JPS628508Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an apparatus for measuring the amount of infrared radiation emitted from the surface of an object.

Conventionally, this type of device has been introduced to converge the infrared rays to be measured using mirrors, lenses, etc., which requires careful adjustment such as positioning the detector to the focal position or detection position. A special signal processing circuit is required to convert the amount of infrared rays into an output signal, and the measurement operation is complicated, the measurement accuracy is poor, and the device is complicated.

In view of the above points, the purpose of the present invention is to provide an infrared radiation measurement device that is simple in measurement operation, capable of highly accurate measurement, and has a simple configuration and is inexpensive. Alternatively, the inner surface of a light pipe in which openings are provided at both ends of the pyramid-shaped part and some parallel pipe parts are provided in the large opening is used as a reflective surface, and the reflective surface of the inner surface of the conical or pyramid-shaped part is The light pipe has an inclined surface of 2 to 10 degrees with respect to the central axis, and the larger opening of the openings at both ends of the light pipe serves as an infrared introduction port,
The infrared radiation amount measuring device is characterized in that a vacuum thermocouple is connected to a small opening at the other end with a light receiving window of the vacuum thermocouple in contact with the small opening.

Next, the infrared radiation measurement device of the present invention will be explained in detail with reference to embodiments of the drawings.

Reference numeral 1 designates a metal light pipe, which has openings 2 and 3 at both ends, and whose inner diameter is gradually reduced from the larger opening 2 to the smaller opening 3 to form a conical or pyramidal part. , its inner surface is a reflective surface 4.

The reflective surface 4 is formed by coating gold, silver, platinum, aluminum, etc. on a mirror-finished base, and has a high infrared reflectance and does not reduce the reflectance due to the formation of oxides, etc. It is considered to be chemically stable.

The large opening 2 of the light pipe 1 serves as an infrared introduction port, and the infrared rays introduced from the large opening 2 are guided to the small opening 3 while being converged.

The angle of the inner reflective surface of the conical or pyramidal portion of the light pipe 1 is such that the infrared rays introduced from the large opening 2 are reflected by the reflective surface 4 and exit from the opening 2 on the introduction side. It is preferable that all the introduced infrared rays are converged on the side of the small opening 3 without being stored, and that the aperture ratio of the large opening 2 to the small opening 3 is large. It is said to be a 10° inclined surface.

As shown in Figure 1, a slightly parallel pipe section is provided at the large opening 2 which is the infrared introduction port of the light pipe 1, and the introduced infrared rays are reflected and exit from the infrared introduction port side. This will be prevented.

This will be explained in more detail with reference to FIGS. 2 and 3.

FIG. 2 shows a light pipe 1 used in an embodiment of the present invention, in which a conical portion (BC,
Openings are provided at both ends of EF), and some parallel pipe sections (AB, DE) are provided in the large opening. FIG. 3 shows an example of a conventional light pipe, in which conical parts (ab, de ) is provided with openings at both ends, and the parallel pipe portions (AB, DE) of the light pipe 1 shown in FIG. 2 are not provided.

In the case of the conventional light pipe shown in Figure 3, due to the nature of light, the light is reflected at the same angle of reflection as the angle of incidence with the normal plane perpendicular to the reflecting surface, so the reflecting surfaces ab and de
The infrared light incident on is the normal line from point d to the ab plane and
The intersection with plane ab is c, and the normal line from point a to plane de is de
If the intersection with the surface is f, the reflected light of the light incident on the reflecting surfaces ac and df is dissipated to the outside through the aperture.

On the other hand, when some parallel pipe parts are provided in a large opening as shown in Figure 2, the normal plane perpendicular to the reflecting surface is always the same as the reflecting surface at the other end of the parallel pipe part. The light that crosses and enters the flat pipe section will not be scattered outside the light pipe section.

5 is a vacuum thermocouple, and the thermocouple is vacuum-sealed in a container having a light-receiving window 6 so as not to be affected by convection heat transfer or the like.

The light receiving window 6 is made of rock salt, potassium rock salt, potassium bromide, etc.
Made of a material with high infrared transmittance. A vacuum thermocouple 5 with good sensitivity is used. It is preferable to use a thermopile in which a large number of thermocouples are connected in series as the vacuum thermocouple 5 because the sensitivity will be further improved.

The light receiving window 6 of the vacuum thermocouple 5 is brought into contact with the small opening 3 of the light pipe 1 to prevent infrared rays from leaking, and the light pipe 1 and the vacuum thermocouple 5 are connected.

In order to measure the amount of infrared rays emitted from a sample object 8 using the infrared radiation measurement device of the present invention, a large opening 2 of a light pipe 1 is placed on the surface of the sample object 8 as shown in FIG. All you have to do is point it close to it.

Then, the infrared rays 9 emitted from the surface of the sample object 8 are introduced into the pipe through the large opening 2 of the light pipe 1, reflected multiple times by the reflective surface 4, or directly transmitted to the other end of the light pipe 1. is converged into a small opening 3.

The focused infrared rays are transmitted to the light receiving window 6 of the vacuum thermocouple 5.
The thermoelectromotive force is outputted to the output end 7 by heating the hot junction of the thermocouple. If this output is read using a potential design (not shown), an electrical output corresponding to the amount of infrared rays emitted from the sample object 8 can be obtained.

By measuring the amount of infrared radiation in this manner, the infrared emissivity of the sample object 8 or the surface temperature of the sample object 8 can be determined as follows.

To calculate the infrared emissivity, first, the amount of infrared rays emitted from a standard blackbody furnace or a standard material with an emissivity of 1 is measured at each temperature above the cold junction temperature of the vacuum thermocouple 5 using the infrared radiation amount measuring device of the present invention. After determining the electrical output, the sample object 8 is heated to an appropriate temperature higher than the cold junction temperature of the vacuum thermocouple 5, and the infrared radiation measurement device of the present invention generates electricity corresponding to the amount of infrared radiation emitted. What is necessary is to find the output and find the ratio of the electrical output of the black body radiation at the same temperature as that of the sample object at this time.

In addition, in order to know the surface temperature of the sample object 8, the relationship between the surface temperature and the amount of infrared radiation of the same object as the sample object 8 is determined experimentally in advance using a surface thermometer, etc. All you have to do is apply the quantity to this relationship.

The infrared radiation measurement device of this invention is a device for measuring the amount of infrared rays emitted as heat according to the temperature of an object, and its structure is suitable for measuring radiation from a flat surface. For example, emissivity measurement of a flat solar heat collecting plate provided with a selective absorption function can be mentioned.

As mentioned above, the infrared radiation measurement device of the present invention has an opening at both ends of a conical or pyramidal part, and the inner surface of the light pipe, which has a large opening with some parallel pipe parts, serves as a reflective surface. done,
The reflective surface of the inner surface of the conical or pyramidal part is inclined at an angle of 2 to 10 degrees with respect to the central axis, the larger opening of the openings at both ends of the light pipe serves as an infrared introduction port, and the other end In the small opening of
Since the vacuum thermocouple is connected by touching the light receiving window of the vacuum thermocouple, a large amount of infrared rays emitted from the object are introduced through the large opening of the light pipe, and this is reflected on the reflective surface of the light pipe. Therefore, all of the infrared radiation is not reflected outside and is guided to a small opening, and is detected as an electrical output by a vacuum thermocouple in the small opening, making it possible to measure the amount of infrared radiation with high accuracy. The value will be high.

In addition, the infrared radiation measurement device of the present invention has an extremely simple device configuration consisting of a combination of a light pipe and a vacuum thermocouple, is inexpensive, and does not require any special signal processing circuit to change the output signal. By appropriately designing the size and shape of the large opening of the light pipe, a sufficient output level can be secured, and by simply bringing the large opening of the light pipe close to the object to be measured, it is possible to generate infrared rays with high sensitivity. It is now possible to measure the amount of radiation.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway front view showing an example of the infrared radiation measurement device of the present invention, Figure 2 is a sectional view of a light pipe used in an embodiment of the present invention, and Figure 3 is an example of a conventional light pipe. FIG. 1 is a light pipe, 2 is a large opening, 3 is a small opening, 4 is a reflective surface, 5 is a vacuum thermocouple, and 6 is a light receiving window.

Claims (1)

[Claims for Utility Model Registration] 1. A light pipe in which openings are provided at both ends of a conical or pyramidal part, and some parallel pipe parts are provided in the large opening, and the inner surface of the light pipe is used as a reflective surface, The reflective surface of the inner surface of the pyramid-shaped or pyramid-shaped part is inclined at an angle of 2 to 10 degrees with respect to the central axis, and the larger opening of the openings at both ends of the light pipe serves as the infrared introduction port, and the smaller opening at the other end serves as an infrared introduction port. 1. An infrared radiation measurement device characterized in that a vacuum thermocouple is connected to an opening with a light receiving window of the vacuum thermocouple in contact with the opening. 2. The infrared radiation amount measuring device according to claim 1, wherein the vacuum thermocouple is a thermopile in which a large number of thermocouples are connected in series.