CN103557985B - A kind of differential pressure method for sensing and sensor thereof - Google Patents
A kind of differential pressure method for sensing and sensor thereof Download PDFInfo
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- CN103557985B CN103557985B CN201310537492.3A CN201310537492A CN103557985B CN 103557985 B CN103557985 B CN 103557985B CN 201310537492 A CN201310537492 A CN 201310537492A CN 103557985 B CN103557985 B CN 103557985B
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Abstract
The invention discloses a kind of differential pressure method for sensing and sensor thereof, it goes the wherein one side of impact one piece of flexible sheet (113) by the pressure that test fluid produces, simultaneously with the another side of narrow spectrum laser according to flexible sheet (113), flexible sheet (113) is deformed, after flexible sheet (113) deforms, the output light intensity receiving optical fiber (41) will change thereupon, by detecting that the variable quantity receiving optical fiber (42) output intensity judges the pressure variety that test fluid causes flexible sheet (113).Owing to adopting such method, this sensor senses accuracy is higher, dependable performance, and structure is simple, and volume mass is all less, and manufacturing cost is also lower.
Description
Technical field
The present invention relates to differential pressure method for sensing and sensor thereof, belong to sensor technical field.
Background technology
Differential pressure pick-up DPS(Differential Pressure Sensor) be a kind of sensor being used for difference between measurement two pressure, be generally used for the pressure reduction measuring a certain equipment or parts rear and front end.In recent years, differential pressure pick-up all has a wide range of applications in many high-acruracy survey occasions such as micro-flow measurement, leakage test, clean room monitoring, environmental sealing detection, gas flow measurement, height of liquid level measurements.
The domestic and international research to differential pressure pick-up now mainly concentrates on traditional piezoresistance type differential pressure transducer and capacitance differential pressure transducer.Piezoresistance type differential pressure transducer structure is simple, and operative end surface is smooth, but there is the contradiction comparing and give prominence between its sensitivity with frequency response, and temperature is also larger to the performance impact of this kind of sensor.Capacitance type sensor is highly sensitive, dynamic response characteristic is good, anti-overload ability is strong, but there is the impact on sensitivity and measuring accuracy of stray capacitance and distributed capacitance in it, and the shortcoming such as the circuit more complicated to be connected with sensor, have influence on its application reliability, because which limit its widespread use.Just because of many deficiencies of traditional differential pressure sensors, start the differential pressure pick-up novel to some to be both at home and abroad studied, Dong Guoqiang etc. are studied utilizing a kind of little differential pressure sensor of magnetic liquid, magnetic liquid displacement process is under pressure relied on to produce electric signal, realize the detection to pressure, it has limitation in the application; The people such as the Jose.L.A.V of the Hao-Jan Sheng in Taiwan etc., the U.S. propose a kind of optical fiber differential pressure pickup structure based on Bragg grating separately, the sensitivity of this fiber grating differential pressure pick-up is higher, but complex structure and cost is very high, is unfavorable for promoting.And intensity modulated as in fiber optic sensor technology with the most a kind of modulator approach, obtain the research of some scholars, but it is little to the Research Literature of the optical fiber differential pressure pickup based on intensity modulated, the Seiichiro Kinugasa of Japan proposes a kind of design of reflection type optical fiber differential pressure pick-up, utilizes the change of reflecting surface and fiber distance to detect the situation of external pressure difference; Tong Chengguo etc. devise a kind of optical fiber differential pressure pickup of double C-type bourdon tube, detect in two double C-type bourdon tubes according to intensity modulated principle to pressure reduction.
But the problem that prior art does not still solve the realization of sensor, the rationality of sonde configuration parameter, many key factors such as duty, compensation of error of reflecting surface are brought, therefore in prior art, such sensor construction is very complicated, and performance is reliable not, processing and manufacturing cost is also very high, and volume is large usually, very heavy, use inconvenience, also there is very large room for improvement.This is first technical matters that prior art exists.
In addition; sensor probe is reliable and stable at work; be not vulnerable to the interference of the factors such as extraneous collision, vibration; simultaneously in order to the error protecting the sensitive element in probe, avoid the difference due to this body structure of popping one's head in bring; must encapsulate probe; and the encapsulation of sensor probe, this is second technical matters that prior art exists.
For the reflection type optical fiber differential pressure pick-up of intensity modulated principle, the output light intensity of different probe will certainly be subject to the impacts such as bias light, fiber lengths, fibre-optical bending degree, coupled apparatus, thus making testing result there is comparatively big error, this is the 3rd technical matters that prior art exists.
Summary of the invention
For solving three problems that prior art exists, must compensate from the light intensity of sensor probe configuration, sensor package and probe output light and setting about.For this reason, such object can be realized from following three aspects.
The problems such as sensor construction is complicated in order to solve, performance is reliable not and processing cost is high and volume mass is large, intend adopting so a kind of differential pressure method for sensing and sensor thereof, the main points of this method for sensing are, it carries out sensing by the test fluid (as hydraulic oil) producing pressure for weighing measured object, the pressure that this test fluid is produced goes the wherein one side of impact one piece of flexible sheet, and flexible sheet is deformed; Narrow spectrum laser in the another side incident optical of flexible sheet irradiates, and receives reflected light with reception optical fiber; Like this, after flexible sheet deforms, because reflection angle changes, reflected light changes thereupon, cause the output light intensity receiving optical fiber to change, like this by detecting that the variable quantity receiving optical fiber output intensity judges the pressure variety that test fluid causes flexible sheet thereupon.Like this, just by being convenient to the light intensity change of measuring, the pressure change of not easily measuring can being judged, thus determine the pressure difference value of different measured objects, realizing the object of differential pressure sensing.
As a kind of optimal way, test fluid produces pressure by the mode of an inflow test chamber to flexible sheet, and flexible sheet is arranged in test chamber and the direction that test fluid flows in test chamber forms closed barrier.Test chamber is closed, but is being provided with an opening towards the direction of measured object, when test fluid pours in test chamber from the opening of test chamber, will produce fluid pressure, thus cause the distortion of flexible sheet to the flexible sheet in test chamber.When the media environment in chamber changes, elastic membrane sector-meeting produces distortion owing to being under pressure, and the medium preferably in test chamber is in a kind of equally distributed situation, and therefore it will produce an equally distributed load to the surface of whole film.Adopt such test chamber, the fluid pressure that test fluid can be made to produce evenly and exactly makes flexible sheet produce distortion, improves the precision detecting sensing.
In order to avoid flexible sheet is subjected to displacement at edge when being subject to the pressure that test fluid produces, a sensor probe housing can be adopted to be fastened thereon by described flexible sheet, sensor probe housing can adopt monolithic construction with test chamber, and flexible sheet is fixedly installed between sensor probe housing and test chamber.Because flexible sheet is securely held, the fluid pressure no matter test fluid causes it is much, all only can make elastic deformation occurs in its face, and its edge can not be made to be subjected to displacement, prevent like this because thin slice is broken emat sensor by fluid impact.In addition, incident light is irradiated to flexible sheet by the fixed orifice in sensor probe housing.The surface of fixed orifice and flexible sheet in vertical state, can be guaranteed when incident optical, the incident light irradiating angle receiving the fibre bundle of optical fiber or the two formation or reflection angle can not arbitrarily offset.
In order to make sensor, there is good static properties, the winding degree that so flexible sheet produces when compressive deformation will be very little, consider the specific works situation of sensor construction flexible sheet, the performance of comprehensive various material, preferred 35CrMnSi material carries out preparation of sections.This material is also known as low-alloy super-strength steel, there is after thermal treatment good comprehensive mechanical property, high strength, enough toughness, quenching degree, weldability (weld preheating), formability are all better, but its corrosion stability and antioxygenic property are comparatively general, serviceability temperature, usually not higher than 200 DEG C, is generally use after lonneal or isothermal quenching.
Based on aforesaid this method for sensing, a kind of like this reflection type optical fiber bundle differential pressure pick-up of intensity compensation can be adopted, it comprises the identical pressure detection probe of two structures and for the incident optical of transmission light source in this pressure detection probe and the radiative reception optical fiber for receiving pressure detection probe, and formation fibre bundle assembled by incident optical and reception optical fiber in fixed orifice.This pressure detection probe inside is fixed with one piece of flexible sheet, and the two sides being arranged in flexible sheet in this pressure detection probe is respectively equipped with a test chamber and can inserts the fixed orifice of probe for fibre bundle.Test chamber is used for test fluid and flows in it and to produce fluid pressure to flexible sheet.Test chamber is provided with at least one can for test fluid inflow test fluid entrance wherein.Preferably such: sensor is provided with two light sources, is assumed to S1, S2, two detection probe one, probe two, two photodetectors D1, D2, the fiber coupler of four one-to-two, and the fiber bundle structure of incident optical and mirror based fiber optica set bunchy forms.Sensor light source selects semiconductor laser, and this laser instrument has very narrow output spectrum live width and outstanding side mode suppression ratio, and it exports peak wavelength is 1310nm.PIN photodiode selected by photodetector, and this photodiode work wavelength coverage is 1100nm ~ 1650nm, and dark current is 1nA to the maximum, and optical responsivity is minimum is 0.85A/W, response time 0.1ns.Light source is made to mate better with the spectral characteristic of photodetector two elements like this.
What light source sent couples light in incident optical, be transferred to fiber exit end face by incident optical, emergent light is irradiated in reflection shell fragment (flexible sheet), and the part light after the reflection of reflection shell fragment enters into and receives in optical fiber, by reception Optical Fiber Transmission to photodetector, carry out opto-electronic conversion.Enter into the intensity of reflected light size received in optical fiber, determined by reflection shell fragment and the distance received between fiber end face, when under External Force Acting, reflection shell fragment diminishes with the distance receiving optical fiber, thus the intensity of reflected light entering into reception optical fiber is changed, the deformation size of reflecting surface can be determined by the variable quantity of output light intensity, thus determine the size of ambient pressure P.
Certainly, the pressure detection probe of this sensor also comprises a probing shell, and above-mentioned fixed orifice, flexible sheet and test chamber are all positioned within this probing shell.Test chamber and probing shell are preferably processed into one-piece construction.The Material selec-tion metal material of probing shell, in processing conveniently, preferably adopts metallic aluminium bar.
For solving the encapsulation problem of sensor probe, make probe firm, be convenient to processing and realize, be convenient to assembling, be convenient to maintain and replace, intend adopting so a kind of method for packing and structure:
Differential pressure pick-up of the present invention is two free style structures simultaneously worked of popping one's head in, and probe segment can be freely movable, can the position detected be needed to detect by unrestricted choice; In detection, probe can be directly fixed on and detect position, and need not carry out drainage, thus avoid that drainage tube drainage process occurs freeze, block and sluggishness; According to detection needs, the probe that physical dimension is different from sensing range can also be designed, in order to meet some specific demands etc., requires that two probes are symmetrical as much as possible identical simultaneously.For single probe, in encapsulation, following requirement to be met: fibre bundle well aims at the center of flexible sheet, adjustable, the fibre bundle of distance of fibre bundle and flexible sheet can well be fixed, and this is also the difficult point place of this probe encapsulation.
So present invention employs mechanical type packaged type, this mode can ensure machining precision, and assembly precision, makes the structure of each probe processed identical, thus be beneficial to and realize standardization, seriation, universalization, the metrical error that can also well avoid structural failure to bring.
In order to realize above-mentioned requirements, the feature of this sensor package is: adopt thread bush to be fixed the fibre bundle in fixed orifice, fibre bundle can not be moved, avoid fibre bundle to shake the error brought.Specific practice is: from the screw thread precession of export-oriented flexible sheet direction in the internal thread fixed orifice formed at probing shell with a cylindrical external thread end cap, there is a threaded hole at end cap central place, with a thread bush, fibre bundle is enveloped again, the internal thread of the external thread of thread bush and the threaded hole at end cap central place matches, and enables thread bush screw in end cap or screw out.Therefore, the thread connection form of thread bush and end cap, realize thread bush can precession freely in end cap (preferred thread pitch is 0.2mm, thread bush outer wall mark precession length scale, minimum scale is 0.1mm), thus the distance realizing fibre bundle and flexible sheet is adjustable; (because the initial distance of fibre bundle and flexible sheet directly determines the detection sensitivity of the sensor static characteristics crucial with the linearity these two, set up the initial distance of getting well rational fibre bundle and flexible sheet, raising detection perform.The optimum initial distance that simultaneously different fibre bundle end face structures is corresponding is different, so require that the distance of fibre bundle and flexible sheet is adjustable.) the hole axle of fixed orifice of the threaded hole of end cap, thread bush and probe keeps coaxial, this cylindrical encapsulating structure of such employing, add the right alignment having ensured each part man-hour, can ensure that fibre bundle well aims at the center of flexible sheet, structure is simply applicable.Flexible sheet can well be fixed, and easily assembling and replacing.
At the another side of flexible sheet, adopt a back-up ring to be blocked by flexible sheet, flexible sheet, by the screw thread precession of this end cap and back-up ring squeezing fixing method, can reach good fixation, not easily loosen.Meanwhile, as flexible sheet needs to change, screwing out end cap can realize, simply applicable.Meanwhile, at the test fluid inlet ambient of the test chamber of probe, also packing ring is set, screen pack is set in test fluid porch, the fluid entering test chamber is filtered.
The stability of test chamber and medium uniformity are the requirements ensureing that of sensing accuracy is important, and test chamber therefore must be made to reduce the disturbance of fluid.So adopt such structure: fill a cup-shaped vitreum in test chamber, vitreum is stuck between back-up ring and sensor housing, makes test chamber be cup-shaped cavity structure, can reduce the volume of test chamber like this, thus make the fluid of delay little.Reduce to detect the uneven of cavity pressure simultaneously, make the pressure acted on flexible sheet more easily become even.Select vitreum be because its easily shaping, hardness is high, the long-term corrosion etc. of fluid-resistant.
In order to prevent test fluid from revealing, an O-ring seal can also be installed additional between flexible sheet and back-up ring.Flexible sheet is fixed by end cap, end cap and housing adopt interference fit structure, fibre bundle is fixed in thread bush, add the circularity and right alignment that ensure sensor housing, end cap, thread bush man-hour preferably, thus the center alignment issues of fibre bundle and flexible sheet can be ensured, avoid the error that in detecting, certain probe causes because of the position deviation of fibre bundle and flexible sheet.Thread bush and end cap adopt thread connection, and are carved with scale on thread bush surface, thus can be adjusted the distance of fibre bundle and flexible sheet by the precession of threaded engagement.Can also make to form dark chamber between fibre bundle and flexible sheet by mechanical encapsulation, thus the noise avoiding bias light to bring.
What fibre bundle differential pressure pick-up detection probe adopted is intensity modulated principle, by monitoring to the intensity size variation of light the change judging measurand, the light intensity change that such light source, optical fiber, optical fibre device and photo-detector etc. cause will cause error to testing result.In order to avoid or reduce this metrical error, just should consider to carry out intensity compensation to this type of intensity modulation optical fiber sensor, thus improve the detection Stability and dependability of sensor.
The light intensity compensation method that this sensor of the present invention adopts is: first sensor adopts two light sources alternately luminous, during one of them light source luminescent, first light wave is coupled into an incident optical, again through the Y type coupling mechanism of one-to-two, the two-way light wave being divided into power equal, one tunnel directly arrives a photodetector through reference path, and be converted to voltage signal through this detector and export, namely the size of this voltage signal reflects the size of light source output power half; Another road after testing light path arrives detection probe one, after flexible sheet reflection, another photodetector is arrived again through receiving optical fiber, be converted to voltage signal through this detector to export, namely the size of this voltage signal reflects second half of light source output power, the luminous power size received after reflection; Calculate the ratio of these two output voltages again in the later stage, this ratio size just has nothing to do with the changed power of light source, is reflected the size of detection probe one pressure by this ratio, just can eliminate the error that light source fluctuation produces.
During another one light source luminescent, with said process in like manner, reflected the size of another detection probe two place pressure by ratio.
Again by the difference of the ratio of calculating detection probe one, detection probe two output, or the ratio of ratio.Finally reflect the pressure difference value between two probes.And the intensity compensation by asking the difference of ratio can realize light source fluctuation; The intensity compensation (but the pressure difference detection scope of this method is little) that can realize light source fluctuation, photodetector and fibre loss by asking the ratio of ratio.
Light path adopts the distribution form of light bridge-type, the reference path of two light sources is made to arrive same photodetector through Y type coupling mechanism, the reflected light receiving light path of two detection probe arrives another photodetector through Y type coupling mechanism, thus simplify the overall light channel structure of sensor, make light path optical fiber layout simple, reduce detector number simultaneously, make the data processing module in later stage have also been obtained simplification.Finally realize the design of economy and reliability.
Accompanying drawing explanation
Fig. 1 is differential pressure pick-up sonde configuration schematic diagram;
Fig. 2 is differential pressure method for sensing schematic diagram;
Fig. 3 is differential pressure pick-up probe encapsulating structure schematic diagram;
Fig. 4 is the fibre bundle index path of differential pressure method for sensing;
Fig. 5 is fiber bundle structure schematic diagram;
Fig. 6 is that light bridge balance strength compensates schematic diagram;
Incident optical coordinate diagram when Fig. 7 is light intensity calculating;
Fig. 8 is the EF schematic cross-section in Fig. 7;
Fig. 9 receives fiber end face and reflective taper position relationship;
P-M curve when Figure 10 is parameter d change in Fig. 7;
P-M curve when Figure 11 is parameter r change in Fig. 7;
P-M curve when Figure 12 is parameter l change in Fig. 7;
Figure 13 is the data and curves of experiment (1);
Figure 14 is the data and curves of experiment (2);
Figure 15 be experiment (1) and (2) in two sensing probes under different pressure effects, when forming different differential pressure Δ P, the R value situation of change of output.
Description of reference numerals: 11-pops one's head in one, 111-test chamber, 112-probing shell, 113-flexible sheet, 12-probe two, 21-photodetector one, 22-photodetector two, 31-measured object one, 32-measured object two, 4-fibre bundle, 41-receives optical fiber, 42-incident optical, 51-light source one, 52-light source two, 61-coupling mechanism one, 62-coupling mechanism two, 63-coupling mechanism three, 64-coupling mechanism four, 71-signal processor one, 72-signal processor two, 81-end cap, 82-thread bush, 83-O-ring seal, 84-screen pack, 85-back-up ring, 86-packing ring, 87-vitreum.
Embodiment
Below in conjunction with drawings and Examples, the present invention is described in further detail.
First see Fig. 1, Fig. 1 illustrates the structural principle of differential pressure pick-up of the present invention probe, as we can see from the figure, differential pressure pick-up has two probes, and namely the structures of probe 1 and probe 2 12, two probe are identical, in probing shell 112, occupy probe near middle position be provided with one piece of flexible sheet 113, probing shell 112 interior separation is become two parts by this flexible sheet 113, is a test chamber 111, and another side is a fixed orifice.Test chamber 111 can flow into for test fluid, and fixed orifice can insert for fibre bundle 4.Fibre bundle 4 receives optical fiber 41 through processing set bunchy (composition graphs 5 can see the structure of fibre bundle 4) by 1 incident optical 42 and 10.
See Fig. 2, Fig. 2 illustrates probe sensing principle of the present invention, and the sonde configuration shown in composition graphs 1, what light source sent couples light in incident optical, be transferred to fiber exit end face by incident optical, emergent light is irradiated in reflection shell fragment (flexible sheet 113 namely in Fig. 1), and the part light after the reflection of reflection shell fragment enters into and receives in optical fiber, by reception Optical Fiber Transmission to photodetector, carry out opto-electronic conversion.Enter into the intensity of reflected light size received in optical fiber, determined by reflection shell fragment and the distance received between fiber end face, when under External Force Acting, reflection shell fragment diminishes with the distance receiving optical fiber, thus the intensity of reflected light entering into reception optical fiber is changed, the deformation size of reflecting surface can be determined by the variable quantity of output light intensity, thus determine the size of ambient pressure P.
See Fig. 3, Fig. 3 illustrates the encapsulating structure of probe, after adopting such encapsulating structure, test fluid flows into from intake, test chamber 111(composition graphs 1 is entered) after screen pack 84, in order to reduce the disturbance of fluid, installed the vitreum 87 with cup-shaped cavity in test chamber 111, vitreum 87 is fixed by probing shell 112 and back-up ring 85.In order to prevent revealing, between flexible sheet 113 and back-up ring 85, install O-ring seal 83 additional.Flexible sheet 113 is fixed by end cap 81, end cap 81 and probing shell 112 adopt thread connection form, fibre bundle 4 is fixed in thread bush 82, add the circularity and right alignment that ensure sensor probe housing 112, end cap 81, thread bush 82 man-hour preferably, thus the center alignment issues of fibre bundle 4 and flexible sheet 113 can be ensured, avoid the error that certain probe in detecting causes because of fibre bundle 4 and the position deviation of flexible sheet 113.Thread bush 82 and end cap 81 adopt thread connection, and are carved with scale on thread bush 82 surface, thus can be adjusted the distance of fibre bundle 4 and flexible sheet 113 by the precession of threaded engagement.Dark chamber can also be formed between fibre bundle 4 and flexible sheet 113 by mechanical encapsulation, thus the noise avoiding bias light to bring.
See Fig. 4, the light intensity that Fig. 4 illustrates this differential pressure method for sensing of the present invention compensates schematic diagram, as we can see from the figure, sensor adopts two light sources alternately luminous (by Control), namely light source 1 and light source 2 52 are alternately luminous, when light source 1 is luminous: the light that light source 1 sends is divided into two-way through coupling mechanism 1, and a road enters probe 1, arrive photodetector 1 through coupling mechanism 2 62 after reflection, another road directly arrives photodetector 2 22.The light path arriving photodetector 2 22 is reference path, reflect the size of light source 1 Output optical power, arrive the light path of photodetector 1 for detecting light path, reflect through probe 1 be reflected back receive optical fiber 41(and now receive optical fiber 41 and assemble fibre bundle 4, composition graphs 1 with incident optical 42) luminous power size (the tested pressure correlation of the size of this power and the external world).Again by asking the ratio of now two detector output voltage signals, the error realized light source power fluctuation etc. causes compensates.The ratio finally obtained just embodies probe one under extraneous pressure P 1 acts on, the output valve of sensor.
When light source 2 52 is luminous: the light that light source 2 52 sends is divided into two-way through coupling mechanism 3 63, and a road enters probe 2 12, arrive photodetector 1 through coupling mechanism 4 64 after reflection, another road directly arrives photodetector 2 22.When its principle and above-mentioned light source 1 luminescence in like manner.Signal in photodetector 1 and photodetector 2 22 processes respectively by signal processor 71 and signal processor 72, and the ratio finally obtained just embodies probe 2 12 under extraneous pressure P 2 acts on, the output valve of sensor.
Pressure difference value △ P between ambient pressure P1 and P2, by popping one's head in, one 11 output valves represent with the probe ratio of 2 12 output valves or difference.
See Fig. 6, Fig. 6 illustrates principle and the light intensity compensation schematic diagram of differential pressure method for sensing of the present invention, two light sources are under the control of the time relay, one after the other luminescence (when namely light source S1 is luminous, light source S2 is not luminous), in Fig. 6 two light source S1, S2 in turn etc. time luminous, t1 represents S1 fluorescent lifetime, and t2 represents S2 fluorescent lifetime, M1, M2 are two differential pressure probes, and D1, D2 are photodetector.In the t1 time, the light that light source S1 sends is divided into two-way through Y type coupling mechanism, and a road enters probe M1, and arrive photodetector D1 after reflection, another road directly arrives photodetector D2; In the t2 time, the light that light source S2 sends is divided into two-way through Y type coupling mechanism, and a road enters probe M2, and arrive photodetector D1 after reflection, another road directly arrives photodetector D2.The electric signal that later stage exports photodetector D1, D2 amplifies, filtering, A/D conversion, again t1 time two detector output signal is divided by, t2 time two detector output signal is divided by and time delay, then t1, t2 time two division signal is divided by, can settling signal process.Sensor light source selects semiconductor laser LD, and this laser instrument has very narrow output spectrum live width and outstanding side mode suppression ratio, and it exports peak wavelength is 1310nm.PIN photodiode selected by photodetector, and this photodiode work wavelength coverage is 1100nm ~ 1650nm, and dark current is 1nA to the maximum, and optical responsivity is minimum is 0.85A/W, response time 0.1ns.The initial distance setting up fibre bundle and diaphragm in sensor probe is 0.5mm, and diaphragm material is stainless steel surfaces aluminized mirror, and fibre bundle is that multiply incident optical and sub-thread outgoing optical fiber are processed into bundle.
As shown in Figure 5, that middle be incident optical TF to the fibre bundle sectional view at probe place, around be reception fiber-optic RF.Increasing the radical receiving optical fiber is to receive more reflected light.This fiber bundle structure is coaxial type fibre bundle, and this fibre bundle is more conventional, and its detection sensitivity is higher, is easier to processing and realizes, and be conducive to the analytical calculation in later stage.
Know-why of the present invention is explained further below by the mathematical analysis of flexible sheet deformation:
1, when the media environment in chamber changes, elastic membrane sector-meeting produces distortion owing to being under pressure, and the medium in usual chamber is in a kind of equally distributed situation, and therefore it will produce an equally distributed load to the surface of whole film.Suppose that cavity pressure is P, the radius of film is R
b, the bending stiffness of film basic unit is k.
2, intensity modulated model:
Owing to being subject to the restriction of structure and light intensity modulation characteristic effective coverage etc., the deflection of flexible sheet is relatively little, so for the ease of analyzing, be that cross section (claiming reflective taper cross section afterwards) d) in plane can approximate processing become a rounded face (in front view its reflector space in y=d(optical fiber and the distance between film, can see that its diameter is EF), the situation below utilizing its front view symmetrical with receiving optical fiber to incident optical carries out the quantitative analysis research of two dimension.
In the figure 7, incident optical left margin light l
aBbe irradiated on deformable membrane, with film curve intersection in B point, and incident optical right margin light l
cDbe irradiated on deformable membrane, with film curve intersection in D point.The coordinate figure of B, D two intersection points in this coordinate system, is the curvilinear equation of deformable membrane in front view, with two incident ray l
aB, l
cDmatrix equation (10), simultaneous solution system of equations, the solution of gained.
Again as shown in Figure 7, left incident ray l
aBafter film reflector, its left reflection ray is l
bE, right incident optical l
cDafter film reflector, its right reflection ray is l
dF.Obtain the straight-line equation of mirror based fiber optica, first should obtain the slope of this straight-line equation, and to know on its line certain any coordinate figure, and the coordinate figure its line being put B, D is obtained, so just should obtain straight line l now
bEslope k
5, straight line l
dFslope k
6.
Establish again incident ray l
aBbe the tangent line L of B point
1between angle be α, tangent line L
1to reflection ray l
bEbetween angle be also α; Same incident ray l
cDbe the tangent line L of D point
2between angle be β, tangent line L
2to reflection ray l
dFbetween angle be also β.If reflection ray l
bE, l
dFslope be respectively k
5, k
6, thus following equation can be set up:
3, simulation calculation:
If Figure 10, Figure 11, Figure 12 are that initial distance d between flexible sheet and optical fiber is respectively 150 μm, 200 μm, 250 μm, 300 μm, fiber radius r is respectively 45 μm, 50 μm, 55 μm, 60 μm, when optical fiber pitch l is respectively 15 μm, 18 μm, 21 μm, 24 μm, flexible sheet is applied to the pressure P of certain limit, make it the convex modification close to optical fiber occurs, thus the reception optical fiber output intensity rate of change curve drawn.
Be not difficult to find out from Figure 10, d value is less, and namely flexible sheet and optical fiber lean on nearer, and so its initial output intensity ratio is larger, and d value is larger, and its initial output intensity ratio is less; Simultaneously under a certain d value determined, along with the increase of pressure P, the distance of flexible sheet and optical fiber can diminish, thus the increase that takes the lead in of output intensity ratio is reduced again, and this and actual conditions match.Scarp slope curve in figure is wider, can obtain larger sensing range; And adverse grade curve is narrower, the good linearity and detection sensitivity can be obtained;
As can be seen from Figure 11, along with the change of fiber core radius r, the change of scarp slope curve width is not obvious; But along with the increase of fiber core radius r value, the peak value of curve increases to some extent;
As can be seen from Figure 12, along with the change of spacing l value, the change of scarp slope curve width is little, namely little on the sensing range impact of pressure P; Along with the increase of spacing l value, the peak value of curve can decline.
4, experimental data:
After sensor probe 1,2 is fixing, complete following process experiment respectively: the applied pressure of (1) sensor probe 2 is 0, change the applied pressure of sensor probe 1, make two detection positions realize the positive pressure differential of 0KPa, 20 KPa, 40 KPa, 60 KPa, 80 KPa, 100 KPa, 120 KPa; (2) applied pressure of sensor probe 1 is 0, changes the applied pressure of sensor probe 2, makes two detection positions realize the Negative Pressure Difference of-120 KPa ,-100 KPa ,-80 KPa ,-40 KPa ,-20 KPa.
Obtain following experimental result (as shown in Table 1 and Table 2):
The experimental data curve simultaneously obtained is as shown in Figure 13, Figure 14:
Figure 15 is for two sensing probes in experiment (1) and (2) are under different pressure effects, when forming different differential pressure △ P, the R value situation of change exported, be not difficult to find out in figure that negative pressure (being greater than probe 1 pressure for probe two pressure here) is better with the front end curve linear degree of malleation (being greater than probe two pressure for probe one pressure here), so follow-uply again translation is carried out to intensity compensation R value, and linearization demarcation can make output valve better corresponding with each pressure difference, thus realize the detection of pressure reduction to external world.
Certainly, more than just embody rule example of the present invention, the technical scheme that the present invention also has other embodiment, all employings to be equal to replacement or equivalent transformation to be formed, all drops within protection domain of the presently claimed invention.
Claims (3)
1. the reflection type optical fiber bundle differential pressure pick-up of an intensity compensation, it is characterized in that: it comprises the identical pressure detection probe one (11) of two structures and probe two (12) and for the incident optical (42) of transmission light source in these two probes and the radiative reception optical fiber (41) for receiving pressure detection probe, incident optical (42) and reception optical fiber (41) assemble fibre bundle (4); Probing shell (112) inside of these two probes are fixed with one piece of flexible sheet (113), the two sides being arranged in flexible sheet (113) in probe be respectively equipped with a test chamber (111) and can supply fibre bundle (4) insertion to pop one's head in fixed orifice; In test chamber (111), fill the vitreum (87) of a cup-shaped, vitreum (87) is stuck between back-up ring and sensor housing, makes test chamber be cup-shaped cavity structure; Vitreum (87) is fixed by probing shell (112) and back-up ring (85).
2. the reflection type optical fiber bundle differential pressure pick-up of intensity compensation according to claim 1, is characterized in that: described test chamber (111) and probing shell (112) are processed into one-piece construction.
3. the reflection type optical fiber bundle differential pressure pick-up of intensity compensation according to claim 1, is characterized in that: described test chamber (111) is provided with at least one can for test fluid inflow test fluid entrance wherein.
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| CN108775981A (en) * | 2018-06-12 | 2018-11-09 | 南昌大学 | A kind of high-precision differential type diaphragm optical fiber pressure capsule system |
| CN110017935A (en) * | 2019-04-18 | 2019-07-16 | 广东万和热能科技有限公司 | A kind of wind pressure sensor |
| CN110522424B (en) * | 2019-08-21 | 2020-12-29 | 清华大学 | Novel pressure sensor and physiological signal measuring method thereof |
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2088248U (en) * | 1990-12-21 | 1991-11-06 | 东南大学 | Double diaphragm optical fiber differential pressure pickup |
| CN1059970A (en) * | 1990-09-15 | 1992-04-01 | 大连理工大学 | Compensating method of high-precision and-intensity optical fibre sensor with dual-wavelength modulation |
| CN1589396A (en) * | 2001-09-21 | 2005-03-02 | 株式会社山武 | Physical quantity measuring method and its device |
| CN101169334A (en) * | 2007-11-21 | 2008-04-30 | 北京理工大学 | Intensity modulation type optical fiber sensor multiplexing method |
| CN201233250Y (en) * | 2008-06-19 | 2009-05-06 | 上海前所光电科技有限公司 | Grouping synchronization type optical fiber sensing analyzer |
| CN101799304A (en) * | 2010-04-12 | 2010-08-11 | 哈尔滨工程大学 | Reflection type differential strength modulating optical fiber sensing device and method thereof |
| CN203551183U (en) * | 2013-11-04 | 2014-04-16 | 贵州大学 | Reflective optical-fiber-bundle differential pressure sensor with intensity compensation |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3999600B2 (en) * | 2001-09-21 | 2007-10-31 | 株式会社山武 | Physical quantity measuring device |
-
2013
- 2013-11-04 CN CN201310537492.3A patent/CN103557985B/en not_active Expired - Fee Related
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1059970A (en) * | 1990-09-15 | 1992-04-01 | 大连理工大学 | Compensating method of high-precision and-intensity optical fibre sensor with dual-wavelength modulation |
| CN2088248U (en) * | 1990-12-21 | 1991-11-06 | 东南大学 | Double diaphragm optical fiber differential pressure pickup |
| CN1589396A (en) * | 2001-09-21 | 2005-03-02 | 株式会社山武 | Physical quantity measuring method and its device |
| CN101169334A (en) * | 2007-11-21 | 2008-04-30 | 北京理工大学 | Intensity modulation type optical fiber sensor multiplexing method |
| CN201233250Y (en) * | 2008-06-19 | 2009-05-06 | 上海前所光电科技有限公司 | Grouping synchronization type optical fiber sensing analyzer |
| CN101799304A (en) * | 2010-04-12 | 2010-08-11 | 哈尔滨工程大学 | Reflection type differential strength modulating optical fiber sensing device and method thereof |
| CN203551183U (en) * | 2013-11-04 | 2014-04-16 | 贵州大学 | Reflective optical-fiber-bundle differential pressure sensor with intensity compensation |
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