A shield for a cryogenic blackbody radiation source

Abstract

This invention relates to a protective device for a low-temperature blackbody radiation source, belonging to the field of low-temperature radiation metrology and calibration technology. It solves the problem in existing technologies where the temperature inside the blackbody cavity is easily affected by the external environment when calibrating infrared instruments and equipment using a low-temperature blackbody radiation source, leading to temperature instability within the blackbody cavity. The invention includes a protective body, a piping assembly, and a cap. The protective body has a protective cavity extending through it, with one end connected to the opening of the blackbody cavity and the other end serving as a measuring end. The cap is positioned at the measuring end of the protective cavity. The protective cavity is connected to an external dry nitrogen source via the piping assembly, which supplies both low-temperature and room-temperature dry nitrogen to the protective cavity, isolating the blackbody cavity from the external environment. This invention effectively isolates the blackbody cavity from the external environment, preventing external environmental influences on the temperature inside the blackbody cavity and maintaining its stability.

Description

Technical Field

[0001] This invention relates to the field of low-temperature radiation metrology and calibration technology, and in particular to a protective device for a low-temperature blackbody radiation source. Background Technology

[0002] Low-temperature blackbody radiation sources play a crucial role in calibrating infrared instruments and equipment, directly impacting the accuracy of temperature measurements. During the use of low-temperature blackbody radiation sources, external air easily enters the blackbody cavity. Due to the low temperature, water vapor in the entering air undergoes frost, condensation, and fogging. This phenomenon significantly alters the surface emissivity of the blackbody cavity's inner walls and induces medium absorption, resulting in a marked decrease in the effective emissivity of the blackbody cavity and causing temperature instability within it. Furthermore, the entry of external air also disturbs the temperature within the blackbody cavity, contributing to its instability. This temperature instability leads to significant errors during the calibration of infrared instruments and equipment, affecting the accuracy of temperature measurements. Summary of the Invention

[0003] Based on the above analysis, the present invention aims to provide a protective device for a low-temperature blackbody radiation source, in order to solve the problem that when using a low-temperature blackbody radiation source to calibrate infrared instruments and equipment in the prior art, the temperature inside the blackbody cavity is easily affected by the external environment, resulting in unstable temperature inside the blackbody cavity.

[0004] The objective of this invention is mainly achieved through the following technical solutions:

[0005] A protective device for a low-temperature blackbody radiation source includes a protective body, a piping assembly, and a cap. The protective body has a protective cavity that extends through it. One end of the protective cavity is connected to the opening of the blackbody cavity in the low-temperature blackbody radiation source, and the other end is a measuring end. The cap is disposed at the measuring end of the protective cavity. The protective cavity is connected to an external dry nitrogen source through the piping assembly, which is used to input low-temperature dry nitrogen and room-temperature dry nitrogen into the protective cavity, thereby isolating the blackbody cavity from the external environment.

[0006] Furthermore, the piping assembly includes a main pipeline, a heat exchanger, a first branch, and a second branch.

[0007] Furthermore, the main pipeline is connected to an external, room-temperature dry nitrogen source.

[0008] Furthermore, one end of each of the first branches is connected to the main pipeline, and the other end is connected to the protective cavity via a heat exchanger. The first branch is used to provide low-temperature dry nitrogen to the protective cavity.

[0009] Furthermore, the heat exchanger is placed in the cooling medium of the low-temperature blackbody radiation source to cool the dry nitrogen gas in the first branch.

[0010] Furthermore, one end of the second branch is connected to the main branch, and the other end is connected to the protective cavity. The second branch is used to provide the protective cavity with room temperature dry nitrogen.

[0011] Furthermore, the cover includes a cover plate and a plug.

[0012] Furthermore, the cover plate is provided with a measuring hole.

[0013] Furthermore, the measuring hole is coaxial with the opening end of the blackbody cavity.

[0014] Furthermore, the plug can be inserted into the measuring hole.

[0015] The technical solution of this invention can achieve at least one of the following effects:

[0016] (1) The present invention provides a protective device for a low-temperature blackbody radiation source, comprising a protective body, a pipeline assembly, and a cover. The protective body has a protective cavity that extends through the protective body. One end of the protective cavity is connected to the opening of the blackbody cavity, and the other end is a measuring end. The cover is disposed at the measuring end of the protective cavity. The protective cavity is connected to an external dry nitrogen source through the pipeline assembly, which is used to input low-temperature dry nitrogen and room-temperature dry nitrogen into the protective cavity, thereby isolating the blackbody cavity from the external environment. The present invention achieves the isolation of the blackbody cavity from the external environment, avoiding the influence of the external environment on the temperature inside the blackbody cavity, keeping the temperature inside the blackbody cavity stable, thereby avoiding errors when calibrating infrared instruments and equipment, improving the accuracy of temperature calibration of infrared instruments and equipment, and consequently improving the accuracy of temperature measurement by infrared instruments and equipment.

[0017] (2) The protective cavity of the present invention is provided with a first protective zone, a second protective zone and a third protective zone, which are sequentially connected. The first protective zone is connected to the opening end of the blackbody cavity. The first and second protective zones are connected by pipeline components. Low-temperature dry nitrogen is input to the first protective zone and room-temperature dry nitrogen is input to the second protective zone through the pipeline components to form a temperature barrier to prevent external ambient air from entering the blackbody cavity and reduce temperature fluctuations in the blackbody cavity. By adjusting the amount of room-temperature dry nitrogen input to the second protective zone, the temperature of the mixture of room-temperature dry nitrogen and low-temperature dry nitrogen from the first protective zone is increased to adjust the temperature of the third protective zone, so that the third protective zone forms an environmental isolation zone. This not only prevents external ambient air from entering the blackbody cavity, but also isolates the external ambient temperature and prevents the external ambient temperature from penetrating the protective cavity, thereby avoiding the influence of the external environment on the temperature inside the blackbody cavity and keeping the temperature inside the blackbody cavity stable. This avoids errors when calibrating infrared instruments and equipment, improves the accuracy of temperature calibration of infrared instruments and equipment, and thus improves the accuracy of temperature measurement by infrared instruments and equipment.

[0018] (3) The present invention also includes a stirring component, which includes a driving mechanism and a stirring mechanism, which are disposed in the second air blowing port; the stirring mechanism is connected to the driving mechanism, and the driving mechanism drives the stirring mechanism to move, and the stirring mechanism continuously changes the direction of the room temperature dry nitrogen blown out from the second air blowing port, thereby stirring the room temperature dry nitrogen blown into the second protection zone, thereby accelerating the mixing of the room temperature dry nitrogen with the low temperature dry nitrogen from the first protection zone, improving the mixing efficiency and mixing uniformity, thereby improving the efficiency of adjusting the temperature of the mixed dry nitrogen, so as to save the use of dry nitrogen; and at the same time, it can reduce the axial dimension of the second protection zone, thereby avoiding the axial dimension of the protection cavity being too long, which would cause inconvenience in use.

[0019] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0020] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0021] Figure 1 This is a schematic diagram of the protective device according to Embodiment 1 of the present invention;

[0022] Figure 2 This is a cross-sectional view of the protective device according to Embodiment 1 of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of the protective body according to Embodiment 1 of the present invention;

[0024] Figure 4 for Figure 3 Enlarged view of part A in the middle;

[0025] Figure 5 for Figure 3 Enlarged view of part B in the middle;

[0026] Figure 6 This is an exploded view of the stirring component in Embodiment 2 of the present invention;

[0027] Figure 7 for Figure 6 Enlarged view of part C.

[0028] Figure label:

[0029] 100. Low-temperature blackbody radiation source; 101. Blackbody cavity;

[0030] 1. Protective body; 11. First protective zone; 111. First air chamber; 112. First mixing chamber; 113. First air outlet; 114. First vent hole; 12. Second protective zone; 121. Second air chamber; 122. Second mixing chamber; 123. Second air outlet; 124. Second vent hole; 125. Premixed air hole; 126. Guide plate; 13. Third protective zone; 131. Pressure relief air passage; 132. Step; 2. Piping assembly; 21. Main pipeline; 22. Heat exchanger; 23. First branch; 24. Second branch; 3. Cover; 31. Cover plate; 32. Plug; 4. Agitator assembly; 41. Drive mechanism; 411. Slide rail; 412. Blade; 42. Agitator mechanism; 421. Gear plate; 422. Drive protrusion; 423. Oscillating blade. Detailed Implementation

[0031] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0032] Example 1

[0033] In one specific embodiment of the present invention, a protective device for a low-temperature blackbody radiation source is disclosed, such as... Figure 1As shown, the device is installed on a low-temperature blackbody radiation source 100. When using the low-temperature blackbody radiation source 100 to calibrate infrared instruments and equipment, it is used to prevent the external environment from affecting the temperature inside the blackbody cavity 101 of the low-temperature blackbody radiation source 100, so as to keep the temperature inside the blackbody cavity 101 stable and improve the accuracy of the calibration of infrared instruments and equipment. The protective device includes a protective body 1, a pipeline assembly 2, and a cover 3. The protective body 1 has a protective cavity that extends through the protective body 1. One end of the protective cavity is connected to the opening end of the blackbody cavity 101, and the other end is a measuring end that is connected to the external environment and is used to place the infrared instruments and equipment to be calibrated. The protective cavity is connected to an external dry nitrogen source through the pipeline assembly 2. The pipeline assembly 2 is used to input dry nitrogen into the protective cavity to isolate the blackbody cavity 101 from the external environment, so as to prevent air from the external environment from entering the blackbody cavity 101. At the same time, it can also isolate the temperature of the external environment, thereby avoiding the influence of the external environment on the temperature inside the blackbody cavity 101, and keeping the temperature inside the blackbody cavity 101 stable. The temperature remains stable. The cover 3 is installed at the measuring end of the protective cavity. When not calibrating, it is used to seal the protective cavity, so that the protective cavity and the blackbody cavity 101 form a closed cavity to isolate the external environment from the blackbody cavity 101 and prevent foreign objects from entering the blackbody cavity 101 and causing damage. During calibration, the cover 3 is removed, the infrared instrument is placed at the measuring end, and the instrument is aligned with the blackbody cavity 101 for calibration. Compared with the prior art, in this embodiment, when calibrating the infrared instrument, dry nitrogen is introduced into the protective cavity through the pipeline assembly 2 to isolate the blackbody cavity 101 from the external environment, so as to prevent air from the external environment from entering the blackbody cavity 101 and to isolate the external temperature, thereby avoiding the influence of the external environment on the temperature inside the blackbody cavity 101 and keeping the temperature inside the blackbody cavity 101 stable. This avoids errors when calibrating the infrared instrument, improves the accuracy of temperature calibration of the infrared instrument, and thus improves the accuracy of temperature measurement by the infrared instrument.

[0034] Preferably, such as Figure 2 As shown, the cover 3 includes a cover plate 31 and a plug 32. The cover plate 31 is installed inside the protective cavity and has a measuring hole. The measuring hole is coaxial with the opening end of the blackbody cavity 101. The plug 32 can be inserted into the measuring hole. During non-calibration, the protective cavity is sealed by inserting the plug 32 into the measuring hole, so that the protective cavity and the blackbody cavity 101 form a closed cavity to isolate the external environment from the blackbody cavity 101 and prevent foreign objects from entering the blackbody cavity 101 and causing damage to it. During calibration, the plug 32 is removed, and the infrared instrument is aligned with the measuring hole, so that the infrared instrument can be aligned with the blackbody cavity 101 for calibration, which facilitates operation.

[0035] Preferably, such as Figure 3As shown, the protective cavity is provided with a first protective zone 11, a second protective zone 12, and a third protective zone 13, which are sequentially connected. The first protective zone 11 is connected to the opening end of the blackbody cavity 101 and is also connected to the pipeline assembly 2. Low-temperature dry nitrogen gas with the same temperature as the inside of the blackbody cavity 101 is input into the first protective zone 11 through the pipeline assembly 2 to form a low-temperature barrier, thereby preventing external ambient air from entering the blackbody cavity 101 and reducing temperature fluctuations within the blackbody cavity 101. The second protective zone 12 is connected to the pipeline assembly 2. Room-temperature dry nitrogen gas is input into the second protective zone 12 through the pipeline assembly 2, and the room-temperature dry nitrogen gas is mixed with the low-temperature dry nitrogen gas from the first protective zone 11 to form mixed dry nitrogen gas, and the temperature of the mixed dry nitrogen gas is regulated. The third protective zone 13 is used to collect the mixed dry nitrogen gas and blow it outwards to the external environment, forming an environmental isolation zone to further prevent external air from entering. The nitrogen gas enters the blackbody cavity 101 through the protective cavity. Simultaneously, by adjusting the flow rate of room-temperature dry nitrogen, the temperature of the mixed dry nitrogen is regulated, preventing condensation and the formation of white mist from the nitrogen blowing from the third protective zone 13 into the external environment. This prevents instability in the calibration environment during infrared instrument calibration, thus avoiding interference with the calibration process. Furthermore, the sequentially arranged first protective zone 11, second protective zone 12, and third protective zone 13 form a low-temperature zone, a mixed temperature-regulating zone, and an environmental isolation zone, respectively. This not only prevents external ambient air from entering the blackbody cavity 101 but also isolates it from external ambient temperature, preventing it from penetrating the protective cavity. This avoids external environmental influence on the temperature within the blackbody cavity 101, maintaining a stable temperature and preventing errors during infrared instrument calibration. This improves the accuracy of temperature calibration for infrared instruments, thereby enhancing the accuracy of temperature measurements.

[0036] Preferably, the inner wall of the third protective zone 13 is provided with a pressure relief channel 131. The pressure relief channel 131 can maintain the pressure balance between the protective cavity and the external environment, and prevent the mixed dry nitrogen from not being discharged in time, causing the mixed dry nitrogen to flow back into the blackbody cavity 101, thus avoiding the impact on the temperature inside the blackbody cavity 101.

[0037] Preferably, the inner wall of the measuring end of the third protective zone 13 is provided with multiple steps 132. By installing caps 3 of different specifications on the steps, the distance between the measuring hole and the blackbody cavity 101 can be adjusted, thereby enabling the measurement of infrared instruments and meters with different focal lengths.

[0038] Preferably, such as Figure 4As shown, the first protective zone 11 has a first gas chamber 111, a first mixing chamber 112, and a first air outlet 113 on its cavity wall. The first gas chamber 111, the first mixing chamber 112, and the first air outlet 113 are connected in sequence. The first gas chamber 111 is provided with a first connector, which is connected to the pipeline assembly 2. Low-temperature dry nitrogen is introduced into the first gas chamber 111 through the pipeline assembly 2. The first mixing chamber 112 is used to mix, disperse, and homogenize the low-temperature dry nitrogen. The first air outlet 113 is connected to the protective cavity and used for... The low-temperature dry nitrogen gas, which is mixed, dispersed, and homogenized in the first mixing chamber 112, is blown into the protective chamber, forming a low-temperature gas curtain inside the protective chamber. This prevents external ambient air, temperature, and room-temperature dry nitrogen gas in the second protective zone 12 from entering the blackbody cavity 101, reducing temperature fluctuations within the blackbody cavity 101 and keeping the temperature within the blackbody cavity 101 stable. This avoids errors when calibrating infrared instruments and equipment, improves the accuracy of temperature calibration of infrared instruments and equipment, and consequently improves the accuracy of temperature measurement by infrared instruments and equipment.

[0039] Preferably, the first gas chamber 111 and the first mixing chamber 112 are both annular cavities, and the first air outlet 113 is an annular air outlet; a first partition is provided between the first gas chamber 111 and the first mixing chamber 112, and the first partition is provided with a plurality of first vent holes 114. The first mixing chamber 112 is connected to the first gas chamber 111 through the plurality of first vent holes 114; since the diameter of the first vent holes 114 is small, the low-temperature dry nitrogen gas input through the pipeline assembly 2 first fills the first gas chamber 111, and then is input into the first mixing chamber 112 through the plurality of first vent holes 114. After being mixed, dispersed and homogenized in the first mixing chamber 112, it is blown into the protective cavity from the first air outlet 113 to form a continuous low-temperature air curtain, thereby forming a continuous temperature barrier, which can effectively prevent external ambient air from entering the blackbody cavity 101, and at the same time prevent external ambient temperature from radiating to the blackbody cavity 101, thereby reducing the temperature fluctuation in the blackbody cavity 101.

[0040] Preferably, the first air outlet 113 is tilted away from the blackbody cavity 101, so that the point where the low-temperature dry nitrogen gas converges in the protective cavity is far away from the blackbody cavity 101. This prevents the low-temperature dry nitrogen gas from converging and mixing with the room-temperature dry nitrogen gas in the second protective zone 12, thus further reducing temperature disturbance in the blackbody cavity 101 and keeping the temperature in the blackbody cavity 101 stable. This avoids errors when calibrating infrared instruments and equipment, further improves the accuracy of temperature calibration of infrared instruments and equipment, and further improves the accuracy of temperature measurement by infrared instruments and equipment.

[0041] Preferably, multiple first connectors are provided, and the multiple first connectors are evenly arranged around the circumference, thereby improving the uniformity and flow rate of the low-temperature drying nitrogen input, so that the low-temperature drying nitrogen can quickly and evenly fill the first gas chamber 111, thereby ensuring that the low-temperature drying nitrogen blown into the protective chamber from the first air outlet 113 forms a continuous low-temperature gas curtain.

[0042] Preferably, such as Figure 5 As shown, the second protective zone 12 has a second air chamber 121, a second mixing chamber 122, and a second air outlet 123 on its cavity wall. The second air chamber 121, the second mixing chamber 122, and the second air outlet 123 are connected in sequence. The second air chamber 121 is provided with a second connector, which is connected to the pipeline assembly 2. Room temperature dry nitrogen is introduced into the second air chamber 121 through the pipeline assembly 2. The second mixing chamber 122 is used to mix, disperse, and homogenize the room temperature dry nitrogen. The second air outlet 123 is connected to the protective cavity and is used to inject nitrogen into the second mixing chamber. The room-temperature dry nitrogen gas, after being mixed, dispersed, and homogenized within zone 122, is blown into the protective chamber. This room-temperature dry nitrogen gas mixes with the low-temperature dry nitrogen gas from the first protective zone 11 to form a mixed dry nitrogen gas. The temperature of the mixed dry nitrogen gas is then adjusted and it flows into the third protective zone 13. This prevents the nitrogen gas blown from the third protective zone 13 into the external environment from condensing with the external air to form white fog. This prevents instability in the calibration environment during the calibration of infrared instruments and equipment, thus interfering with the calibration and further ensuring the accuracy of temperature calibration for infrared instruments and equipment.

[0043] Preferably, both the second gas chamber 121 and the second mixing chamber 122 are annular cavities, and the second air outlet 123 is an annular air outlet. A second partition is provided between the second gas chamber 121 and the second mixing chamber 122, and the second partition is provided with a plurality of second vent holes 124. The second mixing chamber 122 is connected to the second gas chamber 121 through the plurality of second vent holes 124. Since the diameter of the second vent holes 124 is small, the room temperature dry nitrogen gas input through the pipeline assembly 2 first fills the second gas chamber 121, and then enters the second mixing chamber 122 through the plurality of second vent holes 124. After being mixed, dispersed and homogenized in the second mixing chamber 122, it is blown into the protective chamber from the second air outlet 123. The formation of a room-temperature air curtain, which further creates a temperature barrier, effectively prevents external ambient air and temperature from entering the blackbody cavity 101, reducing temperature fluctuations within the blackbody cavity 101. Simultaneously, room-temperature dry nitrogen mixes with low-temperature dry nitrogen from the first protection zone 11 to form mixed dry nitrogen, and the temperature of the mixed dry nitrogen is regulated so that the temperature of the mixed dry nitrogen flowing into the third protection zone 13 is close to room temperature. This prevents condensation of external air upon encountering the mixed dry nitrogen flowing out of the protection cavity during the calibration of infrared instruments and equipment, which could cause instability in the calibration environment and interfere with the calibration of infrared instruments and equipment, thus further ensuring the accuracy of temperature calibration of infrared instruments and equipment.

[0044] Preferably, the second air outlet 123 is tilted away from the blackbody cavity 101, so that the point where the room temperature dry nitrogen gas converges in the protective cavity is far away from the low temperature gas curtain, so as to prevent damage to the low temperature gas curtain and prevent room temperature dry nitrogen gas from entering the blackbody cavity 101, thereby further reducing the impact on the temperature inside the blackbody cavity 101, keeping the temperature inside the blackbody cavity 101 stable, thereby avoiding errors when calibrating infrared instruments and equipment, further improving the accuracy of temperature calibration of infrared instruments and equipment, and further improving the accuracy of temperature measurement of infrared instruments and equipment.

[0045] Preferably, the second blowing port 123 is provided with a premixing air hole 125. The premixing air hole 125 is inclined towards the blackbody cavity 101. The premixing air hole 125 is used to premix the blown room temperature dry nitrogen gas with the low temperature dry gas after the convergence, thereby improving the mixing efficiency and the efficiency of adjusting the temperature of the dry nitrogen gas, and saving the amount of dry nitrogen gas used.

[0046] Preferably, multiple premixed gas holes 125 are provided, and the multiple premixed gas holes 125 are evenly arranged around the circumference, so that the room temperature dry nitrogen can be mixed with the low temperature dry gas after the convergence more quickly and evenly, thereby further improving the efficiency of adjusting the temperature of the dry nitrogen.

[0047] Preferably, the second air outlet 123 is further provided with a guide plate 126, which is annular and is used to guide a portion of the room temperature dry nitrogen gas to smoothly enter and be blown out through the premixed gas hole 125.

[0048] Preferably, multiple second connectors are provided, and the multiple second connectors are evenly arranged around the circumference, which can improve the uniformity and flow rate of room temperature dry nitrogen input, so that room temperature dry nitrogen can quickly and evenly fill the second gas chamber 121, thereby ensuring that the room temperature dry nitrogen blown into the protective chamber from the second air outlet 123 can quickly mix with the low temperature dry gas after convergence, thereby further improving the efficiency of regulating the temperature of dry nitrogen.

[0049] Preferably, the pipeline assembly 2 includes a main pipeline 21, a heat exchanger 22, a first branch 23, and a second branch 24. The main pipeline 21 is connected to an external ambient temperature dry nitrogen source. One end of the first branch 23 and the second branch 24 are both connected to the main pipeline 21. The other end of the first branch 23 is connected to a first connector via the heat exchanger 22 to provide low-temperature dry nitrogen to the first protection zone 11. The other end of the second branch 24 is connected to a second connector to provide ambient temperature dry nitrogen to the second protection zone 12. The heat exchanger 22 is located in the cooling medium of the low-temperature blackbody radiation source 100 and is used to cool the dry nitrogen in the first branch 23, so that the temperature of the low-temperature dry nitrogen supplied from the first branch 23 to the first protection zone 11 is consistent with the temperature inside the blackbody cavity 101, thereby avoiding the influence on the temperature inside the blackbody cavity 101 and maintaining the temperature stability inside the blackbody cavity 101 to ensure the calibration accuracy of infrared instruments and equipment.

[0050] Preferably, the first branch 23 is provided with a first regulating valve, which is used to regulate the flow rate of low-temperature dry nitrogen gas input to the first protection zone 11.

[0051] Preferably, a second regulating valve is provided on the second branch 24. The second regulating valve is used to regulate the flow rate of room temperature dry nitrogen gas input to the second protection zone 12. By regulating the flow rate of room temperature dry nitrogen gas, the temperature of the mixed dry nitrogen gas can be regulated so that the nitrogen gas blown from the third protection zone 13 to the external environment will not condense with the external air to form white mist.

[0052] Example 2

[0053] Example 2 is a further improvement based on Example 1, such as... Figure 3As shown, the protective device also includes a stirring component 4, which is disposed inside the second air inlet 123. The stirring component 4 is used to stir the room temperature dry nitrogen gas blown into the second protective zone 12, so that the stirred room temperature dry nitrogen gas can be quickly mixed with the low temperature dry nitrogen gas from the first protective zone 11, thereby improving the mixing efficiency and mixing uniformity, and thus improving the efficiency of adjusting the temperature of the mixed dry nitrogen gas, so as to save the use of room temperature dry nitrogen gas; and at the same time, it can reduce the axial dimension of the second protective zone 12, thereby avoiding the axial dimension of the protective cavity being too long, which would cause inconvenience in use.

[0054] Preferably, such as Figure 5 As shown, the stirring assembly 4 includes a driving mechanism 41 and a stirring mechanism 42. The stirring mechanism 42 is connected to the driving mechanism 41. The driving mechanism 41 drives the stirring mechanism 42 to move. The stirring mechanism 42 continuously changes the direction of the room temperature dry nitrogen gas blown out from the second air outlet 123, thereby stirring the room temperature dry nitrogen gas blown into the second protective zone 12. This accelerates the mixing of the room temperature dry nitrogen gas with the low temperature dry nitrogen gas from the first protective zone 11, improves the mixing efficiency and uniformity, and thus improves the efficiency of adjusting the temperature of the mixed dry nitrogen gas, thereby saving the use of dry nitrogen gas. At the same time, it can reduce the axial dimension of the second protective zone 12, thereby avoiding the axial dimension of the protective cavity being too long, which would cause inconvenience in use.

[0055] Preferably, multiple agitation mechanisms 42 are provided, and the multiple agitation mechanisms 42 are evenly arranged circumferentially within the second air inlet 123, thereby improving the uniformity and comprehensiveness of agitation of the room temperature dry nitrogen gas blown into the second protection zone 12, and enabling the room temperature dry nitrogen gas to be quickly mixed with the low temperature dry nitrogen gas from the first protection zone 11.

[0056] Preferably, such as Figure 6 As shown, the drive mechanism 41 includes a slide rail 411 and blades 412. The slide rail 411 is fitted inside the second air outlet 123 and can rotate around the second air outlet 123. The blades 412 are fixedly installed on the slide rail 411. Multiple blades 412 are provided and are evenly arranged around the circumference. When room temperature dry nitrogen is blown into the protective cavity from the second mixing chamber 122 through the second air outlet 123, the airflow pushes the blades 412 to drive the slide rail 411 to rotate.

[0057] Preferably, the slide rail 411 is provided with drive teeth.

[0058] Preferably, such as Figure 7As shown, the agitation mechanism 42 includes a geared disc 421, a drive protrusion 422, a swivel blade 423, and a rotating shaft. The geared disc 421 is rotatably disposed within the second air inlet 123 and meshes with the drive teeth on the slide rail 411. The drive protrusion 422 is fixedly mounted on the geared disc 421 and is eccentrically disposed on the end face of the geared disc 421. The swivel blade 423 is rotatably mounted within the second air inlet 123 via the rotating shaft and can intermittently contact the drive protrusion 422, thereby driving the swivel blade 423 to oscillate. The oscillating blade 423 continuously changes the direction of the room-temperature dry nitrogen gas blown out from the second air outlet 123, thereby agitating the room-temperature dry nitrogen gas blown into the second protective zone 12. This accelerates the mixing with the low-temperature dry nitrogen gas from the first protective zone 11, improving mixing efficiency and uniformity. Consequently, it increases the efficiency of adjusting the temperature of the mixed dry nitrogen gas, thus saving on the use of dry nitrogen gas. At the same time, it can reduce the axial dimension of the second protective zone 12, thereby avoiding an excessively long axial dimension of the protective cavity, which would cause inconvenience in use.

[0059] Preferably, the agitation mechanism 42 further includes a torsion spring (not shown in the figure), which is sleeved on the rotating shaft. One end of the torsion spring is fixedly connected to the second air inlet 123, and the other end is fixedly connected to the swing blade 423, so that the swing blade 423 can maintain a certain initial angle, and after the swing blade 423 swings, it can automatically return to the initial angle, thereby increasing the swing amplitude of the swing blade 423, which in turn improves the agitation amplitude of the room temperature dry nitrogen gas blown into the second protection zone 12, further accelerating the mixing with the low temperature dry nitrogen gas from the first protection zone 11, and further improving the mixing efficiency and mixing uniformity.

[0060] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A protective device for a low-temperature blackbody radiation source, characterized in that, The device includes a protective body (1), a pipeline assembly (2), and a cover (3). The protective body (1) has a protective cavity that extends through the protective body (1). One end of the protective cavity is connected to the opening of the blackbody cavity (101) in the low-temperature blackbody radiation source, and the other end is a measuring end. The cover (3) is placed at the measuring end of the protective cavity. The protective cavity is connected to an external dry nitrogen source through the pipeline assembly (2). The pipeline assembly (2) is used to input low-temperature dry nitrogen and room-temperature dry nitrogen into the protective cavity to isolate the blackbody cavity (101) from the external environment.

2. The protective device for a low-temperature blackbody radiation source according to claim 1, characterized in that, The piping assembly (2) includes a main pipeline (21), a heat exchanger (22), a first branch (23), and a second branch (24).

3. A protective device for a low-temperature blackbody radiation source according to claim 2, characterized in that, The main pipeline (21) is connected to an external ambient temperature dry nitrogen source.

4. A protective device for a low-temperature blackbody radiation source according to claim 3, characterized in that, One end of the first branch (23) is connected to the main branch (21), and the other end is connected to the protective cavity via a heat exchanger (22). The first branch (23) is used to provide low-temperature dry nitrogen to the protective cavity.

5. A protective device for a low-temperature blackbody radiation source according to claim 4, characterized in that, The heat exchanger (22) is placed in the cooling medium of the low-temperature blackbody radiation source (100) to cool the dry nitrogen in the first branch (23).

6. A protective device for a low-temperature blackbody radiation source according to claim 5, characterized in that, One end of the second branch (24) is connected to the main branch (21), and the other end is connected to the protective cavity. The second branch (24) is used to provide the protective cavity with room temperature dry nitrogen.

7. A protective device for a low-temperature blackbody radiation source according to claim 6, characterized in that, The cover (3) includes a cover plate (31) and a plug (32).

8. A protective device for a low-temperature blackbody radiation source according to claim 7, characterized in that, The cover plate (31) is provided with a measuring hole.

9. A protective device for a low-temperature blackbody radiation source according to claim 8, characterized in that, The measuring hole is coaxial with the opening end of the blackbody cavity (101).

10. A protective device for a low-temperature blackbody radiation source according to claim 9, characterized in that, The plug (32) can be inserted into the measuring hole.

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