JPH02245624A - Radiation temperature measuring apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radiation temperature measuring device suitable for measuring the radiation temperature of a measurement object when the measurement object moves on a conveyance path.

[Prior Art] FIG. 4 is a diagram showing an example of a conventional radiation temperature measuring device developed by the applicant and found in Japanese Patent Laid-Open No. 61-210921. In the figure, 1 is a measuring object, 2 is a radiation source that emits radiant energy to the measuring object 1, 3 is a shutter means as a contribution rate changing means for changing the radiant energy that the radiation source 2 radiates to the measuring object 1, and 4 is a shutter means. Aperture 2a of radiation source 2
5 is an output signal of the radiation detector 4, an output signal of a temperature detector 20 that detects the temperature of the radiation source 2, and an atmosphere in the vicinity of the shutter means 3. It is an arithmetic means consisting of an analog circuit, a microcomputer, etc., to which an output signal of the temperature detector 30 for detecting the temperature inside is provided.

Next, the operation of the radiation temperature measuring device will be explained.

As shown in the figure, the shutter means 3 is almost closed, and the measurement object 1 is
Radiation detection l in the state where only the radiant energy from the
Output signals EO and El of I4.

Find E2, perform a predetermined calculation using the calculation means 5,
Find the radiation temperature of the measuring object.

The method of calculation at this time is disclosed in Japanese Patent Application Laid-Open No. 61-21092.
Since it is described in Publication No. 1, its details will be omitted.

[Problem to be solved by the invention] However, in the conventional radiation temperature measuring device described above,
When the measurement object l is moving on a conveyance path such as a conveyor, the distance between the measurement device and the measurement object changes depending on the situation at that time, and as a result, it is difficult to accurately measure the radiation temperature of the measurement object. The problem was that it couldn't be done.

This invention was made to solve the above problems, and provides a radiation temperature measuring device that can accurately measure temperature even under conditions where the distance between the measuring object and the measuring device changes. It is an object.

[Means for Solving the Problems] Therefore, the radiation temperature measuring device according to the present invention includes a radiation source that emits radiant energy to a measurement object, a radiation detector that detects radiant energy from the measurement object, and a radiation temperature measurement device that emits radiant energy to a measurement object. and a contribution rate changing means for changing the contribution rate of the radiant energy emitted by the source to the measuring object, and measuring the temperature of the measuring object based on the output of the radiation detector in different states of the contribution rate changing means. The radiation thermometer is characterized in that it includes distance measuring means for measuring the distance between the measuring object and a certain specified location, and the temperature of the measuring object is corrected based on the distance measured by the distance meter.

[Function] The distance measuring means in the present invention measures the distance between the measuring object and a certain specific place.

Then, approximate correction of temperature is performed based on the measured distance.

[Example] Hereinafter, an example of the radiation temperature measuring device according to the present invention will be described based on the drawings.

FIG. 1(a) is a diagram showing an embodiment of the radiation temperature measuring device according to the present invention, and FIG. 1(b) is a partially omitted side view of the same device. In FIG. 0, IA is a measurement object. 2A is a temperature controller that controls the temperature of the radiation source 2, and 3A is the output signal of the radiation detector 4. , an A/D converter that converts the output signal of the temperature detector 20 of the radiation source 2, the output signal of the temperature detector 30 that detects the temperature of the shutter means 3, and the output signal of the distance meter IA from analog signals to digital signals, respectively; 4A is A
The microcomputer serves as a calculation means for performing predetermined calculations on the digital signal output from the /D converter 3A and obtaining the temperature of the measuring object 1.

Here, the distance meter IA is constituted by, for example, a laser light emitting source and a light receiving source. The distance to the measurement object 1 is measured by receiving the light reflected by the light receiving source.

Next, the operation of the radiation temperature measuring device having the above-described configuration will be explained.

As in the conventional case, the output signals Eo, E+, and E2 of the radiation detector 4 are obtained in the following states: when the shutter means 3 is closed and only the radiation energy from the measurement object 1 can pass through, when it is half-open, and when it is fully open. It is calculated and output to the microcomputer 4A corresponding to the calculation means 5.

At the same time, the distance meter IA as a distance measuring means measures the object 1 to be measured.
The distance to a specific reference position is measured and the result is output to the microcomputer 4A.

Here, the microcomputer 4A performs the following calculation based on the b force signal of the radiation detector 4 and the distance JIIL output from the distance meter IA.

The temperature of the measuring object 1 is T, the emissivity is ε, the temperature of the radiation source 2 is Tr, the emissivity is εr, and the radiation energy equivalent to temperature is E
(T) and the temperature Ta of the shutter means 3 is the output signal E of the radiation detector 4 when the shutter means 3 is fully closed, half open, or fully open. , EIE2 are each as follows.

E o -s E(T) + (1-ε)E(Ta)
-(1)Et=gE(T)+(1-g)gr
E(Tr)F+ −<2)” (1-g)E(T
a) (1-Fl)Ez=gE(T)+(1-g)gr
E(Tr)F2-(3)+ (f-6)ET(Ta)
(1-F2) Here, F,, F2 are the contribution factors of the radiation energy from the radiation source 2 reflecting off the measurement object l and entering the radiation detector 4, and F l < F 2 .

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

Further, when ε is obtained by subtracting equations (2) and (3), the following equation is obtained. Here, assuming that the difference in contribution rate is D=F2-F, the following equation can be obtained from equation (1).

E (a,, = E o-1-g) E ('
ra) ,,, (6)ε Here, R and D can be approximated by the predetermined functional relationship o=s0+S,R-(7), D is found from R, and the emissivity ε, Temperature T is found.

However, in the conventional method, equation (7) is a function at a constant distance, and an error occurs when the distance to the measurement target changes.

In order to solve the above problem, we experimentally determined S, , S, when the measurement distance was changed, and the relationship shown in Figure 2 was obtained.

As can be seen in FIG. 2, the coefficients S, , S, are functions of the measurement distance 111L between the measurement object 1 and the radiation detector 4, and can be approximated, for example, by the following equation.

So (L)=aOL2+bot,+c0-(e)S
, (L)=a,L"+b,L+C,-(9) Two pieces,
a O+ A I + bO+ b+ is a constant.

From the following distance, (8). Using equation (9), S
By determining O(L) and st (L) and determining D from equation (7), the emissivity ε and the humidity temperature can be determined without being subject to distance fluctuations.

As shown in FIG. 3, the error in the difference in contribution rate to distance variation is much smaller in the present invention than in the conventional example.

[Effects of the Invention] As explained above, according to the radiation temperature measuring device of the present invention, a distance measuring means for measuring the distance between a measurement object and a certain specified place is provided, and the distance measured by the distance meter is provided. Since the temperature correction is performed based on the difference in the shape coefficient of the measurement object, the temperature can be measured with less error even when the measurement object has distance fluctuations, such as on a production line.

[Brief explanation of drawings]

FIG. 1(a) is a diagram showing an embodiment of the radiation temperature measuring device according to the present invention, FIG. 1(b) is a partially omitted side view of the same device, and FIG. 2 is an experimentally determined coefficient S2. ．． A diagram showing the relationship between S+ and the distance to the measurement object, Figure 3 is a diagram showing the variation in the measurement of the radiation temperature of the measurement object after correction, and Figure 4 is an example of a conventional radiation temperature measuring device. FIG. 1-Measurement object, 2--Radiation source, 3--Shutter means (contribution rate changing means), 4--Radiation detector, 5--Calculating means, IA--Distance meter (distance measuring means), 2A-temperature controller, 3A-A/D converter, 4A
...Microcomputer.

Claims (1)

[Claims] A radiation source that emits radiant energy to a measurement object; a radiation detector that detects radiant energy from the measurement object;
and a contribution rate changing means for changing the contribution rate of the radiant energy emitted by the radiation source to the measurement object, the temperature of the measurement object being determined based on the output of the radiation detector in different states of the contribution rate changing means. A radiation thermometer for measuring , comprising a distance measuring means for measuring the distance between the object to be measured and a specified location, and correcting the temperature of the object to be measured based on the distance measured by the distance meter. Radiation temperature measurement device.