JPH0523700B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an apparatus for measuring the emissivity and temperature of an object (object) to be measured such as a steel plate.

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

[Problems to be Solved by the Invention] However, this method has problems such as the need for a large device for driving the comparative hot plate.

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

[Means for Solving the Problems] The present invention includes a light source and a detector that emit or receive light at at least two or more predetermined angles with respect to the normal to a measurement position of a measurement object, and a light source and a detector that emit light or receive light at at least two predetermined angles with respect to the normal to a measurement position of a measurement object, and a The contribution rate ratio, which is the ratio of the difference between each of the two detection signals due to light emission and light reception with respect to angle and the detection signal when no light is coming from the light source, has a predetermined relationship with the contribution rate difference. This radiation temperature measuring device is equipped with a calculating means for determining emissivity based on the emissivity and calculating the temperature of the object to be measured from this emissivity.

[Embodiment] FIG. 1 is a configuration explanatory diagram showing a first embodiment of the present invention.

In the figure, 1 is the measurement target, 21 and 22 are
A light source that emits light to measurement object 1, 3 is light source 2
A detector such as a photoelectric element that receives light reflected by the measurement object 1 from 1 and 22; 4 is an analog circuit, a microcomputer, and a personal computer that performs predetermined calculations based on the detection signal from the detector 3; It is a calculation means such as. The light source 21 emits light at a predetermined angle θ ₁ , the light source 22 emits light at a predetermined angle θ ₂ , and the detector 3 receives the light at a predetermined angle θ ₀ with respect to the normal l to the measurement position P of the measurement object 1 . In addition, the light sources 21, 2
2 turns on the power supply E by the switch means S ₁ and S ₂ .
The light sources 21 and 22 and the detector 3 are provided with visual field limiting means L ₁ , L ₂ , L ₃ such as rod lenses and microlenses, which are controlled to turn on and off by turning them off. Note that, for example, the calculation means 4 controls the switch means S ₁ and S ₂ .

Temperature of measurement object 1 is T, emissivity is ε, light source 2
Let Er be the radiant energy of 1 and 22, Ei be the output signal of the detector 3, Ta be the ambient temperature, and E(T) be the radiant energy equivalent to a black body at temperature T.

When both the switch means S ₁ and S ₂ are off, the light source 21,
22 is off and only the radiant energy from the measurement object 1 is detected; switch means S ₁ is on and the light source 21 is on; and switch S ₂ is on and the light source 22 is on. The output signals E ₀ , E ₁ , E ₂ of the detector 3 are as follows.

E ₀ = εE(T) + (1-ε) E (Ta) ...(1) E ₁ = εE(T) + g ₁ (1-ε) Er + (1-g ₁ ) (1-ε) E (Ta) ……(2) E ₂ =εE(T)+g ₂ (1−ε)Er +(1−g ₂ )(1−ε)E(Ta)……(3) Here, g ₁ , g ₂ is the rate at which the radiant energy from the light source 2 is diffusely reflected by the measurement object 1 and enters the detector 3.

In other words, when no light comes from the light sources 21 and 22, the first term on the right side of equation (1) is the radiant energy from the measurement object 1 itself, and the second term is the contribution of the radiant energy due to the ambient temperature Ta of the wall surface (not shown), etc. It's a minute. (2),
The second term on the right side of equation (3) is the contribution from the light source 21 or 22, and the third term is the contribution from the surroundings.

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

E ₁ −E ₀ =g ₁ (1−ε)Er −g ₁ (1−ε)E(ta) E ₂ −E ₀ =g ₂ (1−E)Er −g ₂ (1−ε)E( Ta) Taking the ratio R, the following formula is obtained.

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

E ₁ −E ₂ =(g ₁ −g ₂ )(1−ε) {Er−E(Ta)} From this, the emissivity ε becomes the following formula.

ε=1−(E ₁ −E ₂ )/[(g ₁ −g ₂ )・{Er−E(Ta)}] …(5) Here, D=g ₁ −g ₂ and R=g It has been experimentally found that the relationship with ₂ /g ₁ is D=f(R) as shown in FIG. 2, which is a predetermined functional relationship. In other words, D can be found from R, and the other values on the right side of equation (5) can be found through measurements, 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), we can calculate from equation (5). By substituting the emissivity ε, etc., the true temperature of the measurement object 1 can be found.

In other words, before the measurement, as shown in FIG. 2, the functional relationship D=f between D and R obtained by measurement
(R) is stored in the calculation means 4.

Next, during measurement, the switch means S ₁ and S ₂ are turned on and off to control the lighting and extinguishment of the light sources 21 and 22, and E ₀ and E ₁ in equations (1), (2), and (3) are controlled. , E ₂ are detected by the detector 3, and the ambient temperature Tr and the radiant energy Er of the light source 2 are detected by a temperature detector (not shown), etc., and are supplied to the calculation means 4, respectively.

The calculation means 4 calculates the ratio R of equation (4) from the signals E ₀ , E ₁ , and E ₂ , calculates D from this, and calculates the signal Ta.
Then, calculate E(Ta) and calculate the right side of equation (5) to find the radiation ε. Furthermore, the temperature T of the measurement object 1 can be determined by calculating equation (6) using the emissivity ε.

FIG. 3 is a configuration explanatory diagram showing a second embodiment of the present invention. In this example, one light source 2 emits light at an angle θ ₀ with respect to the normal l, and the light is received by two detectors 31 and 32 at angles θ ₁ and θ ₂ . Switch S
on and off, and using the outputs E ₁ and E ₂ of the detectors 31 and 32 when the light source 2 is on, and the output E ₀ of either of the detectors 31 and 32 when the light source 2 is off, the above Similarly, by equations (1) to (6), measurement target 1
The emissivity ε and temperature T are determined.

FIG. 4 is a configuration explanatory diagram showing a third embodiment. In this example, in the second embodiment shown in FIG. 3, the light from the light source 2 is interrupted by a chopper 5 having a notch as shown in FIG. The light is collected by fibers 62 and 63 and received by detectors 31 and 32. In this case, since the optical fibers 61, 62, and 63 are used, the detection section is small and non-guided, and since the light source 2 is interrupted by the chopper 5, the light source 2 is stable. The calculations are similar to those in the previous embodiment. Also,
Visual field measuring means L ₁ , L ₂ , L ₃ are provided at the tips of the fibers. In this example, the light projection angle θ ₀ with respect to the normal line of the light source 2 and the light reception angle θ ₁ of the detector 31 are approximately θ ₀ =θ ₁ =0, and the light is projected from the vertical direction of the measurement object 1.
An example of receiving light is shown.

FIG. 6 is a configuration explanatory diagram showing a fourth embodiment. In this example, in the example shown in FIG. 1, the light from the light source 2 is interrupted by a chopper 5 having two types of apertures as shown in FIG. , the light is again received by the detector 3 via the optical fiber 63. Opening hole 51 of Chiyotsupa 5,
51, the light is emitted from the optical fiber 61, and the light is opened 5
2 and 52, the light is emitted from the optical fiber 62.

Alternatively, light sources, detectors, etc. may be arranged so that light can be emitted and received at many angles, and an appropriate angle may be selected and calculated depending on the surface condition of the object to be measured.

[Effect of the invention] Since emissivity and temperature are measured in advance by using the fact that the difference in contribution rates has a predetermined relationship with the ratio of contribution rates, it is possible to measure emissivity and temperature with a simple configuration. It is possible to measure the temperature of the correct target. In particular, since it does not have a heat source, there is no deterioration of the detector etc. due to heat generation, and it does not have large moving parts that move the heat source, so it is small and compact.
Moreover, by using an optical fiber, it becomes non-inductive.

[Brief explanation of the drawing]

FIG. 1, FIG. 3, FIG. 4, FIG. 5, FIG. 6, and FIG. 7 are configuration explanatory diagrams showing one embodiment of the present invention;
FIG. 2 is a diagram showing the relationship between the contribution rate difference D and the ratio R. 1... Measurement object, 2, 21, 22... Light source,
3, 31, 32...Detector, 4...Calculating means, 5
...Chiyotsupa, 61, 62, 63...Optical fiber, _L1 , _L2 , _L3 ...Visual field limiting means.

Claims (1)

[Claims] 1. Two or more light sources of the same radiant energy that emit or receive light at two or more predetermined angles with respect to the normal to the measurement position of the measurement object, and one detector or one
Two light sources and two or more detectors, and two detection signals E1 when reflected from the measurement target by light emitting and receiving light at different angles and incident independently on the detector with contribution rates g1 and g2, respectively. , E2 and the detection signal when there is no radiant energy from the light source.
Ratio of difference from E0 = (E2 - E0) / (E1 - E0) = g2 /
g1 is calculated, and the difference D in the contribution rate is calculated based on the relationship experimentally determined in advance between the ratio of contribution rates R = g2 / g1 and the difference in contribution rates D = (g1 - g2). It is characterized by comprising a calculation means for determining the emissivity of the object to be measured using the difference D, the ambient temperature determined by a temperature detector, etc., and the radiant energy of the light source, and calculating the temperature of the object to be measured from this emissivity. Radiation temperature measurement device. 2. The radiation temperature measuring device according to claim 1, which includes a case where the light emitting angle and the light receiving angle with respect to the normal line of one light source and one detector are made to match. 3. The radiation temperature measuring device according to claim 2, wherein the light emitting angle and the light receiving angle with respect to the normal line of the light source and the detector are approximately 0 degrees. 4. The radiation temperature measuring device according to any one of claims 1 to 3, characterized in that it emits or receives light using an optical fiber. 5. Claims 1 to 4, characterized in that the light source or the detector is provided with field-of-view limiting means such as a gradient index rod lens or a microlens.
The radiation temperature measuring device according to any one of paragraphs. 6. The radiation temperature measuring device according to any one of claims 1 to 5, characterized in that the light from the light source is intermittent by a chopper so that the light is not emitted.