JP2009085795A - Method for measuring reflectivity or transmittance of electromagnetic waves at high temperatures - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring method enabling measurement, without using a standard sample, of the true reflectivity of a body itself relative to an electromagnetic wave at a high temperature, for a wide range of incident angles and reflection angles, and also enabling transmittance to be measured. <P>SOLUTION: In this method for measuring a reflectivity or a transmittance at a high temperature by irradiating an electromagnetic wave to a high-temperature sample, and by detecting the electromagnetic wave reflected by the sample or the electromagnetic wave transmitted through the sample, while heating an irradiation portion at a prescribed temperature by irradiating a beam to at least either surface of the front and rear surfaces of the sample by a heating means, the electromagnetic wave is irradiated to the irradiation portion from an electromagnetic wave irradiation means, and an electromagnetic wave detection means is moved concentrically around the sample, and the electromagnetic wave reflected by the sample or the electromagnetic wave transmitted through the sample is detected during movement. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for measuring the reflectance or transmittance of an electromagnetic wave at a high temperature of a sample by irradiating the sample with a high temperature with an electromagnetic wave, detecting the electromagnetic wave reflected by the sample or transmitted through the sample.

  In recent years, as a measure against global warming and energy saving, it is very important to block heat transmitted from these heat sources to the furnace body in order to suppress heat radiation from industrial furnaces, incinerators, and the like. Insulation materials are used for heat insulation in industrial furnaces and incinerators, and as a result of evaluation of the heat insulation performance, in addition to thermal conductivity, reflection characteristics of electromagnetic waves at high temperatures are attracting attention.

  Until now, the reflectance of electromagnetic waves at high temperatures of an object has been measured using a measuring apparatus having the configuration shown in FIG. 9 (see Non-Patent Document 1). In the illustrated measuring apparatus, a window 31 is opened at the center of the bottom of the heating furnace 30, and a sample mounting base 32 is disposed in the furnace so as to face the window 31. The sample mounting base 32 is capable of horizontal movement, and a standard material 40 having a known electromagnetic wave reflectance value close to 100% and a known electromagnetic wave reflectance value and a sample 41 are mounted side by side. Further, an electromagnetic wave irradiation device 33 and an electromagnetic wave detection device 34 are disposed below the heating furnace 30 so as to face each other. Further, just below the center of the window 31, as shown in the figure, the electromagnetic wave irradiation device 33 is disposed. The first reflector 35a that guides the electromagnetic wave irradiated from the first sample plate 32 to the sample mounting base 32 through the window 31, and the second reflector that guides the electromagnetic wave reflected by the standard sample 40 or the sample 41 and passed through the window 31 to the electromagnetic wave detection device 34. A reflector 35b is provided.

In the measurement, the heating furnace 30 is heated and the standard sample 40 and the sample 41 are set to a predetermined temperature (T ° C.). Next, after moving the standard sample 40 to the measurement position, the electromagnetic wave is irradiated from the electromagnetic wave irradiation device 33 and reflected by the standard sample 40. The reflected electromagnetic wave is detected by the electromagnetic wave detection device 34, and the received intensity is measured. Subsequently, the sample 41 is moved horizontally to the measurement position, irradiated with electromagnetic waves under the same conditions, and the received intensity is measured. Then, from the reception intensity of the standard sample 40 and the reception intensity of the sample 41, the electromagnetic wave reflectance at T ° C. of the sample 41 is calculated from the following equation.
Receiving intensity of sample Electromagnetic wave reflectivity (%) of sample at T ℃ = ――――――――――― × 100
Standard sample reception intensity

“High-Temperature Light Reflection Spectrometer for Thermal Energy Window Coating”: Y. Kagawa, T. Naganuma, K. Matsumura, S. Zhu, The American Ceramic Society Bulletin, 82 (11) 2003, pp.9301-9305.

  In the above measuring method, the standard sample 40 is required. However, since the electromagnetic wave reflectance of the standard sample 40 is not 100%, the electromagnetic wave reflectance of the sample 41 is not a true value because it is obtained as a relative value. In addition, since the standard sample 40 is repeatedly used, it may be exposed to a high temperature every time it is measured, and may deteriorate over time to change the reflectance. In addition, the higher the temperature, the less material that can be used as the standard sample, and the measurement temperature is limited to about 1000 ° C.

  In the above measurement method, the incident angle of the electromagnetic wave on the standard sample 40 and the sample 41 is fixed. However, in practice, electromagnetic waves are incident on the heat insulating material from various directions, and thus it can be said that the evaluation of the reflection characteristics is insufficient only with the reflectance for a specific incident angle. For example, even if the reflectivity is high for an electromagnetic wave incident at a certain angle, the reflectivity is low for an electromagnetic wave incident at a different angle, that is, the transmittance is high, which reduces the heat insulation performance. However, the above measurement method cannot be known because the incident angle is constant. In addition, electromagnetic waves may be reflected in various directions when there are minute irregularities on the surface. However, since the detectable reflection angle is fixed in the above measurement method, the actual reflection characteristics are evaluated. It ’s hard to say.

  Although it is conceivable to increase the number of windows 31 of the heating furnace 30 and cause electromagnetic waves to enter and exit, the number of windows 31 is limited from the viewpoint of maintaining the thermal stability in the furnace, and further the number of windows is reduced. Even if it is increased, the position of the window 31 is fixed, so the incident / exit angle is still limited. Further, by increasing the opening area of the window 31 and making the inclination angles of the reflectors 35a and 35b variable, the incident angle of the electromagnetic wave to the standard sample 40 and the sample 41 and the detection from the standard sample 40 and the sample 41 can be detected. Although it is conceivable to change the reflection angle, since the opening area of the window 31 cannot be increased so as to maintain the thermal stability in the furnace, changes in the incident angle and the reflection angle are limited. Even if heat resistance glass is provided in the window 31 and the thermal stability in the furnace can be maintained, electromagnetic waves enter and exit through the window 31, so that the heat resistance glass absorbs and reflects the electromagnetic waves, and the measurement accuracy decreases.

  Furthermore, since it is necessary to heat the whole circumference | surroundings of the sample 10 with the heating furnace 30, electric power consumption is also large.

  Therefore, the present invention provides a measurement method that can measure the true reflectance of electromagnetic waves at a high temperature of an object itself at a wide range of incident angles and reflection angles, and can also measure the transmittance without using a standard sample. Objective. In addition, the high temperature said by this invention means the temperature over room temperature.

In order to solve the above problems, the present invention provides the following method for measuring reflectance or transmittance at high temperatures.
(1) In a method of measuring the reflectance or transmittance of an electromagnetic wave at a high temperature by irradiating a high temperature sample with an electromagnetic wave, detecting the electromagnetic wave reflected by the sample or the electromagnetic wave transmitted through the sample,
At least one of the front and back surfaces of the sample is irradiated with light by a heating means to heat the irradiated portion to a predetermined temperature, and the irradiated portion is irradiated with electromagnetic waves from the electromagnetic wave irradiating means, and the electromagnetic waves are concentrically centered on the sample. A method for measuring the reflectivity or transmittance of electromagnetic waves at a high temperature, wherein the detecting means is moved and electromagnetic waves reflected by the sample or transmitted through the sample are detected during the movement.
(2) The method for measuring reflectance or transmittance of electromagnetic waves at high temperatures as described in (1) above, wherein the electromagnetic waves are irradiated while changing the incident angle to the sample.
(3) The method of measuring reflectivity or transmittance of electromagnetic waves at high temperatures according to (1) or (2) above, wherein infrared rays, visible light or microwaves are irradiated from the electromagnetic wave irradiation means.

  Since the method for measuring reflectance or transmittance at high temperature of the present invention does not use a standard sample, the absolute value of the reflectance of the sample with respect to electromagnetic waves can be measured. Is also possible. In addition, since the reflectance can be measured while continuously changing the incident angle of the electromagnetic wave on the sample and the reflection angle from the sample, the reflection characteristics of the sample can be found in more detail. Furthermore, since the heating means is configured to irradiate the sample with light, energy saving can be achieved. Furthermore, the transmittance of the sample at a high temperature can also be measured.

  Hereinafter, a high-temperature reflectance or transmittance measuring method (hereinafter simply referred to as “measuring method”) according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic view showing an embodiment of a measuring apparatus for carrying out the measuring method of the present invention. A motor 1 is installed at the center of the apparatus, and a central portion of a long support base 2 is fixed to a spindle shaft of the motor 1. That is, the support base 2 can rotate in the horizontal direction around the spindle axis of the motor 1. A holder 11 for holding the sample 10 is attached to the center of the support base 2. The sample 10 has a plate shape and is held so as to be orthogonal to the long axis of the support base 2.

  Heaters 4 and 5 are attached to the support base 2 with the sample 10 interposed therebetween. For example, the heaters 4 and 5 may be configured to reflect light from a halogen lamp on a parabolic reflection surface and collect the light on a sample surface in a spot shape. The heating spot S can be heated to about 1200 ° C. The heaters 4 and 5 are attached to a frame mounted on the support base 2, but the frame is omitted in FIG. 1 for the sake of clarity. Further, in order to block the light beam reflected by the sample 10, a heat insulating material (not shown) may be disposed so as to cover the upper part of the sample 10.

  As shown in an enlarged view in FIG. 2, the holder 11 includes a pair of clamping pieces 11a. The sample 10 is sandwiched by 11b. In addition, a thermocouple 12 is inserted into the sample 10 from the side surface 10a, and the temperature in the vicinity of the heating spot S by the heaters 4 and 5 is measured.

  In addition, a pipe line 15 for circulating cooling water is provided inside the support base 2 for controlling the temperature of the sample 10.

  A circular or arc-shaped rail 20 centering on the center of rotation of the support base 2 is installed outside the support base 2. In addition, when making it circular arc shape, it is preferable to set it as more than half of the circumference so that the incident side of the electromagnetic wave R mentioned later may be open | released, and to 2/3 to 3/4 (refer FIG. 4). . An electromagnetic wave detection device 21, for example, an infrared detector moves along the rail 20. That is, the electromagnetic wave detection device 21 concentrically circulates outside the circumference formed by the rotation of the support base 3.

  Further, an electromagnetic wave irradiation device 22, for example, an infrared transmitter, is installed at an arbitrary position on the outside of the rail 20, and the electromagnetic wave R such as infrared light irradiated from the electromagnetic wave irradiation device 22 is reflected on the sample 10 by mirrors 23a to 23c. To the heating spot S. Therefore, as shown in FIG. 3, the heaters 4 and 5 are installed so as to heat the sample 10 obliquely from above with respect to the traveling axis of the electromagnetic wave R so as not to prevent the electromagnetic wave R from entering the sample 10. . In consideration of the heating efficiency, the inclination angle θ is preferably 10 to 60 °.

  The electromagnetic wave R reflected by the sample 10 is detected by the electromagnetic wave detection device 21. When the sample surface is smooth, the electromagnetic wave R is reflected at the same angle as the incident angle to the sample 10. For example, if the sample 10 has minute irregularities, it is scattered and cannot be detected at the same detection angle as the incident angle. There is. However, in the measurement method of the present invention, the electromagnetic wave detection device 21 continuously moves in an arc along the rail 20, so that the electromagnetic wave R can be reliably detected regardless of the angle reflected by the sample 10.

  The reflectance or transmittance of the sample 10 is measured as follows.

  FIG. 4 is a schematic view of the measuring apparatus as viewed from above (however, heaters 4 and 5 are omitted). As shown in FIG. 4A, before the sample 10 is mounted on the support base 2, electromagnetic wave detection is performed. The device 21 is arranged so as to coincide with the traveling direction of the electromagnetic wave R, and the initial received intensity (Io) of the electromagnetic wave R is obtained.

  Next, as shown in (B), the sample 10 is mounted on the support 2 and the electromagnetic wave detection device 21 is moved to the position closest to the mirror 23c. Then, the sample 10 is heated by irradiating light from the heaters 4 and 5, and when reaching a predetermined temperature, the electromagnetic wave R is irradiated toward the sample 10, and the electromagnetic wave detection device 21 is separated from the mirror 23c while continuing the irradiation. The received intensity (Ir) is continuously measured during the movement. Since the electromagnetic wave R is perpendicularly incident on the sample 10, the electromagnetic wave detection device 21 is scattered to a position orthogonal to the support 2, for example, when the electromagnetic wave R is scattered by fine irregularities on the surface of the sample 10. However, the electromagnetic wave R reflected by the sample 10 can be detected substantially completely.

  The ratio (Ir / Io) between the received intensity value (Ir) and the initial received intensity (Io) is the reflectance of the sample 10. Therefore, unlike the conventional method in which the reflectance of the sample is relatively obtained from the reflectance of the standard sample, the true reflectance (absolute reflectance) of the sample 10 is obtained. Moreover, the angular distribution of the reflectance of the sample 10 can also be obtained by measuring the reflectance for each position of the electromagnetic wave detection device 21.

  Further, as shown in FIG. 5, the support table 2 can be rotated by a predetermined angle to change the incident angle (α) of the electromagnetic wave R to the sample 10, and the electromagnetic wave R is irradiated in this state as described above. While moving the electromagnetic wave detection device 21 and measuring the reception intensity at each position, the reflectance of the sample 10 or the angular distribution of the reflectance with respect to a certain incident angle (α in this case) is obtained.

  On the other hand, in order to measure the transmittance, as shown in FIG. 6, the electromagnetic wave R may be incident on the sample 10 perpendicularly, and the electromagnetic wave detection device 21 may be disposed behind the sample 20. Further, the angular distribution of the transmittance can be obtained by rotating the electromagnetic wave detection device 21 behind the sample 10 and measuring the reception intensity at each position.

  Further, by rotating the support 2 to cause the electromagnetic wave R to be incident on the sample 10 at a predetermined incident angle and rotating the electromagnetic wave detection device 21 behind the sample 20 in the same manner as described above, the transmittance for a certain incident angle is obtained. It is also possible to measure the angular distribution of transmittance.

  Although the measurement method of the present invention has been described above, various modifications can be made. For example, microwaves or visible light can be used as the electromagnetic wave R in addition to infrared rays, and the electromagnetic wave detection device 21 and the electromagnetic wave irradiation device 22 are changed correspondingly. In addition, the electromagnetic wave irradiation device 22 can be a multi-wavelength compatible type so that these electromagnetic waves R can be irradiated, and the electromagnetic wave detection device 21 is also a multi-wavelength compatible type. Microwave heating furnaces are also used as industrial furnaces. In addition to heat insulation properties, microwave reflection effects may be a necessary characteristic for heat insulation materials, and knowing microwave reflectivity at high temperatures It becomes important. In addition, halogen heaters and the like are used as heating devices, and the reflectance of visible light at high temperatures is also important in these devices.

  The heaters 4 and 5 may also irradiate the sample 10 with light rays obliquely from below when the support base 2 has a frame shape. Further, when the sample 10 is thin or the heater output is large, the sample 10 may be heated only by the heater 4 facing the surface on which the electromagnetic wave R is incident. Further, a low-power laser can be used.

  The present invention will be further described below with reference to examples, but the present invention is not limited thereto.

Example 1
A silicon substrate (20 × 20 × 0.6 mmt, platinum layer thickness 200 nm) on which platinum was vapor-deposited was used as the sample 10 and mounted on the holder 11 of the measuring apparatus having the configuration shown in FIG. Then, as shown in FIG. 5, the support 2 is rotated so that the incident angle (α) of the electromagnetic wave R to the sample 10 is 15 °, and the front and back surfaces of the sample 10 are attached with a halogen lamp as the heaters 4 and 5. Heating was performed, and an infrared ray having a wavelength of 5 μm was irradiated as an electromagnetic wave R from the electromagnetic wave irradiation device 22. The electromagnetic wave detection device 21 was installed at a position where the reflection angle (β) by the sample 10 was 15 °. Prior to the measurement, as shown in FIG. 4, the initial received intensity (Io) without the sample 10 was measured.

  The reflectance was measured at room temperature and the temperature of the heating spot S at 200 ° C, 300 ° C, 400 ° C, 500 ° C and 600 ° C. The measurement results are shown in FIG. For comparison, the reflectance described in “Thermal Radiative Properties” :: YS Touloukian, CY Ho, TFI / Prenum, 1970) is also shown as a reference value, but the reflectance of a high-temperature object is accurately measured by the measuring device of the present invention. It turns out that it can measure well.

(Example 2)
As the sample 10, an Al ₂ O ₃ —SiO ₂ porous body (20 × 20 × 5 mmt) having irregularities on the surface was used and attached to the holder 11 of the measuring apparatus having the configuration shown in FIG. Then, as shown in FIG. 5, the support 2 is rotated so that the incident angle (α) of the electromagnetic wave R to the sample 10 is 15 °, and the front and back surfaces of the sample 10 are attached with a halogen lamp as the heaters 4 and 5. Heated. The heating temperature was 600 ° C. at the heating spot S. Prior to the measurement, as shown in FIG. 4, the initial received intensity (Io) without the sample 10 was measured.

  The reflectivity is that the electromagnetic wave irradiation device 22 emits infrared rays having a wavelength of 5 μm as the electromagnetic wave R, the reflection angle (β) from the sample 10 is moved to 0 ° to 90 °, and the reception intensity at each position. Was obtained by measuring. The measurement results are shown in FIG. 8, and it can be seen that infrared rays are reflected in various directions.

It is a schematic diagram which shows one Embodiment of the measuring apparatus for enforcing the measuring method of this invention. It is an enlarged view which shows a sample periphery. It is the figure seen from the support stand side surface in order to show the attachment state of a heater. It is a schematic diagram for demonstrating the measuring method of a reflectance. It is a schematic diagram for demonstrating the method to change the incident angle of the electromagnetic wave to a sample, and to measure a reflectance. It is a schematic diagram for demonstrating the measuring method of the transmittance | permeability. 3 is a graph showing measurement results of Example 1. 6 is a graph showing measurement results of Example 2. It is a schematic diagram which shows the structure of the conventional reflectance measuring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Support stand 4 Heater 5 Heater 10 Sample 11 Holder 20 Rail 21 Electromagnetic wave detection apparatus 22 Electromagnetic wave irradiation apparatuses 23a-23c Mirror

Claims (3)

In a method of irradiating an electromagnetic wave to a high temperature sample, detecting the electromagnetic wave reflected by the sample or the electromagnetic wave transmitted through the sample, and measuring the reflectance or transmittance of the electromagnetic wave at high temperature,
At least one of the front and back surfaces of the sample is irradiated with light by a heating means to heat the irradiated portion to a predetermined temperature, and the irradiated portion is irradiated with electromagnetic waves from the electromagnetic wave irradiating means, and the electromagnetic waves are concentrically centered on the sample. A method for measuring the reflectivity or transmittance of electromagnetic waves at a high temperature, wherein the detecting means is moved and electromagnetic waves reflected by the sample or transmitted through the sample are detected during the movement.   2. The method of measuring reflectivity or transmittance of electromagnetic waves at high temperature according to claim 1, wherein the electromagnetic waves are irradiated while changing the incident angle to the sample.   The method for measuring reflectance or transmittance of electromagnetic waves at high temperature according to claim 1 or 2, wherein infrared rays, visible light or microwaves are irradiated from the electromagnetic wave irradiation means.

Images