CN103017936B - Thermochromic optical fiber temperature sensor and sensing method thereof - Google Patents

Abstract

The invention relates to a thermochromic optical fiber temperature sensor and a sensing method thereof. The sensor comprises a light source, incident optical fiber, a thermochromic probe, a heat transfer head, an emergent optical fiber, a fiber spectrometer and a computer. Thermochromic material is distributed at one end of the heat transfer head. The incident optical fiber and the emergent optical fiber are disposed at one end of the thermochromic probe. The heat transfer head is disposed on the inner side of the other end of the thermochromic probe. One thermochromic material end of the heat transfer head is opposite to the incident optical fiber and the emergent optical fiber. The other non-thermochromic-material end of the heat transfer head is connected with an object to be measured. The light source is connected with the incident optical fiber. The fiber spectrometer and the computer are connected with the emergent optical fiber. The thermochromic optical fiber temperature sensor is capable of monitoring temperature accurately. The sensing method enables equipment with the optical fiber temperature sensor to be simple and cost to be lower. The method and device are normally operable in areas with severe environments, such as electric field and high corrosion areas.

Description

Thermic look becomes fibre optic temperature sensor and method for sensing thereof

Technical field

The invention belongs to optical sensor field, be specifically related to a kind of thermic look and become fibre optic temperature sensor and method for sensing thereof.

Background technology

Electric system is the guarantee of industrial and agricultural production and the national economic development, and for alleviating the situation of power tense, electric system is towards UHV (ultra-high voltage), jumbo ac transmission and D.C. high voltage transmission future development.The various contacts of generating plant, Substation Electric Equipment, tie point, due to the effect of high voltage, large electric current, under heavy load, likely the high heat due to contact point causes burning and having a power failure of equipment.Thereby be the important content that ensures electric power netting safe running to the on-line monitoring of the various tie point temperature in electrification in high voltage transmission network and control.

For a long time, the temperature of switch cabinet contact is difficult to Real-Time Monitoring, and this is because of switch cubicle limited space, but in cabinet, element is more, and electrification in high voltage element is mostly exposed, and conventional thermometry cannot be used.Common temperature monitoring method mainly adopts thermopair, thermal resistance, semiconductor temperature sensor equitemperature sensing element to realize, and this method or sensor itself be with metal, under strong magnetic field circumstance, and the functional failure of sensor; Need plain conductor signal transmission, in compact switch cubicle, the system that the realize difficulty that insulate is reliably very large.

Summary of the invention

In order to solve problems of the prior art, the invention provides a kind of thermic look and become fibre optic temperature sensor and method for sensing thereof, the method that this sensor and method for sensing thereof make to realize monitoring temperature is simpler, has reduced cost, has improved sensitivity.

The technical scheme that technical solution problem of the present invention adopts is as follows:

Thermic look becomes fibre optic temperature sensor, and this sensor comprises: light source, incident optical, thermic look become probe, heat transfer head, outgoing optical fiber and fiber spectrometer and computing machine, and one end distribution thermic look of heat transfer head becomes material; Incident optical and outgoing optical fiber are arranged on thermic look and become the one end of popping one's head in, and heat transfer head is arranged on thermic look and becomes the other end of popping one's head in; The heat transfer head one end that becomes material with thermic look relative with outgoing optical fiber with incident ray, and the heat transfer head one end that becomes material without thermic look is connected with testee; Light source is connected with incident optical, and fiber spectrometer and computing machine are connected with outgoing optical fiber.

Thermic look becomes the method for sensing of fibre optic temperature sensor, and the method comprises the steps:

Step 1: heat transfer head is fixed in the adjustable controlled board of a temperature, regulate the temperature of controlled board, make temperature become material temperature sensitive range lower than thermic look, be set the integral time of fiber spectrometer and computing machine, open stable white light source, receive and record the spectral signal that outgoing optical fiber sends;

Step 2: according to the temperature of certain step interval rising controlled board, receive and record the spectral signal that outgoing optical fiber sends, become material temperature sensitive range until controlled board temperature reaches thermic look;

Step 3: reduce controlled temperature according to the interval in step 2, receive and record the spectral signal that outgoing optical fiber sends, until controlled board temperature is got back to the initial temperature in step 1;

Step 4: by the temperature data in fiber spectrometer and computer recording step 2 and step 3, spectral signal is converted to the tristimulus values of colourity;

Step 5: set up regression equation according to the tristimulus values of temperature data and colourity, determine that the thermocolour of selected thermic look change material is related to mathematic(al) representation, realize the method for sensing of thermic look change fibre optic temperature sensor.

Inventive principle: light source becomes light sources transmit in probe to thermic look by incident optical, illumination is mapped on the heat transfer head that scribbles thermic look change material, and light is mapped in outgoing optical fiber through being reflected into, and outgoing optical fiber is connected to fiber spectrometer and computing machine.Testee is delivered to thermic look by temperature by heat transfer head and becomes after material, when temperature reaches the temperature of thermochromic material variable color, material variable color, the data that fiber spectrometer and computing machine are received change, convert the tristimulus coordinates of colourity to by spectroscopic data, set up the relation of the tristimulus values of temperature and colourity, thereby realize monitoring temperature.

The invention has the beneficial effects as follows: the present invention can realize monitoring temperature accurately, the method becomes simply the equipment of fibre optic temperature sensor, and cost has also obtained reduction, and the method and device can also can normally work in the severe area of environmental baseline, as electric field, severe corrosive area.

Brief description of the drawings

Fig. 1 thermic look of the present invention becomes the structural representation of fibre optic temperature sensor.

Fig. 2 thermic look of the present invention becomes the schematic diagram of probe.

In figure: 1, light source, 2, incident optical, 3, thermic look becomes probe, 4, thermic look becomes material, 5, heat transfer head, 6, outgoing optical fiber and 7, fiber spectrometer and computing machine.

Embodiment

Below in conjunction with drawings and Examples, the present invention is described in further details.

Thermic look becomes fibre optic temperature sensor, and as shown in Figure 1, this sensor comprises: light source 1, incident optical 2, thermic look become probe 3, heat transfer head 5, outgoing optical fiber 6 and fiber spectrometer and computing machine 7, and one end distribution thermic look of heat transfer head 5 becomes material 4; Incident optical 2 and outgoing optical fiber 6 are arranged on one end of thermic look change probe 3, and heat transfer head 5 is arranged on the other end of thermic look change probe 3; Heat transfer head 5 one end that become material 4 with thermic look relative with outgoing optical fiber 6 with incident ray 2, and heat transfer head 5 one end that become material 4 without thermic look are connected with testee; Light source 1 is connected with incident optical 2, and fiber spectrometer and computing machine 7 are connected with outgoing optical fiber 6.Heat transfer head 5 is near testee, in the time that the temperature of testee reaches the susceptibility temperature range of thermic look change material 4, the color relation on heat transfer head 5 with one end of thermic look change material 4 can change, when light source 1 emits beam, when being delivered to heat transfer head 5 one end and becoming on material 4 with thermic look by incident optical 2, become the reflection of material 4 through thermic look, enter on fiber spectrometer and computing machine 7 by outgoing optical fiber 6, convert the tristimulus coordinates of colourity to by spectroscopic data, set up the relation of the tristimulus values of temperature and colourity, thereby realize the monitoring to temperature.

The structure that thermic look becomes probe 3 can be polyhedron, and the quantity of face is more than or equal to three, as shown in Figure 2, in the present embodiment, the structure that thermic look becomes probe 3 is pentahedron, and wherein three arrange hole, and heat transfer head 5, incident optical 2 and outgoing optical fiber 6 are arranged in hole.Thermic look becomes probe 3 entirety and adopts polytetrafluoroethylmaterial materials to form, and has strengthened conduction and the thermal energy collecting effect of heat along base material, and it is of a size of length and is: 30mm × 30mm × 25mm, chamber wall thickness is: 5mm.Heat transfer head 5 entirety adopt boron nitride ceramics, a kind of white high heat conduction, the good base material of high stable chemical characteristic, form it and be of a size of heating end diameter × painting material end diameter, become together with probe 3 can closely be linked in heat transfer head 5 by processing thermic look, reach temperature and be almost delivered on thermochromatic material 4 completely and overall thermic look becomes probe 3 temperature and can too highly not cause measuring inaccurate.Wherein the thermal conductivity of boron nitride ceramics is 45w/ (mK), coefficient of heat conductivity 0.256 w/ (mK) of teflon, and both all insulate.The thermic look that is chosen at this temperature province variable color according to the main temperature province that will monitor becomes material 4, a kind of thermic look change material 4 never variable color is 10 DEG C to the temperature range of complete variable color, can mix to realize larger discoloring temperature region by multiple material, utilize spray gun that thermic look is become to material 4 and uniformly spray on heat transfer head 5.

Discoloration mechanism and material category that thermic look becomes material are relatively extensive, the present invention has selected leuco dye (LD, Leuco dyes) become material as thermic look, for the detection alarm demand to 50 DEG C of left and right in electric system, selected by cresol red, benzyl p-hydroxybenzoate (weak acid), and the thermic look of positive hexadecanol configuration becomes paint as thermic look change material.The temperature variant linear zone of color is 42 DEG C-57 DEG C, the scope of about 15 DEG C.

Thermic look becomes the method for sensing of fibre optic temperature sensor, and the method comprises the steps:

Step 1: heat transfer head 5 is fixed in the adjustable controlled board of a temperature, regulate the temperature of controlled board, make temperature become material 4 responsive to temperature scopes lower than thermic look, be 20ms the integral time that fiber spectrometer and computing machine 7 are set, opening light source 1 is 50W Halogen lamp LED, colour temperature 3000K, the stable white light light source of energy distribution covering visible light scope, receive and record spectral signal that outgoing optical fiber 6 sends wherein effective measurement spectral coverage of fiber spectrometer and computing machine 7 be 380nm-780nm;

Step 2: according to the temperature of 1 DEG C of step interval rising controlled board, receive and record the spectral signal that outgoing optical fiber 6 sends, become material 4 responsive to temperature scopes until controlled board temperature reaches thermic look;

Step 3: reduce the temperature of controlled board according to the interval of 1 DEG C, receive and record the spectral signal that outgoing optical fiber 6 sends, until controlled board temperature is got back to the initial temperature in step 1;

By step 1, two and three, record thermic look and become material 4 temperature data T and spectroscopic data S (λ).Because the thermal conduction capability of heat transfer head 5 is very good, the temperature conduction of controlled board becomes material 4 to thermic look does not almost have the loss of heat, so the temperature of controlled board is similar to the temperature of thermic look change material 4, the temperature of controlled board is increased to 60 DEG C, a spectroscopic data of 1 DEG C of record of every rising from 40 DEG C; The temperature of controlled board is down to 40 DEG C, a spectroscopic data of 1 DEG C of record of every reduction from 60 DEG C.

Step 4: by the temperature data in fiber spectrometer and computing machine 7 recording steps two and step 3, by conversion formula, spectral signal is converted to the tristimulus values of colourity;

$X=K{\∫}_{380}^{780}S\left(\mathrm{\λ}\right)\stackrel{\‾}{X}\left(\mathrm{\λ}\right)R\left(\mathrm{\λ}\right)\mathrm{d\λ}$

$Y=K{\∫}_{380}^{780}S\left(\mathrm{\λ}\right)\stackrel{\‾}{Y}\left(\mathrm{\λ}\right)R\left(\mathrm{\λ}\right)\mathrm{d\λ}$

$Z=K{\∫}_{380}^{780}S\left(\mathrm{\λ}\right)\stackrel{\‾}{Z}\left(\mathrm{\λ}\right)R\left(\mathrm{\λ}\right)\mathrm{d\λ}$

$K=\frac{100}{{\∫}_{380}^{780}S\left(\mathrm{\λ}\right)\stackrel{\‾}{Y}\left(\mathrm{\λ}\right)\mathrm{d\λ}}$

In formula, S (λ) is spectroscopic data,

for the colour vision characteristic parameter of human eye, R (λ), for thermic look becomes material 4 reflection behavior of surface, tries to achieve the tristimulus values X of the tristimulus values of thermic look change material 4 colourities, Y, Z.

Step 5: become the tristimulus values X of material 4 temperature data T and colourity according to thermic look, Y, Z sets up regression equation, determines that the thermocolour of selected thermic look change material 4 is related to mathematic(al) representation, realizes the method for sensing of thermic look change fibre optic temperature sensor.

Owing to selecting the tristimulus values X of colourity of valid interval, Y, is related to approximately linear between Z and temperature data T, in the hope of regression equation form be:

T (X, Y, Z)=a ₁x+a ₂y+a ₃z+a ₀wherein a ₀, a _1,, a ₂, a ₃for the undetermined coefficient of equation.

Step 6: by confirmatory experiment, determine that thermocolour in this device is related to the uncertainty of mathematic(al) representation.

Improving in step 2 temperature, to adjust step interval be 0.5 DEG C, and the number of temperature spot increases to 39, and repeating step 2 10 times utilizes the regression equation calculation temperature value of setting up in step 5, obtains temperature value poor of model calculated value and experimental record.

T _diff?=?T _cal-T _test。

Wherein, T _difffor statistical standard difference, T _calfor model calculated value _,t _testfor experiment value, with T _diffstatistical standard poor as uncertainty δ T.

$\mathrm{\δT}=\sqrt{\frac{{\mathrm{\Σ}}_{j=1}^{j=(2n-1)\×M}{T}_{\mathrm{diff}}^2}{(2n-1)\×M-1}}$

Claims (5)

1. thermic look becomes fibre optic temperature sensor, and this sensor comprises: light source, incident optical, thermic look become probe, heat transfer head, outgoing optical fiber and fiber spectrometer and computing machine, it is characterized in that, one end distribution thermic look of heat transfer head becomes material; Described incident optical and outgoing optical fiber are arranged on thermic look and become the one end of popping one's head in, and heat transfer head is arranged on thermic look and becomes the other end of popping one's head in; Described heat transfer head one end with thermic look change material is relative with outgoing optical fiber with incident optical, and the heat transfer head one end that becomes material without thermic look is connected with testee; Light source is connected with incident optical, and fiber spectrometer and computing machine are connected with outgoing optical fiber.

2. thermic look as claimed in claim 1 becomes fibre optic temperature sensor, it is characterized in that, the material that described thermic look becomes probe is tetrafluoroethene.

3. thermic look as claimed in claim 1 becomes fibre optic temperature sensor, it is characterized in that, the material of described heat transfer head is boron nitride.

4. thermic look according to claim 1 becomes the method for sensing of fibre optic temperature sensor, it is characterized in that, the method comprises the steps:

Step 1: heat transfer head is fixed in the adjustable controlled board of a temperature, regulate the temperature of controlled board, make temperature become material temperature sensitive range lower than thermic look, be set the integral time of fiber spectrometer and computing machine, open stable white light source, receive and record the spectral signal that outgoing optical fiber sends;

Step 2: according to the temperature of certain step interval rising controlled board, receive and record the spectral signal that outgoing optical fiber sends, become material temperature sensitive range until controlled board temperature reaches thermic look;

Step 3: reduce the temperature of controlled board according to the interval in step 2, receive and record the spectral signal that outgoing optical fiber sends, until controlled board temperature is got back to the initial temperature in step 1;

Step 4: by the temperature data in fiber spectrometer and computer recording step 2 and step 3, spectral signal is converted to the tristimulus values of colourity;

Step 5: set up regression equation according to the tristimulus values of temperature data and colourity, determine that the thermocolour of selected thermic look change material is related to mathematic(al) representation, realize the method for sensing of thermic look change fibre optic temperature sensor.

5. thermic look as claimed in claim 4 becomes the method for sensing of fibre optic temperature sensor, it is characterized in that, the method also comprises step 6: by confirmatory experiment, determine that this thermic look becomes the uncertainty that thermocolour in fibre optic temperature sensor is related to mathematic(al) representation.

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