JPS62142246A - Temperature measuring method - Google Patents

Abstract

PURPOSE:To improve temperature measuring accuracy by selecting a suitable number of combinations of two optional wavelengths within a wavelength range in the spectrum distribution of radiation energy of a temperature measuring object. CONSTITUTION:A light beam 2 generated from a temperature measuring object 1 is led to a spectroscope 4 by a fiber 3, and the spectrum distribution of radiation energy of the object 1 is measured. This analog data is stored in a memory 8 of a computer 6 through an A/D converter 5. Subsequently, the operating a keyboard 10, a suitable number of combinations of two optional wavelengths are selected within a wavelength range of the spectrum distribution which is measured by the spectroscope 4. Also, at every combination of this wavelength, by using two wavelengths lambda1, lambda2 and radiation energies W1, W2 which are stored in the memory 8 corresponding to said wavelengths, a temperature value is calculated by a two-color temperature calculating method. Subsequently, in a CPU7, the frequency distribution of this calculated temperature value is derived, a temperature value frequency distribution diagram is generated on a monitor 11, and also, from the frequency distribution of each temperature value, a temperature of the temperature measuring body 1 is determined and displayed on the monitor 11.

Description

[Detailed Description of the Invention] <Industrial Application Fields> This invention uses the energy V- emitted from a temperature measuring object to conduct temperature measurement without contact! 2. Concerning the method of determining the temperature i1+11 to perform the measurement.

(Prior art and its problems) It is a well-known fact that the energy radiated from a body depends on the temperature of the body. The two-color temperature derivation method has been widely used as a temperature measurement method using such a source 1p.

The temperature measurement principle of the dichromatic temperature algorithm is shown below. The energy W (λ, -1-) radiated from ten objects can be theoretically calculated using the following formula 'C' based on Blank's formula. Mr.... (1) Here, W (λ, 1'): watt/m27r) 3rd wavelength λ: Wavelength (nm) T: Temperature of the object (°K) ε: 1 Ka (Tree 9) ．Q・
1 ° Takuyuki As can be seen from equation (1) above, the radiation I of the object
) If the J rate ε is clear, the temperature of the object -1 can be determined by measuring 1L of radiant energy W·3 of a certain wavelength λ. However, in reality, the emissivity ε of an object changes depending on the temperature T, and it also changes greatly due to slight changes in the chemical and physical states of six substances at the same temperature. Only the exact number is known.

Therefore, in the two-color temperature calculation method, even if the emissivity ε of the object is unknown, a method is adopted in which temperature measurement is performed using r+J function. However, this method assumes that the temperature measuring object is a gray body whose rate ε is constant C with respect to the wavelength λ, and an appropriate 2
wavelength λ1. Specify λ2, measure the respective radiant energies W and W2, and calculate the temperature of the object from the ratio.

If this is explained using a theoretical formula, it is as follows.

Now, radiant energy W1. emitted from an object with wavelengths λ and λ and emissivity of ε and ε. When the ratio R of W2 is determined, the following equation 19 can be obtained using the above equation (1).

Here, since the temperature measuring object is assumed to be a gray body, the equation (2) becomes as follows.

Equation (4) above does not include the emissivity ε, so even if the value of the emissivity ε is unknown, the two wavelengths λ1. λ
2 radiant energy w1. By measuring W2,
It is possible to determine the temperature T of an object. As a temperature measurement device using such a two-color temperature 'fAt; two wavelengths λ
1. By adjusting the radiant energy of λ2 to be proportional to the ratio of W, W, 2, the temperature of the object can be measured by the above equation (4) regardless of the emissivity ε of the temperature measuring object.

As explained above, the two-color temperature calculation method uses the specified wavelength λ
This measurement method assumes that the emissivities ε and ε of λ and λ are equal. However, the emissivity ε of a large object varies greatly depending on the oxidation/reduction state of the substance, the roughness of the surface, etc., and there is no guarantee that the rate of change will always be uniform with respect to the wavelength λ. Furthermore, it is difficult to predict in advance the regularity of changes in emissivity ε with respect to wavelength λ based on measurement conditions and the like.

The selected wavelength λ1゜λ using Jj in the dichroic system 1 good arithmetic method
If the emissivity ε and ε2 of Color temperature calculation method
When the temperature value was determined by changing the selected wavelength, the result was shown in Figure 4. Jj is on the ff1 diagram,
The hζ axis represents the wavelength, and the vertical axis represents the relative intensity of equation (4).
We have expanded the area circled in the lower right corner. As shown in the figure, there are four combinations of two wavelengths (λ, λ2): (550, 660 nm), (660, 730 nm), (
550, 730 nm) and (500, 580 nm), the temperature T was calculated using the two-color temperature calculation method, and the results were 1728°C, 1553°C, 1668°C, and 1678°C, respectively.
℃ was obtained, and considerable differences in tube temperature values were observed depending on the selected wavelength. Note that the curve P in FIG. 4 corresponds to the actually measured spectral distribution.

In this way, the temperature lI/l determined by the two-color temperature calculation method
However, what actually differs depending on the selected wavelengths λ and λ2 is the radiation of the object! It is thought that a temperature error expressed by equation (5) occurs because the emissivity ε is constant even though Vε varies depending on the wavelength.

As explained above, the two-color temperature calculation method C cannot accurately measure the temperature of an object because it is affected by the change in the emissivity ε of the object with respect to the wavelength λ, which causes variations in the zero temperature. I had a problem.

(Objective of the Invention) The temperature measurement method of the present invention has been made in order to solve the above problems, and provides a temperature measurement method that can improve temperature measurement accuracy by reducing the influence of changes in the emissivity ratio with respect to wavelength. The purpose is to provide.

(Means for Achieving the Object) In order to achieve the above object, the temperature measurement method of the present invention measures the spectral distribution of energy radiated from a temperature measuring object, and measures the spectral distribution of energy radiated from a temperature measuring object, 2
Select an appropriate number of combinations of wavelengths, and for each combination, calculate the temperature value using the two-color temperature calculation method using the two-wave Iq for that combination and the measured radiant energy values of the two wavelengths, and calculate the q output. The temperature of the temperature measuring object is determined from the measured temperature (direct frequency i1i).

(Example) FIG. 1 is a block diagram showing an example of a temperature measuring device for carrying out the temperature measuring method of the present invention. In this device, light 2 generated from an object 1 whose temperature is to be measured is
It is configured to be guided to a spectrometer 1 using a quartz fiber 3 or the like to measure the spectral distribution li of radiant energy. As the spectrometer 4, a spectrometer S having a photodiode array detector is used, for example, so as to be able to measure spectral differences in a predetermined wavelength range, but the model is not particularly limited.

Ablog data representing the radiant energy value of each wavelength detected by the photodiode array of the spectrometer 4 is output from the spectrometer 4 in time series for each wavelength.
It is configured to be converted into digital data by a D converter 5 and input to a combi coater 6. The computer 6 has a central processing unit (CPU) 7 connected via a bus to a central processing unit (CPU) 7 for performing various operations and giving various commands to external devices. On boat 9, the above A/D change 111j! The device 5 is connected to input means such as a keyboard 10 for inputting a selected wavelength, and output means of a monitor 11'8 for displaying a temperature frequency distribution diagram and measured temperature values.

Next, a second temperature measurement method using the above temperature measurement device will be described.
This will be explained using flowchart J shown in the figure. First, in step S1, the light 2 generated from the temperature measuring object 1 is guided to the spectrometer 4 through the fiber 3, and the spectral distribution of the radiant energy of the temperature measuring object 1 is measured by the photodiode array of the spectrometer 4. The measurement wavelength range of the spectrometer 4 is not particularly limited, but as an example, it is possible >+S light (550
Each rIIIll-1 energy is measured at predetermined wavelength intervals, such as 5 nm, over the range (nm-650 nm). In this way, the energy of each wavelength measured by the photodiode array of the spectrometer 4 (ana[
The 1g data is output in time series to the Δ/D converter 5 and converted into digital data, and is sent to the I10 port 9 of the combi coater 6. J 7 It is stored in the storage area 8. As a result, data representing the spectrum of the radial energy A=- (1i) of the temperature measuring object 1 is stored in the memory 8.

Next, the operator operates the keyboard 10 to select any two within the spectral distribution range measured by the spectrometer 4.
Select an appropriate number of wavelength combinations. More 6, this selection work is done by measuring L
J: Go ahead and store the selected wavelength in the memory 8 in advance. When the wave 1 constant work is carried out in this way, C
For each combination of wavelengths selected, the two wavelengths λ and λ related to that combination, and the wavelength λ
, λ2 are stored in the memory 8 and have 10 radiant energies W1 and W2, the two-color temperature calculation method (already described (
4) The temperature value is calculated by the formula (Step S2)
),.

When the temperature value output processing for each wavelength combination 1σ is completed, the CPU 7 calculates the frequency distribution of the temperature values and Q output temperature values for each temperature value, and calculates the 110 boats 9. A temperature value frequency distribution map is created on monitor 11 through
Step 83). Again, J3 at CP tJ 7,
The temperature of the temperature measuring object is determined from the cloth (1/,) of each temperature value obtained, and is sent to the monitor 1 via the 1,10 boat 9.
1 (step S4). This temperature measurement 1 is done by determining the temperature t, for example, by determining the high temperature (I゛1) of the output y1 degree by the two-color 1111'1 degree operation Q method, or [Yo temperature R! , self-indulgence 11%nnnn7
By finding the median value of 1i, one tooth is removed.

In fact, using the method described in ``2'', we measured the radiant energy of each visible light spectral distribution rn) of a certain temperature measuring object 1 at 5 diagonal and a1 intervals, and within that wavelength range, we measured the appropriate IJ of 210 rounds,
A combination of two wavelengths was selected, a temperature value was calculated for each combination V by the two-color temperature algorithm, and a temperature value frequency diagram was created based on the calculated crystallinity.

An example of this is shown in FIG. The horizontal axis shows the dedicated temperature value, and the vertical axis shows the number of lockouts.As shown in Figure 3, the two-color temperature KI
One shift of measurement using the rotor method is 1000℃ depending on the selected wavelength.
Variations occur over a wide range from 1900°C to 1900°C. Also, although it is not clearly shown in the figure, there is no consistent trend in the wavelengths for which temperatures are calculated that deviate from the median of the frequency distribution, and even if the wavelengths used in the Futura Atma calculation method are the same, The temperature value indicates a value close to the median value or fMi that is quickly determined depending on the temperature and measurement conditions. Using this temperature frequency diagram 15, the temperature of the temperature measuring object was determined based on the most frequently used temperature value for the cylinder, and the measured temperature value was 1460°C. In fact, when the true temperature of the temperature measuring object 1 was simultaneously measured using a thermocouple, the temperature measurement result was 1460°C, which was 311 degrees Celsius! The temperature values were consistent with those measured using the same method.

In addition, in the above example, 210 +Pl"1 values are calculated at 5 dm intervals for each 550 nm to 650 nm spectrum component 5 using the two-color wetness calculation method, but the measurement wavelength range and the number of measured values Needless to say, is not limited to the above. That is, regarding the number of measured values, the minimum combined μ number that can eliminate the influence of non-uniformity of emissivity due to the wavelength of the temperature measuring object is sufficient.

Furthermore, in the above embodiment, the spectral distribution measured by the spectrometer 4 is input into the computer 6 online, but the operator inputs the data of the spectral distribution measured by the spectrometer 4 using the keyboard 10. It may also be configured to be input to the computer 6. Furthermore, the above-mentioned two-color temperature calculation process, temperature frequency distribution map creation process, and measured temperature value determination process can be performed manually without using the combi coater 6, or can be performed manually and by using a computer.
You can also make it so that 1f<river J.

According to this temperature measurement method, it is possible to reduce the influence of changes in emissivity ε with respect to the wavelength of the temperature measuring object 1, and Jl) 1 temperature 7
You can improve your level of performance. In addition, it is possible to automatically remove the effects of light scattering and absorption caused by smoke, water, etc. that exist between the temperature measuring object 1 and the quartz fiber 3'8, and in this respect, humidity measurement is also possible. Viscosity can be improved.

(Effect of the invention) According to the temperature measuring device of the present invention,
Measure the spectral distribution 11 of Y energy using the 1llll + hot water object, determine an appropriate number of combinations of 2 waves to 7 within the wavelength range of the spectral distribution, and add two colors to each combination Uf0. Base 1 JII performance C') According to Buddha, calculate the temperature (n for C) and determine the humidity of the temperature measuring object from the frequency distribution of the temperature (L). In order to reduce the effect of changes in the family α1/' on , temperature measurement lI'
Is the effect of being able to aim for the direction of Iα 1'? It will be done.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an example of a temperature measuring device in which the temperature measuring method of the present invention is implemented, Fig. 2 is a diagram showing its operation, and Fig. 3 is an example of the temperature frequency distribution created by the above device. The figure shown in FIG. 4 is a diagram showing the relationship between a measuring device and a selected wavelength using the conventional two-color thirst calculation method. 1...Temperature measuring object, 4...Spectrometer 6...Computer agent For patent attorney purposes -,! r 11 Shigeaki Bentakuju Yoshitake Yatoshi Benri 1~ Takahiro Arita Figure 2 Toukou Kaishu

Claims (2)

[Claims] (1) Measure the spectral distribution of energy emitted from the temperature measuring object, select an appropriate number of combinations of any two wavelengths within the wavelength range of the spectral distribution, and for each combination, A temperature measurement method characterized by calculating a temperature value by a two-color temperature calculation method using a wavelength and measured radiant energy values of the two wavelengths, and determining the temperature of a temperature measuring object from the frequency distribution of the calculated temperature values. . (2) The temperature measuring method according to claim 1, wherein the temperature of the temperature measuring object is determined by determining the most frequently calculated temperature value using a two-color temperature calculation method.