CN1017928B - Mercury temperature sensor with optical fiber - Google Patents
Mercury temperature sensor with optical fiberInfo
- Publication number
- CN1017928B CN1017928B CN 91100630 CN91100630A CN1017928B CN 1017928 B CN1017928 B CN 1017928B CN 91100630 CN91100630 CN 91100630 CN 91100630 A CN91100630 A CN 91100630A CN 1017928 B CN1017928 B CN 1017928B
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- CN
- China
- Prior art keywords
- mercury
- optical fiber
- waveguide
- fiber
- temperature sensor
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- Measuring Temperature Or Quantity Of Heat (AREA)
Abstract
The present invention relates to an optical fiber mercury temperature sensor. The present invention comprehensively uses mercury with good heat expansion performance and optical reflection and absorption performance as a temperature sensing medium, combines optical fibers and mercury for forming a new type of temperature sensing optical waveguide for safely and reliably measuring the temperature of severe, inflammable and explosive environment with very strong electromagnetic interference and has wide temperature measurement ranges.
Description
The invention belongs to field of thermometers, be specifically related to a kind of mercury temperature sensor with optical fiber.
Existing temperature sensor such as the BrP GB2130719 that utilizes optical fiber to combine with liquid phase is according to the temperature variant feature of liquid refractive index.Its concrete structure is that the covering with optical fiber end removes a part, is replaced by liquid (as glycerine), and be provided with one deck reflectance coating on fiber end face.Liquid refractive index is higher than the refractive index of the original covering of optical fiber and varies with temperature in temperature-measuring range.When temperature variation, the light intensity that is mapped to the liquid from optical fiber pack changes, and changes thereby make along the light intensity of optical fiber backspace.The weak point of this invention is: 1) refractive index regional little with the temperature monotone variation, thereby limited temperature-measuring range; 2) the temperature variant rule of refractive index can not be described with the mathematical analysis formula, so the corresponding signal process complexity; 3) fiber end face must have reflectance coating, therefore makes difficulty.
In the fibre optic temperature sensor of warm area, other temperature sensing medium also has: semiconductor material covering (Jap.P. JP60-149934), plastics covering (BrP GB1582768), anisotropy clad (German patent DE 3045085) etc. in measurement.The complex structure of the fibre optic temperature sensor of these structures, stability and reliability all can not satisfy the requirement of practicability fully.Therefore, still can not measure effectively environment temperatures inflammable, explosive, that electromagnetic interference (EMI) is extremely strong such as oil tank, vapour jar, motor and transformers.
Aforesaid invention all is to utilize the optical characteristics of medium to vary with temperature and the feature that changes, and the temperature variant rule of optical characteristics is comparatively complicated, and variable range is little.This just these inventions have the main root of weak point.
U.S. Pat 4036060 discloses a kind of temp measuring method and device.This device has utilized the expand with heat and contract with cold characteristic and the reflective characteristic of liquid, by incident light and catoptrical measurement with relatively reach the purpose of measuring temperature.The reflection of light face is the concave surface that the liquid surface in the container forms that is contained near fiber end face.Its weak point is: 1) reflecting surface must be a concave surface.The condition that forms concave surface is that the angle of wetting of liquid and outer casing inner wall must be less than 90 °.Therefore, the good media of reflective characteristic such as mercury can not be selected for use, media such as silicone oil as be shown in the examples or aquadag suspending liquid can only be selected for use.2) light from the incident optical outgoing has certain angle of divergence, has only a seldom part by entering the emergent light fibre after the reflection of the reflecting surface before the optical fiber, and the loss of light is bigger.Therefore the distance of reflecting surface and fiber end face can not be too big.This just makes temperature-measuring range and resolution be restricted.The maximum temperature-measuring range of this patent is-50 ℃～+ 150 ℃.3) container is formed its complex structure by two adjoining truncated cones and a spherical liquid reservoir.
The objective of the invention is to solve stability, reliability and the practicality of fibre optic thermometer in middle warm area (30～+ 300 ℃) wide range scope, and make that it is simple in structure, be easy to make.Design a kind of temperature sensor of thermometric safely and reliably that can be used for carrying out in the rugged surroundings inflammable, explosive, that electromagnetic interference (EMI) is extremely strong.
Technical scheme of the present invention is, in the sleeve pipe of sealing, mercury is housed, and the main fiber of diameter less than the sleeve pipe interior diameter be housed, form the waveguide of vacuum covering by main fiber and vacuum, form the waveguide of mercury covering by mercury and main fiber, and form reflecting surface naturally at its end face, waveguide of vacuum covering and the waveguide of mercury covering constitute the temperature-sensitive waveguide together, main fiber links to each other with outgoing optical fiber with incident optical by shunt, and sleeve pipe is sealed by fluid sealant.
Main fiber is that the transparent material of n1 draws by refractive index, and the refractive index of coating layer of transparent be the material of n2 as covering and protective seam, refractive index n 1 must be greater than n2.
The structure of shunt is that incident optical and outgoing optical fiber and main fiber are in the same place with arc welding, and is coated with one deck silicon rubber at the optical fiber outer wall and is protected.Shunt can be contained in the Sealed casing pipe, also can be contained in outside the Sealed casing pipe.
Advantage of the present invention is: the temperature-sensitive waveguide utilizes the reflective and extinction characteristic of mercury and the characteristic of expanding with heat and contract with cold, so its temperature measurement range is identical with traditional mercury thermometer, has from-30 °～+ 300 ℃ measurement range; Owing to use Photoelectric Detection, so its precision is better than traditional mercury thermometer greatly; Because the loss of light in the mercury medium is directly proportional with variation of temperature and for linear relationship, so that signal Processing greatly simplify; Mercury thermometer with traditional during use is the same, need not vertical use; Because temperature-sensitive signal and transmission signals all are light, therefore no electric signal, and can grow Distance Transmission can be used for carrying out temperature survey under the extremely strong rugged surroundings of inflammable and explosive and electromagnetic interference (EMI).
The present invention has following accompanying drawing:
Fig. 1 shunt is contained in the mercury temperature sensor with optical fiber structural drawing outside the Sealed casing pipe,
Fig. 2 shunt is contained in the mercury temperature sensor with optical fiber structural drawing in the Sealed casing pipe;
Fig. 3 shunt structural representation;
Fig. 4 shunt section of structure;
Fig. 5 waveguide loss and waveguide length empirical curve.
Embodiment:
Mercury 2 is housed in Sealed casing pipe 1, and the main fiber 3 of diameter less than sleeve pipe 1 interior diameter is housed.In Sealed casing pipe 1, mercury 2 is formed mercury covering waveguide 4 with main fiber 3, and forms reflecting surface naturally at its end face, and vacuum 5 is formed vacuum covering waveguide 6 with main fiber 3, and mercury covering waveguide 4 constitutes the temperature-sensitive waveguide with vacuum covering waveguide 6.Main fiber 3 is that the transparent material (as: quartz glass, multicomponent glass, organic glass etc.) of n1 draws by refractive index, and the refractive index of coating layer of transparent is that the material (as: silicon rubber) of n2 is as covering and protective seam.Refractive index n 1 must be greater than n2.Main fiber 3 links to each other with outgoing optical fiber 9 with incident optical 8 by shunt 7.Sleeve pipe 1 is by fluid sealant 10 sealings.Shunt 7 can be contained in (as accompanying drawing 1) outside the Sealed casing pipe 1, also can be contained in by (as accompanying drawing 2) within the Sealed casing pipe 1.
Because main fiber 3 forms a kapillary with the inner chamber of sleeve pipe 1, the surface tension of mercury is very big, and mercury can not flow freely in kapillary, so this sensor does not need non-perpendicular use.
Shunt 7 can adopt commercially available commercial prod; also can adopt the structure shown in accompanying drawing 3 and 4; incident optical 8 and outgoing optical fiber 9 are the multi-mode communication silica fibre of standard; its diameter is 125 μ m; incident optical 8 and outgoing optical fiber 9 are in the same place with main fiber 3 usefulness arc weldings, and are coated in the outer wall do protection covering of optical fiber 3 with silicon rubber 11.Though this shunt optical loss is big, make simple, economical and practical.
Light imports main fiber 3 into by incident optical 8, shunt 7.In vacuum covering waveguide 6, because the refractive index of vacuum is lower than the refractive index of any medium, so light is transmitted by total reflection losslessly.In mercury covering waveguide 4, light is the generating unit sub reflector on the mercury interface, reaches end, and the mercury boundary reflection from end face is returned.Because the lossy transmission of light in mercury covering waveguide 4, its loss is directly proportional with the length of mercury covering waveguide 4, and the length of mercury covering waveguide 4 is directly proportional with temperature, so the loss of light is directly proportional with temperature.So can obtain temperature value by the relative intensity variation that detects incident light and emergent light.
Fig. 5 is the experimental result curve of the mercury covering waveguide that constitutes when being 250 μ m quartz fibres of diameter for main fiber.Wherein L is that the length Pi of mercury waveguide is the light intensity of input waveguide, and Po is the light intensity that reflects.This result shows that incident light is linear with the length of waveguide with the logarithm (being waveguide loss) of the ratio of emergent light.This brings great convenience with regard to giving the signal processing circuit that is connected with temperature sensor.
Utilize the principle of this mercury waveguide and the pressure transducer that structure can also be made gaging pressure.
Claims (4)
1; a kind of by Sealed casing pipe (1); the mercury temperature sensor with optical fiber that incident optical (8) and outgoing optical fiber (9) are formed; it is characterized in that in Sealed casing pipe (1), being equipped with mercury (2); and the main fiber (3) of diameter less than sleeve pipe (1) interior diameter be housed; main fiber (3) is the transparent material drawing of n1 by refractive index; and the refractive index of coating layer of transparent is that the material of n2 is as covering and protective seam; refractive index n 1 must be greater than n2; form vacuum covering waveguide (6) by vacuum (5) and main fiber (3) and form mercury covering waveguide (4) by mercury (2) and main fiber (3); and form reflecting surface naturally at its end face; vacuum covering waveguide (6) and mercury covering waveguide (4) constitute the temperature-sensitive waveguide together; main fiber (3) links to each other with outgoing optical fiber (9) with incident optical (8) by shunt (7), and sleeve pipe (1) is sealed by fluid sealant (10).
2, mercury temperature sensor with optical fiber as claimed in claim 1 is characterized in that shunt (7) is contained in the Sealed casing pipe (1).
3, mercury temperature sensor with optical fiber as claimed in claim 1 is characterized in that shunt (7) is contained in outside the Sealed casing pipe (1).
4, mercury temperature sensor with optical fiber as claimed in claim 1; the structure that it is characterized in that shunt (7) is for incident optical (8) and outgoing optical fiber (9) and main fiber (3) with arc welding together, and is coated with one deck silicon rubber (11) at the optical fiber outer wall and protected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 91100630 CN1017928B (en) | 1991-02-05 | 1991-02-05 | Mercury temperature sensor with optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 91100630 CN1017928B (en) | 1991-02-05 | 1991-02-05 | Mercury temperature sensor with optical fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1052946A CN1052946A (en) | 1991-07-10 |
| CN1017928B true CN1017928B (en) | 1992-08-19 |
Family
ID=4904736
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 91100630 Expired CN1017928B (en) | 1991-02-05 | 1991-02-05 | Mercury temperature sensor with optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1017928B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1037010C (en) * | 1995-12-21 | 1998-01-14 | 高军 | Technology for recovering beet foam-free dregs pressing water |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105606250B (en) * | 2016-02-15 | 2021-07-13 | 深圳市诺安太赫兹技术有限公司 | High-resolution temperature sensor based on built-in liquid bag and fixed wavelength |
| CN105571742B (en) * | 2016-02-15 | 2021-04-30 | 深圳市诺安环境安全股份有限公司 | Ultra-high resolution temperature sensor based on external liquid bag and fixed wavelength |
| CN105628247B (en) * | 2016-02-15 | 2021-03-16 | 深圳市诺安环境安全股份有限公司 | Ultra-high resolution temperature sensor based on external liquid bag and spectrum valley point |
| CN107091699A (en) * | 2017-06-29 | 2017-08-25 | 大唐贵州兴仁发电有限公司 | A kind of optical fiber temperature sensor |
| CN109029777A (en) * | 2018-09-10 | 2018-12-18 | 曲阜师范大学 | Fibre optic thermometer based on principle of interference |
| CN109990912B (en) * | 2019-05-22 | 2024-06-14 | 上海应用技术大学 | Temperature detection device |
| CN110207846B (en) * | 2019-06-26 | 2021-02-02 | 哈尔滨工程大学 | Capillary tube optical fiber temperature sensor |
-
1991
- 1991-02-05 CN CN 91100630 patent/CN1017928B/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1037010C (en) * | 1995-12-21 | 1998-01-14 | 高军 | Technology for recovering beet foam-free dregs pressing water |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1052946A (en) | 1991-07-10 |
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