CN204228235U - Based on the optical fiber continous way liquid level sensor system of CMFTIR effect - Google Patents
Based on the optical fiber continous way liquid level sensor system of CMFTIR effect Download PDFInfo
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- CN204228235U CN204228235U CN201420597514.5U CN201420597514U CN204228235U CN 204228235 U CN204228235 U CN 204228235U CN 201420597514 U CN201420597514 U CN 201420597514U CN 204228235 U CN204228235 U CN 204228235U
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Abstract
The utility model embodiment provides a kind of optical fiber continous way liquid level sensor system based on CMFTIR effect, relates to sensory field of optic fibre, can realize resolution high, and range is large, and robustness is good, and simple for structure.Described optical fiber continous way liquid level sensor system comprises: LED light source, the first light power meter, the second light power meter and fibre optic liquid level sensor; Wherein, described fibre optic liquid level sensor comprises nylon rod, Active Optical Fiber and passive fiber, the center section of Active Optical Fiber and passive fiber mutually fits tightly rear screw and is wrapped on described nylon rod and forms the continuous macrobend coupled structure of optical fiber, and except this part, all cover has the black fever draw; One end of Active Optical Fiber connects LED light source, and the other end connects described first light power meter; One end of passive fiber connects described second light power meter, other end black cap sealed; First light power meter and the second light power meter are positioned at same one end of fibre optic liquid level sensor.
Description
Technical field
The utility model relates to sensory field of optic fibre, particularly relates to a kind of optical fiber continous way liquid level sensor system based on CMFTIR (cladding mode frustrated total internal reflection, cladding mode frustrated total internal reflection) effect.
Background technology
At chemical production field, the storage of fluid chemical product, handling, in the processes such as transport, the Aulomatizeted Detect of liquid level is the important guarantee realizing safety work.Especially at dangerous chemicals in transit, due to the long-distance risk existing and occur to leak of jolting, if the Real-Time Monitoring of the meticulous change of liquid level effectively can not be realized, just likely cause dangerous situation to expand, even can endanger human life's safety.In addition, some chemical liquid is inflammable and explosive, such as oil, alcohol etc., requires the non-electrical measurement of liquid level signal in level gauging, to avoid electric spark blast accident occurs.More special situation, such as Fushun second branch factory of oil is in the multiple district of thunder and lightning, and electronic instrument is usually subject to electromagnetic interference (EMI) and cannot normally works.Therefore, adopt the method for optical fiber liquid level sensing, both real-time robotization was solved targetedly, non-electrical measurement, the problems such as electromagnetism interference, can ensure again economical and practical simultaneously, obtain actual application in some enterprise and become the trend of future development, there is wide development space and important social economic value.
At present, existing fibre optic liquid level sensor is mainly divided into extrinsic two classes of originally seeking peace.Extrinsic type is only utilize optical fiber as signal transmission medium, and sensing realizes indeed through additional modulating device, such as 3EFL2I series fibre fluid level transmitter, the float of employing and light code transmitter.This class sensor, usually with the mechanical motion mechanism of float and complexity, measures under being suitable for the steady quiescent conditions of liquid level, is difficult to meet in handling, the needs measured in real time under liquid level consecutive variations in transportation.Intrinsical refers to and utilizes optical fiber self as sensor.Wherein the most successfully will count pressure-sensitive formula fibre optic liquid level sensor, it utilizes foil gauge to experience the pressure of tank bottoms, and is measured the pressure values acted on foil gauge by optical fiber, thus obtains level value.Pressure-sensitive formula fibre optic liquid level sensor can be divided into light intensity reflective by the difference according to foil gauge deformation induction mode, Fabry Perot formula, micro-curved formula, birefringence formula, Bragg grating formula, long-period gratings formula etc., but owing to causing sensors with auxiliary electrode not to be suitable for handling the acceleration of generation and extra pressure in motion process, transport, the dynamic real-time measurement in motion process.In addition, the optical fiber liquid level utilizing frustrated total internal reflection principle to realize in addition probe representative equally, mainly contain two kinds of realization means, one is obtain 90 ° of total internal reflection inclined-planes at the end face of simple optical fiber by technical finesse (polishing or electric spark stretch), and light returns along original optical path after total internal reflection from the input of optical fiber one end; Two is, after utilizing prism to polish 90 ° of reflecting slant, use two optical fiber as input optical fibre and output optical fibre respectively.Through development, this type optical fiber probe has obtained extraordinary discrimination, but often difficulty of processing is larger, reflection end face vulnerable to pollution, what is more important, the sensor of sonde-type still cannot avoid mechanical moving structure, cannot be applied to and need continuously, in real time, the occasion of dynamic monitoring.The continuous level sensing of dynamic wide range optical fiber is not by the technical barrier of capturing in field always.Nineteen ninety-five being published in the fibre optic liquid level sensor proposing in the document on " IEEE Transactions onInstrumentation and Measurement " magazine " A digital leveltransducer based on optical fiber " to leak based on evanescent field light, can realize the continuous liquid level resolution of 25mm by the Betta of industrial engineering institute of Italian Cassino university.Betta removes the part of clad of optical fiber by the method for chemical corrosion, because the method needs accurately to control cladding thickness, adds the difficulty of manufacture, and is destroyed due to the original cladding structure of optical fiber, and the robustness of this sensor is deteriorated.North Dakota in 2013 founds the continuous liquid level sensor that proposes to have utilized long period fiber grating to make in the article " Simultaneous detection of liquidlevel and refractive index with a long-period fiber grating basedsensor device " that the Ying Huang of university and University of Missouri and Baokai Chen etc. delivers on " MEASUREMENT SCIENCE ANDTECHNOLOGY " magazine, achieve liquid level Resolution Error and be less than 1mm, measurement range reaches 30mm.Although this sensor achieves continuous liquid level sensor and higher resolution, range is too small, and cost of manufacture is too high, detecting instrument complex and expensive.
Utility model content
Embodiment of the present utility model provides a kind of optical fiber continous way liquid level sensor system based on CMFTIR effect, and transducer range is large, and resolution is high, and robustness is good, and simple for structure.
For achieving the above object, embodiment of the present utility model adopts following technical scheme:
Based on an optical fiber continous way liquid level sensor system for CMFTIR effect, comprising: LED light source, the first light power meter, the second light power meter and fibre optic liquid level sensor;
Wherein, described fibre optic liquid level sensor comprises nylon rod, Active Optical Fiber and passive fiber, the center section of described Active Optical Fiber and described passive fiber mutually fits tightly rear screw and is wrapped on described nylon rod and forms continuous macrobend coupled structure, and the optical fiber except center section all overlaps the black fever draw;
One end of described Active Optical Fiber connects LED light source, and the other end connects described first light power meter; One end of described passive fiber connects described second light power meter, other end black cap sealed; Described first light power meter and described second light power meter are positioned at same one end of described fibre optic liquid level sensor.
Optionally, described continuous macrobend coupled structure comprises: parallel continuous macrobend coupled structure, multiple twin continuous macrobend coupled structure and the continuous macrobend coupled structure of superposition;
Wherein, described parallel continuous macrobend coupled structure be described Active Optical Fiber and described passive fiber center section side by side parallel place rear screw be closely wrapped on described nylon rod;
Described multiple twin continuous macrobend coupled structure is that the center section of described Active Optical Fiber and described passive fiber is with after fixed step size multiple twin, high temperature wire is utilized to be wound around two outer fiber, make two close fiber optic laminatings, and form integral structure, then this structure is wound on nylon rod with fixed pitch;
Described superposition continuous macrobend coupled structure is by after carve the dark pickup groove of 2mm on nylon rod, first Active Optical Fiber is closely wound in bottom in nylon rod groove, then passive fiber superposition is wound on Active Optical Fiber.
Optionally, described Active Optical Fiber and described passive fiber are that covering is thinner, the plastic optical fiber POF that pliability is good.
Optionally, described POF optical fiber comprises standard traffic plastic optical fiber, the plastic-clad optical fiber of sensor fibre or silica core.
Optionally, described nylon rod posts in the cylindrical drum of two ends uncovered of high-reflecting film inside being inserted in.
The optical fiber continous way liquid level sensor system based on CMFTIR effect that technique scheme provides, cladding mode frustrated total internal reflection (CMFTIR) effect in standard traffic plastic optical fiber is utilized to realize continuous level gauging, without the need to destroying optical fiber original structure, simplify technology difficulty, significantly reduce cost, effectively improve the robustness of sensor.Utilize optical fiber macrobend coupled structure to strengthen CMFTIR effect, to obtain higher sensitivity, make the liquid level Sensitivity of sensor be greater than 0.7nw/mm.Propose based on multiple twin continuous macrobend coupled structure, parallel continuous macrobend coupled structure and the continous way liquid level sensor superposing continuous macrobend coupled structure three kinds of different implementations first, the liquid level sensor wherein based on the continuous macrobend coupled structure of multiple twin tests measurement range more than 365mm.Meanwhile, utilize dark field detection method, by the dark field signal of detection forward macrobend coupling port, effectively reduce ground unrest, significantly improve system signal noise ratio, liquid level resolution is less than 0.2mm.This programme, without the need to complicated weak signal extraction circuit and loaded down with trivial details related operations such as lock-in amplifiers, reduce further system complexity and cost, and improves system response time.
Accompanying drawing explanation
The structured flowchart of a kind of optical fiber continous way liquid level sensor system based on CMFTIR effect that Fig. 1 provides for the utility model embodiment;
The structural representation of a kind of parallel continuous macrobend coupled structure continous way liquid level sensor system that Fig. 2 provides for the utility model embodiment;
The structural representation of the continous way liquid level sensor system of the continuous macrobend coupled structure of a kind of multiple twin that Fig. 3 provides for the utility model embodiment;
A kind of structural representation superposing the continous way liquid level sensor system of continuous macrobend coupled structure that Fig. 4 provides for the utility model embodiment;
What Fig. 5 provided for the utility model embodiment a kind ofly makes two of multiple twin optical fiber realize the structural representation that luminous energy stablizes coupling;
Fig. 6 for the utility model embodiment provide under the continuous macrobend coupled structure of multiple twin, the relation schematic diagram between forward coupling output power and liquid level;
Fig. 7 for the utility model embodiment provide under parallel continuous macrobend coupled structure, the relation schematic diagram between forward coupling output power and liquid level.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, be clearly and completely described the technical scheme in the utility model embodiment, obviously, described embodiment is only the utility model part embodiment, instead of whole embodiments.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the utility model protection.
The utility model embodiment provides a kind of optical fiber continous way liquid level sensor system based on CMFTIR effect, as shown in the block diagram in Fig. 1, described continous way liquid level sensor system comprises: LED light source 0, the first light power meter 1, second light power meter 2 and fibre optic liquid level sensor 4.
Wherein, as shown in Figure 2, described fibre optic liquid level sensor 4 comprises nylon rod 41, Active Optical Fiber 42 and passive fiber 43, the center section of described Active Optical Fiber 42 and described passive fiber 43 mutually fits tightly rear screw and is wrapped on described nylon rod 41 and forms continuous macrobend coupled structure and non-sensitive part, and on the optical fiber except center section (i.e. non-sensitive part), all cover has the black fever draw 44.
The center section of two optical fiber is wrapped on nylon rod 41, forms continuous macrobend coupled structure, and this structure to external world medium refraction index is responsive, is the non-sensitive part of two optical fiber; Other parts are that non-sensitive part all puts the black fever draw 44, avoid the impact of unnecessary visible ray.
Optionally, described macrobend coupled structure comprises: parallel continuous macrobend coupled structure, multiple twin continuous macrobend coupled structure or superpose continuous macrobend coupled structure; Wherein, described parallel continuous macrobend coupled structure as shown in Figure 2, place rear screw and be closely wrapped on described nylon rod 41 by the center section side by side parallel of described Active Optical Fiber 42 and described passive fiber 43; The continuous macrobend coupled structure of described multiple twin as shown in Figure 3, after the center section multiple twin of described Active Optical Fiber 42 and described passive fiber 43, utilizes high temperature resistant wire 45 to be wound around two outer fiber, makes two close fiber optic laminatings, and forms integral structure.Then this structure is wound on nylon rod 41 with fixed pitch; Active Optical Fiber 42 as shown in Figure 4, after cutting on nylon rod 41, is first closely wound in bottom in groove by the continuous macrobend coupled structure of described superposition, then passive fiber 43 superposition is wound on Active Optical Fiber 42.
As Figure 1-Figure 4, one end of described Active Optical Fiber 42 connects LED light source 0, and the other end connects described first light power meter 1; One end of described passive fiber 42 connects described second light power meter 2, other end black block 3 sealing; Described first light power meter 1 and described second light power meter 2 are positioned at same one end of described fibre optic liquid level sensor 4.One end that described second light power meter 2 connects is passive fiber forward macrobend coupling port.
Optionally, described Active Optical Fiber and described passive fiber are that covering is thinner, the POF (Plastic Optical Fiber, plastic optical fiber) that pliability is good.All employing plastic optical fibers make macrobend coupled structure and all belong to this patent right, and instantiation comprises: the series standard communication POF optical fiber taking SK-40 as representative, sensor fibre, the plastic-clad optical fiber etc. of silica core.
Optionally, as shown in Figure 5, closely be wound around with high temperature resistant wire 45 after the center section multiple twin of described two optical fiber, to get rid of the interval error being wound around between two optical fiber and loosening and cause, realize the stable coupling of luminous energy, the internal stress simultaneously avoiding optical fiber multiple twin to produce and the optical fiber caused burst apart.
Optionally, described nylon rod posts in the cylindrical drum of the two open ends of high-reflecting film inside being inserted in.Described high-reflecting film not only can prevent the impact of visible ray, can also be reflected back partial radiation light, improves the efficiency of light energy utilization.
When the covering of optical fiber itself propagates light as waveguide, light at covering-environmental interface by experiences total internal reflection.When extraneous medium becomes liquid from air, the refractive index of extraneous medium becomes large, close to the refractive index even exceeding covering.Now the total internal reflection condition of covering is suppressed or destroys, and can not turn back in fibre core, thus be radiated surrounding space, and produce loss at the part light of covering-environmental interface reflection.This effect is called " cladding mode frustrated total internal reflection " (CMFTIR) effect by us.In common straight optical fiber structure, CMFTIR effect is faint to ignoring.Therefore, need special structure to strengthen CMFTIR effect, and the key strengthening CMFTIR effect is the ratio improving cladding mode in optical fiber.In this example, we utilize the continuous macrobend coupled structure of optical fiber multiple twin to realize the enhancing of CMFTIR effect, first the light of LED light source is imported Active Optical Fiber, macrobend coupling effect is there is in luminous energy by " macrobend coupled structure " position (being helically wound around the part on nylon rod), on the one hand, luminous energy is coupled into passive fiber from Active Optical Fiber; On the other hand, macrobend coupling effect inspires a large amount of cladding modes in passive fiber.Now, CMFTIR effect is enhanced.Utilize POF fibre cladding mould frustrated total internal reflection effect, because liquid refractivity is higher than air refraction, when liquid level changes, the height that liquid floods optical fiber sensitive structure changes, outer fiber refractive index is caused to increase, thus destroy the total internal reflection condition of part of clad pattern, make a part of cladding mode luminous energy generation loss.Along with the rising of liquid level, the luminous energy propagated in optical fiber decreases.Meanwhile, utilize optical fiber macrobend to be coupled the energy trasfer realized between Active Optical Fiber to passive fiber, the cladding mode energy accounting on the one hand in passive fiber is higher, thus obtains more significant CMFTIR effect; Luminous energy is made to be transferred to details in a play not acted out on stage, but told through dialogues from light field on the one hand, due to ground unrest extremely low in passive fiber, judge by the forward coupled end output power change detecting passive fiber the height that optical fiber is entirely flooded by liquid, can good signal to noise ratio (S/N ratio) be obtained, realize continuous Real-time Liquid Level Measurement.
Prove that optical fiber macrobend coupled structure strengthens CMFTIR effect with experiment below:
Control group: single straight optical fiber, a termination LED light source, a termination light power meter.Finger touches optical fiber, and the power that power meter measures gained does not change, and shows almost not observe CMFTIR effect in complete straight optical fiber.
Experimental group 1: simple optical fiber forms macrobend ring structure, a termination LED light source, a termination light power meter.Finger touches the top of fibre-optical bending part, and the normalized power that power meter measures gained declines about 5%, shows that now CMFTIR effect has and to a certain degree strengthens.This is because optical fiber macrobend causes the change of optical fiber internal mold field, in curved fiber, produce relatively more cladding mode, finger touches and causes more cladding modes to radiate, thus causes the decline of luminous power.Though now have CMFTIR effect to strengthen, but DeGrain.
Multiple twin macrobend coupled structure (TMBCS) made by experimental group 2: two optical fiber, finger touches TMBCS top, compared under straight optical fiber and single macrobend situation, the forward coupled end of passive fiber exports normalized power and have dropped 30%-40%, and fall improves greatly.This is owing to utilizing macrobend details in a play not acted out on stage, but told through dialogues to be coupled, and makes the ratio of the cladding mode in the passive fiber of TMBCS be much higher than Active Optical Fiber, thus strengthens CMFTIR effect further, the Be very effective of enhancing.
From above-mentioned experiment, multiple twin macrobend coupled structure can strengthen CMFTIR effect greatly, significantly improves the sensitivity of sensor, improves measuring accuracy.
Below apply one and specifically test proof, the continous way liquid level sensor system that the utility model provides is used for measuring liquid level and can realizes.
Adopt the multiple twin continuous macrobend coupled structure continous way liquid level sensor shown in Fig. 3 by sensor fibre, light power meter and LED light source composition.Sensor fibre be by two bare fibres (Active Optical Fiber and passive fiber) with after fixed step size multiple twin, utilize high temperature resistant wire to be wound around two outer fiber, make two close fiber optic laminatings, and form integral structure.Then this structure is helically wound around on nylon rod with fixed pitch.The sensitive part of sensor fibre is close to the part fiber through the coupling of spiral winding generation macrobend on nylon rod, and the optical fiber be not wrapped on nylon rod is non-sensitive position.In order to shield the impact of visible ray, the bare fibre of the non-sensitive part of two optical fiber being inserted in after in black plastic pipe, then connecting on light power meter or on LED light source.Utilize high temperature resistant wire to be closely wrapped on the multiple twin optical fiber of non-sensitive part, loosen to get rid of to be wound around between two optical fiber the interval error that causes, realize the stable coupling of luminous energy, the internal stress simultaneously avoiding optical fiber multiple twin to produce and the optical fiber that causes bursts apart.In the process of adding water, splashing non-sensitive part to prevent liquid causes result inaccurate, after posting the cylindrical drum of the two open ends of high-reflecting film inside being inserted by nylon rod, the more overall container putting into dress liquid.Only needing when adding water to add water in the middle of cylindrical drum and container, erroneous judgement can not be caused because spattering upper liquid.Wherein high-reflecting film not only can prevent the impact of visible ray, can also be reflected back partial radiation light, improves the efficiency of light energy utilization.
In the experiment of multiple twin continuous macrobend coupled structure level sensing, repeatedly add water in container with friction speed, pouring (A, B, C, D, E five times).Experimental result as shown in Figure 6.
It is relevant with the arrangement of optical fiber that sensor exports Level Performance slope of a curve, and when optical fiber pitch is even, curve is more level and smooth, but in non-linear.When pitch uneven distribution, now family curve undulate change, but overall close to linear.For the result that multiple twin macrobend coupled structure is measured under uneven pitch, linear fit is carried out to it.Can find, because its waveform changes, will larger error of fitting be caused.Utilize the method changing pitch, by test, careful adjustment is carried out to pitch, Level Performance curve finally can be made to present linearly, thus reduce error of fitting, improve measuring accuracy, obtain the linear relationship between forward coupling output power and liquid level.
The utility model embodiment still provides a kind of liquid-level detecting method, and liquid level can measure by the continous way liquid level sensor system according to Fig. 1-Fig. 4, said method comprising the steps of:
101, LED light source provides luminous energy to Active Optical Fiber.
102, the Output optical power obtaining passive fiber forward and be coupled is measured by the second light power meter.
103, acquisition liquid level to be measured is calculated according to described forward coupling output luminous power.
The energy of whole liquid level sensing device is provided by LED light source, and LED light source provides luminous energy to Active Optical Fiber, according to the principle of foregoing description, according to the forward coupled end i.e. output power detected of the second light power meter, can calculate and obtain liquid level to be measured.
In the utility model embodiment, if the employing of described continous way liquid level sensor system is the continuous macrobend coupled structure of multiple twin shown in Fig. 3, then the pass between described forward coupling output luminous power and described liquid level is: L
liquid=(P
2-b)/K, wherein, P
2(unit: nw) is forward coupled end output power, L
liquid(unit: cm) is liquid level, and K, b are fitting coefficient.In this patent, forward coupled end output power can be detected by our liquid level sensor.Described continous way liquid level sensor system need carry out curve fitting according to measured data, and calculates acquisition testing liquid liquid level according to concrete fitting formula.In the multiple twin of the present embodiment continuous macrobend coupled structure liquid level sensor, K=-6.8402nw/cm, b=492.9387nw.
Known average sensitivity S is defined as:
Wherein Δ y is the variable quantity of forward coupled end output power, and Δ x is liquid level variable quantity.In this example, Δ y=250nw, Δ x=365mm, then
In this example, because the resolution of power meter is less than 0.1nw.Then the resolution of liquid level sensor system is:
If what described continous way liquid level sensor system adopted is the parallel spiral formula macrobend coupled structure shown in Fig. 2, repeatedly add water in container with friction speed, pouring (A, B, C, D, E, F six times).Its experimental result is as Fig. 7.Adopt the method for matching, the pass simulated between described forward coupling output luminous power and described liquid level is:
L
liquid＝(P
2-b)/K
Wherein, P
2(unit: nw) is forward coupled end output power, L
liquid(unit: cm) is liquid level, and K, b are fitting coefficient, by detecting forward coupled end output power, thus can obtain liquid level L
liquid.
When the power bracket detected is at 104-122nw, K=-2.0310nw/cm, b=132.2276nw.
When the power bracket detected is at 122-183nw, K=-20.7494nw/cm, b=281.5061nw.
When the power bracket detected is at 183-205nw, K=-5.2159nw/cm, b=209.0623nw.
The average sensitivity of parallel spiral formula macrobend coupled structure liquid level sensor is:
Resolution due to power meter is 0.1nw, so the resolution of liquid level sensor system is:
The application utilizes macrobend coupled structure forward macrobend coupling port to extract the extremely low details in a play not acted out on stage, but told through dialogues transducing signal of ground unrest, be not vulnerable to the impact of source noise, and general fibre optic liquid level sensor affects for avoiding light source fluctuation, usual employing lock-in amplify circuit, difference and related operation improve signal to noise ratio (S/N ratio), but while adding complexity, cost, also reduce response speed.Continuous liquid level sensor of the present utility model utilizes " cladding mode frustrated total internal reflection " (CMFTIR) effect, adopt continuous macrobend coupled structure, enhance CMFTIR effect on the one hand, the detection of liquid level is realized on the one hand with the method for dark field detection, achieve in real time dynamically, continous way liquid level sensor.The method and system of application the application carries out level sensing, and level gauging resolution is high, and response speed is very fast and with low cost.
The above; be only embodiment of the present utility model; but protection domain of the present utility model is not limited thereto; anyly be familiar with those skilled in the art in the technical scope that the utility model discloses; change can be expected easily or replace, all should be encompassed within protection domain of the present utility model.Therefore, protection domain of the present utility model should described be as the criterion with the protection domain of claim.
Claims (5)
1., based on an optical fiber continous way liquid level sensor system for cladding mode frustrated total internal reflection CMFTIR effect, it is characterized in that, comprising: LED light source, the first light power meter, the second light power meter and fibre optic liquid level sensor;
Wherein, described fibre optic liquid level sensor comprises nylon rod, Active Optical Fiber and passive fiber, the center section of described Active Optical Fiber and described passive fiber mutually fits tightly rear screw and is wrapped on described nylon rod and forms continuous macrobend coupled structure, and the optical fiber except center section all overlaps the black fever draw;
One end of described Active Optical Fiber connects LED light source, and the other end connects described first light power meter; One end of described passive fiber connects described second light power meter, other end black cap sealed; Described first light power meter and described second light power meter are positioned at same one end of described fibre optic liquid level sensor.
2. optical fiber continous way liquid level sensor system according to claim 1, is characterized in that, described continuous macrobend coupled structure comprises: parallel continuous macrobend coupled structure, multiple twin continuous macrobend coupled structure and the continuous macrobend coupled structure of superposition;
Wherein, described parallel continuous macrobend coupled structure be described Active Optical Fiber and described passive fiber center section side by side parallel place rear screw be closely wrapped on described nylon rod;
Described multiple twin continuous macrobend coupled structure is that the center section of described Active Optical Fiber and described passive fiber is with after fixed step size multiple twin, high temperature wire is utilized to be wound around two outer fiber, make two close fiber optic laminatings, and form integral structure, then this structure is wound on nylon rod with fixed pitch;
Described superposition continuous macrobend coupled structure is by after carve the dark pickup groove of 2mm on nylon rod, first Active Optical Fiber is closely wound in bottom in nylon rod groove, then passive fiber superposition is wound on Active Optical Fiber.
3. optical fiber continous way liquid level sensor system according to claim 1, is characterized in that, described Active Optical Fiber and described passive fiber are that covering is thinner, the plastic optical fiber that pliability is good.
4. continous way liquid level sensor system according to claim 3, is characterized in that, described plastic optical fiber comprises standard traffic plastic optical fiber, the plastic-clad optical fiber of sensor fibre or silica core.
5. the optical fiber continous way liquid level sensor system according to any one of claim 1-4, is characterized in that,
Described nylon rod is inserted in inner side and posts in the cylindrical drum of two ends uncovered of high-reflecting film.
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| CN109099848B (en) * | 2018-09-26 | 2020-05-22 | 中北大学 | Three-dimensional displacement measuring sensor based on polymer optical fiber |
| CN113280890A (en) * | 2021-06-01 | 2021-08-20 | 重庆理工大学 | Reflection type spiral optical fiber liquid level sensor |
| CN113280890B (en) * | 2021-06-01 | 2023-01-20 | 重庆理工大学 | Reflection type spiral optical fiber liquid level sensor |
| CN113959527A (en) * | 2021-10-21 | 2022-01-21 | 南昌大学 | Liquid level sensor prepared based on plastic optical fiber macrobending method |
| CN113959527B (en) * | 2021-10-21 | 2023-11-24 | 南昌大学 | Liquid level sensor prepared based on plastic optical fiber macrobending method |
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