CN104155008A - Method for correcting measuring errors of infrared temperature monitoring system - Google Patents

Abstract

The invention relates to a method for correcting measuring errors of an infrared temperature monitoring system. In the prior art, when an infrared temperature measuring instrument is used for measuring the temperature of an object to be measured, the area of the object to be measured is constant, when the distance between an infrared temperature measuring instrument probe and the object to be measured exceeds an infrared temperature measuring instrument distance coefficient ratio, temperature collected by the temperature measuring instrument is the mixed temperature of the object to be measured and background temperature beyond the range of the object to be measured, so that the measuring accuracy is greatly reduced. According to the method provided by the invention, infrared temperature measuring error correction values corresponding to different distances exceeding an effective distance are obtained according to temperature values and environmental temperature measured by the infrared temperature measuring instrument as well as parameters of atmospheric transmissivity, the area of the object to be measured, and the like, so that the problem that a conventional infrared temperature measuring error correction method is larger in error, does not has universality, and is complex, is solved; the method is convenient to use, does not need simulation experiments, and has certain universality and applicability.

Description

A kind of Infrared Temperature Detection System measuring error modification method

Technical field

The present invention relates to a kind of infrared thermography technology, particularly a kind of Infrared Temperature Detection System measuring error modification method.

Background technology

Along with the development of infrared temperature-test technology, what infrared thermometer was a large amount of is applied in the industrial circles such as electric power, oil, chemical industry.The degree of accuracy of industry spot infrared measurement of temperature, directly affects the result of infrared diagnostics.In actual applications, there are a series of subjective and objective factors to affect the accuracy of infrared detection.Due to the restriction of safety requirements or measuring condition, tend to regulate according to actual needs infrared thermometer range-to-go, but the distance coefficient of infrared thermometer is than fixing, in the time exceeding certain distance, because the visual field of thermometric increases, the emittance that detector receives comprises the emittance of target and background simultaneously, and temperature measurement accuracy is by large high attenuation.

Existing infrared monitoring system temperature measurement error modification method mainly comprises correction factor method and calibration curve revised law.Correction factor method is in different distance, to measure the variation of same heat source temperature with distance by simulated experiment, obtains one group of temperature with the correction factor data that detect change of distance.Although it is more convenient that this method uses, correction factor all obtains under given conditions, in the time of environment for different, will cause larger error.Calibration curve correction ratio juris is identical with correction factor method with relative merits.

Document: Chen Heng, Yin Zengqian. thermometric distance correction methods [J] in equipment failure infrared diagnostics. laser and infrared, 1998,28 (4): 220-223. has proposed thermometric distance correction methods in a kind of infrared diagnostics, but the correction formula providing has certain limitation, because electrical equipment fault temperature is generally no more than 300 DEG C, the attenuation coefficient proposing in the document cannot record by experiment, therefore in the situation that measured temperature is lower, this modification method exists significantly not enough.

Summary of the invention

While the present invention be directed to present infrared measurement of temperature method for different environment, to cause the problem of larger error, proposed a kind of Infrared Temperature Detection System measuring error modification method, solve existing infrared measurement of temperature error correcting method error larger, do not possess ubiquity, the problem of method complexity.

Technical scheme of the present invention is: a kind of Infrared Temperature Detection System measuring error modification method, specifically comprises the steps:

1) infrared thermometer is aimed at the thermometric region of measured target, the thermometric light path of infrared thermometer is carried out to calibration adjustments, make the center of circle in thermometric region and the pupil that enters of infrared thermometer be centered close to same level height; be the distance coefficient ratio of infrared thermometer, distance coefficient, than pop one's head in for temperature measurer distance B between measured target and the ratio of infrared thermometer field number S now, is fixing parameter, and defining measured target region area is A ₀, the emissivity in measured target region is ε _{0 λ}temperature is made as T ₀;

2) increase gradually the distance d between infrared thermometer and measured target, make the visual field of infrared thermometer exceed measured target region, now the area of temperature measurer visual field is A, and the temperature that temperature measurer collects is measured target region A ₀with overflow measured target scope A-A ₀mixing temperature, the emissivity of overflowing measured target scope region is ε _{1 λ}, temperature is T ₁;

3) infrared thermometer is converted into voltage signal by infrared eye by total infrared radiation signal after the visual field increase collecting, and infrared thermometer is converted into temperature value by the voltage signal of acquisition and shows;

4) can carry out error correction to infrared thermometer measured temperature Tr, after revising, object surface temperature is:

$T_0={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right\{\frac{1}{{\mathrm{\τ}}_{\mathrm{a\λ}}}\·k({T_r}^m-{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m)-(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m-[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\left\}\right\}}^{\frac{1}{m}},$

k is the ratio of infrared thermometer visual field area and measured target area;

5) supposition ambient temperature is A-A ₀the temperature in region and atmospheric temperature, environment temperature equate, i.e. T ₁=T _u=T _a,, to infrared thermometer measured temperature T _rcarry out error correction, in the time of thermometric closely, can ignore the impact of atmospheric transmittance, the now spectral-transmission favtor τ of atmosphere _{a λ}=1, atmosphere emissivity ε _{a λ}=1-τ _{a λ}, λ represents the service band of infrared thermometer, can be similar to and think that the slin emissivity of measured target equates with measured target Surface absorption rate, be i.e. ε in the time that testee surface meets grey body _{0 λ}=α _{0 λ}, ε _{1 λ}=α _{1 λ},

Object surface temperature after revising $T_0={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right[k\·{T_r}^m-(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m\left]\right\}}^{\frac{1}{m}},$

Wherein ${T_r}^m=\frac{1}{k}[{\mathrm{\ϵ}}_{0\mathrm{\λ}}{T_0}^m+(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m],$

A＝πR ²＝πd ²tg ²θ

Wherein $\mathrm{tg\θ}=\frac{1}{2}\·\frac{D}{S}$

R is the radius of temperature measurer visual field, A ₀area determined by the surface configuration of measured target;

ε in formula _{0 λ}for the slin emissivity of measured target, m is constant, according to the service band value of infrared thermometer, when service band is 8～14 μ m, gets m=4.09, when service band is 3～5 μ m, gets m=9.3.

Described Infrared Temperature Detection System measuring error modification method, described step 3) in infrared eye the visual field collecting is increased after total infrared radiation signal be converted into voltage signal, changing voltage V _sfor:

V _s＝A _RA ₀d ^-2{τ _aλ[ε _0λf(T ₀)+(1-α _0λ)f(T _u)]+ε _aλf(T _a)}+(k-1)A _RA ₀d ^-2{τ _aλ[ε ₁λf(T ₁)+(1-α _1λ)f(T _u)]+ε _aλf(T _a)}

Wherein A _rfor the area of infrared thermometer detector,

Voltage signal is converted into temperature and shows, concrete grammar is:

Make K _m=A _rad ^-2, because device temperature and its voltage signal are corresponding and proportional one by one, make V _s/ K _m=f (T _r), temperature displayed value is:

$\begin{array}{c}f\left(T_r\right)=\frac{1}{k}\left\{{\mathrm{\τ}}_{\mathrm{a\λ}}\right[{\mathrm{\ϵ}}_{0\mathrm{\λ}}f\left(T_0\right)+(1-{\mathrm{\α}}_{0\mathrm{\λ}})f\left(T_u\right)]+{\mathrm{\ϵ}}_{\mathrm{a\λ}}f\left(T_a\right)\}\\ +\frac{k-1}{k}\left\{{\mathrm{\τ}}_{\mathrm{a\λ}}\right[{\mathrm{\ϵ}}_{1\mathrm{\λ}}f\left(T_1\right)+(1-{\mathrm{\α}}_{1\mathrm{\λ}})f\left(T_u\right)]+{\mathrm{\ϵ}}_{\mathrm{a\λ}}f\left(T_a\right)\}\end{array},$

$T_r={\left\{\frac{1}{k}\right\{{\mathrm{\τ}}_{\mathrm{a\λ}}{{\{{\mathrm{\ϵ}}_{0\mathrm{\λ}}T}_0}^m+(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m+[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\}+k{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m\}}^{\frac{1}{m}}.$

Beneficial effect of the present invention is: Infrared Temperature Detection System measuring error modification method of the present invention, by using infrared thermometer, measured target temperature is measured, and constantly increase the distance between infrared thermometer and measured target, obtain the temperature value at different distance place.Calculate according to parameters such as measured temperature value and environment temperature and atmospheric transmissivities, obtain the infrared measurement of temperature distance correction value at different distance place.Measuring error modification method of the present invention is easy to use, without simulated experiment, possesses certain ubiquity and application.

Brief description of the drawings

Fig. 1 is the infrared radiation illustraton of model that infrared thermometer of the present invention visual field is greater than measured target area;

Fig. 2 is embodiment of the present invention installation drawing;

Fig. 3 is error correction process flow diagram of the present invention.

Embodiment

Because the distance coefficient of infrared thermometer is fixed than the value of D: S, distance coefficient is than pop one's head in for temperature measurer distance B between measured target and the ratio of infrared thermometer field number S now.So distance dependent that the thermometric visual field size of infrared thermometer and temperature measurer are popped one's head between target.Actual range d between infrared measurement of temperature instrument probe and measured target is the changing value that can need to regulate according to thermometric, and the area of measured target is fixed value.Measured target area is A ₀, the slin emissivity of measured target is ε _{0 λ}, temperature is T ₀, A ₀area determined by the surface configuration of measured target, as shown in black shade part in Fig. 1, measured target is circular, now A ₀=π r ², r is radius of a circle.Along with the increase of distance d between temperature measurer probe and measured target, as shown in fig. 1, the visual field area of temperature measurer will increase, and measured target will be overflowed in temperature measurer visual field, and the region surface emissivity of overflowing measured target scope is ε _{1 λ}, temperature is T ₁, the temperature that now temperature measurer collects is the mixing temperature of measured target and the ambient temperature of overflowing measured target scope, and A ₀region and A-A ₀the mixing temperature in region, will reduce the precision of thermometric greatly, and now the area of temperature measurer visual field is A, as shown in Figure 1.

Embodiment device figure as shown in Figure 2, while using infrared thermometer 1 to measure measured target temperature, the area of measured target is fixed, when infrared thermometer 1 pop one's head in and measured target between distance while exceeding infrared thermometer 1 distance coefficient than claimed range, measuring accuracy will reduce greatly, measuring error will increase, the present invention can calculate according to parameters such as the measured temperature value of infrared thermometer 1 and environment temperature and atmospheric transmissivities, obtains the infrared measurement of temperature error correction values at off-limits different distance place.Measuring error modification method of the present invention is easy to use, without simulated experiment, possesses certain ubiquity and application.Solve to a certain extent infrared thermometer 1 exceeding distance coefficient than the problem sharply increasing apart from rear temperature measurement error, strengthened the industry spot application power of infrared thermometer 1.

First, according to the thermometric requirement of infrared thermometer 1, the blackbody furnace that is x by opening diameter 2 is placed on same level height with the pupil that enters of infrared thermometer 1, to the adjusting that collimates of the thermometric light path of infrared thermometer 1, make the opening that enters pupil and blackbody furnace 2 of infrared thermometer 1 on same level straight line.

Connect the power supply of blackbody furnace 2, open temperature regulation switch, regulate and keep the temperature constant of blackbody furnace 2, open infrared thermometer 1, the open area of blackbody furnace 2 is circular, and x is the opening diameter of blackbody furnace 2, keeps the distance between infrared thermometer 1 and blackbody furnace 2 to be be S>=x.In this case, the open area of blackbody furnace 2 will be overflowed in the visual field of infrared thermometer.From above, infrared thermometer thermometric will produce very large error.Use laser range finder to measure to the horizontal range between blackbody furnace 2 openings infrared measurement of temperature instrument probe, and record.Wherein, the distance coefficient ratio of infrared thermometer 1, the distance B of popping one's head between measured target for temperature measurer and the ratio of infrared thermometer field number S now, aperture area is A ₀.

Distance between infrared thermometer 1 and blackbody furnace 2 is time, i.e. S>=x.The area of temperature measurer visual field is A, and A is greater than the area A that diameter is the thermometric region of x ₀, the infrared radiation illumination that infrared thermometer collects is infrared radiation illumination total in visual field.Want to record temperature, need to determine radiant illumination total in visual field, can release total radiant illumination that infrared eye receives, i.e. A ₀the radiant illumination in region adds A-A ₀the radiant illumination in region:

E _λ＝A ₀d ^-2[τ _aλε _0λL _bλ(T ₀)+τ _aλ(1-α _0λ)L _bλ(T _u)+ε _aλL _bλ(T _a)]+(A-A ₀)d ^-2[τ _aλε _1λL _bλ(T ₁)+τ _aλ(1-α _1λ)L _bλ(T _u)+ε _aλL _bλ(T _a)] (1)

In formula, ε _λfor slin emissivity, α _λfor Surface absorption rate, τ _{α λ}for the spectral-transmission favtor of atmosphere, ε _{α λ}for atmosphere emissivity, T ₀for object surface temperature, T _ufor environment temperature, T _αfor atmospheric temperature, d is that this target is to the distance between surveying instrument.A ₀for the effective area of the corresponding target of infrared thermometer minimum space subtended angle θ.A is the background area total area, i.e. infrared thermometer visual field area now, and the part that exceeds diameter in visual field and be the thermometric region of x is A-A ₀the emissivity in region is ε _{1 λ}, temperature is T1, α _{1 λ}for its Surface absorption rate, L _{b λ}(T) be the radiation power of the temperature object that is T.λ represents the service band of infrared thermometer, and different-waveband can affect to some extent on above-mentioned parameter, in the time working in fixed band, can ignore the impact of λ.Make A=kA ₀, formula (1) can turn to:

E _λ＝A ₀d ^-2[τ _aλε _0λL _bλ(T ₀)+τ _aλ(1-α _0λ)L _bλ(T _u)+ε _aλL _bλ(T _a)]+(k-1)A ₀d ^-2[τ _aλε _1λL _bλ(T ₁)+τ _aλ(1-α _1λ)L _bλ(T _u)+ε _aλL _bλ(T _a)] (2)

Infrared thermometer is converted into voltage signal by infrared eye by infrared radiation signal total in the visual field collecting, and concrete grammar is:

The ir radiant power that measured target sends is converted to voltage signal by infrared eye, its output voltage V entering after infrared thermometer _sfor:

$\begin{array}{c}{V}_s=A_R{A}_0{d}^{-2}\left\{{\mathrm{\τ}}_{\mathrm{a\λ}}\right[{\mathrm{\ϵ}}_{0\mathrm{\λ}}{\∫}_{{\mathrm{\λ}}_1}^{{\mathrm{\λ}}_2}{R}_{\mathrm{\λ}}{L}_{\mathrm{b\λ}}\left(T_0\right)\mathrm{d\λ}+(1-{\mathrm{\α}}_{0\mathrm{\λ}}){\∫}_{{\mathrm{\λ}}_1}^{{\mathrm{\λ}}_2}{R}_{\mathrm{\λ}}{L}_{\mathrm{b\λ}}\left(T_u\right)\mathrm{d\λ}]+{\mathrm{\ϵ}}_{\mathrm{a\λ}}{\∫}_{{\mathrm{\λ}}_1}^{{\mathrm{\λ}}_2}{R}_{\mathrm{\λ}}{L}_{\mathrm{b\λ}}\left(T_a\right)\mathrm{d\λ}\}\\ +(k-1)A_R{A}_0{d}^{-2}\left\{{\mathrm{\τ}}_{\mathrm{a\λ}}\right[{\mathrm{\ϵ}}_{1\mathrm{\λ}}{\∫}_{{\mathrm{\λ}}_1}^{{\mathrm{\λ}}_2}{R}_{\mathrm{\λ}}{L}_{\mathrm{b\λ}}\left(T_1\right)d\mathrm{\λ}+(1-{\mathrm{\α}}_{1\mathrm{\λ}}){\∫}_{{\mathrm{\λ}}_1}^{{\mathrm{\λ}}_2}{R}_{\mathrm{\λ}}{L}_{\mathrm{b\λ}}\left(T_u\right)\mathrm{d\λ}]+{\mathrm{\ϵ}}_{\mathrm{a\λ}}{\∫}_{{\mathrm{\λ}}_1}^{{\mathrm{\λ}}_2}{R}_{\mathrm{\λ}}{L}_{\mathrm{b\λ}}\left(T_a\right)\mathrm{d\λ}\}\end{array}---\left(3\right)$

Wherein A _rfor the area of infrared thermometer detector, order r _λfor the responsiveness of infrared thermometer detector, λ ₁and λ ₂for service band scope lower limit and the upper limit of infrared thermometer.F (T) is the spoke out-degree of measured target in the time that temperature is T, and formula (3) can turn to:

V _s＝A _RA ₀d ^-2{τ _aλ[ε _0λf(T ₀)+(1-α _0λ)f(T _u)]+ε _aλf(T _a)}+(k-1)A _RA ₀d ^-2{τ _aλ[ε _1λf(T ₁)+(1-α _1λ)f(T _u)]+ε _aλf(T _a)} (4)

Infrared thermometer is converted into temperature by above-mentioned voltage signal and shows, concrete grammar is:

Make K _m=A _rad ^-2.Because device temperature and its voltage signal are corresponding and proportional one by one, make V _s/ K _m=f (T _r), formula (4) can turn to:

$\begin{array}{c}f\left(T_r\right)=\frac{1}{k}\left\{{\mathrm{\τ}}_{\mathrm{a\λ}}\right[{\mathrm{\ϵ}}_{0\mathrm{\λ}}f\left(T_0\right)+(1-{\mathrm{\α}}_{0\mathrm{\λ}})f\left(T_u\right)]+{\mathrm{\ϵ}}_{\mathrm{a\λ}}f\left(T_a\right)\}\\ +\frac{k-1}{k}\left\{{\mathrm{\τ}}_{\mathrm{a\λ}}\right[{\mathrm{\ϵ}}_{1\mathrm{\λ}}f\left(T_1\right)+(1-{\mathrm{\α}}_{1\mathrm{\λ}})f\left(T_u\right)]+{\mathrm{\ϵ}}_{\mathrm{a\λ}}f\left(T_a\right)\}\end{array}---\left(5\right)$

According to Planck law, the spoke out-degree f (T) in different-waveband is directly proportional to the m power of dut temperature, and m is constant.Can obtain thus formula (6):

$T_r={\left\{\frac{1}{k}\right\{{\mathrm{\τ}}_{\mathrm{a\λ}}{{\{{\mathrm{\ϵ}}_{0\mathrm{\λ}}T}_0}^m+(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m+[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\}+k{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m\}}^{\frac{1}{m}}---\left(6\right)$

T in formula _rfor the body surface temperature that temperature measurer records, T ₀for measured target surface true temperature, i.e. temperature error modified value.

$T_0={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right\{\frac{1}{{\mathrm{\τ}}_{\mathrm{a\λ}}}\·k({T_r}^m-{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m)-(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m-[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\left\}\right\}}^{\frac{1}{m}}---\left(7\right)$

In the time of thermometric closely, can ignore the impact of atmospheric transmittance, now τ _{a λ}=1, ε _{a λ}=1-τ _{a λ}.In the time that testee surface meets grey body, can be similar to and think ε _λ=α _λ, i.e. ε _{0 λ}=α _{0 λ}, ε _{1 λ}=α _{1 λ}.Generally, can suppose A-A ₀the temperature in region and atmospheric temperature equate with environment temperature, i.e. T ₁=T _u=T _a.Substitution formula (7), formula (7) can abbreviation be:

$T_r=\frac{1}{k}[{\mathrm{\ϵ}}_{0\mathrm{\λ}}{T_0}^m+(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m]---\left(8\right)$

Can be obtained by formula (9)

$T_0={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right[k\·{T_r}^m-(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m\left]\right\}}^{\frac{1}{m}}---\left(9\right)$

K is the ratio of infrared thermometer visual field area and measured target area,

Due to, the open area A of blackbody furnace 2 ₀for circle, so

$k=\frac{A}{A_0}=\frac{{\mathrm{\πR}}^2}{\mathrm{\π}{r}^2}=\frac{R^2}{r^2}=\frac{d^2{\mathrm{tg}}^2\mathrm{\θ}}{r^2}---\left(10\right)$

R and r represent respectively region A and A ₀radius.

Wherein $\mathrm{tg\θ}=\frac{1}{2}\·\frac{D}{S}---\left(11\right)$

$r=\frac{x}{2}---\left(12\right)$

Above-mentioned formula (7) and formula (9) are described infrared monitoring system error correction formula, formula (7) is spendable general formula all under any condition, formula (9) is the abbreviation formula can ignore the affecting of atmospheric transmittance in the time of thermometric closely time, restrictive condition is less, only needs to know the slin emissivity ε of measured target _{0 λ}, without knowing measured target Surface absorption rate and A-A ₀the emissivity in region and absorptivity are used in the time of close-in measurement, calculate easier.Described error correction formula possesses certain ubiquity and applicability, is core content of the present invention and technology place, does not need again to derive in the time carrying out error correction, can directly use, and be for derivation is described at this.

Use infrared thermometer 1 to gather the temperature of blackbody furnace 2, and increase gradually distance, make then gather a temperature every 1m.Take multiple measurements in same distance, get the mean value of measuring temperature.Obtaining 10 groups of temperature-averaging values that collect is respectively: T _b1, T _b2, T _b3, T _b4, T _b5, T _b6, T _b7, T _b8, T _b9, T _b10.Adopt alcohol thermometer to measure environment temperature, obtain environment temperature T _u.Generally, can suppose that ambient temperature is A-A ₀the temperature in region and atmospheric temperature equate with environment temperature, i.e. T ₁=T _u=T _a, also can use thermocouple thermometer to measure ambient temperature.Atmospheric transmissivity τ _{a λ}can obtain according to existing general method, not repeat them here.The emissivity ε of measured material _{0 λ}with absorptivity α _{0 λ}and the emissivity ε of background area _{1 λ}with absorptivity α _{1 λ}determined the acquisition of can tabling look-up by material.K value can be obtained by above-mentioned formula (10) (11) (12), by above 10 groups of above-mentioned formula of temperature data substitution (7):

$T_{01}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right\{\frac{1}{{\mathrm{\τ}}_{\mathrm{a\λ}}}\·k({T_{b1}}^m-{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m)-(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m-[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\left\}\right\}}^{\frac{1}{m}}---\left(1a\right)$

$T_{02}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right\{\frac{1}{{\mathrm{\τ}}_{\mathrm{a\λ}}}\·k({T_{b2}}^m-{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m)-(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m-[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\left\}\right\}}^{\frac{1}{m}}---\left(1b\right)$

$T_{03}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right\{\frac{1}{{\mathrm{\τ}}_{\mathrm{a\λ}}}\·k({T_{b3}}^m-{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m)-(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m-[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\left\}\right\}}^{\frac{1}{m}}---\left(1c\right)$

$T_{04}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right\{\frac{1}{{\mathrm{\τ}}_{\mathrm{a\λ}}}\·k({T_{b4}}^m-{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m)-(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m-[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\left\}\right\}}^{\frac{1}{m}}---\left(1d\right)$

$T_{05}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right\{\frac{1}{{\mathrm{\τ}}_{\mathrm{a\λ}}}\·k({T_{b5}}^m-{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m)-(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m-[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\left\}\right\}}^{\frac{1}{m}}---\left(1e\right)$

$T_{06}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right\{\frac{1}{{\mathrm{\τ}}_{\mathrm{a\λ}}}\·k({T_{b6}}^m-{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m)-(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m-[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\left\}\right\}}^{\frac{1}{m}}---\left(1f\right)$

$T_{07}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right\{\frac{1}{{\mathrm{\τ}}_{\mathrm{a\λ}}}\·k({T_{b7}}^m-{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m)-(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m-[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\left\}\right\}}^{\frac{1}{m}}---\left(1g\right)$

$T_{08}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right\{\frac{1}{{\mathrm{\τ}}_{\mathrm{a\λ}}}\·k({T_{b8}}^m-{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m)-(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m-[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\left\}\right\}}^{\frac{1}{m}}---\left(1h\right)$

$T_{09}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right\{\frac{1}{{\mathrm{\τ}}_{\mathrm{a\λ}}}\·k({T_{b9}}^m-{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m)-(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m-[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\left\}\right\}}^{\frac{1}{m}}---\left(1i\right)$

$T_{010}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right\{\frac{1}{{\mathrm{\τ}}_{\mathrm{a\λ}}}\·k({T_{b10}}^m-{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m)-(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m-[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\left\}\right\}}^{\frac{1}{m}}---\left(1j\right)$

The T calculating ₀₁to T ₀₁₀value, be the temperature value after error correction.

ε in formula _{0 λ}for the slin emissivity of measured target, α _{0 λ}for measured target Surface absorption rate, τ _{a λ}for the spectral-transmission favtor of atmosphere, ε _{a λ}for atmosphere emissivity, T _afor atmospheric temperature, ε _{1 λ}be A-A for infrared thermometer visual field exceeds measured target region ₀the slin emissivity in region, T ₁be A-A for infrared thermometer visual field exceeds measured target region ₀the temperature in region, T _ufor environment temperature, m is constant, according to the service band value of infrared thermometer, when service band is 8～14 μ m, gets m=4.09, when service band is 3～5 μ m, gets m=9.3.K is the ratio of infrared thermometer visual field area and measured target area,

In the time that distance is relatively near, can ignore the impact of atmospheric transmittance, can calculate by above-mentioned formula (9),

$T_{01}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right[k\·{T_{b1}}^m-(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m\left]\right\}}^{\frac{1}{m}}---\left(2a\right)$

$T_{02}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right[k\·{T_{b2}}^m-(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m\left]\right\}}^{\frac{1}{m}}---\left(2b\right)$

$T_{03}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right[k\·{T_{b3}}^m-(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m\left]\right\}}^{\frac{1}{m}}---\left(2c\right)$

$T_{04}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right[k\·{T_{b4}}^m-(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m\left]\right\}}^{\frac{1}{m}}---\left(2d\right)$

$T_{05}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right[k\·{T_{b5}}^m-(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m\left]\right\}}^{\frac{1}{m}}---\left(2e\right)$

$T_{06}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right[k\·{T_{b6}}^m-(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m\left]\right\}}^{\frac{1}{m}}---\left(2f\right)$

$T_{07}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right[k\·{T_{b7}}^m-(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m\left]\right\}}^{\frac{1}{m}}---\left(2g\right)$

$T_{08}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right[k\·{T_{b8}}^m-(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m\left]\right\}}^{\frac{1}{m}}---\left(2h\right)$

$T_{09}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right[k\·{T_{b9}}^m-(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m\left]\right\}}^{\frac{1}{m}}---\left(2i\right)$

$T_{010}={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right[k\·{T_{b10}}^m-(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m\left]\right\}}^{\frac{1}{m}}---\left(2j\right)$

Calculate T ₀₁to T ₀₁₀value, be the temperature value after error correction.

Error correction process flow diagram as shown in Figure 3, specifically comprises: before error correction, first need material behavior and environmental factor to measured target to determine, comprising: determine atmospheric transmissivity τ _{a λ}, determine measured target region A ₀emissivity ε _{0 λ}with absorptivity α _{0 λ}determine background area A-A ₀emissivity ε _{1 λ}with absorptivity α _{1 λ}and temperature T ₁.Measures ambient temperature T _uwith atmospheric temperature T _a.Then the distance coefficient of determining selected infrared thermometer is than the value of D: S.Determine constant m value according to the service band of infrared thermometer, use infrared thermometer to carry out thermometric to measured target, as shown in Figure 1, overflow in the situation of measured target infrared thermometer visual field, record the distance d between infrared measurement of temperature instrument probe and measured target, according to the value of above-mentioned calculation of parameter k, record the actual temperature value of the measured target that infrared thermometer records at every bit place, by above parameter substitution error correction formula, correction formula is drawn by theoretical derivation of infrared measurement of temperature, will obtain the modified value of temperature.

Now laboratory is closely ignored and under atmospheric transmissivity condition, is recorded as stated above one group of temperature value data, stablize thermal source black-body surface temperature by one and be adjusted to 58 DEG C, black matrix opening is that diameter is the circle of 30mm, emissivity is 0.95, calm, without direct sunlight, environment temperature is 17 DEG C, relative humidity is to measure under 50% environment, the distance coefficient ratio of the infrared thermometer adopting is 200: 1, and service band is 8～14 μ m, and it is as shown in table 1 to obtain modified value with above-mentioned modification method.

Empirical tests, revised temperature value will greatly reduce the error of measurement.The present invention has solved infrared thermometer to a certain extent exceeding distance coefficient than the problem sharply increasing apart from rear temperature measurement error, has strengthened the industry spot application power of infrared thermometer, possesses certain ubiquity and practical value.

Claims (2)

1. an Infrared Temperature Detection System measuring error modification method, is characterized in that, specifically comprises the steps:

1) infrared thermometer is aimed at the thermometric region of measured target, the thermometric light path of infrared thermometer is carried out to calibration adjustments, make the center of circle in thermometric region and the pupil that enters of infrared thermometer be centered close to same level height; be the distance coefficient ratio of infrared thermometer, distance coefficient, than pop one's head in for temperature measurer distance B between measured target and the ratio of infrared thermometer field number S now, is fixing parameter, and defining measured target region area is A ₀, the emissivity in measured target region is ε _{0 λ}temperature is made as T ₀;

2) increase gradually the distance d between infrared thermometer and measured target, make the visual field of infrared thermometer exceed measured target region, now the area of temperature measurer visual field is A, and the temperature that temperature measurer collects is measured target region A ₀with overflow measured target scope A-A ₀mixing temperature, the emissivity of overflowing measured target scope region is ε _{1 λ}, temperature is T ₁;

3) infrared thermometer is converted into voltage signal by infrared eye by total infrared radiation signal after the visual field increase collecting, and infrared thermometer is converted into temperature value by the voltage signal of acquisition and shows;

4) can carry out error correction to infrared thermometer measured temperature Tr, after revising, object surface temperature is:

$T_0={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right\{\frac{1}{{\mathrm{\τ}}_{\mathrm{a\λ}}}\·k({T_r}^m-{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m)-(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m-[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\left\}\right\}}^{\frac{1}{m}},$

k is the ratio of infrared thermometer visual field area and measured target area;

5) supposition ambient temperature is A-A ₀the temperature in region and atmospheric temperature, environment temperature equate, i.e. T ₁=T _u=T _a,, to infrared thermometer measured temperature T _rcarry out error correction, in the time of thermometric closely, can ignore the impact of atmospheric transmittance, the now spectral-transmission favtor τ of atmosphere _{a λ}=1, atmosphere emissivity ε _{a λ}=1-τ _{a λ}, λ represents the service band of infrared thermometer, can be similar to and think that the slin emissivity of measured target equates with measured target Surface absorption rate, be i.e. ε in the time that testee surface meets grey body _{0 λ}=α _{0 λ}, ε _{1 λ}=α _{1 λ},

Object surface temperature after revising $T_0={\left\{\frac{1}{{\mathrm{\ϵ}}_{0\mathrm{\λ}}}\right[k\·{T_r}^m-(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m\left]\right\}}^{\frac{1}{m}},$

Wherein ${T_r}^m=\frac{1}{k}[{\mathrm{\ϵ}}_{0\mathrm{\λ}}{T_0}^m+(k-{\mathrm{\ϵ}}_{0\mathrm{\λ}}){T_u}^m],$

A＝πR ²＝πd ²tg ²θ

Wherein $\mathrm{tg\θ}=\frac{1}{2}\·\frac{D}{S}$

R is the radius of temperature measurer visual field, A ₀area determined by the surface configuration of measured target;

ε in formula _{0 λ}for the slin emissivity of measured target, m is constant, according to the service band value of infrared thermometer, when service band is 8～14 μ m, gets m=4.09, when service band is 3～5 μ m, gets m=9.3.

2. Infrared Temperature Detection System measuring error modification method according to claim 1, is characterized in that described step 3) in infrared eye the visual field collecting is increased after total infrared radiation signal be converted into voltage signal, changing voltage V _sfor:

V _s＝A _RA ₀d ^-2{τ _aλ[ε _0λf(T ₀)+(1-α _0λ)f(T _u)]+ε _aλf(T _a)}+(k-1)A _RA ₀d ^-2{τ _aλ[ε _1λf(T ₁)+(1-α _1λ)f(T _u)]+ε _aλf(T _a)}

Wherein A _rfor the area of infrared thermometer detector,

Voltage signal is converted into temperature and shows, concrete grammar is:

Make K _m=A _rad ^-2, because device temperature and its voltage signal are corresponding and proportional one by one, make V _s/ K _m=f (T _r), temperature displayed value is:

$\begin{array}{c}f\left(T_r\right)=\frac{1}{k}\left\{{\mathrm{\τ}}_{\mathrm{a\λ}}\right[{\mathrm{\ϵ}}_{0\mathrm{\λ}}f\left(T_0\right)+(1-{\mathrm{\α}}_{0\mathrm{\λ}})f\left(T_u\right)]+{\mathrm{\ϵ}}_{\mathrm{a\λ}}f\left(T_a\right)\}\\ +\frac{k-1}{k}\left\{{\mathrm{\τ}}_{\mathrm{a\λ}}\right[{\mathrm{\ϵ}}_{1\mathrm{\λ}}f\left(T_1\right)+(1-{\mathrm{\α}}_{1\mathrm{\λ}})f\left(T_u\right)]+{\mathrm{\ϵ}}_{\mathrm{a\λ}}f\left(T_a\right)\}\end{array},$

$T_r={\left\{\frac{1}{k}\right\{{\mathrm{\τ}}_{\mathrm{a\λ}}{{\{{\mathrm{\ϵ}}_{0\mathrm{\λ}}T}_0}^m+(k-1){\mathrm{\ϵ}}_{1\mathrm{\λ}}{T_1}^m+[1-{\mathrm{\α}}_{0\mathrm{\λ}}+(k-1)(1-{\mathrm{\α}}_{1\mathrm{\λ}})]{T_u}^m\}+k{\mathrm{\ϵ}}_{\mathrm{a\λ}}{T_a}^m\}}^{\frac{1}{m}}.$