JPS6047538B2 - How to measure the temperature and emissivity of an object - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method of measuring the temperature of a heated object such as a copper plate whose emissivity changes by simultaneously measuring the emissivity of the object, thereby accurately determining the surface temperature of the object. It concerns the method of measurement.

More specifically, the present invention uses radiation energy from the surroundings, such as radiation temperature measurement of steel plates and other objects heated in the furnace, or metals at room temperature in the atmosphere, in industrial furnaces such as continuous annealing furnaces. In an environment where backlight noise is emitted equal to or greater than the radiant energy from the measurement object, or in an environment where the radiant energy transmission coefficient in the atmosphere changes, and in addition, the emissivity of the measurement object changes. This article concerns a radiation thermometry method that is particularly effective when ordinary radiation thermometry methods are not applicable, such as when

To measure the surface temperature of a stationary or moving heated object in an industrial furnace, a radiation thermometer or radiometer that can measure temperature without contact is convenient and is actually used in many fields.

In other words, inside the furnace, radiant energy from the furnace wall and heat source is reflected by the measurement object and then detected by the radiometer, creating a large disturbance, or noise, and unless this disturbance energy is shielded, accurate temperature measurement will not be possible. It's impossible. Also,
It is well known that radiation temperature measurement generally produces a large temperature measurement error when the emissivity of the measurement object varies. Radiation temperature measurement inside a furnace has the above two problems, so there are many cases where the temperature measurement is practically meaningless5. In particular, when the measurement object is a steel plate such as a thin plate or a thick plate in an annealing furnace, oxidation usually progresses on the surface of the steel plate as it is heated in the furnace, and the emissivity of the steel plate increases accordingly. Due to this change, radiation temperature measurement causes a large error, making it virtually impossible to measure temperature. A similar situation occurs when measuring the radiation temperature of metals near room temperature in the atmosphere. That is, since the temperature of the object to be measured (for example, metal) is around room temperature, the radiant energy from the surface is often equal to or lower than the radiant energy from the surroundings, which is a disturbance. Furthermore, when the atmosphere of the measurement system has absorption characteristics in the detection wavelength range of the radiometer used, radiation temperature measurement also causes large temperature measurement errors when the transmission coefficient of radiant energy changes depending on the concentration of the atmosphere. It turns out.

An object of the present invention is to overcome the problems of radiation temperature measurement that occur in the above-mentioned environments and to make it possible to always measure accurate surface temperatures.

One of the inventors of the present invention has already proposed a method for overcoming the above-mentioned problems of radiation temperature measurement and making accurate temperature measurement possible in Japanese Patent Application No. 52-153447. This method 5 uses a black body radiation source whose temperature is variable in a direction that is mirror-symmetrical to the surface normal of the heated object, and a wavelength of the detected radiation so that the surface of the heated object exhibits specular reflection characteristics. Place the radiometers with selected bands facing the heated object, and change the temperature of the blackbody radiation source! The method is characterized in that the emissivity of the heated object is determined by calculating using the corresponding output of the radiometer, and then the surface temperature of the heated object is determined. Therefore, in this method, the main point of the invention was to select the three detection wavelengths of the radiometer so that the measurement object surface was a specular reflection surface. In contrast, the present invention further generalizes this, and even if the surface of the measurement object is a rough surface, that is, a non-perfectly specular reflective surface, there is still something in the measurement environment that impairs the transmission of radiant energy, such as CO2 or H2O. However, the surface temperature of the object to be measured can be measured with high accuracy. Next, the structure of the present invention will be described in the above-mentioned patent application filed in 1973.
2-153447 and will be explained in detail with reference to the drawings. 4. If the measurement object surface is optically smooth and flat,
In other words, when it is a perfectly specular reflective surface, the following equation holds if the emissivity in the direction of angle θ with respect to the normal N of the measuring object is E(θ) and the reflectance in that direction is r(0). .

The principle of the method will be explained with reference to FIG.

A radiometer 1 and a blackbody radiation source 2 are arranged mirror-symmetrically with respect to the normal N at an angle θ. Now, assuming that the temperature of the measuring object 3 is T1 and the temperature of the blackbody radiation source is T2, the radiant energy E2 detected by the radiometer 1 can be expressed by the following equation. Here, Eb(T) is the radiant energy from a blackbody radiation source at temperature T.

In equation (2), the first term on the right side is the energy radiated from the measurement object surface itself, and the second term is the component of the radiation Eb (T2) from the blackbody radiation source that is specularly reflected by the measurement object surface. (Emissivity r(0) = 1-ε(0)). Next, the detected value when the temperature of the black body radiation source 2 is changed to T3 is E
3, it is similarly expressed by the following equation. (2) and (3)
There are two main equations that include the two unknowns to be found, ε(θ) and T1, so if you solve them as simultaneous equations, you get
ε (0) and T1 can be determined simultaneously. (2)
By subtracting equation (3) from each side and rearranging equation (4), ε(0) can be obtained as shown in the following equation.

? )formula? (3) If you arrange it by proxy in the formula is obtained.

From equation (6), T1 can be found from the output characteristics of the radiometer 1. The above discussion holds true when the measurement object surface is a perfectly specular reflective surface, and this is the case in Japanese Patent Application No. 52-1534.
47. On the other hand, since the general object surface is rough to some extent, it deviates from the ideal state.

This situation is based on the emissivity r(0) = 1-ε(0) of equation (1).
This means that it is smaller than the ideal state due to diffuse reflection. Therefore, instead of r (0), we use f such that O<f<1 and set the apparent emissivity as r(0)・f:(1−E(0))・f, and formulate equation (2). When formula (3) is rearranged, it becomes formulas (7) and (8), respectively. E,=E(
0)・Eb(T,)+(1-E(0))・f −Eb(
T,)...(7)E3=E (0) ・Eb(
T1)+(1-E(0))・f −Eb(T(3)・
...(8) f is named "specular reflection coefficient" which represents the ratio of specular reflection.

From the above two equations, the calculated emissivity can be determined by the following equation. Using this t (0), the temperature can be calculated from the following equation.

Eb(T,) = Thus, introducing the specular reflection coefficient f,
The first feature of the present invention is that the reflection characteristics of the measurement object surface are non-perfect specular reflection characteristics, that is, the wavelength of the detection range of the radiometer makes it possible to easily and accurately measure even rough surfaces. It is.

In the case of a non-perfectly specular reflective surface, when the surrounding wall 4 in FIG. 1 is so hot that the radiation from it cannot be ignored, it is also necessary to deal with this backlight noise.

When the surrounding wall temperature is T4 and the effective emissivity E4 is 1.0, equations (7) and (8) can be rewritten as follows. Here, p is a coefficient representing the degree of diffuse reflection on the measurement surface 3, and is called a "diffuse reflection coefficient."

The third term on the right side of the above two equations is the radiation Eb(
T4) represents the radiant energy that is diffusely reflected on the measurement surface 3 and detected by the radiometer. Next, we are looking for the interval between p<5f. Now, T,=T,=T3=L=T
, that is, if the temperature measurement system is in perfect thermal equilibrium, Eb(T,)
=Eb(T2)=Eb(T3)=Eb(T4)=Eb(
T), both equations (11) and (12) are in the following equations. The following equation (14) is finally obtained from equation (13).

f + p = 1 ... (14) Expression (14) is changed to (11
) and (12), the detected values E2, E3
can be expressed as follows.

If we subtract and rearrange the sides of both equations, E(0) becomes
It is obtained in exactly the same way as equation (9).

t (0)=1 By substituting this E (0) into equation (16), T can be obtained from the following equation.

(\U!C\v) Equations (17) and (18) are the measurement principle equations of the present invention.

That is, the blackbody radiation source 2 and the radiometer 1 are arranged at mirror-symmetrical angles with respect to the normal N of the object surface 3 to be measured, and the radiation energy from the blackbody radiation source 2 is varied. Of the two types of radiant energy Eb(T,) or Eb(T3) corresponding to this change, the radiant energy reflected on the measured object surface 3 (1 on (0)) (1-p)・Eb(T
2) or (1 above (0)) (1-p)・Eb(T3)
and the radiant energy E (0) from the measured object surface 3 itself
Eb(T,) and the temperature T of the surrounding wall 4, the radiometer detects the sum of disturbance components (1-E(0))·d-Eb(T4), and detects the diffusion corresponding to the measured object 3. [Using the reflection coefficient p, emissivity E(0) is determined by equation (17), and then using this E(0), temperature T, is determined by equation (18). An operational block diagram for effectively implementing the method of the present invention is shown in FIG.

In order to implement the operation of FIG. 2, it is necessary to set the temperature of the blackbody radiation source to two different values, T2 and T3. One method for achieving this is as shown in Figure 3.
Two blackbody radiation sources 2'', 2'' are prepared, each at a temperature T
2 and T3 and lead alternately to one radiometer 1 2
A beam optical system is considered. Figure 3a shows the configuration of this system. The radiant flux from each blackbody radiation source 2'', 2'' intersects at one point A on the measurement object surface 3, is reflected there, and one is guided to the rotating mirror M1 via the mirror M2 and the other via the mirror M3. , M1 are alternately incident on the radiometer 1 according to the rotation. In addition, as shown in Figure 3b, measurement points A'', A
'' is slightly different, but the two mirrors M2 and M3 are not required, and a two-beam system can be realized with just one rotating mirror M1.Of course, in this case, the measurement object 3
It is necessary that the surface area is moving or that the temperature and emissivity are uniform over a certain area. Instead of using two blackbody radiation sources 2'', 2'', as shown in Fig. 4, one blackbody radiation source 2 and the sector 5 rotated by a motor MT just before its aperture can be used to obtain the equivalent of two luminous fluxes. system can be realized.

The temperature of the blackbody radiation source 2 is set to T2. On the other hand, the surface 5-1 of the rotating sector 5 is made into a sufficiently black absorbing surface to approximate a blackbody surface, and the temperature and degrees of the surface are compared with the measured object surface temperature T1 and the temperature T2 by water cooling or other treatment. low enough. Therefore Eb(T1) and Eb(T2)
Compared to , the radiation from it can be ignored. Blackbody aperture surface 2
The radiometer 1 alternately detects two types of radiant energy, corresponding to when the rotating sector 5 covers and does not cover -1. Detection value E in the former state
1, the following equation is obtained instead of equation (16).
\VlPlν \A4ノ
1 (1υノ .2 Detection value E in the latter state
2 is given by equation (15), so from both equations, ε
(θ) is obtained as shown in the following equation.

By substituting this ε(θ) into equation (19), T1 can be obtained from the following equation.

Equations (20) and (21) are easier to calculate than the previously obtained equations (17) and (18).

This calculation can be obtained in exactly the same way in the two-beam system described above if T, is compared to T1 and T2 and its radiation is negligibly low. Both the configurations of FIGS.
108, and in the present invention), a diffuse reflection coefficient p is introduced in the calculation, and the object surface to be measured does not necessarily have to be a perfectly specular reflective surface, thereby providing a more realistic measurement method. The place has its characteristics. Next, examples and experimental results will be shown that accurately demonstrate the effects of the present invention.

FIG. 5 schematically shows an experimental setup in the atmosphere without the influence of backlight. As shown in Figure 5, 100Trf
A sample 3 for measuring mφ was placed on a heating furnace 6 and heated. The radiometer 1 and the blackbody radiation source 2 were arranged mirror-symmetrically with respect to each other in a direction with an angle of 0=56 constant. The blackbody radiation source 2 has an aperture diameter D=
5hφ, length L=125? It is a cylindrical cavity made of graphite, and its inner wall temperature T2 is measured by a CA thermocouple 2 attached to the bottom.
-2, and set T2 = 368°C with an accuracy of ±1°C using a PID temperature controller. The solid angle dΩ looking into the aperture from the measurement surface 3-1 is 0.05πSter. It is. Three types of radiometers with different detection elements were used as the radiometer 1. Its specifications are as follows. The experimental procedure is as follows. First, the detection value Eb(T2) was determined by each radiometer 1 for the temperature T2 of the blackbody radiation source 2. Next, set T2 to 36
The temperature was controlled at 8°C. Various samples 3 are heated to a heater 7 on a heating furnace 6.
The surface temperature was measured with a CA thermocouple 8 spot welded to the sample surface 3, and an arbitrary temperature T1 from 200°C to 450°C was measured.
It was set to In order to directly determine the emissivity ε (θ) at each temperature T1, a water-cooled sector 5'' with a blackened surface was installed just in front of the opening 2-1 of the blackbody radiation source 2.The value detected by the radiometer 1 at that time was From E1, A1 is required to L8.

Here, Eb(T1) is obtained in advance in the same way as Eb(T2) because T1 is determined by the CA thermocouple 8 and there is a detected value of blackbody radiation corresponding to that temperature. E (θ) in equation (22) is the true emissivity of sample 3. E1 can be formally written as the following equation.

Next, based on the principle of the method of the present invention, the detected value E2 when the above-mentioned blackened water cooling sector 5'' is removed is expressed by equation (7).

I'll write it here again. −ε (U no f −〜
( ・1--Equation (23) and (2
From equation 4), the emissivity and temperature calculated by this method can be obtained by the following equations (25) and (26), respectively. By the way, the measurement accuracy of the method of the present invention is based on the true emissivity equation (22),
It can be estimated by comparing the emissivity equation (25) obtained by the calculation of the method of the present invention.

Table 1 shows the measurement results obtained by the method of the present invention using cold-rolled steel sheets, stainless steel sheets, and roughened aluminum sheets as samples.

In Table 1, f is set for each sample at an arbitrary temperature T1,
Emissivity ε obtained based on equations (22) and (25)
The values of (θ) are determined to be equal. Also, find the average value 〒 of f and its variation Δf, and use 〒 to find (
Relative errors in emissivity and temperature when calculated based on equations 25) and 26 are also listed. Note that the latter was evaluated at T1=400°C. (25)
The equation can be rearranged for f as shown below. Let ΔE be the variation in ε (θ) when f varies by Δf. (27)
By taking the logarithm of both sides of the equation and differentiating it, it can be seen from equations (28) and (29) that the relative error in emissivity depends on the relative error in f and the value of the emissivity itself.

The relative temperature error ΔT/T1 can be derived from a well-known formula.

Substituting equation (29) into equation (30) to obtain the following equation, however,
C2=14388μm-K ΔE/E(θ), ΔT in Table 1
/T1 is f=〒 in equations (29) and (31).
It is obtained by using E(0) according to equation (22) as E(θ).

As is clear from Table 1, f is the wavelength λ for the same sample.
The longer it gets, the closer it gets to 1. In other words, the sample surface approaches a specular reflection surface. Further, the relative variation Δf/f of f also becomes smaller as λ becomes longer. However, as shown in equations (29) and (31), the emissivity solution and temperature solution calculated by the calculations of the present invention depend on ε(θ) and λ in addition to Δf/f, so measurement accuracy is not necessary. Sushi cannot be said to be superior in long wavelengths either. Table 1
Therefore, the relative error of the emissivity solution is the smallest when λ=8 μm, but the relative error of the temperature solution is the smallest when λ=2.2 μm. FIG. 6 shows that for many samples of cold-rolled steel sheets, λ=2.
The emissivity ((
22)) and the calculated emissivity solution (formula (25)) obtained by the method of the present invention.

An average value of 0.92 was used as f. As can be seen from the figure, the two agree well despite the large change in emissivity associated with the formation of an oxide film on the surface of the copper plate caused by heating. FIG. 7 similarly compares temperature indication by a thermocouple and calculation by the calculation of the present invention. The difference between the two is almost within ±5°C. From Table 1, Figures 6 and 7, it is clear that if the steel type is the same, temperature and emissivity can be measured simultaneously with very good accuracy by setting f to a constant value even if the emissivity changes significantly. It became clear. Since the method of the present invention utilizes specular reflection, it is particularly excellent in eliminating backlight noise.

Therefore, it is considered to be extremely effective for temperature measurement inside a furnace. A simulation furnace was manufactured and a measurement experiment was carried out in the furnace using the method of the present invention. Figure 8 shows an outline of the experimental apparatus. The simulation furnace has a box-like inner wall 4 made of a thin copper plate. The entire surface of the inner wall 4 was coated with black paint (Tetsol) to give an emissivity of 0.95. Three independent heaters 9 were installed on the ceiling and side walls between the inner wall 4 and the outer wall 4''. , the inner wall 4 is heated by radiation.The inner wall temperature T4 is determined by a CA sheath thermocouple embedded in the copper surface (ceiling,
The inner wall 4 can be controlled independently by the 23 side walls (23 locations), and the entire inner wall 4 can be kept at a substantially uniform temperature T4. A pair of side walls of the furnace have a width of 50Wr1n1 and a length of 100TmIf.
An L-shaped opening 10 is provided, one of which allows the blackbody radiation source 2 to be inserted and the inside of the reactor 11 to be viewed with the radiometer 1 from the other. A sample 3 and a sample heating furnace 6 can be inserted from the bottom of the furnace. The sample 3 can be heated and temperature controlled independently on this heating furnace 6. Also, instead of heating the sample 3 from below, it can be kept at room temperature by cooling it with water. In front of the aperture surface 2-1 of the blackbody radiation source 2, there is a water cooling sector 5 that is a blackbody. , the opening surface 2- is driven at regular intervals by the motor 12.
1 can be covered. In such a furnace configuration, when the inner wall temperature T of the simulation furnace becomes uniform,
The surrounding wall 4 may be regarded as a black body at approximately that temperature, and is considered to be in the most severe condition in temperature measurement inside the furnace. The validity of the principle has already been confirmed through experiments in the atmosphere, so here we will calculate the proportion of the radiant energy from the inner wall 4 in the reactor reflected by the measurement surface 3-1 and detected by the radiometer 1. In other words, we conducted an experiment to quantify the proportion of backlight noise. As shown in FIG. 9, the temperature was adjusted so that the inner wall temperature T4 of the simulation furnace was 390°C.

Water cooling sector 5 with blackened open surface 2-1 of black body radiation source 2
'' was covered, then various samples 3 were inserted into the furnace from below.The bottom surface of the samples 3 was constantly water-cooled, so it was kept at room temperature inside the furnace.In this state, the radiation Radiant energy Es was detected in total 1. Most of this detected value is the energy Eb (T4) radiated from the furnace inner wall 4, which is a black body cavity, which is reflected by the measurement surface 3-1 and radiated. The amount of backlight noise can be quantified because the amount comes in one direction in total.The light rate η is defined by the following equation.

70. ．． ,' Since the emissivity of sample 3 has been measured in advance, the diffuse reflection coefficient p can be calculated from equation (33). In this experiment, θ = 67 was set, and the distance between the sector and measurement point 7 was changed in order to change the solid angle dΩ looking into the blackened water-cooled sector 5'' from the measurement point.Table 2 shows the experimental results.

Cold-rolled steel sheets and stainless steel sheets whose emissivity changes as oxidation progresses were used as samples. By changing the distance z from the measurement point of the sample to the sector plane 5''-1, the solid angle looking into the sector plane dΩ = 27r (1-COs (Ta ``1D/2
Find the backlight ratio η for 2')) according to equation (32),
Using the emissivity ε (θ) of each sample from this η, (33
) p and its variation Δp were calculated from the equation.

FIG. 10 illustrates the relationship between p and dΩ. Table 2 or 1st
From Figure 0, p approaches O for each sample as the wavelength λ becomes longer. That is, the sample approaches specular reflection,
Furthermore, as dΩ increases, the diffusion of reflection decreases due to the presence of the sector plane, so p is made smaller.
P. l! :． There is a relationship between f and equation (14). In fact, the actual measured values of f in Table 1 are also listed in Table 2, and it can be seen that equation (14) approximately holds true between the two. From the above, it has become clear that the method of the present invention is effective even in a furnace. Next, a method for determining the dimensions of the aperture 3 of the blackbody radiation source will be described. Emissivity is given by equation (20) both in the atmosphere and in the furnace.

The temperature measurement error is expressed by equation (30) in the atmosphere. Therefore, in the atmosphere, the variation in f of the sample increases the emissivity ε(θ)
It would have been sufficient to perform error analysis based only on equation (29), which can be replaced by the fluctuation of . On the other hand, in the case of inside a furnace, it is also necessary to take into account fluctuations in emissivity due to fluctuations in p and fluctuations in the furnace inner wall temperature T4. Therefore, the following steps were taken to consider how large the solid angle dΩ should be in order for the error to fall within the allowable range. When the apparent measured temperature is Ta, the following equation is satisfied in equation (19). The range of variation of E(θ) is predicted in advance through experiments, and the minimum value of ε(θ) is assumed, and ε(θ)=εθn.

Substituting this into equation (33) yields the following equation.
de
(Oυ) Substituting this equation into equation (34) and using Eb(T) as Vienna's formula, Eb(T)=
If C1·λ−5·Exp(−C2/λ·T) is used, the following equation holds true.

゜ (36
Now, if the allowable temperature measurement error is ΔTa<-Ta-T1℃, then on the left side of equation (36), (゜.゜ΔT
a/T1<1), and when this equation is substituted into equation (36) and rearranged, the maximum allowable value Pmax of the diffuse reflection coefficient p is obtained by the following equation.

In equation (38), if T1 and L in the temperature measurement region are given and λ is selected, a quantitative value of Pmax that brings the temperature measurement error within ±ΔTa/2°C can be obtained.

Therefore, the solid angle DOmax that gives this p=Pmax can be found from FIG. Specific calculations will be made for cold-rolled steel sheets and stainless steel sheets.

Table 3 shows T1=7000C. ．． T4=6000C1700
800° C., calculation results of Pmax and dΩMax necessary to suppress the error within ΔTa=10° C. are shown. From Fig. 10, p becomes smaller as λ becomes longer, and the backlight noise decreases accordingly, but as is clear from Table 3, the DOmax required to suppress the same temperature measurement error ΔTa is conversely the smaller λ is. Small is good. Dfl
Being able to reduce max is very important from a technical standpoint. In the case of stainless steel plates, a very small solid angle is sufficient. Next, a method for determining p based on the roughness of the surface of the object to be measured will be described. p represents the degree of diffuse reflection in a shielded state in a direction at an angle to the normal to the sample surface. Therefore, it is considered that there is a correlation between p and the average inclination angle θa representing the surface roughness of the sample surface. In fact, using the results in Table 2, dΩ=0.2πRa
The relationship between p and 0a for the case of d is illustrated in FIG. Here, as shown in FIG. 12, θa is defined as the center line when the inclination angle of the phase surface is θc(7).

As detailed above, if the necessary solid angle is determined in the furnace according to the surface roughness of the sample surface, and the dimensions of the aperture of the blackbody radiation source and the distance z to the measurement surface are set, the predetermined It is possible to measure temperature and emissivity with an accuracy of .

Note that, in addition to the roughness, the measurement accuracy can be further improved by considering the shape of the object to be measured, changes in shape during transportation, or changes in shape due to heating. The present invention is particularly useful in cases where the measurement object surface is generally rough and has non-perfect specular reflection properties and for objects whose emissivity needs to be measured.

Furthermore, since backlight noise can be eliminated at the same time, it is thought that this method will have a remarkable effect on the radiation temperature measurement of steel plates in furnaces, where the emissivity changes significantly as oxidation progresses. In recent years, new construction of continuous annealing furnaces has been underway.

This differs from conventional models in that it takes a thorough approach to energy conservation in response to the demands of the times, and pursues cost reductions by improving thermal efficiency. For this reason, instead of using a reducing atmosphere inside the furnace, a part of the annealing furnace uses a rapid heating method using direct burners. A furnace with this heating method is NOE (N
If the On tree K constantly changes, install a new blackbody radiation source or a third reference blackbody radiation source, and use the radiometer or a second new radiometer to create an optical path of constant j. The radiation from the reference blackbody radiation source is directly detected without passing through the measured object surface, K is determined from the change, and this value is expressed as (
By substituting equations 43) and 44, it is possible to accurately determine the emissivity ε(θ) and the temperature T1 even if K varies. Note that depending on the environmental conditions of the setting location, a method of eliminating changes in the transmission coefficient K due to atmospheric absorption in the optical path may also be considered.

That is, the detection wavelength r+[;1,12Ete1 of the radiometer used
10/. :FOZ みき0xidizingFumace
). Therefore, the steel plate in the furnace is oxidized by the weakly oxidizing atmosphere in the furnace during running, and its emissivity changes significantly. The present invention solves the problems of backlight noise and emissivity all at once, and is extremely effective for temperature measurement at 0F. Furthermore, in NOF, a small amount of unburned 02 has a subtle effect on the formation of an oxide film on a steel sheet, so in addition to emissivity measurement, it is also possible to obtain useful information regarding the oxide film or the state of oxidation. Furthermore, even if there is an atmosphere or a seal glass in the optical path of the measurement system that has absorption characteristics for the detection wavelength of the radiometer, the present invention measures the transmission coefficient for the atmosphere to ensure accurate temperature measurement. I can make it seem possible.

For example, in equations (15) and (16), if the energies E2 and E3 detected by the radiometer are reduced by the transmission coefficient K (a) <K * 1) due to absorption in the optical path, both The following equations are obtained corresponding to the equations. (4
From equations 1) and (42), the emissivity ε(0) force;-″this E
(θ) is substituted into equation (42) and T1 is obtained from the following equation.

What is necessary is to cause a transparent gas (for example, an inert gas) to flow into the optical path.

By doing so, even in an environment where the transmission coefficient K varies significantly, it is possible to set a stable known value K, and therefore accurate measurement is possible. As described above, the present invention arranges a radiometer and a blackbody radiation source in a diffuse-reflective manner with respect to the normal to the measurement surface, and alternately emits two different amounts of radiation from the blackbody radiation source. In the radiation thermometry method, which measures the surface temperature and emissivity of a surface, a method that originally works when the measurement object is a perfectly specular reflective surface is introduced by introducing the diffuse reflection coefficient p, and the applicable range is generally non-perfectly diffusive. r+mouth 12E1) 0/. ;This is extended to the tqζ reflecting surface.

Clarifying the density relationship between p and the surface roughness of the measurement surface,
Furthermore, a procedure for measuring and evaluating the relationship between p, the detection wavelength, and the solid angle from which the aperture diameter of the blackbody radiation source is viewed from the measurement surface is derived in relation to the measurement error, and it is also possible to deal with variations in the transmission coefficient K. It provides a completely new temperature measurement method that did not exist before.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of the present invention, FIG. 2 is an operational block diagram of the present invention, FIG. 3 A and b are plan schematic diagrams of the present invention, FIG. 4 is a side schematic diagram of the present invention, and FIG. 5 is a schematic diagram of the present invention. 6 is a side view of one embodiment of the present invention in the atmosphere, FIG. 6 is a comparison diagram of the true emissivity value and the emissivity measurement value according to the present invention, and FIG. 7 is a comparison diagram of the true emissivity value and the temperature measurement value according to the present invention. 8 is a side view of an example in which the present invention was implemented in a reactor, FIG. 9 is a schematic diagram of a backlight noise quantification experiment, and FIG. 10 is a PI:. FIG. 11 is a diagram of the experimental values of the relationship between dΩ, FIG. 11 is a diagram of the experimental values of the relationship between p and θa, and FIG. 12 is a diagram of the definition of the average inclination angle θa. ) In the drawing, 1 is a radiometer, 2 is a blackbody radiation source, 3 is a measurement object, and 4 is a furnace wall.

Claims (1)

[Claims] 1. A radiometer and a blackbody radiation source are arranged mirror-symmetrically with respect to the normal to the measurement surface, and two different amounts of radiation are alternately emitted from the blackbody radiation source. In the radiation thermometry method that measures the surface temperature and emissivity of a measurement object, the measured value detected by the radiometer, the temperature of the blackbody radiation source itself, and the diffuse reflection coefficient corresponding to the measurement object are used. A method for measuring the temperature and emissivity of an object, characterized by determining the emissivity of the object to be measured and then measuring the surface temperature of the object. 2. By arranging the radiometer and the blackbody radiation source mirror-symmetrically with respect to the normal to the measurement surface, and by alternately emitting two different amounts of radiation from the blackbody radiation source, the surface temperature of the measurement object can be determined. In the radiation thermometry method that measures emissivity, the measured value detected by the radiometer, the temperature of the blackbody radiation source itself, the diffuse reflection coefficient corresponding to the object to be measured, and the transmission coefficient of the optical path of the measurement system. A method for measuring the temperature and emissivity of an object, characterized by determining the emissivity of the object to be measured and then measuring the surface temperature of the object.