JP2007263929A - Radiation thermometer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation thermometer which has interchangeability, using an objective of the same and an ocular of the same, even when distance coefficients differ in a target identification mechanism of the radiation thermometer, and even when a target size becomes small, it can readily perform visibility. <P>SOLUTION: In a target identification mechanism of a black dot system which is a finder system of the radiation thermometer, which measures the temperature of an object to be measured, according to the infrared rays radiated from the object to be measured, an index which serves as a mark within a finder field of view was added to the perimeter of the diaphragm aperture of an aperture mirror, when the target is visualized. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a radiation thermometer that measures the temperature of an object to be measured by infrared rays emitted from the object to be measured, and is particularly useful for a standard radiation thermometer that performs temperature calibration of a radiation thermometer.

Conventionally, a radiation thermometer has been used as a thermometer to determine the temperature of an object to be measured by capturing the change in the state of the electromagnetic wave by transferring heat (heat radiation) from the object being measured to the temperature sensor. It has been known. For calibration using a standard radiation thermometer which is a standard system of this type of radiation thermometer, zinc (419.527 ° C.), aluminum (660.323 ° C.), silver (961.78 ° C.), copper ( A fixed-point black body utilizing the freezing point of a fixed-point substance of 1084.62 ° C. is employed.

Standard radiation thermometers are defined in accordance with JIS (Japanese Industrial Standards) rules (title General Rules for Performance Test Methods for Radiation Thermometers, Standard Number JIS C 1612: 2000, hereinafter “JIS C 1612”) as described below. Two types of monochromatic radiation thermometers of 0.9 μm type and 0.65 μm type are used.
0.9 μm type: A monochromatic radiation thermometer whose center wavelength in the measurement wavelength band is in the range of 0.85 μm to 0.95 μm, and the spectral sensitivity in the wavelength region separated by 0.1 μm or more from the center wavelength is 2 at the center wavelength. × ^10-4 or less.
0.65 μm type: A monochromatic radiation thermometer with a center wavelength of 0.64 μm to 0.66 μm in the measurement wavelength band, and the spectral sensitivity in a wavelength region separated by 0.1 μm or more from the center wavelength is 1 × of the center wavelength. ^10-4 or less.

FIG. 4 is a configuration diagram of a standard monochromatic radiation thermometer described in JIS C 1612. The standard radiation thermometer 1 is an object to be measured (not shown) via an eyepiece 2, a reticle 32, a neutral density filter 31, a relay lens 4, a deflection mirror 5, an aperture mirror (field stop) 8 and an objective lens 6. ). On the other hand, light (electromagnetic wave) having a measurement wavelength emitted from the object is condensed on the objective lens 6 and arranged on the aperture mirror 8 through the aperture stop 7. The aperture mirror 8 has an aperture 8a that limits the field of view, and only light that has passed through the aperture 8a passes through the condenser lens 9 and the interference filter 10 and is guided to the silicon detection element 11. .

Annex 3 of JIS C 1612 describes a finder method, a marker method, and the like as a target confirmation mechanism that is an area where measurement on a measurement object is performed. The finder method is a mechanism having a finder that can confirm the target size on the main body of the radiation thermometer, like the standard radiation thermometer shown in FIG. As shown in FIG. 5, the finder method includes (a) a black circle method, (b) a single circle method, and (c) a double circle method depending on an index. The black circle method is a mechanism for confirming the portion corresponding to the target size by covering the field of view black with an index as shown in FIG. 5A when the target is identified through the finder.

The black circle method has a characteristic that the optical axis does not shift in principle, and is mainly used for a radiation thermometer with a small target size. Since the standard radiation thermometer is calibrated in a fixed point blackbody furnace with an opening diameter of 10 mm or less, the black circle method is adopted for target confirmation.

JIS C 1612: 2000 Radiation thermometer performance test general rules

In recent years, a high-temperature blackbody furnace using a metal-carbon eutectic point with an opening diameter of about 3 mm has been developed, and the radiation thermometer distance coefficient (Fa: ratio of measurement distance to target size) is 650 (measurement distance a = A target size of about 400 mm and a target size of 0.6 mmφ is required. Here, the distance coefficient is expressed by equation (1).

In radiation thermometers having different distance coefficients, it is desired from the viewpoint of cost to use the same objective lens and the same eyepiece. By reducing the field stop diameter d _b is the diameter of the throttle hole 8a formula (1), the distance the same objective lens in different radiation thermometer of coefficients, it is possible to use an eyepiece, a field stop by reducing the d _b, a black circle in the viewfinder field of view becomes small, a problem that it is difficult to match the black circle in the opening of the fixed point blackbody furnace the target occurs.

As shown in FIG. 4, there is a radiation thermometer that adjusts the diopter by moving the eyepiece in the optical axis direction using a reticle as an index. In this case, the diopter adjustment is performed so that both the black circle appearing through the aperture hole 8a of the aperture mirror 8 and the reticle are in focus, and it is difficult to assemble and adjust the finder system.

In view of the above points, the object of the present invention is to use the same objective lens and eyepiece in the target confirmation mechanism of the radiation thermometer even when the distance coefficient is different, and has a small target size. In some cases, a radiation thermometer that can be easily identified is provided.

In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention is directed to a finder-type black circle target confirmation mechanism for a radiation thermometer that measures the temperature of a measurement object by infrared rays emitted from the measurement object. An index serving as a mark in the viewfinder field when the target is identified is added around the aperture of the mirror.

A second aspect of the present invention is the radiation thermometer according to the first aspect, wherein the index is produced by an etching process.

With the above configuration, according to the present invention, when the distance coefficient is different in the aiming of the radiation thermometer, the optical system including the same objective lens and eyepiece is used, and the compatibility is small. Visualization to the target size becomes simple. Further, by eliminating the conventionally used reticle, the above-described assembly and adjustment operations can be simplified.

In addition, an increase in manufacturing cost can be suppressed by producing the index added to the field stop in the same etching process as the stop hole.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1, 2 and 3. FIG. FIG. 1 and FIG. 2 are diagrams showing an embodiment of the present invention, and are views of a surface of an aperture mirror facing the objective lens side. FIG. 3 is a diagram illustrating a viewfinder field according to the embodiment.

FIG. 1 is a view showing an embodiment of the present invention, and FIG. 1 (a) is a view in which an elliptical index 81 is provided around the aperture hole 8a of the aperture mirror 8. FIG. FIG.1 (b) is the figure which expanded the AA cross section of Fig.1 (a). The index 81 is a groove, and an ellipse is formed around the aperture hole 8a. The aperture 8a and the index 81 are elliptical according to the inclination angle of the aperture mirror 8 so as to be circular in the viewfinder field.

FIG. 2 is a view showing another embodiment of the present invention, and FIG. 2 (a) shows a diagram in which four linear indicators 82 are provided around the aperture hole 8 a of the aperture mirror 8. FIG.2 (b) is the figure which expanded the AA cross section of Fig.2 (a). The index 82 is four grooves, which are linearly formed around the throttle hole 8a. As in FIG. 1, the aperture 8a is an elliptical hole corresponding to the inclination angle of the aperture mirror 8. Of the four indicators in FIG. It is formed longer than the index according to the inclination angle.

By providing the indicators 81 and 82 shown in FIG. 1 and FIG. 2 around the aperture 8a, a mark as shown in FIG. 3 appears around the black circle indicator, Since the aperture 8a that is a black circle is formed, the target is easily identified. 3A shows a field of view when the aperture mirror 8 of FIG. 1 is used, and FIG. 3B shows a viewfinder field of view when the aperture mirror 8 of FIG. 2 is used. The aperture hole 8a of the aperture mirror 8 is a black circle, and on the indicators 81 and 82, the incident light is scattered and observed as a black line circle or four black lines. Depending on the angle of inclination, the aperture 8a and the index 81 are elliptical, and the lengths of the four indices 82 are different in the upper and lower two and the left and right. Observed as four equal lines.

The above-described indicators 81 and 82 can be formed by an etching process, a blasting process, or the like. Since the normal aperture mirror 8 is made of a thin stainless steel plate and the aperture 8a is required to have high processing accuracy, it is formed in the etching process. Therefore, the manufacturing cost can be obtained by forming the indicators 81 and 82 in the same etching process. Can be suppressed.

1 and 2 show the groove-shaped index, but the convex index may be formed by printing or the like. In other words, the shape and number of the indicators provided around the aperture 8a are such that the light incident on the surface facing the objective lens of the aperture mirror 8 on which the indicators are formed is scattered and becomes a marker for target sighting within the field of view. It ’s fine.

As described above, the radiation thermometer described above is a target confirmation mechanism of the finder type black circle method of the radiation thermometer that measures the temperature of the measurement object by infrared rays radiated from the measurement object. When a distance coefficient is different in the aim of the radiation thermometer by adding an index that is a mark in the finder field when sighting is used, it is compatible using an optical system consisting of the same objective lens and eyepiece Visualization to a small target size is easy.

As mentioned above, although the best form in this invention was demonstrated, this invention is not limited with the description and drawing by this form. That is, it is needless to say that other forms, examples, operation techniques, and the like made by those skilled in the art based on this form are included in the scope of the present invention.

It is a figure explaining embodiment of this invention. It is a figure explaining other embodiment of this invention. It is a figure explaining the finder visual field in embodiment of this invention. It is composition explanatory drawing of a standard radiation thermometer. It is a figure which shows the parameter | index of a finder system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radiation thermometer 2 Eyepiece 31 Neutralizing filter 32 Reticle 4 Relay lens 5 Deflection mirror 6 Objective lens 7 Aperture stop 8 Aperture mirror (field stop)
8a Aperture hole 81, 82 Index 9 Condenser lens 10 Interference filter 11 Silicon detection element

Claims (2)

In the target confirmation mechanism of the black circle method, which is the finder method of a radiation thermometer that measures the temperature of the measurement target using infrared rays radiated from the measurement target, when the target is located around the aperture hole of the aperture mirror, A radiation thermometer, characterized by adding an index as a mark. The radiation thermometer according to claim 1, wherein the index is produced by an etching process.

Images