A sealed precision platinum resistance thermometer for measuring temperature

Abstract

The utility model relates to a kind of precision platinum resistance thermometer temperature measuring devices of sealed air filling, including sealing sleeve structure, the precision platinum resistance thermometer is placed in sealing sleeve structure, the sealing sleeve structure side is connected external vacuumizing device and fills inert gas device by valve body structure, top is connected airtight connector by flange structure, and is connected external temperature signal receiving equipment by airtight connector. By air extraction, the whole air valve device is extracted, and air is filled, so that the internal environment of sealing device forms a sealed inert gas protection internal environment, and finally realizes the precision platinum resistance thermometer in ultra-low temperature, dry, pollution-free environment Precise temperature measuring effect. Avoid the influence of fluid moisture and other media on precision platinum resistance thermometer temperature measurement, and at the same time solve the problem that precision platinum resistance thermometer cannot be calibrated in fixed point device.

Description

Technical Field

[0001] This utility model relates to the field of high-precision thermometer calibration technology, specifically to a precision platinum resistance thermometer temperature measuring device that can be sealed and inflated. Background Technology

[0002] Precision platinum resistance thermometers, as high-precision four-wire temperature sensors, are currently calibrated primarily using fixed-point and comparative methods. However, both methods require placing the sensor in different fluid temperature-sensing media (such as silicone oil) during calibration. This operation easily leads to contamination of the thermometer's casing. When this contaminated sensor is used for subsequent precision measurements, the contaminants can diffuse into the measured equipment or clean environment, causing secondary contamination and severely affecting the purity of the measured system and the reliability of the measurement results. Because the sensor leads of precision platinum resistance thermometers are relatively long, and they must maintain a large safety distance from the inner wall within the fixed-point device, their physical structure is difficult to adapt to standard fixed-point devices, making direct and effective calibration impossible within such devices. Therefore, a sealable, gas-fillable precision platinum resistance thermometer temperature measurement device is urgently needed.

[0003] Currently, the following types of high-sealing platinum resistance temperature sensors are available: The high-sealing platinum resistance temperature sensor described in Chinese Patent (Patent No. CN 223389302 U) "A High-Sealing Platinum Resistance Temperature Sensor" achieves high sealing against liquid corrosion through a retractable sealing protection structure, effectively preventing damage from collisions and friction during storage and use. However, this high-sealing platinum resistance sensor device has a complex structure. The platinum resistance sensing wire is permanently encapsulated in a metal protective tube and connecting tube by sealing resin, making it impossible to disassemble. If the platinum resistance is damaged, the entire sensor assembly needs to be replaced.

[0004] The Chinese patent (patent number CN 209623896 U) "A Sealing Device for an External Platinum Resistance Temperature Detector" describes a sealing device for a platinum resistance temperature detector. This device, through a junction box-less design, O-ring sealing, and fine-thread adjustment structure, achieves compact installation while also providing high sealing performance and precise adjustment capability for installation depth. However, the overall structure of this device is relatively large, making calibration and extensibility impossible within a fixed-point device.

[0005] Currently, platinum resistance thermometers require temperature calibration in various high and low temperature precision instruments. However, the diverse range of media used in these instruments can contaminate the thermometer's casing, necessitating manual cleaning after calibration – a time-consuming and labor-intensive process. Furthermore, precision platinum resistance thermometers are four-wire temperature sensors, and their small size makes calibration at fixed points impossible. Therefore, a sealable, gas-fillable precision platinum resistance thermometer measuring device is urgently needed. Utility Model Content

[0006] This invention addresses the technical problems existing in the prior art by providing a precision platinum resistance thermometer temperature measuring device that can be sealed and inflated.

[0007] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: A precision platinum resistance thermometer temperature measuring device that can be sealed and filled with gas includes a sealing sleeve structure. The precision platinum resistance thermometer is placed inside the sealing sleeve structure. The side of the sealing sleeve structure is connected to an external vacuum pumping device and an inert gas filling device through a valve body structure. The top of the sealing sleeve structure is connected to an airtight connector through a flange structure and is connected to an external temperature signal receiving device through the airtight connector.

[0008] The beneficial effects of this utility model are: 1. Place the precision platinum resistance thermometer inside a sealed sleeve structure to completely isolate the external temperature measuring medium (such as silicone oil, moisture, impurities) from direct contact with the thermometer, avoid contamination of the thermometer shell, and thus prevent secondary contamination of the measured system (such as semiconductor clean environments, biomedical equipment) during subsequent use, ensuring the purity of the measured system and the reliability of the measurement results. 2. By connecting the external vacuum device and the inert gas filling device through the valve body structure, the residual air in the sleeve can be removed and inert gas (such as helium or nitrogen) can be filled in, forming a stable, dry, and low-interference internal environment, effectively reducing the influence of thermal resistance, and providing basic conditions for high-precision temperature measurement in extreme environments such as ultra-low temperature. 3. By using an airtight connector to connect to an external temperature signal receiving device (such as a bridge), the temperature signal is stably transmitted in a sealed environment. At the same time, the overall structure is compact and can be adapted to fixed-point devices, solving the problem that traditional precision platinum resistance thermometers cannot be calibrated in fixed-point devices due to long leads and poor structural adaptability.

[0009] Furthermore, the sealing sleeve structure includes an upper sleeve and a lower sleeve, which are welded coaxially and fixed as a single unit. The precision platinum resistance thermometer probe is placed in the lower sleeve, and the probe's tail lead is placed in the upper sleeve. The lower sleeve is specifically for holding the thermometer probe, while the upper sleeve holds the tail lead, achieving physical separation between the probe and the lead. This allows for a reasonable allocation of space within the sleeve, preventing interference from lead entanglement on the probe's temperature measurement and facilitating precise thermometer positioning during assembly. It is also compatible with precision platinum resistance thermometers of different lengths, improving the device's compatibility with different thermometer models and expanding its application range.

[0010] Furthermore, both the upper and lower sleeves are made of stainless steel. Stainless steel possesses excellent resistance to high and low temperatures, corrosion resistance, and thermal conductivity, making it suitable for ultra-low temperature measurement and harsh industrial environments. It provides reliable physical protection for the internal thermometer and does not experience drastic thermal expansion and contraction due to temperature changes, thus reducing the impact of the sleeve's own thermal deformation on the internal temperature measurement environment and indirectly improving temperature measurement accuracy.

[0011] Furthermore, the valve body structure includes a stainless steel valve tube and a filling / vacuuming valve. One end of the stainless steel valve tube is welded to the upper sleeve, and the other end is connected to the filling / vacuuming valve. The filling / vacuuming valve enables centralized control of the internal air path of the sleeve, eliminating the need for additional complex piping, simplifying the operation process, and allowing operators to quickly complete vacuuming and inert gas filling operations, thus improving the efficiency of the device.

[0012] Furthermore, the vacuuming and charging valve is a stainless steel ferrule flow needle valve. The stainless steel ferrule flow needle valve has precise flow regulation capabilities, accurately controlling the vacuuming speed and inert gas charging rate, preventing sudden pressure changes inside the sleeve due to excessively rapid airflow, or localized temperature fluctuations due to uneven charging, thus ensuring a stable internal environment. Simultaneously, the needle valve has excellent sealing performance; when closed, it completely blocks the gas path, preventing inert gas leakage.

[0013] Furthermore, the flange structure includes an upper flange and a lower flange, which are connected by hexagonal socket head cap screws and sealed with fluororubber rings. The lower flange is welded to the upper sleeve, and the upper flange is connected to an airtight connector by hexagonal socket head cap screws. The upper and lower flanges form a high-strength, high-airtightness connection structure through screws and fluororubber rings, which can prevent leakage of inert gas inside the sleeve and isolate external impurities from entering. The detachable flange connection also facilitates the later opening of the sleeve to replace a damaged thermometer.

[0014] Furthermore, the lower flange is provided with a fluororubber sealing ring groove. The groove structure can accurately position the fluororubber sealing ring, preventing the sealing ring from shifting or falling off during assembly, and ensuring that the sealing ring fits tightly with the upper and lower flanges; at the same time, the groove can limit the compression of the sealing ring, avoiding damage to the sealing ring due to excessive compression or sealing gaps due to insufficient compression, further improving the airtightness of the flange connection.

[0015] Furthermore, the upper flange and the airtight connector are sealed by a square rubber gasket. The airtight connector itself is airtight, and together with the square rubber gasket between it and the upper flange, a double airtight guarantee is formed by the self-sealing of the plug and the sealing of the flange interface; at the same time, the rubber material has a certain degree of elasticity, which can buffer the pressure during assembly and prevent the flange or airtight connector from being damaged due to rigid contact.

[0016] Furthermore, the airtight connector includes an airtight aviation plug, which extends into the upper sleeve and is soldered to the tail lead of the precision platinum resistance thermometer. The upper glass sintered socket of the airtight aviation plug is soldered to the shielding wire. The aviation plug achieves integrated connection between the thermometer lead and the external shielding wire, avoiding complex wiring and making the device structure more compact. Simultaneously, the interface design of the aviation plug has excellent anti-interference performance, reducing the impact of external electromagnetic interference on the temperature signal and ensuring the accuracy of signal transmission.

[0017] Furthermore, the tail of the shielded wire is melted into a 4-wire configuration, forming a four-core shielded wire. The precision platinum resistance thermometer employs a four-wire measurement principle, which eliminates the influence of lead resistance on the measurement results. It also facilitates wiring and connection, reduces mutual interference between leads, and makes subsequent connection to a bridge circuit for measurement easier. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the planar structure of an embodiment of the present utility model; Figure 2 This is a three-dimensional structural diagram of an embodiment of the present invention, omitting the air intake and exhaust valve; Figure 3 This is a schematic diagram of the lower flange structure of an embodiment of the present utility model; Figure 4 This is a schematic diagram of the upper flange structure according to an embodiment of the present utility model; Figure 5 This is a schematic diagram of the airtight aviation plug structure according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the fluororubber sealing ring structure according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the square rubber pad structure according to an embodiment of the present utility model; The attached diagram lists the components represented by each number as follows: 1. Airtight aviation connector; 2. Square rubber gasket; 3. Top flange; 4. Bottom flange; 5. Top sleeve; 6. Inflation / extraction valve; 7. Lead wire; 8. Precision platinum resistance thermometer; 9. Socket head screw; 10. Fluororubber sealing ring; 11. Bottom sleeve; 12. Stainless steel valve tube; 13. Fluororubber sealing ring groove. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0021] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this technology based on the specific circumstances.

[0022] In the description of this application, spatial relation terms such as "below," "under," "below," "below," "above," "over," etc., are used herein to describe the relationship between one element or feature shown in the figures and other elements or features. It should be understood that, in addition to the orientation shown in the figures, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figures is flipped, an element or feature described as "below" or "under" or "below" of other elements or features will be oriented "above" other elements or features. Therefore, the exemplary terms "below" and "under" can include both upper and lower orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein are interpreted accordingly.

[0023] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to implement and use the present invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the present invention can be implemented without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the present invention with unnecessary detail. Therefore, the present invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0024] like Figures 1 to 7As shown, this embodiment provides a sealable, gas-fillable precision platinum resistance thermometer temperature measuring device, including a sealing sleeve structure. The precision platinum resistance thermometer is placed inside the sealing sleeve structure. The side of the sealing sleeve structure is connected to an external vacuum pumping device and an inert gas filling device via a valve body structure. The top is connected to an airtight connector via a flange structure, and is also connected to an external temperature signal receiving device via the airtight connector. Specifically: The sealing sleeve structure includes an upper sleeve 5 and a lower sleeve 11, which are welded coaxially and fixed as a single unit. The probe of a precision platinum resistance thermometer 8 is placed in the lower sleeve 11, and the lead wire 7 at the tail of the probe is placed in the upper sleeve 5. The lower sleeve 11 is specifically for holding the thermometer probe, and the upper sleeve 5 holds the tail lead wire 7, thus achieving physical partitioning between the probe and the lead wire 7. This allows for a reasonable allocation of the internal space of the sleeve, avoiding interference from the lead wire 7 winding around the probe's temperature measurement, and facilitating precise positioning of the thermometer during assembly. It can accommodate precision platinum resistance thermometers 8 of different lengths, improving the device's compatibility with different models of thermometers and expanding its application range.

[0025] In this embodiment, both the upper sleeve 5 and the lower sleeve 11 are made of stainless steel. Stainless steel has excellent resistance to high and low temperatures, corrosion resistance, and thermal conductivity, making it suitable for ultra-low temperature measurement and harsh industrial environments. It provides reliable physical protection for the internal thermometer and does not experience drastic thermal expansion and contraction due to temperature changes, thus reducing the impact of the sleeve's own thermal deformation on the internal temperature measurement environment and indirectly improving temperature measurement accuracy.

[0026] The valve body structure includes a stainless steel valve tube 12 and a filling / exhaust valve 6. One end of the stainless steel valve tube 12 is welded to the upper sleeve 5, and the other end is connected to the filling / exhaust valve 6. The filling / exhaust valve 6 removes residual air from the inside of the sealing sleeve structure and fills it with an inert gas (helium or nitrogen) to reduce thermal resistance and ensure high-precision temperature measurement in ultra-low temperature and dry environments.

[0027] In this embodiment, the vacuuming / filling valve 6 is a stainless steel ferrule flow needle valve. The stainless steel ferrule flow needle valve has precise flow regulation capabilities, accurately controlling the vacuuming speed and inert gas filling rate. This prevents sudden pressure changes inside the sleeve due to excessively rapid airflow or localized temperature fluctuations caused by uneven filling, ensuring a stable internal environment. Simultaneously, the needle valve has excellent sealing performance; when closed, it completely blocks the gas path, preventing inert gas leakage.

[0028] The flange structure includes an upper flange 3 and a lower flange 4, which are connected by hexagonal socket head cap screws 9 and sealed with fluororubber sealing rings 10. The lower flange 4 is welded to the upper sleeve 5, and the upper flange 3 is connected to an airtight connector by hexagonal socket head cap screws 9. The upper and lower flanges form a high-strength, high-airtightness connection structure through screws and fluororubber sealing rings 10, which can prevent leakage of inert gas inside the sleeve and isolate external impurities from entering. At the same time, the detachable flange connection method facilitates the later opening of the sleeve to replace the damaged thermometer.

[0029] In this embodiment, the lower flange 4 is provided with a fluororubber sealing ring groove 13. The groove structure can accurately position the fluororubber sealing ring 10, preventing the sealing ring from shifting or falling off during assembly, and ensuring that the sealing ring fits tightly with the upper and lower flanges; at the same time, the groove can limit the compression of the sealing ring, avoiding damage to the sealing ring due to excessive compression, or sealing gaps due to insufficient compression, further improving the airtightness of the flange connection.

[0030] In this embodiment, the upper flange 3 and the airtight connector are sealed by a square rubber gasket 2. The airtight connector itself is airtight, and together with the square rubber gasket 2 between it and the upper flange, a double airtight guarantee is formed by the self-sealing of the plug and the sealing of the flange interface; at the same time, the rubber material has a certain degree of elasticity, which can buffer the pressure during assembly and prevent the flange or airtight connector from being damaged due to rigid contact.

[0031] The airtight connector includes an airtight aviation plug 1, which extends into the upper sleeve 5 and is soldered to the tail lead 7 of the precision platinum resistance thermometer 8. The glass sintered socket above the airtight aviation plug 1 is soldered to the shielding wire. The aviation plug achieves integrated connection between the thermometer lead 7 and the external shielding wire, avoiding complex wiring and making the device structure more compact. Simultaneously, the interface design of the aviation plug has good anti-interference performance, reducing the impact of external electromagnetic interference on the temperature signal and ensuring the accuracy of signal transmission.

[0032] In this embodiment, the tail of the shielded wire is melted into a 4-wire configuration, forming a four-core shielded wire. The precision platinum resistance thermometer 8 adopts a four-wire measurement principle, which can eliminate the influence of lead resistance on the measurement results, while also facilitating wiring and connection, reducing mutual interference between leads, and making it convenient for subsequent connection and measurement with temperature signal receiving equipment.

[0033] The working principle of the above structure: First, the vacuum valve 6 (stainless steel ferrule flow needle valve) is connected to the stainless steel valve tube 12, and an external vacuum device is connected through the vacuum valve 6 to remove residual air inside the sealed sleeve structure, forming a preliminary vacuum. Then, the vacuum valve 6 is disconnected from the vacuum device, and an external inert gas charging device is connected to purge helium or nitrogen to the set pressure and maintain a stable pressure. After that, the vacuum valve 6 is closed to form a closed inert gas protective chamber. Finally, a 4-wire shielded cable is connected to an external temperature signal receiving device (such as a bridge) to transmit the temperature signal and achieve high-precision temperature measurement.

[0034] While embodiments or examples of this disclosure have been described with reference to the accompanying drawings, it should be understood that the above embodiments are merely exemplary embodiments or examples, and the scope of this utility model is not limited by these embodiments or examples, but only by the granted claims and their equivalents. Various elements in the embodiments or examples may be omitted or replaced by their equivalents. Furthermore, the steps may be performed in a different order than that described in this disclosure. Further, various elements in the embodiments or examples may be combined in various ways. Importantly, as the technology evolves, many elements described herein can be replaced by equivalents that appear after this disclosure.

Claims

1. A sealable, gas-fillable precision platinum resistance thermometer temperature measuring device, characterized in that, It includes a sealed sleeve structure, in which the precision platinum resistance thermometer is placed. The side of the sealed sleeve structure is connected to an external vacuum pumping device and an inert gas filling device through a valve body structure, and the top is connected to an airtight connector through a flange structure, and is also connected to an external temperature signal receiving device through the airtight connector.

2. The temperature measuring device for a sealable, gas-fillable precision platinum resistance thermometer according to claim 1, characterized in that, The sealing sleeve structure includes an upper sleeve and a lower sleeve, which are welded together coaxially and fixed as one piece. The precision platinum resistance thermometer probe is placed in the lower sleeve, and the probe tail lead is placed in the upper sleeve.

3. The temperature measuring device for a sealable, gas-fillable precision platinum resistance thermometer according to claim 2, characterized in that, Both the upper sleeve and the lower sleeve are made of stainless steel.

4. The temperature measuring device for a sealable, gas-fillable precision platinum resistance thermometer according to claim 1, characterized in that, The valve body structure includes a stainless steel air valve pipe and a filling / exhaust valve. One end of the stainless steel air valve pipe is welded to the upper sleeve, and the other end is connected to the filling / exhaust valve.

5. The temperature measuring device for a sealable, gas-fillable precision platinum resistance thermometer according to claim 4, characterized in that, The air filling valve is a stainless steel compression fitting flow needle valve.

6. The temperature measuring device for a sealable, gas-fillable precision platinum resistance thermometer according to claim 1, characterized in that, The flange structure includes an upper flange and a lower flange, which are connected by hexagonal socket head cap screws and sealed with fluororubber sealing rings. The lower flange is welded to the upper sleeve, and the upper flange is connected to an airtight connector by hexagonal socket head cap screws.

7. The temperature measuring device for a sealable, gas-fillable precision platinum resistance thermometer according to claim 6, characterized in that, The lower flange is provided with a fluororubber sealing ring groove.

8. The temperature measuring device for a sealable, gas-fillable precision platinum resistance thermometer according to claim 6, characterized in that, The upper flange and the airtight connector are sealed by a square rubber gasket.

9. The temperature measuring device for a sealable, gas-fillable precision platinum resistance thermometer according to claim 1, characterized in that, The airtight connector includes an airtight aviation plug that extends into the upper sleeve and is soldered to the tail lead of a precision platinum resistance thermometer. The glass sintered socket above the airtight aviation plug is soldered to the shielding wire.

10. A sealable, gas-fillable precision platinum resistance thermometer temperature measuring device according to claim 9, characterized in that, The end of the shielded wire is melted into a 4-wire pattern to form a four-core shielded wire.

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