A dry body furnace for improving calibration accuracy of short-branch sanitary temperature sensor

Abstract

This invention discloses a dry block furnace for improving the calibration accuracy of short-branch sanitary temperature sensors, specifically relating to the field of temperature metrology and calibration technology. The invention utilizes an independent heat-conducting adapter plate, placing the flange of the short-branch thermometer to be calibrated in contact with the top surface of the adapter plate, while the bottom surface of the adapter plate only contacts the upper surface of the constant-temperature block. By placing a heat-conducting adapter plate with an air insulation layer between the constant-temperature block and the flange of the thermometer to be calibrated, the significant heat load of the flange is successfully removed from the constant-temperature block. This prevents the vertical temperature field of the constant-temperature block from being disturbed by external heat dissipation, and its heat is not directly affected by the heat dissipation load of the flange. This improves the calibration accuracy of the short-branch thermometer, transferring the heat load of the tested thermometer flange away from the core constant-temperature block, thereby protecting the uniformity and stability of the internal temperature field of the constant-temperature block.

Description

Technical Field

[0001] This invention relates to the field of temperature measurement and calibration technology, specifically to a dry block furnace for improving the calibration accuracy of short-branch sanitary temperature sensors. Background Technology

[0002] In the field of temperature metrology, dry block furnaces are widely used for temperature calibration in industrial settings due to their portability, speed, and cleanliness. For example, the existing low-temperature dry block furnace disclosed in patent publication CN113514167A, by increasing the furnace opening diameter and setting a T-shaped thermostat, solves the problem of difficulty in inserting sensors with complex external protective tube structures (such as flanges). However, in actual calibration processes, especially for short-branch thermometers, the following shortcomings still exist: heat loss and temperature field disturbance, and the flange of the sensor under test directly contacts the upper surface of the thermostat and the heat spreader. As a large heat sink, the flange directly absorbs a large amount of heat from the upper surface of the heat exchange block, which disrupts the axial temperature field (vertical temperature field) inside the heat exchange block, generating a large temperature gradient. This distorts the originally uniform and stable temperature field region within the heat exchange block, ultimately affecting the accuracy of calibration. Furthermore, the heat source path is unclear. In existing technologies, the heat of the flange comes from both the isothermal block and the heat exchange block. This dual heat source supply method makes the heat flow complex and difficult to control precisely. Therefore, a dry block furnace is needed that can facilitate the insertion of a short-supported thermometer with a flange while minimizing interference with the calibrated temperature field. Thus, a dry block furnace for improving the calibration accuracy of short-supported sanitary temperature sensors is proposed. Summary of the Invention

[0003] The purpose of this invention is to provide a dry block furnace for improving the calibration accuracy of short-branch sanitary temperature sensors, thereby solving the problems mentioned in the background art.

[0004] The main technical problem solved by this invention is: In the existing technology, the flange of the sensor under test is in direct contact with the upper surface of the constant temperature block and the heat spreader, and directly absorbs a large amount of heat from the upper surface of the heat spreader. This causes the axial temperature field (vertical temperature field) inside the heat spreader to be destroyed, resulting in a large temperature gradient. This distorts the originally uniform and stable temperature field region inside the heat spreader, ultimately affecting the accuracy of calibration. The heat of the flange comes from both the constant temperature block and the heat spreader. This dual heat source supply method makes the heat flow complex and difficult to control precisely.

[0005] This invention can be achieved through the following technical solutions: A dry block furnace for improving the calibration accuracy of short-branch sanitary temperature sensors includes a furnace body, wherein a furnace opening is provided in the middle of the top surface of the furnace body, and a furnace opening platform is provided inside the furnace body and directly below the furnace opening. The furnace platform includes a uniform temperature block, a constant temperature block, and an insulation layer wrapped around the constant temperature block, arranged sequentially from the inside out. The uniform temperature block is used to provide a stable and uniform temperature field for the probe of the thermometer to be calibrated. The constant temperature block has a cubic structure and a blind hole is opened in the center of its upper end face. The temperature equalization block is installed in the blind hole and the upper end face of the temperature equalization block is flush with the upper end face of the constant temperature block. An adapter plate for heat conduction is snapped onto the furnace opening platform. The adapter plate is used to support and thermally couple the flange short-branch thermometer to be calibrated, and to isolate the direct thermal contact between the flange of the thermometer to be calibrated and the temperature equalization block. The adapter has a central probe hole that matches the diameter of the temperature sensing probe of the thermometer to be calibrated, and the adapter is used to accommodate and position the temperature sensing probe of the thermometer to be calibrated. The temperature equalization block has a socket in the center, and the temperature sensing probe of the thermometer to be calibrated passes through the central probe hole and is inserted into the socket of the temperature equalization block. A temperature measuring hole for inserting a standard thermometer is provided on one side of the socket; The lower surface of the adapter piece is provided with a circular clearance recess located outside the central probe hole, and the diameter of the circular clearance recess is the same as the diameter of the temperature equalization block. When the adapter is installed on the furnace opening platform, an air insulation layer is formed between the circular clearance recess and the upper surface of the heat spreader to block the direct heat transfer path between the adapter and the heat spreader.

[0006] A further technical improvement of the present invention is that: the upper part of the constant temperature block is an inverted frustum-shaped structure, the top end face of the inverted frustum-shaped structure is a circular plane, the diameter of the circular plane matches the diameter of the adapter piece, and is used to support the adapter piece; The inverted frustum-shaped sidewalls are inclined surfaces that taper inwards from top to bottom, with the ends of the inclined surfaces smoothly transitioning to the main body of the constant temperature block below.

[0007] A further technical improvement of the present invention is that the adapter is a circular thin sheet structure made of a high thermal conductivity metal material, and its diameter is equal to the diameter of the flange of the thermometer to be calibrated.

[0008] A further technical improvement of the present invention is that: the edge of the adapter is provided with a radially inwardly extending opening, the opening being connected to the central probe hole, and the opening being used to accommodate and lead out the probe wire of the standard thermometer.

[0009] A further technical improvement of the present invention is that: the lower surface of the adapter piece is provided with a ring of downwardly protruding positioning bosses; The upper surface of the constant temperature block is provided with a positioning groove that matches the shape and size of the positioning boss. During assembly, the positioning boss is embedded in the positioning groove to achieve precise positioning of the adapter on the furnace opening platform and form a tight heat-conducting contact surface.

[0010] A further technical improvement of the present invention is that, during heat transfer, the constant temperature block conducts heat with the adapter plate, and the adapter plate conducts heat with the flange of the thermometer to be calibrated.

[0011] A further technical improvement of the present invention is that a handle is installed on the upper surface of the furnace body near the furnace opening.

[0012] A further technical improvement of the present invention is that: a detachable wellhead heat insulation component is installed inside the furnace opening; when calibrating a universal long needle thermometer, the wellhead heat insulation component is installed on the furnace opening; when calibrating a short branch thermometer, the wellhead heat insulation component is removed from the furnace opening.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. By setting an independent heat conduction adapter, the flange of the short-branch thermometer to be calibrated is in contact with the top surface of the adapter, while the bottom surface of the adapter is in contact with the upper surface of the constant temperature block. By setting a heat conduction adapter with an air insulation layer between the constant temperature block and the flange of the thermometer to be calibrated, the huge heat load of the flange is successfully separated from the constant temperature block. This makes the vertical temperature field of the constant temperature block no longer affected by external heat dissipation, and its heat is not directly affected by the heat dissipation load of the flange. This improves the calibration accuracy of the short-branch thermometer and transfers the heat load of the flange of the thermometer under test from the core constant temperature block, thereby protecting the uniformity and stability of the internal temperature field of the constant temperature block. 2. By clearly defining the heat source of the flange of the thermometer to be calibrated as a constant temperature block (conducted through an adapter), the complexity of the temperature field caused by dual heat sources in the existing technology is solved, the accuracy of calibration is precisely controlled, the heat source path is optimized, and system disturbances are reduced. 3. The adapter integrates multiple functions. The positioning boss and positioning groove work together to achieve fast and accurate positioning and efficient heat conduction. The opening solves the problem of leading out the standard thermometer wires, eliminating the need to make complex grooves on the temperature equalization block or constant temperature block. The circular avoidance recess precisely controls the formation of the air insulation layer. Attached Figure Description

[0014] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0015] Figure 1 This is a three-dimensional structural diagram of the furnace body of the present invention; Figure 2 This is a three-dimensional half-sectional structural diagram of the temperature equalization block and the temperature constant block of the present invention; Figure 3 This is a schematic diagram of the cross-sectional structure of the temperature equalization block and the temperature constant block of the present invention; Figure 4 This is a schematic diagram of the exploded structure of the adapter sheet and the temperature equalization block of the present invention; Figure 5 This is a three-dimensional structural diagram of the adapter sheet of the present invention from another angle; Figure 6 This is a schematic diagram showing the calibration status of the short-branch sanitary temperature sensor of the present invention. Figure 7 This is a schematic diagram showing the calibration status of the long needle-shaped temperature sensor of the present invention; Figure 8 This is a schematic diagram of the thermal path of the present invention; Figure 9 This is a schematic diagram of the furnace opening and wellhead insulation component of the present invention; Figure 10 This is a schematic diagram of the furnace opening and wellhead insulation component of the present invention from another direction; Figure 11 This is a schematic diagram of the thermostatic block of the present invention.

[0016] In the diagram: 1. Furnace body; 2. Furnace opening; 3. Handle; 4. Temperature equalization block; 5. Temperature constant block; 6. Center probe hole; 7. Opening; 8. Adapter plate; 9. Positioning groove; 10. Positioning boss; 11. Blind hole; 12. Insulation layer; 13. Insertion hole; 14. Circular clearance recess; 15. Temperature measuring hole; 16. Wellhead insulation component. Detailed Implementation

[0017] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0018] Please see Figures 1-11 As shown, the present invention provides a dry block furnace for improving the calibration accuracy of short-branch sanitary temperature sensors, including a furnace body 1, a furnace opening 2 provided in the middle of the top surface of the furnace body 1, and a furnace opening platform provided inside the furnace body 1 and directly below the furnace opening 2. The furnace platform includes a uniform temperature block 4, a constant temperature block 5, and an insulation layer 12 wrapped around the constant temperature block 5, arranged sequentially from the inside to the outside. The uniform temperature block 4 is used to provide a stable and uniform temperature field for the probe of the thermometer to be calibrated. The constant temperature block 5 has a cubic structure, and a blind hole 11 is opened in the center of its upper end face. The temperature equalization block 4 is installed in the blind hole 11, and the upper end face of the temperature equalization block 4 is flush with the upper end face of the constant temperature block 5. An adapter plate 8 for heat conduction is snapped onto the furnace mouth platform. The adapter plate 8 is used to support and thermally couple the flange short support thermometer to be calibrated, and to isolate the direct thermal contact between the flange of the thermometer to be calibrated and the temperature equalization block 4. The adapter 8 has a central probe hole 6 that matches the diameter of the temperature sensing probe of the thermometer to be calibrated, and the adapter 8 is used to accommodate and position the temperature sensing probe of the thermometer to be calibrated. The temperature equalization block 4 has a socket 13 in the center. The temperature sensing probe of the thermometer to be calibrated passes through the central probe hole 6 and is inserted into the socket 13 of the temperature equalization block 4. A temperature measuring hole 15 for inserting a standard thermometer is provided on one side of the socket 13; A circular clearance recess 14 is provided on the lower surface of the adapter plate 8 and outside the central probe hole 6. The diameter of the circular clearance recess 14 is the same as the diameter of the temperature equalization block 4. When the adapter 8 is installed on the furnace opening platform, an air insulation layer is formed between the circular clearance recess 14 and the upper surface of the heat spreader 4 to block the direct heat transfer path between the adapter 8 and the heat spreader 4.

[0019] The constant temperature block 5, with its large heat capacity and independent temperature control, can easily meet the heat dissipation requirements of the flange without affecting the temperature field of the core calibration area.

[0020] like Figure 6 As shown, when calibrating the short-branch sanitary temperature sensor, the wellhead insulation is removed, the probe of the thermometer to be calibrated is passed through the central probe hole 6 and inserted into the insertion hole 13 of the temperature equalization block 4, and its flange is attached to the upper surface of the adapter plate 8. The probe of the standard reference thermometer is also inserted into the temperature measuring hole 15 of the temperature equalization block 4, and its wire is led out from the opening 7.

[0021] When the dry block furnace body 1 is started, the constant temperature block 5 is heated. The heat is mainly transferred through two paths: the main heating path: the heat from the constant temperature block 5 is efficiently transferred to the adapter plate 8 through the tight fit of the snap-fit ​​(positioning boss 10 and positioning groove 9), and then transferred by the adapter plate 8 to the flange of the thermometer to be calibrated. Since the constant temperature block 5 has a large heat capacity and independent temperature control, it bears the main heat dissipation load; the core temperature field path: the heat exchange block 4 obtains heat from the constant temperature block 5 to establish a highly uniform and stable vertical temperature field in the area of ​​its internal insertion hole 13 and temperature measuring hole 15. Due to the presence of the air insulation layer, the heat dissipation of the flange has almost no impact on the temperature distribution inside the heat exchange block 4.

[0022] Finally, calibration is completed by comparing the readings of the standard thermometer with those of the thermometer under test. During this process, the sensing element of the thermometer under test is located within the stable temperature field of the temperature equalization block 4, while the thermal disturbance caused by heat dissipation from its flange is confined to the adapter plate 8, thus achieving high-precision calibration.

[0023] By setting an independent heat conduction adapter 8, the flange of the short-branch thermometer to be calibrated is in contact with the top surface of the adapter 8, while the bottom surface of the adapter 8 is in contact only with the upper surface of the constant temperature block 5. By setting the heat conduction adapter 8 with an air insulation layer between the temperature equalization block 4 and the flange of the thermometer to be calibrated, the huge heat load of the flange is successfully separated from the temperature equalization block 4. This ensures that the vertical temperature field of the temperature equalization block 4 is no longer disturbed by external heat dissipation, and the stability and uniformity of its internal temperature field are fundamentally guaranteed. Its heat is not directly affected by the heat dissipation load of the flange, thereby improving the calibration accuracy of the short-branch thermometer. The heat load of the flange of the thermometer under test is transferred away from the core temperature equalization block 4, thus protecting the uniformity and stability of the internal temperature field of the temperature equalization block.

[0024] The heat source of the flange of the thermometer to be calibrated is clearly defined as the constant temperature block 5 (conducted through the adapter plate 8), avoiding contact with the temperature equalization block 4, and is separated by an air insulation layer, so that the heat is conducted from the constant temperature block 5 to the adapter plate 8. This solves the problem of temperature field complexity caused by dual heat sources in the existing technology and precisely controls the accuracy of calibration.

[0025] See Figure 2 , Figure 3 and Figure 11 As shown, the upper part of the constant temperature block 5 is an inverted frustum-shaped structure, and the top end face of the inverted frustum-shaped structure is a circular plane. The diameter of the circular plane matches the diameter of the adapter plate 8 and is used to support the adapter plate 8. The inverted frustum-shaped sidewalls are inclined surfaces that taper inwards from top to bottom, with the ends of the inclined surfaces smoothly transitioning to the main body of the thermostatic block 5 below.

[0026] See Figure 4 As shown, the adapter 8 is a circular thin sheet structure made of a high thermal conductivity metal material (such as aluminum alloy), and its diameter is equal to the diameter of the flange of the thermometer to be calibrated. The flange of the thermometer to be calibrated enters through furnace opening 2 and contacts the top surface of the adapter plate 8.

[0027] See Figure 4 and Figure 5 As shown, the edge of the adapter 8 has a radially inwardly extending opening 7, which communicates with the central probe hole 6, and the opening 7 is used to accommodate and lead out the probe wire of the standard thermometer.

[0028] The lower surface of the adapter 8 is provided with a ring of downward protruding positioning bosses 10; The upper end face of the constant temperature block 5 is provided with a positioning groove 9 that matches the shape and size of the positioning boss 10; During assembly, the positioning boss 10 is embedded in the positioning groove 9 to achieve precise positioning of the adapter piece 8 on the furnace opening platform and form a tight heat-conducting contact surface.

[0029] The adapter plate 8 integrates multiple functions. The positioning boss 10 and the positioning groove 9 work together to achieve fast and accurate positioning and efficient heat conduction. The opening 7 solves the problem of leading out the standard thermometer wire, eliminating the need to open complex grooves on the temperature equalization block 4 or the constant temperature block 5. The circular avoidance pit 14 precisely controls the formation of the air insulation layer.

[0030] See Figure 2 , Figure 4 and Figure 8 As shown, during heat transfer, the thermostatic block 5 conducts heat with the adapter plate 8, and the adapter plate 8 conducts heat with the flange of the thermometer to be calibrated.

[0031] The temperature equalization block 4 is used to provide a stable and uniform temperature field for the probe of the thermometer to be calibrated and the probe of the standard reference thermometer, and its heat is not directly affected by the heat dissipation load of the flange.

[0032] See Figure 1 As shown, a handle 3 is installed on the upper surface of the furnace body 1 on the side adjacent to the furnace opening 2.

[0033] See Figure 2 , Figure 3 , Figure 9 and Figure 10 As shown, a removable wellhead insulation component 16 is installed inside the furnace opening 2. When the dry-block furnace is used to calibrate a general-purpose long-needle thermometer, it is installed on the furnace opening 2. When calibrating a short-branch thermometer, it is removed. At this time, the diameter of the furnace opening 2 expands, which is just enough to accommodate the flange of the short-branch thermometer. The wellhead insulation component 16 can be installed on the furnace opening 2 by threaded connection or snap-fit ​​connection. Figure 7 As shown, a wellhead heat insulation component 16 is installed for calibrating a general-purpose long needle thermometer.

[0034] In use, this invention uses an independent heat conduction adapter 8. The flange of the short-branch thermometer to be calibrated is in contact with the top surface of the adapter 8, while the bottom surface of the adapter 8 is in contact with the upper surface of the constant temperature block 5. By setting the heat conduction adapter 8 with an air insulation layer between the temperature equalization block 4 and the flange of the thermometer to be calibrated, the huge heat load of the flange is successfully separated from the temperature equalization block 4. This prevents the vertical temperature field of the temperature equalization block 4 from being disturbed by external heat dissipation, and its heat is not directly affected by the heat dissipation load of the flange. This improves the calibration accuracy of the short-branch thermometer and transfers the heat load of the flange of the thermometer under test from the core temperature equalization block 4, thereby protecting the uniformity and stability of the internal temperature field of the temperature equalization block. The heat source of the flange of the thermometer to be calibrated is clearly defined as the constant temperature block 5 (conducted through the adapter plate 8), which solves the problem of temperature field complexity caused by dual heat sources in the existing technology, accurately controls the accuracy of calibration, optimizes the heat source path, and reduces system disturbance; The adapter plate 8 integrates multiple functions. The positioning boss 10 and the positioning groove 9 work together to achieve fast and accurate positioning and efficient heat conduction. The opening 7 solves the problem of leading out the standard thermometer wire, eliminating the need to open complex grooves on the temperature equalization block 4 or the constant temperature block 5. The circular avoidance pit 14 precisely controls the formation of the air insulation layer.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A dry block furnace for improving the calibration accuracy of short-branch sanitary temperature sensors, comprising a furnace body (1), characterized in that: The furnace body (1) has a furnace opening (2) in the middle of its top surface, and a furnace opening platform is located inside the furnace body (1) and directly below the furnace opening (2). The furnace platform includes a uniform temperature block (4), a constant temperature block (5), and an insulation layer (12) wrapped around the constant temperature block (5) arranged sequentially from the inside to the outside. The uniform temperature block (4) is used to provide a stable and uniform temperature field for the probe of the thermometer to be calibrated. The constant temperature block (5) has a cubic structure and a blind hole (11) is provided at the center of its upper end face. The temperature equalization block (4) is installed in the blind hole (11) and the upper end face of the temperature equalization block (4) is flush with the upper end face of the constant temperature block (5). An adapter plate (8) for heat conduction is snapped onto the furnace mouth platform. The adapter plate (8) is used to support and thermally couple the flange short branch thermometer to be calibrated, and to isolate the direct thermal contact between the flange of the thermometer to be calibrated and the temperature equalization block (4). The adapter (8) has a central probe hole (6) that matches the diameter of the temperature sensing probe of the thermometer to be calibrated, and the adapter (8) is used to accommodate and position the temperature sensing probe of the thermometer to be calibrated. The temperature equalization block (4) has a socket (13) in the center. The temperature sensing probe of the thermometer to be calibrated passes through the central probe hole (6) and is inserted into the socket (13) of the temperature equalization block (4). A temperature measuring hole (15) for inserting a standard thermometer is provided on one side of the socket (13); The lower surface of the adapter (8) and outside the central probe hole (6) is provided with a circular clearance recess (14), the diameter of which is the same as the diameter of the temperature equalization block (4). When the adapter (8) is installed on the furnace opening platform, an air insulation layer is formed between the circular clearance recess (14) and the upper surface of the heat exchange block (4) to block the direct heat transfer path between the adapter (8) and the heat exchange block (4).

2. A dry block furnace for improving the calibration accuracy of short-branch sanitary temperature sensors according to claim 1, characterized in that, The upper part of the constant temperature block (5) is an inverted frustum-shaped structure. The top end face of the inverted frustum-shaped structure is a circular plane. The diameter of the circular plane matches the diameter of the adapter (8) and is used to support the adapter (8). The sidewall of the inverted frustum is a sloping surface that tapers inward from top to bottom, and the end of the sloping surface smoothly transitions to the main body of the constant temperature block (5) below.

3. A dry block furnace for improving the calibration accuracy of short-branch sanitary temperature sensors according to claim 1, characterized in that, The adapter (8) is a circular thin sheet structure made of a high thermal conductivity metal material, and its diameter is equal to the diameter of the flange of the thermometer to be calibrated.

4. A dry block furnace for improving the calibration accuracy of short-branch sanitary temperature sensors according to claim 1, characterized in that, The edge of the adapter (8) is provided with a radially inwardly extending opening (7), which communicates with the central probe hole (6) and is used to accommodate and lead out the probe wire of the standard thermometer.

5. A dry block furnace for improving the calibration accuracy of a short-branch hygienic temperature sensor according to claim 1, characterized in that, The lower surface of the adapter piece (8) is provided with a ring of downward protruding positioning bosses (10). The upper end face of the constant temperature block (5) is provided with a positioning groove (9) that matches the shape and size of the positioning boss (10). During assembly, the positioning boss (10) is embedded in the positioning groove (9) to achieve precise positioning of the adapter piece (8) on the furnace opening platform and form a tight heat-conducting contact surface.

6. A dry block furnace for improving the calibration accuracy of a short-branch hygienic temperature sensor according to claim 5, characterized in that, During heat transfer, the thermostat block (5) conducts heat with the adapter (8), and the adapter (8) conducts heat with the flange of the thermometer to be calibrated.

7. A dry block furnace for improving the calibration accuracy of a short-branch hygienic temperature sensor according to claim 1, characterized in that, A handle (3) is installed on the upper surface of the furnace body (1) on the side adjacent to the furnace opening (2).

8. A dry block furnace for improving the calibration accuracy of a short-branch sanitary temperature sensor according to claim 1, characterized in that, The furnace opening (2) is equipped with a removable wellhead insulation component (16); when calibrating a universal long needle thermometer, the wellhead insulation component is installed on the furnace opening (2); when calibrating a short branch thermometer, the wellhead insulation component (16) is removed from the furnace opening (2).

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