JPS6179123A - Measuring instrument for emissivity and temperature of body - Google Patents

Abstract

PURPOSE:To easily measure the emissivity and temperature of an object body by calculating the emissivity on the basis of the relation between a difference between a detected value when radiant energy is incident and a detected value when not and the emissivity of the object body, and calculating the temperature from it. CONSTITUTION:A scan type radiation thermometer 2 which scans the object body 1 to detect radiant energy from it and radiation sources 31 and 32 which radiates radiant energy to the object body 1 in the scanning area of the thermometer 2 are provided. Then, a coefficient of correction as the ratio of the difference between the detected value when the radiant energy from the radiation sources 31 and 32 which is reflected by the object body 1 is incident on the thermometer 2 and that when not and a value regarding the temperature of the radiation sources is in specific relation with the emissivity of the object body 1, so the emissivity is calculated from it, and an arithmetic means 6 calculates the temperature of the object body 1. Consequently, a correct temperature distribution after the emissivity of the object body 1 is corrected is measured through the simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of the Invention The present invention relates to an apparatus for measuring the emissivity and temperature of steel plates and the like using a scanning radiation thermometer.

(2) Prior art As disclosed in Japanese Patent Laid-Open No. 57-161521, for example, the applicant has determined that the emissivity of the object to be measured is based on the change in the output of the radiation detector when the distance between the comparison hot plate and the object to be measured is changed. We are proposing a method to find the .

However, this method requires a large device to drive the comparative heating plate, and also has problems such as the difficulty of measuring the emissivity and temperature pattern over a wide range of the measurement object because of the single-point measurement. There is.

(3) Purpose of the Invention In view of the above points, the purpose of the present invention is to provide a device for measuring the emissivity and temperature of an object, which makes it possible to more easily measure the emissivity and temperature of the object over a wide range. It is to be.

(4) Summary of the Invention This invention provides a method for determining the difference between detected values when radiant energy from a radiation source reflected from a measurement object is incident on a scanning radiation thermometer and when it is not, and the value related to the radiation source temperature. This is an apparatus for measuring the emissivity and temperature of an object, which calculates the emissivity based on the fact that a correction coefficient, which is a ratio, has a predetermined relationship with the emissivity of the object to be measured, and calculates the temperature from this emissivity.

(5) Embodiment of the Invention FIG. 1 is an explanatory diagram showing an embodiment of the invention.

In the figure, 1 is a measurement object such as a steel plate that runs perpendicular to the paper surface, and 2 is a CO that scans the width direction of the measurement object 1 perpendicularly to detect the radiant energy from the measurement object 1.
D or scanning radiation thermometer using scanning mirror, etc., 31.3
2 is located on both sides of the scanning line of the scanning radiant hygrometer 2, and emits radiant energy to the measuring object 1 in the scanning area of the scanning radiant hygrometer 2, and the radiant energy reflected from the measuring object 1 is the scanning radiant temperature. a radiation source arranged to be incident on the total 2;
4 is an aperture that supports the scanning radiodensitometer 2 and the radiation source 31.32 and emits the radiant energy of the radiation source 31.32;
A background radiation plate (wall) having an opening for receiving the radiation energy of the scanning formation@thermometer 2; 5 is a temperature detector such as a thermocouple or a resistance thermometer to detect the temperature of the background radiation plate 4; 6 is a temperature detector such as a thermometer; , the scanning radiation thermometer 2, the radiation source 31, 32, and the temperature detector 5 are supplied with the output signals, and a microcomputer, a personal computer, or an arithmetic means using an analog circuit performs predetermined arithmetic processing to obtain a temperature signal. be.

The scanning radiation thermometer 2 will be described below as a one-axis (-dimensional) scanning type, but the same applies to a surface scanning type, and the number of radiation sources 31 and 32 may be one, and the background radiation The plate 4 may be a normal wall surface.

The temperature of the measuring object 1 is T1. E(
S), the radiant energy of a black body under temperature is E (T).

When the scanning radiation thermometer 2 scans the measurement object 1, the second
As shown, a high output signal is obtained when radiant energy from the radiation sources 31, 32 is incident.

If the output signal when the radiation energy from the radiation sources 31 and 32 is incident on the scanning radiation thermometer 2 is E(31>), and the output signal when the radiation energy is not incident is E(S2), the following equation holds true.

E (S + ) −ε E (T) +
a ρ 6r (Tr ) + βρE (TV)...
・・・・・・・・・・・・(1)E(82)−εE(T
) 1ρE (TW) − ε E (T) + α
ρE(Twi+βρE(Tw)・・・・・・・・・
(2) Here, α is the ratio of the radiation energy from the radiation source 31, 32 reflected by the measurement object 1 and incident on the scanning radiation thermometer 2, and β is the ratio of the radiation energy from the background radiation plate 4. The rate at which the radiant energy is reflected by the measuring object 1 and enters the scanning TLL thermometer 2 is α+β-1.

In other words, when the scanning radiation thermometer 2 looks at the radiation source 31.32, the first term on the right side of equation (1) is the radiation energy from the measurement object 1 itself, and the second term is the radiation energy from the tIl radiation source 31.32. The third term of the radiation energy is the contribution of the radiation energy from the background radiation plate 4, and the scanning radiation thermometer 2 is the radiation source 31.3.
On the right side of equation (2) when not looking at 2, the radiation source is 31.32
There is no influence, and only the contribution from the background radiation plate 4 is made.

When equations (1) and (2) are subtracted, the following equation is obtained.

E (S+)-E (82) -ao (6r E (Tr) -E (Tw)
)E (S+) −E (2 αρ−−−−−−−−−−−−−− ・・・・・・(3
) εr E (Tr) −E (Tw) Here, let the left side be k, and the value on this left side can be determined by measurement from the right side.

On the other hand, it has been experimentally found that the relationship between K-αρ and emissivity ε is a linear relational expression as shown in the following equation.

ε-A-Bk =A-8(αρ)・・・・・・・・・(
4) When this relationship is illustrated, as shown in FIG. 3, the straight lines differ depending on the type of objects M1, M2, etc.

Coefficients A (AI, A2...), B (Bl, B2,...
・) is determined in advance through experiments for each type of object to be measured.

Therefore, since ε + ρ-1-1, the formula (2) becomes the formula % (), and by substituting the emissivity ε obtained from the formula (4) into the formula (5), the true temperature of the measuring object 1 is is found.

Note that in the above equation, Tw can be omitted if the temperature Tw of the background radiation plate 4 is sufficiently small.

In other words, before the measurement, the storage means included in the calculation means 6 has the following information:
Emissivity εrS of the radiation source 31.32 Coefficients A1, A2, . . . , B1.82, .corresponding to the type of the measurement object 1
. . . are stored in advance so that they can be selected and read out according to the type of the measurement object 1.

During measurement, the scanning radiation thermometer 2 scans the measurement object 1,
An output signal Ei corresponding to each scanning position Xi is supplied to the calculation means 6. At this time, for example, output signals when radiation #I31.32 is scanned at scanning positions X2 and XS with E2 and E5, El, E3. E4, E6 are the positions X2, Xs where the radiant energy of the radiation source 31.32 is reflected by the measuring object 1.
Let the output signals be from the positions on both sides of . In addition, the radiation source 31
．． The temperature signal Tr of 32 and the output signal of the temperature detector 5 which detects the temperature Tw of the background radiation plate 4 are supplied to the calculation means 6.

The calculation means 6 performs calculations such as El+23 E4+26 E2-□, Es-□ to obtain the numerator of equation (3), and calculates Tr%Tw to obtain E.
(Tr >, E (Tw ), use ε, calculate 6r E (Tr ) − E (Tw ), use it as the denominator of equation (3), find αρ−k from equation (3), and calculate this Using the two sticks and the value of ASB, calculate the two emissivities ε from equation (4).The average value of these two emissivities ε is taken as the emissivity of the measurement object, and the radiant energy detection signal Ei of each point Xi Substitute it into equation (5) and find the temperature at each point,
It can be the output of the calculation means 6.

In this way, using the radiation sources 31 and 32, the measuring object 1
It is possible to find the emissivity ε of and find the temperature at each point.

After determining the emissivity ε in advance, the apertures of the radiation sources 31 and 32 may be shuttered to perform continuous measurements.

FIG. 4 shows another embodiment, in which the same reference numerals as in FIG. 1 indicate the same components. In this example, a 3WA radiation source 31.
32 and 33 are provided at a predetermined angle to the scanning radiation thermometer 2 with respect to the normal line of the measurement object 1,
It is controlled to a predetermined temperature Tr by temperature controllers 71, 72, and 73. Moreover, the output of the calculation means 6 is
Displayed on CRT display 74, analog recorder 75,
It is set to be recorded. Moreover, the emissivity ε may not be the average value of the radiation sources 31, 32, 33, but may be divided into three zones along the traveling direction of the measurement object 1, and the emissivity for each zone may be determined.

FIG. 5 shows another embodiment, in which the same reference numerals as in FIGS. 1 and 4 indicate the same components. In this example, one radiation fJ1
s3i is configured to radiate radiant energy along the scanning line height of the scanning radiation thermometer 2 by parallel translation or swing scanning, and when the radiant energy from the radiation source 31 is incident on approximately the same point. The emissivity ε for each point on the scanning line λ is determined based on the detected value of the scanning radiation thermometer 2 when the sensor is not in use, and the continuous value of the temperature T for each point is obtained from this emissivity ε for each point. It will be done. These calculations are performed by calculation means 6 having storage means. By this, the measuring object 1
Accurate temperature measurement is possible even with variations in emissivity distribution.

In addition, when the scanning radiation thermometer 2 is a surface (two-dimensional) scanning type, there is at least one radiation source 31 that emits radiant energy within its scanning area, or at least one radiation source 31 that emits radiant energy within its scanning area. The emissivity and temperature distribution can be obtained by similar calculations using the radiation source 31 that is scanned by the radiation source 31.

(6) Effects of the invention Since emissivity and concentration are measured using a scanning radiation hygrometer, taking advantage of the predetermined relationship between emissivity and correction coefficient, the configuration is simple. With this, it is possible to measure the correct temperature distribution with emissivity correction over a wide range of the measurement object. Furthermore, by changing the correction coefficient of the relational expression, it is possible to deal with various objects, and by scanning a plurality of radiation sources or radiation sources, more accurate and continuous emissivity and temperature distribution can be measured.

[Brief explanation of the drawing]

1, 4, and 5 are configuration explanatory diagrams showing one embodiment of the present invention, FIG. 2 is a waveform diagram for explaining the operation, and FIG. 3 is a
FIG. 3 is a relationship diagram between emissivity and correction coefficient.

Claims (1)

[Claims] 1. A scanning radiation thermometer that scans the object to be measured and detects radiant energy from the object; a radiation source, a difference between detected values when radiant energy from the radiation source reflected by the measurement object is incident on the scanning radiation thermometer and when it is not incident on the scanning radiation thermometer, and a value related to the radiation source temperature; and calculation means for determining the emissivity based on the fact that the correction coefficient, which is the ratio of Emissivity and temperature measurement equipment. 2. The emissivity and the correction coefficient are a linear relational expression, and at least one set of coefficients of the linear expression is stored for each type of measurement object, and a calculation means is used to select and calculate the coefficients. An apparatus for measuring emissivity and temperature of an object according to claim 1, characterized in that: 3. The detection value when the radiant energy from the radiation source is reflected by the measurement object and enters the scanning radiation thermometer, and the detection value of the radiant energy from near the reflection position where the radiant energy from the radiation source is reflected by the measurement object. 3. An apparatus for measuring emissivity and temperature of an object according to claim 1 or 2, wherein the emissivity is calculated using a difference between the detected value and the detected value. 4. A radiation source is provided on the scanning line of the scanning radiation thermometer that vertically scans the measurement object, or at a predetermined angle to the scanning radiation thermometer with respect to the normal to the measurement object. Claims 1 to 3 characterized by
Apparatus for measuring the emissivity and temperature of the object described in Section 1. 5. Claims 1 to 5, characterized in that a plurality of the radiation sources that radiate a plurality of radiant energies to the measurement object or a radiation source that scans and radiates radiant energy to the measurement object are used. A device for measuring emissivity and temperature of an object according to item 4. 6. An apparatus for measuring emissivity and temperature of an object according to claims 1 to 5, characterized in that the radiation source includes a background radiation plate having an aperture that emits radiant energy.