higher level sensing resolution ratio in the region in dark pond.
Fig. 4 illustrates the level sensing group similar with the level sensing component 300 of the level sensing component 115 of Fig. 1 and Fig. 3
Another specific embodiment of part 400.Only level sensing component 400 includes two optical fiber.Specifically, the liquid level of Fig. 4 passes
Feel the optical fiber 301 and other optical fiber 405 that component 400 includes Fig. 3.Optical fiber 405 has the characteristic essentially identical with optical fiber 301,
Such as there are multiple sensitive zones, each sensitive zones include the Bragg grating and strained layer along 405 length of optical fiber arrangement.Optical fiber
The sensitive zones of 405 sensitive zones stray fiber 301, but the interval region section aligned with optical fiber 301.Optical fiber 405 includes
The first sensitive zones that Bragg grating 410 and corresponding strained layer 406 are formed, the second Bragg grating 411 and corresponding are answered
The third sensing unit that the second sensitive zones that change layer 407 is formed, third Bragg grating 412 and corresponding strained layer 408 are formed
The 4th sensitive zones that domain, Bragg grating 413 and corresponding strained layer 409 are formed.Bragg grating 112 shown in FIG. 1
It can also be configured according to Bragg grating 410,411,412,413.
As shown in figure 4, the first sensitive zones 401 of optical fiber 405 and the first sensitive zones 302 of optical fiber 301 are long along optical fiber
Degree offset.Equally, 304 phase deviation of the second sensitive zones of the second sensitive zones 402 and optical fiber 301 of optical fiber 405.Along optical fiber
Remaining sensing unit of 405 length and the offset very little between remaining sensing unit of 301 length of optical fiber.Optical fiber 301 and optical fiber
The different channels of 405 incoming fiber optic grating demodulation instrument.The central wavelength of Bragg grating 410,411,412,413 can be with cloth loudspeaker
Lattice grating 313,314,315,316 is identical, respectively 1541nm, 1538nm, 1535nm, 1532nm.It can also be according to other etc.
Difference column distribution, such as 1543nm, 1540nm, 1537nm, 1534nm.The level sensing of embodiment shown in Fig. 4 and Fig. 3 composition
300 compare, and the sensitivity of level sensing component 400 may be higher.
Although the spacing of the sensitive zones of optical fiber 301 and optical fiber 405 is roughly the same in Fig. 4, in other embodiments,
The spacing of the two sensitive zones may be just different.Such as the sensitive zones uniform intervals of optical fiber 301, the sensing unit of optical fiber 405
Domain is unevenly spaced.In other specific embodiments, the sensitive zones of optical fiber 301 and the sensitive zones of optical fiber 405 may all be
It is non-uniform, but the same area in the sensitive zones of the two comparatively dense dark pond about shown in Fig. 1.In other specific embodiment
In, the sensitive zones of optical fiber 301 and the sensitive zones of optical fiber 405 may be unevenly spaced, and the sensing of the two comparatively dense
Area distribution is in the different zones in dark pond.
In addition, the sensory package 300 of the analysis through data processing system 102, Fig. 3 detects as described previously for Fig. 3
The liquid level 317 of liquid 124 is between the second sensitive zones 304 and third sensitive zones 306 of optical fiber 301.By by optical fiber
The sensitive zones of 405 sensitive zones and optical fiber 301 are deviated, and can be used for further refining the survey of level sensing component 300
Amount.
In Fig. 4, data processing system 102 is by corresponding calibration number in the wavelength 103 received and memory 104
Processing is compared according to 106, the maximum Bragg grating region of wavelength change is obtained, determines the position of liquid level.As shown in figure 4,
Bragg grating 412 is immersed in liquid 124, and Bragg grating 411 is not immersed in liquid 124, so, data processing system
It is Bragg grating 412 that system 102, which analyzes the maximum Bragg grating of wavelength change come, it is possible thereby to determine liquid 124
Liquid level 317 liquid level between the second sensitive zones 402 and third sensitive zones 403.Therefore, liquid can be more accurately determined
Face 317 is between the third sensitive zones 403 of optical fiber 405 and the second sensitive zones 306 of optical fiber 301.Accordingly, with respect to figure
The measurement result resolution ratio of the measurement result of scheme shown in 3, scheme shown in Fig. 4 is more accurate.But associated with optical fiber 301
Operation transient affair in, additional optical fiber may seem redundancy.
Fig. 1-4 different component parts corresponds to each other.Such as the block diagram of Fig. 1 can be with any one reality shown in Fig. 2-4
Apply that example is corresponding, the optical fiber 201 of 114 corresponding diagram 2 of optical fiber of Fig. 1, the optical fiber 405 in the optical fiber 301 or Fig. 4 of Fig. 3.Similar,
The sensitive zones 302,304,306 and 308 of sensitive zones 202 or Fig. 3 in 116 corresponding diagram 2 of Fig. 1 sensitive zones.
A kind of method 500 for measuring liquid level has been illustrated in Fig. 5.Method 500 can be by the system 100 of Fig. 1, and Fig. 2's is
Unite 200 and Fig. 3, and the combination of 4 level sensing component 300 and 400 or both is completed.
Method 500 includes, before installation, by the corresponding reference center of Bragg grating in fiber grating liquid level sensory package
Wavelength is stored into data processing system, and determines the relative distance 501 between each sensitive zones；Fiber grating liquid level is passed
Feel in component Configuration to dark pond, the tail optical fiber of optical fiber is connect with armored optical cable, accesses (FBG) demodulator 502 by terminal box；Fiber grating
(FBG) demodulator, for recording the central wavelength of the Bragg grating of the fiber grating liquid level sensory package at each terminal box, and
Transfer data to data processing system 503；Data processing system receives each channel grating that the (FBG) demodulator sends over
Central wavelength 504, the central wavelength that analysis detection arrives identifies the corresponding central wavelength 505 of each Bragg grating；It will be specific
The initial center wavelength of Bragg grating is compared with the measuring center wavelength of the specific Bragg grating, is occurred most with determining
The Bragg grating 506 of the central wavelength changed greatly；The Bragg grating institute of maximum variation occurs according to determining central wavelength
Position between the sensitive zones at place and each sensitive zones determines the liquid level 5076 of liquid in dark pond；Generate an expression liquid level
Output 508.
It should be understood that for those of ordinary skills, it can be modified or changed according to the above description,
And all these modifications and variations should all belong to the protection domain of appended claims of the present invention.
Claims (10)
1. a kind of dark pit level measuring system based on strained layer around Bragg grating, which is characterized in that fiber grating liquid level
Sensory package, fiber Bragg grating (FBG) demodulator, terminal box, data processing system, fiber grating liquid level sensory package are placed in dark pond, are used
In sensing liquid level in dark pond, optical fiber pigtail is connect with optical cable, passes through terminal box incoming fiber optic grating demodulation instrument；Fiber grating solution
Instrument is adjusted, for recording the central wavelength of the Bragg grating of fiber grating liquid level sensory package at each terminal box, and by data
It is transmitted to data processing system；The center for each channel grating that data processing system reception optical fiber grating demodulation instrument sends over
Wavelength determines the sensitive zones contacted with liquid, and raw compared with the corresponding original wavelength data stored carry out analysis
It is shown at output.
2. the dark pit level measuring system according to claim 1 based on strained layer around Bragg grating, feature exist
In an optical fiber is axially fixed in capillary in fiber grating liquid level sensory package, and tail optical fiber is connect with optical cable, by connecing
Wire box is connected to fiber Bragg grating (FBG) demodulator, and optical fiber includes multiple sensitive zones along fiber lengths interval, wherein each sensing
Region includes to generate to the strained layer around the Bragg grating and Bragg grating of the reflectance spectrum of incident photoresponse.
3. the dark pit level measuring system according to claim 2 based on strained layer around Bragg grating, feature exist
In, it further include an optical fiber in fiber grating liquid level sensory package, two optical fiber are axially fixed in same capillary, and second
Optical fiber includes the second Bragg grating group and surrounding strained layer, wherein the first optical fiber and the second intelligent acess fiber grating solution
The different channels of instrument are adjusted, the Bragg grating on two optical fiber is deviated along the length direction of optical fiber.
4. the dark pit level measuring system according to claim 2 or 3 based on strained layer around Bragg grating, feature
It is, Bragg grating is carved on every optical fiber, be spaced 1.5cm, Bragg grating possesses the pre-stretching amount of 3nm, by from top to bottom
Sequence, the wavelength of wavelength 3nm incremented by successively, two optical fiber can be identical, can also be different, wave-length coverage is in 1534nm~1558nm
Interior, minimum is no more than 1532nm, and maximum wavelength is no more than 1557nm.
5. the dark pit level measuring system according to claim 1 or 2 or 3 based on strained layer around Bragg grating,
It is characterized in that, fiber grating liquid level sensory package further includes heating device, and heating device is heated every 4 hours, heating
It is closed after 15~25 minutes, the heat source in heating device is connect with heating coil, is heated to capillary, to increase in optical fiber
Heat differential between the parts lower than liquid level other higher than the part of liquid level and optical fiber, heating coil are enclosed in capillary
Around.
6. the dark pit level measuring system according to claim 1 or 2 or 3 based on strained layer around Bragg grating,
It is characterized in that, it is 1530nm~1560nm that fiber Bragg grating (FBG) demodulator, which demodulates range,.
7. the dark pit level measuring system according to claim 1 or 2 or 3 based on strained layer around Bragg grating,
Be characterized in that, data processing system include store nominal data memory, processor by specific Bragg grating it is initial in
The long measuring center wavelength with the specific Bragg grating of cardiac wave compares；Liquid immerses below capillary, fluid temperature
Low compared with air, wavelength reduces, and sensitive zones where the maximum Bragg grating of wavelength change are immersion liquid near liquid level
Sensitive zones, the liquid level of liquid in dark pond is determined according to the position between each sensitive zones.
8. the dark pit level measuring system according to claim 1 or 2 or 3 based on strained layer around Bragg grating,
It is characterized in that, the thermal expansion coefficient of strained layer and the thermal expansion coefficient of optical fiber are different, and strained layer includes polymeric layer；Optical fiber includes
Multiple interval regions, between every a pair of of neighboring sensor region, interval region is not wrapped for the interval region setting of multiple interval regions
Include strained layer；Capillary selects stainless steel or other corrosion-resistant metal materials, heating coil outer layer covers to have insulating layer, insulating layer
Inside and outside is stainless steel, and centre is evacuated, and applies water-proof and anti-corrosive material in outer layer.
9. the dark pit level measurement method of strained layer around a kind of Bragg grating based on claims 1 or 2 or 3 systems,
It is characterized in that, this approach includes the following steps, step 1, fiber grating liquid level sensory package is configured in dark pond, optical fiber
Tail optical fiber is connect with armored optical cable, accesses (FBG) demodulator by terminal box；Step 2, fiber Bragg grating (FBG) demodulator record at each terminal box
The central wavelength of the Bragg grating of the fiber grating liquid level sensory package, and transfer data to data processing system；Step
Rapid three, data processing system receives the central wavelength for each channel grating that the (FBG) demodulator sends over, what analysis detection arrived
Central wavelength identifies the corresponding central wavelength of each Bragg grating；Step 4, by the initial center wave of specific Bragg grating
The long measuring center wavelength with the specific Bragg grating compares, to determine the cloth loudspeaker for the central wavelength that maximum variation occurs
Lattice grating；Step 5, according to sensitive zones and each biography locating for the Bragg grating of the determining maximum variation of central wavelength generation
Position between sensillary area domain determines the liquid level of liquid in dark pond；Step 6 generates the output of an expression liquid level.
10. the dark pit level measurement method of strained layer around Bragg grating according to claim 9, which is characterized in that
The optical fiber of fiber grating liquid level sensory package there are when the second optical fiber, send out according to central wavelength on two optical fiber by data processing system
Position locating for the Bragg grating of raw maximum variation between sensitive zones and each sensitive zones further more accurately determines
Liquid level.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910371117.3A CN110057426B (en) | 2019-05-06 | 2019-05-06 | Dark pool liquid level measurement system and method based on strain layer around Bragg grating |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910371117.3A CN110057426B (en) | 2019-05-06 | 2019-05-06 | Dark pool liquid level measurement system and method based on strain layer around Bragg grating |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110057426A true CN110057426A (en) | 2019-07-26 |
| CN110057426B CN110057426B (en) | 2021-03-16 |
Family
ID=67322215
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910371117.3A Active CN110057426B (en) | 2019-05-06 | 2019-05-06 | Dark pool liquid level measurement system and method based on strain layer around Bragg grating |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110057426B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111307362A (en) * | 2020-03-25 | 2020-06-19 | 电子科技大学 | Fiber bragg grating pressure sensor and using method thereof |
| CN113375760A (en) * | 2020-07-31 | 2021-09-10 | 长江三峡通航管理局 | Ship lock operation dynamic water level monitoring method based on single-point multiple sensors |
| US20230130817A1 (en) * | 2019-12-26 | 2023-04-27 | Henan Polytechnic University | The fiber bragg grating intelligent device and method for monitoring coal level in bunker |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009115422A1 (en) * | 2008-03-18 | 2009-09-24 | Siemens Aktiengesellschaft | Device for monitoring tanks on a ship |
| CN101718571A (en) * | 2009-12-04 | 2010-06-02 | 天津理工大学 | Tilt fiber bragg grating (TFBG) liquid level change measuring instrument |
| CN101793542A (en) * | 2010-03-16 | 2010-08-04 | 合肥工业大学 | High-sensitivity optical fiber grating liquid level/fluid pressure sensor |
| CN101975627A (en) * | 2010-10-30 | 2011-02-16 | 山东省科学院海洋仪器仪表研究所 | System for detecting temperature and depth of sea water by fiber bragg grating |
| CN202075015U (en) * | 2011-05-17 | 2011-12-14 | 华中科技大学 | Spiral side emitting optical fiber liquid level sensor |
| CN102865900A (en) * | 2012-09-14 | 2013-01-09 | 武汉理工大学 | FBG (Fiber Bragg Grating) liquid level sensor and preparation method thereof |
| KR20130049615A (en) * | 2011-11-04 | 2013-05-14 | 한국광기술원 | Temperature-compensated flow rate measuring apparatus based on fiber bragg grating sensors |
| CN103196520A (en) * | 2012-01-06 | 2013-07-10 | 中国计量学院 | Transmission-type optical fiber liquid level sensor with irregular core structure |
| CN103674179A (en) * | 2013-12-16 | 2014-03-26 | 昆明理工大学 | Optical fiber Bragg optical grating liquid level sensor of differential type lever structure and using method thereof |
| CN104089682A (en) * | 2014-07-18 | 2014-10-08 | 厦门大学 | Liquid level measurement device and method |
| CN106248174A (en) * | 2016-08-17 | 2016-12-21 | 河海大学 | A kind of soil stone dam seepage saturated surface optical fiber monitoring device and method |
| CN106404121A (en) * | 2016-12-02 | 2017-02-15 | 哈尔滨理工大学 | Optical fiber liquid level measurement device and method |
| CN106706075A (en) * | 2015-07-21 | 2017-05-24 | 张银强 | Method of measuring the position of the continuous casting molten steel liquid surface position with fiber optical grating sensor |
| CN207540631U (en) * | 2017-11-03 | 2018-06-26 | 深圳伊讯科技有限公司 | A kind of fiber grating Level monitor |
-
2019
- 2019-05-06 CN CN201910371117.3A patent/CN110057426B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009115422A1 (en) * | 2008-03-18 | 2009-09-24 | Siemens Aktiengesellschaft | Device for monitoring tanks on a ship |
| CN101718571A (en) * | 2009-12-04 | 2010-06-02 | 天津理工大学 | Tilt fiber bragg grating (TFBG) liquid level change measuring instrument |
| CN101793542A (en) * | 2010-03-16 | 2010-08-04 | 合肥工业大学 | High-sensitivity optical fiber grating liquid level/fluid pressure sensor |
| CN101975627A (en) * | 2010-10-30 | 2011-02-16 | 山东省科学院海洋仪器仪表研究所 | System for detecting temperature and depth of sea water by fiber bragg grating |
| CN202075015U (en) * | 2011-05-17 | 2011-12-14 | 华中科技大学 | Spiral side emitting optical fiber liquid level sensor |
| KR20130049615A (en) * | 2011-11-04 | 2013-05-14 | 한국광기술원 | Temperature-compensated flow rate measuring apparatus based on fiber bragg grating sensors |
| CN103196520A (en) * | 2012-01-06 | 2013-07-10 | 中国计量学院 | Transmission-type optical fiber liquid level sensor with irregular core structure |
| CN102865900A (en) * | 2012-09-14 | 2013-01-09 | 武汉理工大学 | FBG (Fiber Bragg Grating) liquid level sensor and preparation method thereof |
| CN103674179A (en) * | 2013-12-16 | 2014-03-26 | 昆明理工大学 | Optical fiber Bragg optical grating liquid level sensor of differential type lever structure and using method thereof |
| CN104089682A (en) * | 2014-07-18 | 2014-10-08 | 厦门大学 | Liquid level measurement device and method |
| CN106706075A (en) * | 2015-07-21 | 2017-05-24 | 张银强 | Method of measuring the position of the continuous casting molten steel liquid surface position with fiber optical grating sensor |
| CN106248174A (en) * | 2016-08-17 | 2016-12-21 | 河海大学 | A kind of soil stone dam seepage saturated surface optical fiber monitoring device and method |
| CN106404121A (en) * | 2016-12-02 | 2017-02-15 | 哈尔滨理工大学 | Optical fiber liquid level measurement device and method |
| CN207540631U (en) * | 2017-11-03 | 2018-06-26 | 深圳伊讯科技有限公司 | A kind of fiber grating Level monitor |
Non-Patent Citations (1)
| Title |
|---|
| 周院芳: "《高速公路软基智能信息化监测技术》", 30 April 2013, 冶金工业出版社 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20230130817A1 (en) * | 2019-12-26 | 2023-04-27 | Henan Polytechnic University | The fiber bragg grating intelligent device and method for monitoring coal level in bunker |
| CN111307362A (en) * | 2020-03-25 | 2020-06-19 | 电子科技大学 | Fiber bragg grating pressure sensor and using method thereof |
| CN113375760A (en) * | 2020-07-31 | 2021-09-10 | 长江三峡通航管理局 | Ship lock operation dynamic water level monitoring method based on single-point multiple sensors |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110057426B (en) | 2021-03-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110057426A (en) | Dark pit level measuring system and method based on strained layer around Bragg grating | |
| CN102052930B (en) | Fiber grating distributed strain sensor and strain monitoring method thereof | |
| CN101949744B (en) | Fiber grating-based transformer internal temperature detection system | |
| CN102147297B (en) | Distributed optical fiber temperature sensing measurement device and method | |
| CN108507697A (en) | A kind of sea water temperature depth profile sampling towed system based on Fibre Optical Sensor | |
| CN201892586U (en) | Optical fiber grating-based internal temperature detection system for transformer | |
| CN105698831B (en) | Twin-core fiber grating array sensing network and distributed sensing information acquisition method | |
| CN201909686U (en) | Distributed optical fiber temperature sensing and measuring device | |
| Korenko et al. | Novel fiber-optic relative humidity sensor with thermal compensation | |
| GB2517822A (en) | Time division multiplexing (tdm) and wavelength division multiplexing (wdm) fast-sweep interrogator | |
| AU2012283100B2 (en) | Optical network configuration with intrinsic delay for swept-wavelength interferometry systems | |
| CN115248064A (en) | Battery module detection method and detection system | |
| CN105806380B (en) | A kind of multiplexing demodulation equipment based on long-period fiber grating reflection sensor | |
| Wang et al. | High-sensing-resolution distributed hot spot detection system implemented by a relaxed pulsewidth | |
| RO126339A0 (en) | Device for measuring and monitoring the axial winding tightening force in power transformers during operation | |
| Magalhães et al. | Fiber-based distributed bolometry | |
| Kim et al. | Temperature monitoring techniques of power cable joints in underground utility tunnels using a fiber Bragg grating | |
| Datta et al. | Challenges and opportunities in distributed anti-Stokes Raman thermometry | |
| CN202994328U (en) | Fiber grating sensor | |
| CN214585039U (en) | Miniature soil moisture content measuring device and system | |
| Kim et al. | A study on internal temperature monitoring system for power transformer using pptical Fiber Bragg Grating sensors | |
| CN204389060U (en) | Transformer optical fiber grating temperature-measuring system | |
| CN103852190A (en) | Fiber bragg grating sensor for measuring temperature in ArF excimer laser cavity | |
| CN102680140A (en) | Method for measuring temperature of inflammable and explosive article based on optical fiber grating temperature sensor | |
| CN107063393A (en) | A kind of level sensor system based on single mode multimode single-mode fiber structure and Bragg grating |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |