A method of calibrating a thermometer

Abstract

This invention relates to a thermometer calibration method, belonging to the field of low-temperature radiation metrology calibration technology. It solves the problems of easy error and low accuracy in existing thermometer calibration techniques. This invention uses a low-temperature blackbody radiation device to calibrate the thermometer, including the following steps: Step S1: Stabilizing the temperature inside the blackbody cavity to the target temperature and isolating the cavity from the external environment; Step S2: Installing the thermometer; Step S3: Setting the calibration temperature point and gradually increasing the temperature inside the blackbody cavity from the lowest calibration temperature to the highest calibration temperature; Step S4: Collecting and recording data; Step S5: Processing and analyzing the data. This invention isolates the blackbody cavity from the external environment, preventing external influences on the temperature inside the cavity and maintaining a stable temperature. This avoids errors during thermometer calibration and improves the accuracy of temperature calibration.

Description

Technical Field

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

[0002] Thermometers play a crucial role in temperature measurement. In extremely cold aerospace environments, the application of cryogenic radiation thermometers is becoming increasingly widespread. To ensure the accuracy of cryogenic radiation thermometer measurements, calibration is essential to avoid excessive measurement errors that could lead to inaccurate temperature readings. Current technology typically uses cryogenic blackbodies for calibration, but the external environment can easily affect the temperature of the blackbodies during calibration, causing instability and resulting in significant errors during calibration, thus impacting the accuracy of temperature measurements. Summary of the Invention

[0003] Based on the above analysis, the present invention aims to provide a thermometer calibration method to solve the problems of easy error and low calibration accuracy in the prior art thermometer calibration.

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

[0005] A method for calibrating a thermometer, using a low-temperature blackbody radiation device, includes the following steps:

[0006] Step S1: Regulate the internal temperature of the blackbody cavity to a stable level below the target temperature, and isolate the internal temperature of the blackbody cavity from the external environment;

[0007] Step S2: Install the thermometer;

[0008] Step S3: Set the calibration temperature point and control the temperature inside the blackbody cavity to gradually increase from the lowest calibration temperature to the highest calibration temperature;

[0009] Step S4: Collect and record data;

[0010] Step S5: Process and analyze the data.

[0011] Furthermore, the process of regulating the internal temperature of the blackbody cavity to stabilize at the target temperature specifically includes: turning on the cooling system in the low-temperature blackbody radiation device, setting the target low-temperature value, causing the internal temperature of the blackbody cavity to drop to the target temperature, and maintaining stability after the internal temperature of the blackbody cavity reaches the target temperature to ensure that the temperature uniformity of the internal temperature of the blackbody cavity meets the specified standard.

[0012] Furthermore, the isolation of the blackbody cavity from the external environment specifically includes: adjusting the flow rate of dry nitrogen gas input into the isolation cavity through the gas path system to isolate the blackbody cavity from the external environment.

[0013] Furthermore, the regulation of the flow rate of dry nitrogen gas into the isolation chamber via the gas path system specifically includes: inputting low-temperature dry nitrogen gas with the same temperature as that inside the blackbody cavity into the first isolation zone via the gas path system to form a low-temperature barrier.

[0014] Furthermore, the method of adjusting the flow rate of dry nitrogen entering the isolation chamber through the gas path system specifically includes: inputting room temperature dry nitrogen into the second isolation zone through the gas path system, and mixing the room temperature dry nitrogen with the low temperature dry nitrogen from the first isolation zone to form mixed dry nitrogen, which flows into the third isolation zone, and then blowing nitrogen into the external environment through the third isolation zone.

[0015] Furthermore, the method of adjusting the flow rate of dry nitrogen entering the isolation chamber through the gas path system specifically includes: adjusting the flow rate of room temperature dry nitrogen entering the second isolation zone through the gas path system to adjust the temperature of the mixed dry nitrogen.

[0016] Furthermore, the installation of the thermometer specifically includes: installing the thermometer to be calibrated on the measuring hole on the sealing plate, ensuring that the temperature sensing part of the thermometer is in an effective heat exchange position with the blackbody radiation source, and connecting the thermometer to the data acquisition system.

[0017] Furthermore, the step of setting the calibration temperature point and controlling the temperature inside the blackbody cavity to gradually increase from the lowest calibration temperature to the highest calibration temperature specifically includes: while controlling the calibration temperature inside the blackbody cavity to gradually increase from the lowest calibration temperature to the highest calibration temperature, simultaneously adjusting the flow rate of low-temperature dry nitrogen gas input to the first isolation zone and the flow rate of room-temperature dry nitrogen gas input to the second isolation zone, thereby adjusting the temperature of the room-temperature dry nitrogen gas mixed with the low-temperature dry nitrogen gas from the first isolation zone.

[0018] Furthermore, the data acquisition and recording specifically includes: after each calibration temperature point has stabilized, acquiring and recording the thermometer's measured value at the calibration temperature point through a data acquisition system according to the sampling frequency specified in the standard.

[0019] Furthermore, the data processing and analysis specifically includes: comparing the measured value of the thermometer at each calibration temperature point with the calibration temperature value inside the set blackbody cavity, calculating the deviation between the two, and fitting the calibration curve of the thermometer based on the deviation values ​​of multiple calibration temperature points.

[0020] The technical solution of this invention can achieve at least one of the following effects:

[0021] (1) A thermometer calibration method of the present invention uses a low-temperature blackbody radiation device to calibrate the thermometer, comprising the following steps: Step S1: stabilizing the temperature of the inner cavity of the blackbody cavity to a target temperature and isolating the inner cavity of the blackbody cavity from the external environment; Step S2: installing the thermometer; Step S3: setting a calibration temperature point and controlling the temperature of the inner cavity of the blackbody cavity to gradually increase from the lowest calibration temperature to the highest calibration temperature; Step S4: collecting and recording data; Step S5: processing and analyzing the data. The present invention isolates the blackbody cavity from the external environment, preventing the external environment from affecting the temperature inside the blackbody cavity, thus maintaining a stable temperature inside the blackbody cavity, thereby avoiding errors during thermometer calibration and improving the accuracy of thermometer temperature calibration.

[0022] (2) The low-temperature blackbody radiation device used in this invention includes an isolation device, which includes an isolation body, a gas path system, and an end cap. The isolation body has an isolation cavity that extends through the isolation body. One end of the isolation cavity is connected to the opening end of the blackbody cavity, and the other end is a measuring end. The end cap is located at the measuring end of the isolation cavity. The isolation cavity is connected to an external dry nitrogen source through the gas path system. The gas path system is used to input low-temperature dry nitrogen and room-temperature dry nitrogen into the isolation cavity, thereby isolating the blackbody cavity from the external environment. This 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 the thermometer and improving the accuracy of temperature calibration of the thermometer.

[0023] (3) The isolation device used in this invention has a first isolation zone, a second isolation zone, and a third isolation zone in its isolation chamber. The first isolation zone, the second isolation zone, and the third isolation zone are arranged sequentially and are connected to the opening end of the blackbody cavity. The first isolation zone and the second isolation zone are connected by a gas path system. Low-temperature dry nitrogen is input to the first isolation zone and room-temperature dry nitrogen is input to the second isolation zone through the gas path system to form a temperature barrier to prevent external ambient air from entering the blackbody cavity and reduce temperature fluctuations within the blackbody cavity. By adjusting the amount of room-temperature dry nitrogen input to the second isolation zone, the temperature of the mixture of room-temperature dry nitrogen and low-temperature dry nitrogen from the first isolation zone is increased to adjust the temperature of the third isolation zone, so that the third isolation 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, preventing the external ambient temperature from penetrating the isolation chamber. This avoids the external environment from affecting the temperature within the blackbody cavity, keeps the temperature within the blackbody cavity stable, and avoids errors when calibrating the thermometer, thus improving the accuracy of temperature calibration and consequently improving the accuracy of temperature measurement.

[0024] (4) The isolation device used in this invention also includes a disturbance mechanism, which includes a power component and a disturbance component. The power component and the disturbance component are disposed inside the second jet nozzle. The disturbance component is connected to the power component and is driven by the power component to move. The disturbance component continuously changes the direction of the room temperature dry nitrogen blown out from the second jet nozzle, thereby agitating the room temperature dry nitrogen blown into the second isolation zone. This accelerates the mixing of the room temperature dry nitrogen with the low temperature dry nitrogen from the first isolation zone, improves the mixing efficiency and the mixing uniformity, and thus improves the efficiency of adjusting the temperature of the mixed dry nitrogen, thereby saving the use of dry nitrogen. At the same time, it can reduce the axial dimension of the second isolation zone, thereby avoiding the axial dimension of the isolation cavity being too long, which would cause inconvenience in use.

[0025] 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

[0026] 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.

[0027] Figure 1 This is a flowchart of the thermometer calibration process in Embodiment 1 of the present invention;

[0028] Figure 2 This is a schematic diagram of the isolation device according to Embodiment 2 of the present invention;

[0029] Figure 3 This is a cross-sectional view of the isolation device according to Embodiment 2 of the present invention;

[0030] Figure 4 This is a schematic diagram of the structure of the isolation body in Embodiment 2 of the present invention;

[0031] Figure 5 for Figure 4 Enlarged view of part A in the middle;

[0032] Figure 6 for Figure 4 Enlarged view of part B in the middle;

[0033] Figure 7 This is an exploded view of the disturbance mechanism of Embodiment 2 of the present invention;

[0034] Figure 8 for Figure 7 Enlarged view of part C.

[0035] Figure label:

[0036] 1. Blackbody source; 11. Shell; 12. Blackbody cavity; 2. Isolation device; 21. Isolation body; 211. First isolation zone; 2111. First buffer chamber; 2112. First confluence chamber; 2113. First jet nozzle; 2114. First connecting hole; 212. Second isolation zone; 2121. Second buffer chamber; 2122. Second confluence chamber; 2123. Second jet nozzle; 2124. Second connecting hole; 2125. Pilot hole; 2126. Air guide plate; 2 13. Third isolation zone; 2131. Pressure relief channel; 2132. Flange; 22. Gas system; 221. Main gas path; 222. Heat exchanger; 223. First branch gas line; 224. Second branch gas line; 23. End cap; 231. Sealing plate; 232. Sealing plug; 24. Disturbance mechanism; 241. Power assembly; 2411. Rotary slip ring; 2412. Fan blade; 242. Disturbance assembly; 2421. Gear; 2422. Drive block; 2423. Swing plate. Detailed Implementation

[0037] 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.

[0038] Example 1

[0039] In one specific embodiment of the present invention, a calibration method for a thermometer is disclosed, used for calibrating a low-temperature radiation thermometer, such as... Figure 1 As shown, the main steps include:

[0040] Step S1: Regulate the temperature of the inner cavity of the blackbody cavity 12 to a stable level below the target temperature, and isolate the inner cavity of the blackbody cavity 12 from the external environment;

[0041] Specifically, the internal temperature of the blackbody cavity 12 is reduced to the target temperature and maintained stable.

[0042] Furthermore, the low-temperature blackbody radiation device is placed in a temperature-stable and low-vibration environment, the cooling system in the low-temperature blackbody radiation device is turned on, the target low-temperature value is set, the inner cavity of the blackbody cavity 12 is lowered to the target temperature, and the inner cavity of the blackbody cavity 12 is kept stable after reaching the target temperature, so as to ensure that the temperature uniformity of the inner cavity of the blackbody cavity 12 meets the specified standard.

[0043] Specifically, by adjusting the flow rate of dry nitrogen gas entering the isolation chamber through the gas path system 22, the blackbody cavity 12 is isolated from the external environment to avoid the external environment affecting the temperature inside the blackbody cavity 12, thereby keeping the temperature inside the blackbody cavity 12 stable and avoiding errors when calibrating the thermometer, thus improving the accuracy of temperature calibration of the thermometer.

[0044] Furthermore, low-temperature dry nitrogen gas, at the same temperature as that inside the blackbody cavity 12, is input into the first isolation zone 211 through the gas path system 22, forming a low-temperature barrier; room-temperature dry nitrogen gas is input into the second isolation zone 212 through the gas path system 22, and the room-temperature dry nitrogen gas is mixed with the low-temperature dry nitrogen gas from the first isolation zone 211 to form mixed dry nitrogen gas, which flows into the third isolation zone 213, and nitrogen gas is blown out into the external environment through the third isolation zone 213, forming an environmental isolation zone; simultaneously, the flow rate of room-temperature dry nitrogen gas input into the second isolation zone 212 is adjusted through the gas path system 22 to regulate the temperature of the mixed dry nitrogen gas, in order to prevent The temperature of the mixed dry nitrogen is too low to prevent the nitrogen blown into the external environment from condensing and forming white fog. The first isolation zone 211, the second isolation zone 212, and the third isolation zone 213 form a low-temperature zone, a mixed temperature regulation zone, and an environmental isolation zone, respectively. This not only prevents the external ambient air from entering the blackbody cavity 12, but also isolates the external ambient temperature and prevents the external ambient temperature from penetrating the isolation cavity. This avoids the external environment from affecting the temperature inside the blackbody cavity 12, keeps the temperature inside the blackbody cavity 12 stable, and avoids errors when calibrating the thermometer, thus improving the accuracy of the temperature calibration of the thermometer.

[0045] Step S2: Install the thermometer;

[0046] Specifically, the thermometer to be calibrated is installed on the measuring hole on the sealing plate 231 to ensure that the temperature sensing part of the thermometer is in an effective heat exchange position with the blackbody radiation source, and the thermometer is connected to the data acquisition system to ensure that the data can be accurately transmitted and recorded.

[0047] Step S3: Set the calibration temperature point and control the temperature of the inner cavity of the blackbody cavity 12 to gradually increase from the lowest calibration temperature to the highest calibration temperature;

[0048] Specifically, the calibration temperature point is determined according to the accuracy requirements and calibration range of the thermometer. The calibration temperature point is set through the control system of the low-temperature blackbody radiation device, and the calibration temperature inside the blackbody cavity 12 is controlled to gradually increase from the lowest calibration temperature to the highest calibration temperature. During the process of controlling the calibration temperature inside the blackbody cavity 12 to gradually increase from the lowest calibration temperature to the highest calibration temperature, it is also necessary to simultaneously adjust the flow rate of low-temperature dry nitrogen gas input to the first isolation zone 211 and the flow rate of room-temperature dry nitrogen gas input to the second isolation zone 212, so as to adjust the temperature of the room-temperature dry nitrogen gas mixed with the low-temperature dry nitrogen gas from the first isolation zone 211, and avoid the nitrogen gas blown into the external environment from condensing with the external air to form white fog.

[0049] Step S4: Collect and record data;

[0050] Specifically, after each calibration temperature point stabilizes, the thermometer's measured value at that calibration temperature point is collected and recorded by the data acquisition system according to the sampling frequency specified in the standard.

[0051] Step S5: Process and analyze the data;

[0052] Specifically, the measured value of the thermometer at each calibration temperature point is compared with the calibration temperature value inside the set blackbody cavity 12, and the deviation between the two is calculated. Based on the deviation values ​​of multiple calibration temperature points, a calibration curve of the thermometer is fitted. This calibration curve reflects the relationship between the measurement error of the thermometer and the temperature in the low temperature range, thereby facilitating the correction of the thermometer so that the thermometer can measure accurate temperature values.

[0053] Example 2

[0054] In another specific embodiment of the present invention, a low-temperature blackbody radiation device for Example 1 is disclosed, such as... Figure 2 As shown, it includes a blackbody source 1 and an isolation device 2. The isolation device 2 is installed on the blackbody source 1 to prevent the external environment from affecting the temperature of the blackbody source 1, so as to keep the temperature of the blackbody source 1 stable and improve the accuracy of thermometer calibration.

[0055] Preferably, such as Figure 3 As shown, the blackbody source 1 includes a housing 11, a blackbody cavity 12, and a cooling system. The blackbody cavity 12 is installed inside the housing 11, and a low-temperature medium is filled between the blackbody cavity 12 and the housing 11. The cooling system is used to control the temperature of the low-temperature medium, thereby regulating the temperature inside the blackbody cavity 12 so that the temperature of the blackbody cavity 12 meets the target temperature requirement.

[0056] Preferably, the isolation device 2 includes an isolation body 21, a gas path system 22, and an end cap 23. The isolation body 21 has an isolation cavity that extends through the isolation body 21. One end of the isolation cavity is connected to the opening of the blackbody cavity 12, and the other end is a measuring end connected to the external environment for placing the thermometer to be calibrated. The isolation cavity is connected to an external dry nitrogen source through the gas path system 22, which is used to input dry nitrogen into the isolation cavity to isolate the blackbody cavity 12 from the external environment, preventing air from the external environment from entering the blackbody cavity 12 and isolating the external temperature, thereby avoiding the influence of the external environment on the temperature inside the blackbody cavity 12 and keeping the temperature inside the blackbody cavity 12 stable. The end cap 23 is located at the measuring end of the isolation cavity and is used for non-calibration purposes. The isolation chamber is sealed to form a closed cavity with the blackbody cavity 12, isolating the external environment from the blackbody cavity 12 and preventing foreign objects from entering and damaging it. During calibration, the end cap 23 is removed, the thermometer is placed at the measuring end, and aligned with the blackbody cavity 12 for calibration. In this embodiment, dry nitrogen gas is introduced into the isolation chamber through the gas path system 22 to isolate the blackbody cavity 12 from the external environment, preventing air from entering the blackbody cavity 12 and isolating it from the external temperature. This avoids the external environment affecting the temperature inside the blackbody cavity 12, keeping the temperature inside the blackbody cavity 12 stable, thus avoiding errors during thermometer calibration, improving the accuracy of temperature calibration, and consequently improving the accuracy of temperature measurement.

[0057] Preferably, the end cap 23 includes a sealing plate 231 and a sealing plug 232. The sealing plate 231 is installed on the measuring end inside the isolation cavity. The sealing plate 231 has a measuring hole, which is coaxial with the opening end of the blackbody cavity 12. The sealing plug 232 can be inserted into the measuring hole. During non-calibration, the sealing plug 232 is inserted into the measuring hole to seal the isolation cavity, so that the isolation cavity and the blackbody cavity 12 form a closed cavity to isolate the external environment from the blackbody cavity 12 and prevent foreign objects from entering the blackbody cavity 12 and causing damage to the blackbody cavity 12. During calibration, the sealing plug 232 is removed, and the thermometer is aligned with the measuring hole to calibrate the blackbody cavity 12, which facilitates operation.

[0058] Preferably, such as Figure 4As shown, the isolation chamber is provided with a first isolation zone 211, a second isolation zone 212, and a third isolation zone 213, which are sequentially connected. The first isolation zone 211 is connected to the opening end of the blackbody cavity 12 and is also connected to the gas path system 22. Low-temperature dry nitrogen gas with the same temperature as the inside of the blackbody cavity 12 is input into the first isolation zone 211 through the gas path system 22 to form a low-temperature barrier, thereby preventing external ambient air from entering the blackbody cavity 12 and reducing temperature fluctuations inside the blackbody cavity 12. The second isolation zone 212 is connected to the gas path system 22. Room-temperature dry nitrogen gas is input into the second isolation zone 212 through the gas path system 22, and the room-temperature dry nitrogen gas is mixed with the low-temperature dry nitrogen gas from the first isolation zone 211 to form mixed dry nitrogen gas, and the temperature of the mixed dry nitrogen gas is regulated. The third isolation zone 213 is used to collect the mixed dry nitrogen gas and blow it out to the external environment. This creates an environmental isolation zone, further preventing external air from entering the blackbody cavity 12 through the isolation chamber. Simultaneously, by adjusting the flow rate of room-temperature dry nitrogen, the temperature of the mixed dry nitrogen is adjusted, preventing the nitrogen blown from the third isolation zone 213 into the external environment from condensing and forming white mist. This prevents instability in the calibration environment during thermometer calibration, thus avoiding interference with the calibration. Furthermore, the sequentially set first isolation zone 211, second isolation zone 212, and third isolation zone 213 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 12 but also isolates the external ambient temperature, preventing it from penetrating the isolation chamber. This avoids the external environment affecting the temperature inside the blackbody cavity 12, maintaining a stable temperature within the cavity and preventing errors during thermometer calibration. This improves the accuracy of thermometer temperature calibration and, consequently, the accuracy of temperature measurement.

[0059] Preferably, the inner wall of the third isolation zone 213 is provided with a pressure relief channel 2131. The pressure relief channel 2131 can maintain the pressure balance between the isolation chamber 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 12, thus avoiding the impact on the temperature inside the blackbody cavity 12.

[0060] Preferably, the inner wall of the measuring end of the third isolation zone 213 is provided with multiple flanges 2132. By installing end caps 23 of different specifications on the flanges, the distance between the measuring hole and the blackbody cavity 12 can be adjusted, thereby enabling the measurement of thermometers with different focal lengths.

[0061] Preferably, such as Figure 5As shown, the first isolation zone 211 has a first buffer chamber 2111, a first confluence chamber 2112, and a first jet outlet 2113 on its cavity wall. The first buffer chamber 2111, the first confluence chamber 2112, and the first jet outlet 2113 are connected in sequence. The first buffer chamber 2111 is provided with a first connector, which is connected to the gas path system 22. Low-temperature dry nitrogen gas is introduced into the first buffer chamber 2111 through the gas path system 22. The first confluence chamber 2112 is used to mix, disperse, and homogenize the low-temperature dry nitrogen gas. A jet nozzle 2113 is connected to the isolation chamber and is used to blow the low-temperature dry nitrogen gas, which has been mixed, dispersed and homogenized in the first confluence chamber 2112, into the isolation chamber, and form a low-temperature gas curtain in the isolation chamber to prevent external ambient air, temperature and room-temperature dry nitrogen gas in the second isolation zone 212 from entering the blackbody cavity 12, reduce temperature fluctuations in the blackbody cavity 12, keep the temperature in the blackbody cavity 12 stable, thereby avoiding errors when calibrating the thermometer, improving the accuracy of temperature calibration of the thermometer, and thus improving the accuracy of temperature measurement by the thermometer.

[0062] Preferably, the first buffer chamber 2111 and the first confluence chamber 2112 are both annular cavities, and the first jet nozzle 2113 is an annular jet nozzle; a first partition is provided between the first buffer chamber 2111 and the first confluence chamber 2112, and the first partition is provided with a plurality of first connecting holes 2114, through which the first confluence chamber 2112 communicates with the first buffer chamber 2111; since the diameter of the first connecting hole 2114 is small, the low-temperature dry nitrogen gas input through the gas path system 22 first fills the first buffer chamber 2111, and then enters the first confluence chamber 2112 through the plurality of first connecting holes 2114. After being mixed, dispersed and homogenized in the first confluence chamber 2112, it is blown into the isolation chamber from the first jet nozzle 2113 to form a continuous low-temperature gas curtain, thereby forming a continuous temperature barrier, which can effectively prevent external ambient air from entering the blackbody cavity 12, and at the same time prevent external ambient temperature from radiating to the blackbody cavity 12, thereby reducing temperature fluctuations in the blackbody cavity 12.

[0063] Preferably, the first jet nozzle 2113 is tilted away from the blackbody cavity 12, so that the point where the low-temperature dry nitrogen gas converges in the isolation chamber is far away from the blackbody cavity 12. This prevents the low-temperature dry nitrogen gas from converging and mixing with the room-temperature dry nitrogen gas in the second isolation zone 212, thus further reducing the impact on the temperature inside the blackbody cavity 12 and keeping the temperature inside the blackbody cavity 12 stable. This avoids errors when calibrating the thermometer, further improves the accuracy of temperature calibration of the thermometer, and further improves the accuracy of temperature measurement by the thermometer.

[0064] 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 buffer chamber 2111, thereby ensuring that the low-temperature drying nitrogen blown into the isolation chamber from the first jet port 2113 forms a continuous low-temperature gas curtain.

[0065] Preferably, such as Figure 6 As shown, the second isolation zone 212 has a second buffer chamber 2121, a second confluence chamber 2122, and a second jet outlet 2123 on its cavity wall. The second buffer chamber 2121, the second confluence chamber 2122, and the second jet outlet 2123 are sequentially connected. The second buffer chamber 2121 is provided with a second connector, which is connected to the gas path system 22. Room temperature dry nitrogen is introduced into the second buffer chamber 2121 through the gas path system 22. The second confluence chamber 2122 is used to mix, disperse, and homogenize the room temperature dry nitrogen. The second jet outlet 2123 is connected to... The isolation chamber connection is used to blow room-temperature dry nitrogen gas, which has been mixed, dispersed, and homogenized in the second confluence chamber 2122, into the isolation chamber, and to mix the room-temperature dry nitrogen gas with the low-temperature dry nitrogen gas from the first isolation zone 211 to form mixed dry nitrogen gas. The temperature of the mixed dry nitrogen gas is adjusted and then merged into the third isolation zone 213. This prevents the nitrogen gas blown from the third isolation zone 213 into the external environment from condensing with the external air to form white mist, thereby preventing the calibration environment from becoming unstable during thermometer calibration and interfering with the calibration of the thermometer, and further ensuring the accuracy of the temperature calibration of the thermometer.

[0066] Preferably, the second buffer chamber 2121 and the second confluence chamber 2122 are both annular cavities, and the second jet nozzle 2123 is an annular jet nozzle; a second partition is provided between the second buffer chamber 2121 and the second confluence chamber 2122, and the second partition is provided with a plurality of second connecting holes 2124, through which the second confluence chamber 2122 communicates with the second buffer chamber 2121; since the diameter of the second connecting holes 2124 is small, the room temperature dry nitrogen gas input through the gas path system 22 first fills the second buffer chamber 2121, and then enters the second confluence chamber 2122 through the plurality of second connecting holes 2124, where it is mixed, dispersed and homogenized. Then, the gas is blown into the isolation chamber from the second jet port 2123, forming a room temperature air curtain. This further forms a temperature barrier, which can effectively prevent external ambient air and temperature from entering the blackbody cavity 12, reducing temperature fluctuations within the blackbody cavity 12. At the same time, the room temperature dry nitrogen gas mixes with the low temperature dry nitrogen gas from the first isolation zone 211 to form mixed dry nitrogen gas, and the temperature of the mixed dry nitrogen gas is adjusted so that the temperature of the mixed dry nitrogen gas flowing into the third isolation zone 213 is close to room temperature. This prevents the external air from condensing and forming white fog when it encounters the mixed dry nitrogen gas flowing out of the isolation chamber during thermometer calibration, which would cause instability in the calibration environment and interfere with the thermometer calibration, thus further ensuring the accuracy of the thermometer's temperature calibration.

[0067] Preferably, the second jet nozzle 2123 is tilted away from the blackbody cavity 12, so that the confluence point of the room temperature dry nitrogen in the isolation 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 from entering the blackbody cavity 12, thereby further reducing the temperature influence inside the blackbody cavity 12, keeping the temperature inside the blackbody cavity 12 stable, thereby avoiding errors when calibrating the thermometer, further improving the accuracy of temperature calibration of the thermometer, and further improving the accuracy of temperature measurement by the thermometer.

[0068] Preferably, the second jet nozzle 2123 is provided with a pilot hole 2125, which is inclined toward the blackbody cavity 12. The pilot hole 2125 is used to pre-mix 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.

[0069] Preferably, multiple pilot holes 2125 are provided, and the multiple pilot holes 2125 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 regulating the temperature of the dry nitrogen.

[0070] Preferably, the second jet nozzle 2123 is further provided with a guide plate 2126, 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 pilot hole 2125.

[0071] 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 buffer chamber 2121, thereby ensuring that the room temperature dry nitrogen blown into the isolation chamber from the second jet port 2123 can quickly mix with the low temperature dry gas after convergence, thereby further improving the efficiency of regulating the temperature of dry nitrogen.

[0072] Preferably, the gas path system 22 includes a main gas path 221, a heat exchanger 222, a first branch gas path 223, and a second branch gas path 224. The main gas path 221 is connected to an external ambient temperature dry nitrogen source. One end of each of the first branch gas path 223 and the second branch gas path 224 is connected to the main gas path 221. The other end of the first branch gas path 223 is connected to a first connector via the heat exchanger 222 to provide low-temperature dry nitrogen to the first isolation zone 211. The other end of the second branch gas path 224... Connected to the second connector, it is used to provide room temperature dry nitrogen to the second isolation zone 212; the heat exchanger 222 is located in the low temperature medium in the shell 11, and is used to cool the dry nitrogen in the first branch pipeline 223, so that the temperature of the low temperature dry nitrogen supplied from the first branch pipeline 223 to the first isolation zone 211 is consistent with the temperature inside the blackbody cavity 12, thereby avoiding the influence on the temperature inside the blackbody cavity 12, and thus maintaining the temperature stability inside the blackbody cavity 12 to ensure the calibration accuracy of the thermometer.

[0073] Preferably, the first branch gas pipeline 223 is provided with a first regulating valve, which is used to regulate the flow rate of low-temperature dry nitrogen gas input into the first isolation zone 211.

[0074] Preferably, a second regulating valve is provided on the second branch gas pipeline 224. The second regulating valve is used to regulate the flow rate of room temperature dry nitrogen gas input to the second isolation zone 212. 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 isolation zone 213 to the external environment will not condense with the external air to form white mist.

[0075] Preferably, such as Figure 6As shown, the isolation device 2 also includes a disturbance mechanism 24, which is disposed in the second jet port 2123. The disturbance mechanism 24 is used to disturb the room temperature dry nitrogen gas blown into the second isolation zone 212, so that the disturbed room temperature dry nitrogen gas can be quickly mixed with the low temperature dry nitrogen gas from the first isolation zone 211, 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 isolation zone 212, thereby avoiding the isolation chamber from being too long and causing inconvenience in use.

[0076] Preferably, such as Figure 7 As shown, the disturbance mechanism 24 includes a power component 241 and a disturbance component 242. The disturbance component 242 is connected to the power component 241. The power component 241 drives the disturbance component 242 to move. The disturbance component 242 continuously changes the direction of the room temperature dry nitrogen gas blown out from the second jet port 2123, thereby agitating the room temperature dry nitrogen gas blown into the second isolation zone 212. This accelerates the mixing of the room temperature dry nitrogen gas with the low temperature dry nitrogen gas from the first isolation zone 211, 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 also reduce the axial dimension of the second isolation zone 212, thereby avoiding the axial dimension of the isolation chamber being too long, which would cause inconvenience in use.

[0077] Preferably, multiple disturbance components 242 are provided, and the multiple disturbance components 242 are evenly arranged circumferentially within the second jet port 2123, thereby improving the uniformity and comprehensiveness of the agitation of the room temperature dry nitrogen gas blown into the second isolation zone 212, and enabling the room temperature dry nitrogen gas to quickly mix with the low temperature dry nitrogen gas from the first isolation zone 211.

[0078] Preferably, the power assembly 241 includes a rotating slip ring 2411 and a fan blade 2412. The rotating slip ring 2411 is fitted inside the second jet port 2123 and can rotate around the second jet port 2123. The fan blade 2412 is fixedly mounted on the rotating slip ring 2411. Multiple fan blades 2412 are provided and are evenly arranged around the circumference. When room temperature dry nitrogen is blown into the isolation chamber from the second confluence chamber 2122 through the second jet port 2123, the airflow pushes the fan blade 2412 to drive the rotating slip ring 2411 to rotate.

[0079] Preferably, the rotating slip ring 2411 is provided with driving teeth.

[0080] Preferably, such as Figure 8As shown, the disturbance component 242 includes a gear 2421, a drive block 2422, a swing plate 2423, and a rotating shaft. The gear 2421 is rotatably disposed within the second jet nozzle 2123 and meshes with the drive teeth on the rotating slip ring 2411. The drive block 2422 is fixedly mounted on the gear 2421 and is eccentrically disposed on the end face of the gear 2421. The swing plate 2423 is rotatably mounted within the second jet nozzle 2123 via the rotating shaft and can intermittently contact the drive block 2422, thereby driving the swing plate 2423 to swing. The movement of the swing plate 2423 continuously changes the direction of the room-temperature dry nitrogen gas blown out from the second jet port 2123, thereby agitating the room-temperature dry nitrogen gas blown into the second isolation zone 212. This accelerates the mixing with the low-temperature dry nitrogen gas from the first isolation zone 211, improving mixing efficiency and uniformity. This, in turn, improves 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 isolation zone 212, thereby avoiding the isolation chamber from being too long and causing inconvenience in use.

[0081] Preferably, the disturbance component 242 further includes a return spring (not shown in the figure). The return spring is sleeved on the rotating shaft, with one end fixedly connected to the second jet port 2123 and the other end fixedly connected to the swing plate 2423. This allows the swing plate 2423 to maintain a certain initial angle, and after the swing plate 2423 swings, it can automatically return to the initial angle, thereby increasing the swing amplitude of the swing plate 2423. This, in turn, increases the agitation amplitude of the room temperature dry nitrogen blown into the second isolation zone 212, further accelerating the mixing with the low temperature dry nitrogen from the first isolation zone 211, and further improving the mixing efficiency and mixing uniformity.

[0082] 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 method for calibrating a thermometer, characterized in that, The thermometer is calibrated using a low-temperature blackbody radiation device, including the following steps: Step S1: Adjust the temperature of the inner cavity of the blackbody cavity (12) to the target temperature and isolate the inner cavity of the blackbody cavity (12) from the external environment; Step S2: Install the thermometer; Step S3: Set the calibration temperature point and control the temperature of the inner cavity of the blackbody cavity (12) to gradually increase from the lowest calibration temperature to the highest calibration temperature; Step S4: Collect and record data; Step S5: Process and analyze the data.

2. The calibration method for a thermometer according to claim 1, characterized in that, The method of regulating the inner cavity of the blackbody cavity (12) to stably drop to the target temperature specifically includes: turning on the cooling system in the low-temperature blackbody radiation device, setting the target low temperature value, so that the inner cavity of the blackbody cavity (12) drops to the target temperature, and maintaining stability after the inner cavity of the blackbody cavity (12) reaches the target temperature, so as to ensure that the temperature uniformity of the inner cavity of the blackbody cavity (12) meets the specified standard.

3. The calibration method for a thermometer according to claim 2, characterized in that, The method of isolating the inner cavity of the blackbody cavity (12) from the external environment specifically includes: adjusting the flow rate of dry nitrogen gas input into the isolation cavity through the gas path system (22) to isolate the blackbody cavity (12) from the external environment.

4. The calibration method for a thermometer according to claim 3, characterized in that, The regulation of the flow rate of dry nitrogen gas into the isolation chamber through the gas path system (22) specifically includes: inputting low-temperature dry nitrogen gas with the same temperature as the blackbody cavity (12) into the first isolation zone (211) through the gas path system (22) to form a low-temperature barrier.

5. The calibration method for a thermometer according to claim 4, characterized in that, The method of adjusting the flow rate of dry nitrogen entering the isolation chamber through the gas path system (22) further includes: inputting room temperature dry nitrogen into the second isolation zone (212) through the gas path system (22), and mixing the room temperature dry nitrogen with the low temperature dry nitrogen from the first isolation zone (211) to form mixed dry nitrogen, which flows into the third isolation zone (213), and then blowing nitrogen into the external environment through the third isolation zone (213).

6. The calibration method for a thermometer according to claim 5, characterized in that, The method of adjusting the flow rate of dry nitrogen entering the isolation chamber through the gas path system (22) further includes: adjusting the flow rate of room temperature dry nitrogen entering the second isolation zone (212) through the gas path system (22) to adjust the temperature of the mixed dry nitrogen.

7. The calibration method for a thermometer according to claim 1, characterized in that, The installation of the thermometer specifically includes: installing the thermometer to be calibrated on the measuring hole on the sealing plate (231), ensuring that the temperature sensing part of the thermometer is in an effective heat exchange position with the blackbody radiation source, and connecting the thermometer to the data acquisition system.

8. The calibration method for a thermometer according to claim 1, characterized in that, The setting of the calibration temperature point and the control of the temperature inside the blackbody cavity (12) to gradually increase from the lowest calibration temperature to the highest calibration temperature specifically includes: while controlling the calibration temperature inside the blackbody cavity (12) to gradually increase from the lowest calibration temperature to the highest calibration temperature, simultaneously adjusting the flow rate of low-temperature dry nitrogen gas input to the first isolation zone (211) and the flow rate of room-temperature dry nitrogen gas input to the second isolation zone (212), thereby adjusting the temperature after the room-temperature dry nitrogen gas and the low-temperature dry nitrogen gas from the first isolation zone (211) are mixed.

9. The calibration method for a thermometer according to claim 1, characterized in that, The data acquisition and recording specifically includes: after each calibration temperature point has stabilized, acquiring and recording the thermometer's measured values ​​at the calibration temperature point through a data acquisition system according to the sampling frequency specified in the standard.

10. A method for calibrating a thermometer according to claim 1, characterized in that, The data processing and analysis specifically includes: comparing the measured value of the thermometer at each calibration temperature point with the calibration temperature value inside the set blackbody cavity (12), calculating the deviation between the two, and fitting the calibration curve of the thermometer based on the deviation values ​​of multiple calibration temperature points.

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