Device for measuring emissivity and transmissivity of structural material and window material

Abstract

The invention relates to a device for measuring emissivity and transmissivity of a structural material and a window material. The device comprises a common component, a structural material measuring component and a window material measuring component, the common assembly comprises a temperature control device, a Fourier spectrum radiometer and a standard black body; the standard black body is used for emitting standard spectral radiation; the temperature control device is used for controlling the temperature of the tested material; when the measured material is a structural material, the spectral radiation quantity value of the structural material is measured through the common assembly and the structural material measurement assembly, and the normal spectral emissivity of the structural material is obtained; when the measured material is a window material, the spectral radiation quantity value of the window material is measured through the common assembly and the window material measuring assembly, and the normal spectral emissivity and the spectral transmittance of the window material are obtained. The radiation characteristics of the structural material and the window material can be measured by using one set of hardware equipment.

Description

Technical Field

[0001] The invention relates to the technical field of optical testing, and in particular to a device for measuring the emissivity and transmittance of structural materials and window materials. Background Art

[0002] With the in-depth development of the research on infrared window materials used under special conditions, in order to ensure the imaging quality, a lot of research work has also been carried out on the optical parameters of these materials, mainly including spectral transmittance and emissivity.

[0003] The measurement methods of material transmittance are divided into single optical path method and dual optical path method according to the optical path structure. The advantages of single optical path method are simple structure and low cost, and the disadvantages are that it is not convenient to use and the measurement results are easily affected by the instability of the light source and the change of detector sensitivity. The dual optical path method can effectively reduce the influence of the instability of the light source and the change of detector sensitivity on the measurement results, but its structure is complex. Compared with the measurement device of the single optical path method, the dual optical path method measurement device has an additional spectroscopic system. Both the single optical path measurement method and the dual optical path measurement method are measurement methods based on the monochromator system. The improvement of their spectral resolution is limited by the performance of the monochromator. With the improvement of spectral resolution, the spectral band becomes narrower, which makes the spectral signal weaker and the measurement time becomes longer accordingly. In order to solve these problems, the Fourier transform spectrometer has emerged. The spectrometer has the advantages of wide spectral range, high spectral resolution, and fast measurement speed. It is more and more widely used in the field of infrared spectrum measurement.

[0004] The above methods can all measure the spectral transmittance of infrared window materials at room temperature and can achieve high accuracy. However, there are fewer related research results on transmittance measurement under higher temperature conditions.

[0005] The measurement of emissivity can be classified into calorimetry, reflection, energy, multi-wavelength and other methods according to the measurement method. The advantage of the calorimetry method is that it can not only calculate the emissivity but also other thermophysical parameters based on the heat transfer theory; its disadvantage is that the measurement environment requirements are extremely strict (theoretically it should be an adiabatic environment), and poor control will lead to large errors, so this method is rarely used to measure emissivity alone. The reflection method is based on the law of conservation of energy and Kirchhoff's law. As long as the radiation energy of known intensity is projected onto the surface of the opaque sample to be measured and the surface reflected energy is measured with a reflectometer, the reflectivity of the sample can be obtained and the emissivity can be calculated. And there are few emissivity measurement devices specifically for infrared window materials. Summary of the invention

[0006] In view of the above analysis, an embodiment of the present invention aims to provide a device for measuring the emissivity and transmittance of structural materials and window materials, so as to solve the problems of low accuracy in measuring material transmittance at high temperatures and the lack of a device specifically for measuring the emissivity of window materials.

[0007] The purpose of the present invention is mainly achieved through the following technical solutions:

[0008] The present invention provides a device for measuring the emissivity and transmittance of structural materials and window materials, characterized in that it comprises a common component, a structural material measuring component and a window material measuring component;

[0009] The common components include a temperature control device, a Fourier spectrum radiometer and a standard black body; the standard black body is used to emit standard spectrum radiation; the temperature control device is used to control the temperature of the material being tested;

[0010] When the material to be measured is a structural material, the spectral radiation value of the structural material is measured by the common component and the structural material measuring component to obtain the normal spectral emissivity of the structural material;

[0011] When the material to be measured is a window material, the spectral radiation value of the window material is measured by the common component and the window material measuring component to obtain the normal spectral emissivity or spectral transmittance of the window material.

[0012] Furthermore, the temperature control device is a hollow cubic structure, the material to be tested is placed in the middle sample slot, and electric heating is used around the material to uniformly heat the material to be tested.

[0013] Furthermore, the temperature control device includes two radiation ports, and the two radiation ports correspond to the middle areas of the front and back sides of the material to be tested;

[0014] The temperature control device is designed with a water cooling interlayer.

[0015] Further, the structural material measuring assembly includes a folding and swinging mirror;

[0016] The folding and swinging mirror is placed between the standard black body and the temperature control device, one radiation port of the temperature control device is closed, and the other radiation port is placed opposite to the cavity port of the standard black body radiation cavity and in a straight line with the center of the folding and swinging mirror;

[0017] The radiation signals emitted by the standard black body and the structural material are switched and reflected to the Fourier spectroradiometer by the swing of the folding and swinging mirror to obtain the spectral radiation values ​​of the standard black body and the structural material, and then calculate the emissivity of the structural material.

[0018] Furthermore, the temperature control device controls the temperature of the structural material to be consistent with the temperature of a standard black body;

[0019] The Fourier spectroradiometer measures the spectral radiation value of the structural material and the spectral radiation value of the standard black body respectively.

[0020] Furthermore, when the material to be measured is a window material, the radiation ports on both sides of the temperature control device are respectively placed opposite to the standard black body and the Fourier spectroradiometer in a straight line;

[0021] The temperature control device controls the window material to a set temperature;

[0022] The Fourier spectroradiometer measures the spectral radiation value of the standard black body when it is set at temperature T1 and temperature T2 and the spectral radiation value passing through the window material, so as to obtain the transmittance of the window material.

[0023] Further, the window material measuring assembly includes a moving assembly and a reflector;

[0024] The reflector is placed on a radiation port on one side of the temperature control device and moves simultaneously with the temperature control device, and the other radiation port of the temperature control device is placed opposite to the Fourier spectroradiometer;

[0025] The moving component moves the temperature control device and the standard black body so that the standard black body and the temperature control device are alternately located in front of the Fourier spectroradiometer.

[0026] Furthermore, the temperature control device controls the temperature of the structural material to be consistent with the temperature of a standard black body;

[0027] The Fourier spectroradiometer measures the spectral radiation value of the window material and the spectral radiation value of the standard black body respectively to obtain the emissivity of the window material.

[0028] Further, the common component also includes a first cold shield located in front of an open radiation port of the temperature control device;

[0029] The window material measuring assembly also includes a second cold shield located in front of another radiation port of the temperature control device.

[0030] Furthermore, the first cold shield and the second cold shield are both water-cooled apertures, which are connected to the temperature control device through insulating materials.

[0031] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0032] 1. The structural material emissivity device and the window material transmittance and emissivity measuring device of the present invention are similar. They use a set of hardware equipment and can achieve the radiation characteristic measurement requirements of the structural material and the window material by changing the position, which is easy to operate.

[0033] 2. The device of the present invention can accurately measure the emissivity and transmittance of structures and window materials. The measurement band range is 3μm~5μm, 8μm~14μm, the measurement angle range is ±10°, the temperature range is 300K~800K, and the measurement uncertainty is ≤6% (emissivity uncertainty: 4% for opaque materials, 6% for transparent materials; transmittance uncertainty: 4%).

[0034] 3. The device of the present invention can be placed in a vacuum chamber to expand the measurement temperature range.

[0035] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0037] Figure 1 Schematic diagram of the structure of the device for measuring the emissivity of structural materials in an embodiment of the present invention;

[0038] Figure 2 Schematic diagram of the structure of a window material transmittance measuring device in an embodiment of the present invention;

[0039] Figure 3 Schematic diagram of the structure of the window material emissivity measuring device in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0041] A specific embodiment of the present invention discloses a device for measuring the emissivity and transmittance of structural materials and window materials; a set of equipment can be used to measure the normal spectral emissivity of the structural material, the normal spectral emissivity of the window material and the radiation transmittance of the window material.

[0042] Specifically, it includes common components, structural material measurement components and window material measurement components; in order to avoid the influence of factors such as vibration on the measurement, the whole device is placed on an optical platform.

[0043] The common components include a temperature control device, a Fourier spectrum radiometer and a standard black body; the standard black body is used to emit standard spectrum radiation; the temperature control device is used to control the temperature of the material being tested;

[0044] When the material to be measured is a structural material, the spectral radiation value of the structural material is measured by the common component and the structural material measuring component to obtain the normal spectral emissivity of the structural material;

[0045] When the material to be measured is a window material, the spectral radiation value of the window material is measured by the common component and the window material measuring component to obtain the normal spectral emissivity and spectral transmittance of the window material.

[0046] Furthermore, the temperature control device is a hollow cubic structure, the material to be tested is placed in the middle sample slot, and electric heating is used around the material to uniformly heat the material to measure the radiation characteristics of the material to be tested at different temperatures.

[0047] Specifically, the temperature control device includes two radiation ports, the material to be tested is placed in the temperature control device, and the two radiation ports correspond to the middle areas of the front and back sides of the material to be tested.

[0048] Furthermore, the temperature control device is designed with a water cooling interlayer.

[0049] Specifically, the temperature control device can control the temperature of the material at room temperature to 600° C. The material to be tested is heated and kept warm in the temperature control device so that the material reaches thermal equilibrium.

[0050] Furthermore, the Fourier spectroradiometer is an instrument for analyzing and identifying the composition of a substance. It uses the interaction between matter and radiation to measure the absorption of the substance at different wavelengths, thereby obtaining the spectral radiation of the substance.

[0051] Furthermore, blackbody radiation refers to the radiation emitted by an ideal radiator, which emits the maximum amount of radiation at a specific temperature and wavelength. In order to study the laws of thermal radiation that do not depend on the specific physical properties of matter, physicists have defined an ideal object - a black body, as a standard object for thermal radiation research.

[0052] In the embodiment of the present invention, when the material to be measured is a structural material, the structural material measuring component includes a folding and swinging mirror, and the structural material emissivity measuring device composed of the common component and the structural material measuring component is as follows: Figure 1 The structure shown.

[0053] The folding oscillating mirror is placed between the standard black body and the temperature control device, one radiation port of the temperature control device is closed, and the other radiation port is placed opposite to the port of the standard black body radiation cavity and in a straight line with the center of the folding oscillating mirror. The detection port of the spectroradiometer is directly opposite to the center of the folding oscillating mirror to receive the spectrum of the measured sample and the standard black body radiation reflected by the folding oscillating mirror.

[0054] Specifically, the structural material is a material used to manufacture load-bearing components based on mechanical properties. It is an opaque material, so only one side of the radiation value needs to be measured.

[0055] Furthermore, the temperature control device controls the temperature of the structural material to be consistent with the temperature of a standard black body;

[0056] The radiation signals emitted by the standard black body and the structural material are switched and reflected to the Fourier spectroradiometer by the swing of the folding and swinging mirror. The Fourier spectroradiometer measures the spectral radiation value of the structural material and the spectral radiation value of the standard black body respectively.

[0057] Specifically, the folding and swinging mirror swings between two fixed points to accurately reflect the radiation signals emitted by the standard black body and the structural material into the Fourier spectroradiometer.

[0058] Furthermore, the ratio of the spectral radiation value of the structural material to the spectral radiation value of the standard black body is the normal spectral emissivity of the structural material at the temperature:

[0059]

[0060] Where ε(λ) is the normal spectral emissivity of the structural material; M sample (λ) is the spectral radiation value of the structural material; M B (λ) is the spectral radiation value of the standard black body.

[0061] Considering that the standard black body is actually only an approximate ideal black body, the emissivity of the standard black body cannot reach 1. In this case, if the emissivity of the standard black body is calculated as 1, the measured radiation characteristics of the measured material will be higher than the true value. When calculating the radiation characteristics, the true emissivity of the standard black body must be considered. The true emissivity of the standard black body has been measured as an equipment indicator when manufacturing the standard black body device.

[0062] Therefore, the normal spectral emissivity of the structural material is calculated by the following formula:

[0063]

[0064] Among them, ε B(λ) is the normal spectral emissivity of the standard black body.

[0065] Furthermore, when the material to be measured is a window material, the window material transmittance measuring device composed of the common component and the window material measuring component is as follows: Figure 2 The structure shown.

[0066] Specifically, window materials are generally used as the material of the receiving part of the instrument. They can be used to isolate the external environment, protect internal devices, and have a high transmittance to light of a specific wavelength or wavelength range, thus acting as a window.

[0067] Furthermore, the radiation ports on both sides of the temperature control device are respectively placed opposite to the standard black body and the Fourier spectroradiometer and in a straight line; the cavity opening of the standard black body is placed opposite to the radiation port on one side of the temperature control device.

[0068] The temperature control device controls the window material to a set temperature;

[0069] The standard black body is set at a temperature of T1. After its temperature stabilizes, a Fourier spectrum radiometer is used to measure the radiation value M of the standard black body through the sample. C1 (λ); Take out the sample to be tested and use the Fourier spectroradiometer to directly measure the radiation value M of the standard black body T1 (λ); M C1 (λ) and M T1 The relationship between (λ) is expressed as:

[0070] M C1 (λ)=M T1 (λ)×τ(λ)+M 1

[0071] Among them, M C1 (λ) is the spectral radiation value transmitted through the window material when the standard black body is set at temperature T1; M T1 (λ) is the spectral radiation value of the standard black body at the set temperature T1; τ(λ) is the spectral transmittance of the window material; M 1 is the stray radiation value.

[0072] After the measurement is completed, the standard black body is set at temperature T2. After its temperature stabilizes, the radiation value M of the standard black body is measured again through the sample using a Fourier spectrum radiometer. C2 (λ); Take out the sample to be tested and use the Fourier spectroradiometer to directly measure the radiation value M of the standard black body T2 (λ); M C2 (λ) and M T2 The relationship between (λ) is expressed as:

[0073] M C2(λ)=M T2 (λ)×τ(λ)+M 1

[0074] Among them, M C2 (λ) is the spectral radiation value transmitted through the window material when the standard black body is set at temperature T2; M T2 (λ) is the spectral radiation value of the standard black body when the temperature is set to T2.

[0075] Furthermore, the spectral transmittance of the window material can be derived from the above two equations:

[0076]

[0077] Further, when the material to be measured is a window material, the window material measuring component includes a moving component and a reflector, and the common component and the window material measuring component constitute a window material emissivity measuring device such as Figure 3 The structure shown.

[0078] The reflector is placed on a radiation port on one side of the temperature control device and moves simultaneously with the temperature control device, and the other radiation port of the temperature control device is placed opposite to the Fourier spectroradiometer;

[0079] Specifically, since the window material is a light-transmitting material, when measuring its emissivity, its surface emissivity will be emitted from the back side through the material itself, so it is necessary to simultaneously measure the emissivity of both the front and back surfaces and add them together to obtain the emissivity of the window material itself.

[0080] The reflector is used to reflect the back radiation of the window material into the Fourier spectroradiometer.

[0081] Preferably, the reflector is a gold-plated high-reflectivity reflector with a protective film.

[0082] Furthermore, the temperature control device controls the temperature of the structural material to be consistent with the temperature of a standard black body;

[0083] Furthermore, the moving component moves the temperature control device and the standard black body so that the standard black body and the temperature control device are alternately located in front of the Fourier spectroradiometer;

[0084] Specifically, the moving component moves the temperature control device to make it and the reflector in a straight line in front of the Fourier spectroradiometer to measure the spectral radiation value of the window material;

[0085] Furthermore, the moving component moves the standard black body to be located in front of the Fourier spectroradiometer to measure the spectral radiation value of the standard black body.

[0086] After the measurement is completed, the radiation measurement value of the window material is expressed by the following formula:

[0087] M C (λ)=M B (λ)×ε B (λ)×ε(λ)+M B (λ)×ε B (λ)×ρ(λ)×ε(λ)×τ(λ)

[0088] Among them, M C (λ) is the spectral radiation value of the window material; M B (λ) is the spectral radiation value of the standard black body; ε B (λ) is the normal spectral emissivity of the standard black body; ε(λ) is the normal spectral emissivity of the window material; ρ(λ) is the reflectivity of the reflector; τ(λ) is the spectral transmittance of the window material.

[0089] Furthermore, the normal spectral emissivity of the window material is derived from the above formula:

[0090]

[0091] Furthermore, the common component also includes a first cold shield, which is located in front of the radiation port opened by the temperature control device. When measuring the structural material, it is located at the radiation port facing the standard black body to eliminate the influence of environmental radiation reflected on the surface of the measured material.

[0092] The window material measurement assembly also includes a second cold shield. When measuring the window material, two cold shields are used simultaneously at two radiation ports of the temperature control device to eliminate the influence of environmental radiation reflected on the front and back surfaces of the measured material.

[0093] Specifically, the temperature control device will generate environmental radiation during the heating process. In order to avoid the influence of environmental radiation on the measurement accuracy, a cold shielding device is placed in front of the radiation port of the temperature control device. The device is a water-cooled aperture and is polished internally with an extremely low emissivity. This largely eliminates the adverse effects of environmental radiation on the measurement. The cold shielding device is connected to the water-cooled and heating device through insulating material, eliminating the influence of the cold shielding device on the temperature control accuracy of the water-cooled and heating device.

[0094] Furthermore, the aperture of the water-cooled aperture is larger than the radiation port of the temperature control device.

[0095] In summary, the device for measuring the emissivity and transmittance of a structural material and a window material according to an embodiment of the present invention has the following beneficial effects:

[0096] 1. The device used in the present invention for measuring the emissivity of structural materials and the transmittance and emissivity of window materials is similar. A set of hardware equipment is used to achieve the radiation characteristic measurement requirements of various materials by changing the position, which is easy to operate and makes up for the shortcomings of the prior art.

[0097] 2. The device of the present invention can accurately measure the emissivity and transmittance of structures and window materials. The measurement band range is 3μm~5μm, 8μm~14μm, the measurement angle range is ±10°, the temperature range is 300K~800K, and the measurement uncertainty is ≤6% (emissivity uncertainty: 4% for opaque materials, 6% for transparent materials; transmittance uncertainty: 4%).

[0098] 3. The device of the present invention can be placed in a vacuum chamber to expand the measurement temperature range.

[0099] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A device for measuring the emissivity and transmittance of structural materials and window materials, It is characterized in that Including common components, structural material measurement components and window material measurement components; The common components include a temperature control device, a Fourier spectrum radiometer and a standard black body; the standard black body is used to emit standard spectrum radiation; the temperature control device is used to control the temperature of the material being tested; When the material to be measured is a structural material, the spectral radiation value of the structural material is measured by the common component and the structural material measuring component to obtain the normal spectral emissivity of the structural material; When the material to be measured is a window material, the spectral radiation value of the window material is measured by the common component and the window material measuring component to obtain the normal spectral emissivity or spectral transmittance of the window material.

2. The device according to claim 1, It is characterized in that The temperature control device is a hollow cubic structure, the material to be tested is placed in the middle sample slot, and electric heating is adopted around the material to uniformly heat the material to be tested.

3. The device according to claim 2, It is characterized in that The temperature control device comprises two radiation ports, which correspond to the middle areas of the front and back sides of the material to be tested; The temperature control device is designed with a water cooling interlayer.

4. The device according to claim 3, It is characterized in that The structural material measuring assembly includes a folding and swinging mirror; The folding and swinging mirror is placed between the standard black body and the temperature control device, one radiation port of the temperature control device is closed, and the other radiation port is placed opposite to the cavity port of the standard black body radiation cavity and in a straight line with the center of the folding and swinging mirror; The radiation signals emitted by the standard black body and the structural material are switched and reflected to the Fourier spectroradiometer by the swing of the folding and swinging mirror to obtain the spectral radiation values ​​of the standard black body and the structural material, and then calculate the emissivity of the structural material.

5. The device according to claim 4, It is characterized in that The temperature control device controls the temperature of the structural material to be consistent with the temperature of a standard black body; The Fourier spectroradiometer measures the spectral radiation value of the structural material and the spectral radiation value of the standard black body respectively.

6. The device according to claim 3, It is characterized in that When the material to be tested is a window material, the radiation ports on both sides of the temperature control device are respectively placed opposite to the standard black body and the Fourier spectroradiometer in a straight line; The temperature control device controls the window material to a set temperature; The Fourier spectroradiometer measures the spectral radiation value of the standard black body when it is set at temperature T1 and temperature T2 and the spectral radiation value passing through the window material, so as to obtain the transmittance of the window material.

7. According to the device according to claim 3, It is characterized in that The window material measuring assembly includes a moving assembly and a reflector; The reflector is placed on a radiation port on one side of the temperature control device and moves simultaneously with the temperature control device, and the other radiation port of the temperature control device is placed opposite to the Fourier spectroradiometer; The moving component moves the temperature control device and the standard black body so that the standard black body and the temperature control device are alternately located in front of the Fourier spectroradiometer.

8. The device according to claim 7, It is characterized in that The temperature control device controls the temperature of the structural material to be consistent with the temperature of a standard black body; The Fourier spectroradiometer measures the spectral radiation value of the window material and the spectral radiation value of the standard black body respectively to obtain the emissivity of the window material.

9. The device according to claim 3, It is characterized in that The common component also includes a first cold shield located in front of an open radiation port of the temperature control device; The window material measuring assembly also includes a second cold shield located in front of another radiation port of the temperature control device.

10. The device according to claim 9, It is characterized in that The first cold shield and the second cold shield are both water-cooled apertures, and are connected to the temperature control device through insulation materials.

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