Adjustable thermostat for thermometer calibration

Abstract

The invention provides an adjustable thermostat for thermometer calibration, and belongs to the technical field of device testing, and the adjustable thermostat specifically comprises an outer shell, a soaking block, a first heat insulation layer and a heating assembly. The soaking block is located in the outer shell, the first heat insulation layer surrounds the periphery of the soaking block, a cold source is arranged between the first heat insulation layer and the outer shell, and the heating assembly is located in the first heat insulation layer; a calibration containing cavity is formed in the soaking block, a thermometer is inserted into the calibration containing cavity, a temperature standard reference assembly is further arranged in the soaking block, a closed heat insulation cavity is formed in the soaking block, the heat insulation cavity surrounds the periphery of the calibration containing cavity and the periphery of the temperature standard reference assembly, and the temperature standard reference assembly is used for detecting the internal temperature of the soaking block in real time. The soaking block is provided with an extension pipe communicating with the calibration containing cavity, one end of the extension pipe extends to the outer side of the top end of the outer shell, and the extension pipe is provided with a rapid cooling channel communicating with the interior of the outer shell. The thermometer calibration accuracy and efficiency are improved.

Description

Technical Field

[0001] This application relates to the field of device testing, and in particular to an adjustable thermostat for thermometer calibration. Background Technology

[0002] Cryotherms, as core components for accurately measuring low-temperature environments, are widely used in several key fields such as ultra-low temperature storage in biomedicine, aerospace environment simulation, and laboratory low-temperature experiments. The accuracy of their measurement data directly affects product quality control, experimental result reliability, and industrial production safety. To ensure the accuracy of cryotherm readings, regular calibration and traceability are required using dedicated calibration equipment to provide a stable and controllable low-temperature field. Currently, cryotherm calibration equipment on the market generally suffers from excessive size. Most devices are designed to accommodate long-rod or industrial-grade thermometers, resulting in complex overall structures and significant space requirements, making it difficult to meet the calibration needs of short-rod cryotherms in confined spaces such as laboratories. Regarding temperature control performance, existing equipment often struggles to balance temperature stability and adjustment efficiency. Some devices employ multi-layer insulation designs to pursue higher temperature control accuracy, leading to slow temperature adjustment, especially when significant cooling is required to switch calibration temperature points. Meanwhile, some miniaturized devices suffer from large temperature fluctuations and insufficient temperature control accuracy due to the reduced volume of the heat spreader, which makes the temperature susceptible to influence from the cold source and heating components. Summary of the Invention

[0003] In view of this, this application provides an adjustable thermostat for thermometer calibration, which solves the problems in the prior art and improves calibration accuracy and efficiency.

[0004] The adjustable thermostat for thermometer calibration provided in this application adopts the following technical solution: An adjustable thermostat for thermometer calibration includes a housing, a heat spreader, a first insulation layer, and a heating assembly. The heat spreader is located inside the outer shell, the first heat insulation layer surrounds the outer periphery of the heat spreader, a cold source is provided between the first heat insulation layer and the outer shell, and the heating component is located inside the first heat insulation layer for heating the heat spreader. The heat spreader block is provided with a calibration receiving cavity for inserting a thermometer. The heat spreader block is also provided with a temperature standard reference component. The heat spreader block has a closed heat insulation cavity inside, which surrounds the calibration receiving cavity and the temperature standard reference component. The temperature standard reference component is used to detect the internal temperature of the heat spreader block in real time. The heat spreader block is provided with an extension tube that connects to the calibration receiving cavity. One end of the extension tube extends to the outer side of the top of the outer shell. The extension tube is provided with a rapid cooling channel that communicates with the inside of the outer shell.

[0005] Optionally, the cold source is a liquefied gas.

[0006] Optionally, the rapid cooling channel includes a through hole disposed on the side wall of the extension tube.

[0007] Optionally, the first insulation layer includes a storage tank located within the outer casing, and the storage tank is provided with a vent pipe extending out of the outer casing.

[0008] Optionally, the vent pipe is used to connect to a vacuum pump or an inert gas source.

[0009] Optionally, the temperature standard reference component and the heating component are connected to a controller, which adjusts the thermal power of the heating component according to the temperature detected by the temperature standard reference component.

[0010] Optionally, the heating assembly includes a heating cover surrounding the heat spreader, the heating cover including a plurality of heating units covering the outer surface of the heat spreader, and the controller independently controls the start / stop or heating power of each heating unit.

[0011] Optionally, a second heat insulation layer is provided around the outer periphery of the heating cover.

[0012] Optionally, a temperature monitoring unit is provided inside the heat exchange block near the top, the temperature monitoring unit is used to monitor the temperature of the top of the heat exchange block in real time, and a solenoid valve and / or delivery pump is provided on the rapid cooling channel, the solenoid valve and / or delivery pump and the temperature monitoring unit are electrically connected to the controller; The controller is used to control the solenoid valve and / or delivery pump according to the temperature monitored by the temperature monitoring unit to regulate the cold source medium entering the extension pipe.

[0013] Optionally, the calibration receiving cavity may have multiple chambers.

[0014] In summary, this application includes the following beneficial technical effects: To calibrate short-rod cryogenic thermometers, a miniaturized adjustable cryogenic thermostat was designed, specifically through a reduction in the volume of the outer casing and the heat spreader. To improve the temperature stability of the heat spreader, a first insulation layer was first placed between the heating element and the cold source to slow down the rate at which the cold source affects the temperature of the heat spreader. Furthermore, an insulation cavity was designed between the calibration housing cavity, the outer periphery of the temperature standard reference component, and the heating element to further reduce the rate at which the heating element affects the temperature of the heat spreader, simplifying temperature control and ensuring the accuracy of temperature adjustment, thereby improving calibration precision.

[0015] Meanwhile, by setting up a rapid cooling channel, this application allows the cold source medium in the outer casing to reach the uniformly heated interior through the rapid cooling channel and extension tube under the action of natural flow or active transport when the temperature needs to be reduced for calibration and the temperature reduction is large. This design makes up for the disadvantage of slow temperature change caused by the need to achieve precise temperature control and improves calibration efficiency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the external structure of the adjustable thermostat used for thermometer calibration in this application. Figure 2 This is a cross-sectional view of the adjustable thermostat used for thermometer calibration in this application. Figure 3 This is a cross-sectional view from another angle of the adjustable thermostat used for thermometer calibration in this application; Figure 4 This is an exploded structural diagram of the adjustable thermostat used for thermometer calibration in this application. Figure 5 This is a schematic diagram of the U-shaped heating strip of this application; Figure 6 This is a schematic diagram showing the distribution of through holes in an embodiment of this application.

[0018] Explanation of reference numerals in the attached drawings: 1. Outer shell; 11. Liquefied gas; 2. Heat spreader; 21. Calibration chamber; 22. Extension tube; 23. Through hole; 24. Insulation chamber; 25. Temperature standard reference component; 3. First insulation layer; 31. Storage tank; 32. Vent pipe; 33. Electrical conduit; 4. Heating component; 41. Heating unit; 42. U-shaped heating strip; 5. Temperature monitoring unit; 51. Cold source delivery pipeline. Detailed Implementation

[0019] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0020] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0022] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0023] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0024] This application provides an adjustable thermostat for thermometer calibration.

[0025] like Figures 1 to 4 As shown, an adjustable thermostat for thermometer calibration includes an outer shell 1, a heat spreader 2, a first heat insulation layer 3, and a heating component 4.

[0026] The heat spreader 2 is located inside the outer shell 1. The first heat insulation layer 3 surrounds the outer periphery of the heat spreader 2. A cold source is provided between the first heat insulation layer 3 and the outer shell 1. The heating component 4 is located inside the first heat insulation layer 3 and is used to heat the heat spreader 2. The heat spreader 2 is provided with a calibration cavity 21 for inserting a thermometer. The heat spreader 2 is also provided with a temperature standard reference component 25. The heat spreader 2 is provided with a closed heat insulation cavity 24 inside. The heat insulation cavity 24 surrounds the outer periphery of the calibration cavity 21 and the temperature standard reference component 25. The temperature standard reference component 25 is used to detect the internal temperature of the heat spreader 2 in real time. The heat spreader 2 is provided with an extension tube 22 that communicates with the calibration cavity 21. One end of the extension tube 22 extends to the outer side of the top of the outer shell 1. The extension tube 22 is provided with a rapid cooling channel that communicates with the inside of the outer shell 1.

[0027] In this embodiment, the outer shell 1 and the heat spreader 2 are cylindrical. The height of the outer shell 1 ranges from 500 to 2000 mm. The heat spreader 2 is made of metal, such as aluminum, copper, oxygen-free copper, or aluminum alloy. The heat spreader 2 is fixed inside the outer shell 1 by a connector, and the bottom of the heat spreader 2 is spaced apart from the bottom of the outer shell 1. The height of the heat spreader 2 can range from 30% to 70% of the height of the outer shell 1. The volume of the space between the first insulation layer 3 and the outer shell 1 can range from 5 to 20 liters. The insulation cavity 24 includes an annular cavity region corresponding to the circumferential sidewall of the heat spreader 2 and a columnar cavity region corresponding to the bottom of the heat spreader 2.

[0028] The small adjustable low-temperature thermostat of this application is suitable for calibrating short-rod low-temperature thermometers. The heating element 4 is adjusted to bring the heat spreader 2 to a preset calibration temperature. The thermometer to be calibrated is then inserted into the calibration cavity 21 via the extension tube 22. The depth of the calibration cavity 21 within the heat spreader 2 is 50-90% of the height of the heat spreader 2. The temperature of the thermometer to be calibrated is compared with the temperature detected by the temperature standard reference element 25 to achieve calibration. To calibrate short-rod cryogenic thermometers, a miniaturized adjustable cryogenic thermostat was designed, specifically by reducing the volume of the outer shell 1 and the heat spreader 2. As the volume of the heat spreader 2 decreases, its temperature becomes more susceptible to the influence of the heating element 4 and the cold source, leading to temperature instability. To improve the temperature stability of the heat spreader 2, a first insulation layer 3 is installed between the heating element 4 and the cold source to reduce the rate at which the cold source affects the temperature of the heat spreader 2. Furthermore, an insulation cavity 24 is designed between the outer periphery of the calibration housing 21 and the temperature standard reference component 25 and the heating element 4, further reducing the rate at which the heating element 4 affects the temperature of the heat spreader 2, simplifying temperature control, ensuring temperature adjustment accuracy, and thus improving calibration precision. Meanwhile, by setting up a rapid cooling channel, this application allows the cold source medium in the outer casing 1 to reach the uniformly heated interior through the rapid cooling channel and extension tube 22 under the action of natural flow or active transport when the temperature needs to be reduced for calibration and the temperature reduction is large. This design makes up for the disadvantage of slow temperature change caused by the need to achieve precise temperature control and improves calibration efficiency.

[0029] Therefore, this application reduces the difficulty of temperature control, ensures the accuracy of temperature control, and meets the requirement of rapid and large temperature adjustment.

[0030] The calibration chamber 21 described in this application has multiple chambers, which can calibrate multiple thermometers simultaneously. The temperature standard reference component 25 can be a temperature sensor placed inside the heat spreader 2, or a standard thermometer placed in the calibration chamber 21.

[0031] In this embodiment, the cold source is a liquid liquefied gas 11, which can be liquid oxygen, liquid carbon dioxide, liquid air, liquid helium, or liquid nitrogen. In other embodiments, the outer casing 1 can be connected to a refrigerator via a pipe, and the refrigerator can supply low-temperature air into the casing. The evaporator of the refrigerator can also be installed inside the outer casing 1. Insulation cotton can be wrapped around the outside of the outer casing 1. The temperature range of the small low-temperature adjustable thermostat of this application is -196 to 0℃ or -196 to 50℃, not limited to the above upper temperature limit. It can maintain constant temperature control at any temperature point within the continuously adjustable range, with a control resolution of 1 mK, a temperature field uniformity within 10 mK, and a stability within 10 mK.

[0032] The first heat insulation layer 3 includes a storage tank 31 located within the outer shell 1. The storage tank 31 is provided with a vent pipe 32 extending out of the outer shell 1. The vent pipe 32 is used to connect to a vacuum pump or an inert gas source. Air is extracted from the storage tank 31 by the vacuum pump to maintain the storage tank 31 under negative pressure, with a vacuum degree of 1×10⁻³ Pa to 1×10⁻¹ Pa, or inert gas is introduced into the storage tank 31.

[0033] The temperature standard reference component 25 and the heating component 4 are connected to a controller, which is used to adjust the thermal power of the heating component 4 according to the temperature detected by the temperature standard reference component 25.

[0034] In this embodiment, the storage tank 31 includes a tank body and a top cover. Both the top cover and the tank body have connecting flanges at their openings, which are sealed together. The top cover has perforations for the extension pipe 22 and the vent pipe 32 to pass through. Both the extension pipe 22 and the vent pipe 32 are sealed and fixedly connected to the top cover. The vent pipe 32 passes through the top wall of the outer shell 1 and is sealed and fixedly connected to the top wall of the outer shell 1. The storage tank 31 is fixed inside the outer shell 1 via the vent pipe 32, and the bottom of the storage tank 31 and the inner bottom wall of the outer shell 1 are spaced apart. The top cover also has an electrical port, to which an electrical conduit 33 is sealed and fixedly connected. The electrical conduit 33 passes through the top of the outer shell 1 and is fixedly connected to the top of the outer shell 1. Cables for components such as the heating element 4 pass through the electrical conduit 33.

[0035] The heating assembly 4 includes a heating cover that wraps around the periphery of the heat spreader 2. The heating cover includes a plurality of heating units 41 that cover the outer surface of the heat spreader 2. The controller independently controls the start / stop or heating power of each heating unit 41.

[0036] In one embodiment, the heating cover includes a heating unit 41 covering the top of the heat spreader 2, a plurality of annular heating units 41 covering the sidewalls of the heat spreader 2 and arranged in a vertical direction, and a heating unit 41 covering the bottom wall of the heat spreader 2. Each heating unit 41 is independently controlled by a controller. The controller adjusts the total power of the heating assembly 4 by independently controlling the start and stop of each heating unit 41. Furthermore, the controller further refines the control of the power of the heating assembly 4 by independently controlling the heating power of each started heating unit 41. The heating unit 41 can be a heating film. Figure 5As shown, in another embodiment, the heating cover includes a plurality of U-shaped heating strips 42 evenly distributed around the circumference of the heat spreader 2. Each U-shaped heating strip 42 has a fan-shaped top and bottom and a rectangular middle section. The plurality of U-shaped heating strips 42 are divided into several groups of U-shaped heating strips 42. Each group of U-shaped heating strips 42 constitutes a heating unit 41. Each U-shaped heating strip 42 in the same group is evenly distributed around the circumference of the heat spreader 2. By controlling the number of heating units 41 that are activated, the total power of the heating assembly 4 is changed. Moreover, each U-shaped heating strip 42 of each heating unit 41 is evenly distributed on the outer periphery of the heat spreader 2, ensuring the uniformity of heating of the heat spreader 2 and improving the calibration accuracy. The U-shaped heating strip 42 can be a heating film.

[0037] The heating cover is fitted with a second heat insulation layer, which can be thermal insulation cotton. This further isolates the cold source and the heat source, ensuring the uniformity of their mixing, while concentrating the heat source internally to reduce heat waste.

[0038] A temperature monitoring unit 5 is located inside the heat spreader 2 near its top. This unit monitors the temperature at the top of the heat spreader 2 in real time. A solenoid valve and / or a delivery pump are installed on the rapid cooling channel. The solenoid valve and / or delivery pump, along with the temperature monitoring unit 5, are electrically connected to a controller. The controller controls the solenoid valve and / or delivery pump based on the temperature monitored by the temperature monitoring unit 5 to regulate the flow of the cold source medium into the extension tube 22. The temperature monitoring unit 5 is a temperature sensor; since the cold source enters the heat spreader 2 from the top of the calibration cavity 21, the temperature at the top of the heat spreader 2 changes first, thus providing early detection.

[0039] like Figures 2 to 4 As shown, in one embodiment, the rapid cooling channel is a cold source delivery pipe 51 disposed on the top of the outer casing 1. One end of the cold source delivery pipe 51 extends into the bottom of the inner casing 1, and the other end connects to the extension pipe 22 extending out of the side wall of the outer casing 1. The amount of cooling medium in the outer casing 1 entering the calibration cavity 21 through the cold source delivery pipe 51 and the extension pipe 22 is controlled by the delivery flow rate of the delivery pump or by controlling the opening and closing of the solenoid valve. The solenoid valve or delivery pump can be shut off when the temperature difference between the heat spreader 2 and the preset temperature reaches a set temperature difference threshold, thereby reducing the energy consumed in heating.

[0040] like Figure 6As shown, in another embodiment, the rapid cooling channel includes through holes 23 disposed on the side wall of the extension tube 22. In this embodiment, the cold source is liquefied gas 11. After the liquid level of liquefied gas 11 in the outer shell 1 exceeds the through hole 23, it can flow into the extension tube 22 and enter the interior of the heat spreader 2. In this embodiment, the side wall of the extension tube 22 is provided with multiple rows of through holes 23 arranged at intervals along the vertical direction of the extension tube 22. The multiple through holes 23 in each row are evenly distributed around the circumference of the extension tube 22. By controlling the liquid level of liquefied gas 11 in the outer shell 1, the cold source medium entering the interior of the heat spreader 2 from the extension tube 22 is controlled. When the liquid level drops below the through hole 23, no liquefied gas 11 flows into the extension tube 22. The top opening of the extension tube 22 can be sealed when rapid and significant cooling is required. In this embodiment, the through hole 23 is a micro-hole.

[0041] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An adjustable thermostat for thermometer calibration, characterized in that, It includes an outer shell (1), a heat spreader (2), a first heat insulation layer (3), and a heating assembly (4); The heat spreader (2) is located in the outer shell (1), the first heat insulation layer (3) surrounds the outer periphery of the heat spreader (2), a cold source is provided between the first heat insulation layer (3) and the outer shell (1), and the heating component (4) is located in the first heat insulation layer (3) for heating the heat spreader (2). The heat spreader (2) is provided with a calibration cavity (21) for inserting a thermometer. The heat spreader (2) is also provided with a temperature standard reference component (25). The heat spreader (2) is provided with a closed heat insulation cavity (24) inside. The heat insulation cavity (24) surrounds the calibration cavity (21) and the temperature standard reference component (25). The temperature standard reference component (25) is used to detect the internal temperature of the heat spreader (2) in real time. The heat spreader (2) is provided with an extension tube (22) that connects to the calibration cavity (21). One end of the extension tube (22) extends to the outside of the top of the outer shell (1). The extension tube (22) is provided with a rapid cooling channel that communicates with the inside of the outer shell (1).

2. The adjustable thermostat for thermometer calibration according to claim 1, characterized in that, The cold source is liquefied gas (11).

3. The adjustable thermostat for thermometer calibration according to claim 2, characterized in that, The rapid cooling channel includes a through hole (23) provided on the side wall of the extension tube (22).

4. The adjustable thermostat for thermometer calibration according to claim 2, characterized in that, The first heat insulation layer (3) includes a storage tank (31), which is located in the outer shell (1) and has a vent pipe (32) extending out of the outer shell (1).

5. The adjustable thermostat for thermometer calibration according to claim 4, characterized in that, The vent pipe (32) is used to connect to a vacuum pump or an inert gas source.

6. The adjustable thermostat for thermometer calibration according to claim 1, characterized in that, The temperature standard reference component (25) and the heating component (4) are connected to a controller, which is used to adjust the thermal power of the heating component (4) according to the temperature detected by the temperature standard reference component (25).

7. The adjustable thermostat for thermometer calibration according to claim 6, characterized in that, The heating assembly (4) includes a heating cover wrapped around the periphery of the heat spreader (2), and the heating cover includes a plurality of heating units (41) covering the outer surface of the heat spreader (2). The controller independently controls the start / stop or heating power of each heating unit (41).

8. The adjustable thermostat for thermometer calibration according to claim 7, characterized in that, The heating cover is fitted with a second heat insulation layer on its outer periphery.

9. The adjustable thermostat for thermometer calibration according to claim 1, characterized in that, The heat exchange block (2) is equipped with a temperature monitoring unit (5) near the top. The temperature monitoring unit (5) is used to monitor the temperature of the top of the heat exchange block (2) in real time. The rapid cooling channel is equipped with a solenoid valve and / or a delivery pump. The solenoid valve and / or delivery pump and the temperature monitoring unit (5) are electrically connected to the controller. The controller is used to control the solenoid valve and / or delivery pump according to the temperature monitored by the temperature monitoring unit (5) to regulate the cold source medium entering the extension pipe (22).

10. The adjustable thermostat for thermometer calibration according to claim 1, characterized in that, The calibration accommodating cavity (21) is provided in multiple locations.

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