JPH0521412B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of the Invention The present invention relates to an apparatus for measuring emissivity and temperature of a measuring object such as a steel plate.

(2) Prior art The applicant has proposed, for example, the output of a radiation detector when the distance between the comparative heat plate (auxiliary heat source, radiation source) and the measurement object is changed, as described in Japanese Patent Application Laid-open No. 161521/1983. We have proposed a method to determine the emissivity of a measurement object from the change.

However, this method has problems such as the need for a large device for driving the comparative hot plate.

(3) Purpose of the Invention In view of the above points, the purpose of the present invention is to provide a device that more easily measures the emissivity and temperature of an object.

(4) Means for Solving the Problems In order to achieve the above object, the emissivity and temperature measuring device of the present invention comprises a radiation source that emits radiant energy to a measurement object, and a radiation source that emits radiant energy from the measurement object. a radiation detector for detecting energy; a contribution rate changing means for changing the contribution rate of the radiant energy radiated by the radiation source to the measurement object; and first and second radiation detectors for measuring the temperature of the radiation source and the contribution rate changing means. The temperature detector and the contribution rate changing means reflect the radiant energy from the radiation source on the measurement object and change the contribution rate F ₁ ,
The _two signals are the first and second detected values E ₁ , E ₂ when the radiation energy is incident on the radiation detector at F 2 and the detected value E ₀ when the radiation energy from the radiation source is not incident on the radiation detector. Difference ratio R = (E ₁ −E ₀ /E ₂ −E ₀ )
= F ₁ /F ₂ is determined and the contribution is determined based on the fact that the ratio of contribution rates R = F ₁ /F ₂ and the difference in contribution rates D = F ₂ - _{F 1} are in a predetermined relationship determined experimentally in advance. A difference D in contribution rates is determined and measured using the difference D in contribution rates and the radiant energy related to the first and second detected values E ₁ , E ₂ and the temperatures of the first and second temperature detectors. The present invention is characterized by comprising calculation means for determining the emissivity of the object and determining the temperature of the measured object from this emissivity.

Further, as the contribution rate changing means, a shutter means or a movable light shielding plate having apertures of different sizes may be used.

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

In the figure, 1 is the measurement object, 2 is the radiation source that emits radiant energy to the measurement object 1, and 3 is the contribution rate of water cooling, etc. that changes the radiant energy that the radiation source 2 emits to the measurement object 1. shutter means 4 as changing means, an aperture 2 of the radiation source 2;
5 is the output signal of the radiation detector 4, the output signal of the temperature detector 20 that detects the temperature of the radiation source 2, and the background of the shutter means 3; It is a calculation means consisting of an analog circuit, a microcomputer, a personal computer, etc. to which the output signal of the temperature detector 30 that detects a corresponding temperature is supplied.

Temperature of measurement object 1 is T, emissivity is ε, radiation source 2
temperature is Tr, emissivity is εr, temperature of shutter means 3 is Ta, output signal of radiation detector 4 is Ei, temperature T
Let E(T) be the radiant energy equivalent to a black body.

As shown in the figure, the output signals E ₀ , E ₁ , E ₂ becomes:

E ₀ = εE (T) + (1-ε) E (Ta) ...(1) E ₁ = εE (T) + F ₁ (1-ε) εrE (Tr) + (1-F ₁ ) (1-ε )E(Ta)...(2) _E2 = εE(T)+ _F2 (1-ε)εrE(Tr) +(1- _F2 )(1-ε)E(Ta)...(3) Here, F ₁ and F ₂ are the contribution rates of the radiation energy from the radiation source 2 reflecting off the measurement object 1 and entering the radiation detector 4, and F ₁ <F ₂ .

In other words, when the shutter means 3 is closed, the first term on the right side of equation (1) is the radiant energy from the measuring object 1 itself,
The second term is the contribution of the radiant energy from the shutter means 3, and the radiant energy from the radiation source 2 can be ignored. The second term on the right side of equations (2) and (3) is the contribution from the radiation source 2, and the third term is the contribution from the shutter means 3.

By subtracting equation (1) from equation (2) and subtracting equation (1) from equation (3), the following equation is obtained.

E ₁ −E ₀ =F ₁ (1−ε)εrE(Tr) −F ₁ (1−ε)E(Ta) E ₂ −E ₀ =F ₂ (1−ε)εrE(Tr) −F ₂ ( 1-ε)E(Ta) Taking the ratio R, the following equation is obtained.

R=(E ₁ −E ₀ )/(E ₂ −E ₀ )=F ₁ /F ₂ (4) Further, by subtracting equations (2) and (3), the following equation is obtained.

E ₂ −E ₁ = (F ₂ −F ₁ ) (1−ε) {εrE(Tr)−E
(Ta)} From this, the emissivity ε is given by the following formula.

ε=1−(E ₂ −E ₁ )/[(F ₂ −F ₁ )・{εrE(Tr)−E(Ta)}] …(5) Here, D=F ₂ −F ₁ and R It has been experimentally found that the relationship with =F ₁ /F ₂ is a predetermined functional relationship where D=f(R) as shown in FIG. In other words, D can be found from R, and the other values on the right side of equation (5) are found by measurement, etc., so the emissivity ε
can be found.

Then, from equation (1), E(T) = {E ₀ − (1-ε) E(Ta)}/ε ...(6), so in equation (6), By substituting the emissivity ε, etc., the true temperature of the measuring object 1 is determined.

In other words, before the measurement, as shown in FIG.
(R), and the emissivity εr of the radiation source 2 is stored in the calculation means 5.

Next, during measurement, open and close the shutter means 3, (1),
E ₀ , E ₁ , E ₂ of equations (2) and (3) are detected by the radiation detector 4,
Also, the temperatures Tr and Ta of the radiation source 2 and the shutter means 3 are
are detected by temperature detectors 20 and 40 and supplied to calculation means 5, respectively.

The calculation means 5 calculates the ratio R of equation (4) from the signals E ₀ , E ₁ , and E ₂ , calculates D from this, and calculates the signals Tr,
E(Tr) and E(Ta) are calculated from Ta, and the right side of equation (5) is calculated to find the emissivity ε. Also, emissivity ε
The temperature T of the measuring object 1 is calculated by calculating equation (6) using
can be found.

In the above example, the shutter means 3 was used as the contribution rate changing means, and the contribution rate was changed by changing its opening degree. It may be changed.

(6) Effects of the invention Since emissivity and temperature are measured using the fact that the difference in contribution rates has a predetermined relationship with the ratio of contribution rates, the emissivity can be corrected with a simple configuration. can measure the temperature of the correct object.

[Brief explanation of drawings]

FIG. 1 is a configuration explanatory diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between the difference and ratio of contribution rates. 1... Measurement object, 2... Radiation source, 3... Shutter means (contribution rate changing means), 4... Radiation detector,
5... Calculation means.

Claims (1)

[Claims] 1. A radiation source that emits radiant energy to a measurement object, a radiation detector that detects the radiant energy from the measurement object, and a variable contribution ratio of the radiant energy that the radiation source radiates to the measurement object. a contribution rate changing means that measures the temperature of the radiation source and the contribution rate changing means; Two of the first and second detected values E _{1 and} E ₂ when the radiation energy enters the radiation detector at F 1 and F ₂ and the detected value E ₀ when the radiation energy from the radiation source does not enter the radiation detector Ratio of the difference between two signals R
= (E ₁ - E ₀ / E ₂ - E ₀ ) = F ₁ / F ₂ is calculated, and the ratio of this contribution rate R = F ₁ / F ₂ and the difference in contribution rate D = F ₂ - F ₁ are determined by experiment in advance. A difference D in contribution rates is determined based on _a predetermined relationship _determined by
emissivity of the object, characterized in that the emissivity of the object is determined by calculating the emissivity of the object to be measured using the radiant energy related to the temperature of the second temperature detector, and the calculating means for calculating the temperature of the object to be measured from the emissivity. Temperature measuring device. 2. The device for measuring the emissivity and temperature of an object according to claim 1, wherein the contribution rate changing means is a shutter means or a light shielding plate having movable openings of different sizes.