Dewar-type cryogenic measuring device for a fluorescence instrument

Abstract

The utility model relates to optical detection instrument technical field, concretely is a kind of for Dewar flask formula low temperature measuring device of fluorescence instrument, including chassis, polytetrafluoroethylene positioning ring, positioning platform, hexagonal support column, positioning flat plate, flat plate round table, Dewar flask, support cylinder, cylinder gland, sample tube, the utility model compared with prior art, Dewar flask is integrated as the accessory of a fluorescence spectrophotometer instrument, by injecting liquid nitrogen, maintain stable-196 ℃ low temperature environment;Dewar flask bottom adopts double-layer vacuum structure encapsulation transparent quartz as optical window, light path is direct, signal loss is small, with excellent optical performance;It also has excellent heat insulation effect simultaneously, reduces the liquid nitrogen consumption speed, makes experiment duration longer, and operating cost is lower.

Description

Technical Field

[0001] This utility model relates to the field of optical testing instrument technology, specifically a Dewar bottle-type low-temperature measuring device for fluorescence instruments. Background Technology

[0002] Fluorescence instrumentation, with its advantages of high sensitivity and specificity, has been widely applied in fields such as biomedicine, materials science, and environmental monitoring. Its core principle is to analyze the composition, structure, or environmental state of substances by detecting parameters such as fluorescence intensity, spectral characteristics, and lifetime. However, the fluorescence properties of fluorescent substances, especially fluorescence intensity and lifetime, are highly susceptible to temperature fluctuations: increased temperature intensifies the thermal motion of fluorescent molecules, leading to an increased probability of non-radiative transitions and fluorescence quenching; simultaneously, temperature fluctuations can cause peak shifts in the fluorescence spectrum and decreased signal stability, severely impacting measurement accuracy. Therefore, precise temperature control, including low-temperature environmental control, is crucial for improving analytical reliability in fluorescence measurements.

[0003] Currently, the commonly used temperature control methods in fluorescence detection instruments mainly include semiconductor cooling devices and cryogenic thermostats. However, these methods all have significant limitations, restricting their application in fluorescence measurement. Semiconductor cooling achieves temperature regulation based on the thermoelectric effect, but its effective temperature control is usually no lower than -50℃, with a narrow temperature control range. Furthermore, its cooling efficiency drops sharply near the extreme low temperature, making it difficult to meet the measurement requirements of deep cryogenic environments such as liquid nitrogen at -196℃.

[0004] Furthermore, vibrations and electromagnetic interference generated during semiconductor cooling can adversely affect the acquisition of highly sensitive fluorescence signals. Although cryostats can provide stable low-temperature conditions, their systems are usually bulky and complex. When integrated into fluorescence instruments, the optical path needs to be redesigned and precisely coupled, which is cumbersome and costly. They are also difficult to be compatible with the compact structure and system integration requirements of conventional fluorescence spectrometers or fluorescence microscopes.

[0005] Therefore, it is necessary to design a Dewar bottle-type cryogenic measurement device for fluorescence instruments to achieve stable and reliable ultra-low temperature testing conditions, while also achieving high-quality optical detection compatibility under ultra-low temperature conditions. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a Dewar bottle-type cryogenic measurement device for fluorescence instruments to achieve stable and reliable ultra-low temperature testing conditions, while also achieving high-quality optical detection compatibility under ultra-low temperature conditions.

[0007] To achieve the above objectives, this utility model is a Dewar flask-type low-temperature measuring device for fluorescence instruments, comprising a base, a polytetrafluoroethylene (PTFE) positioning ring, a positioning platform, a hexagonal support column, a positioning plate, a frustum of a plate, a Dewar flask, a supporting cylinder, a cylinder cap, and a sample tube. The PTFE positioning ring is mounted on the base. The horizontally positioned positioning platform and positioning plate are located above the base, and the positioning platform and positioning plate are connected to the base by a hexagonal support column. A supporting cylinder is mounted on the top of the positioning plate, and a cylinder cap is sealed on the top of the supporting cylinder. The body of the Dewar flask passes through the positioning plate and positioning platform in sequence. A frustum of a plate is installed between the body of the Dewar flask and the supporting cylinder. The bottom opening of the Dewar flask is sealed with transparent quartz using a double-layer vacuum structure. The PTFE positioning ring is inserted into the bottom of the Dewar flask. The sample tube passes through the cylinder cap and is placed inside the Dewar flask, with the lower end of the sample tube inserted into the bottom opening of the Dewar flask.

[0008] The chassis is connected to the fluorescence instrument.

[0009] The polytetrafluoroethylene positioning ring is surrounded by a heat-insulating frame, the bottom of which extends to the surface of the chassis, and the top of which extends to the surface of the positioning platform.

[0010] The positioning platform is fixed at the chamfer of the Dewar flask.

[0011] The Dewar flask is filled with liquid nitrogen.

[0012] The body of the Dewar flask is coated with an insulating coating.

[0013] The dimensions of the cylindrical cap are matched with the outer diameter of the supporting cylinder.

[0014] O-rings are provided between the Dewar bottle and the positioning platform, and between the Dewar bottle and the positioning plate.

[0015] The bottom opening of the Dewar flask is a closed structure.

[0016] Compared with the prior art, this invention integrates the Dewar flask into an accessory of a fluorescence spectrophotometer, maintaining a stable -196℃ low-temperature environment by injecting liquid nitrogen; the bottom of the Dewar flask uses a double-layer vacuum structure to encapsulate transparent quartz as an optical window, resulting in a direct optical path, low signal loss, and excellent optical performance; it also has excellent heat insulation effect, reducing the rate of liquid nitrogen consumption, allowing for longer experimental duration and lower operating costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] Figure 2 for Figure 1 AA sectional view. Detailed Implementation

[0019] The present invention will now be further described with reference to the accompanying drawings.

[0020] See Figure 1 , Figure 2 This utility model relates to a Dewar flask-type low-temperature measuring device for fluorescence instruments, comprising a base, a polytetrafluoroethylene (PTFE) positioning ring, a positioning platform, a hexagonal support column, a positioning plate, a frustum of a plate, a Dewar flask, a supporting cylinder, a cylinder cap, and a sample tube. The PTFE positioning ring 12 is mounted on the base 13. The horizontally positioned positioning platform 10 and positioning plate 7 are located above the base 13, and the positioning platform 10 and positioning plate 7 are connected to the base 13 by a hexagonal support column 8. A supporting cylinder is mounted on the top of the positioning plate 7. The cylinder 3 is sealed with a cylindrical cap 2 on its upper part. The body of the Dewar flask 4 passes through the positioning plate 7 and positioning platform 10 in sequence. A flat plate truncated cone 5 is installed between the body of the Dewar flask 4 and the supporting cylinder 3 to further fix the Dewar flask 4. The bottom mouth 41 of the Dewar flask 4 is sealed with transparent quartz using a double-layer vacuum structure. A polytetrafluoroethylene positioning ring 12 is inserted into the bottom of the Dewar flask 4. The sample tube 1 passes through the cylindrical cap 2 and is placed inside the Dewar flask 4, with the lower end of the sample tube 1 inserted into the bottom mouth 41 of the Dewar flask 4.

[0021] The chassis 13 is connected to the fluorescence instrument, enabling the installation of the measuring device and the fluorescence instrument.

[0022] A heat insulation frame 9 surrounds the polytetrafluoroethylene positioning ring 12. The bottom of the heat insulation frame 9 extends to the surface of the chassis 13, and the top of the heat insulation frame 9 extends to the surface of the positioning platform 10, further improving the heat insulation effect.

[0023] To facilitate the installation of the Dewar bottle 4, the positioning platform 10 is fixed at the chamfer of the Dewar bottle 4.

[0024] The Dewar flask 4 is filled with liquid nitrogen. The bottom opening 41 of the Dewar flask 4 is a closed structure. The body of the Dewar flask 4 is coated with an insulating coating to keep the liquid nitrogen inside the flask 4 warm.

[0025] The dimensions of the cylindrical gland 2 are matched with the outer diameter of the supporting cylindrical 3 to ensure a sealing effect.

[0026] O-rings 6 are provided between the Dewar bottle 4 and the positioning platform 10, and between the Dewar bottle 4 and the positioning plate 7, for shock absorption, heat insulation and positioning.

[0027] This invention is installed in the sample chamber of a fluorescence spectrophotometer, forming a complete Dewar flask-type cryogenic measurement assembly. During the experiment, liquid nitrogen is first steadily poured into the Dewar flask 4 through a dedicated container, rapidly cooling the measuring device and maintaining it at a stable low temperature of -196°C. This -196°C temperature is sufficient to freeze the molecular thermal motion of most samples, allowing for the study of the low-temperature properties of materials such as superconductivity, quantum phenomena, or reducing thermal noise interference with signals.

[0028] After the temperature stabilizes, the sample to be tested is placed in a dedicated sample tube 1 and vertically inserted into the Dewar flask 4. Then, the matching cylindrical cap 2 is placed on top. The cylindrical cap 2 has excellent sealing and thermal insulation properties, effectively suppressing liquid nitrogen evaporation and ensuring long-term stability in the low-temperature environment. Under these constant low-temperature conditions, the test sample is in a controllable low-thermal-disturbance state, which helps suppress molecular thermal motion and reduce non-radiative transitions, thereby significantly enhancing the signal-to-noise ratio and measurement stability of the fluorescence signal, meeting the experimental requirements for high-precision low-temperature fluorescence measurement. Transparent quartz serves as the optical window, ensuring that the excitation laser passes through without damage and is focused on the sample. Simultaneously, the fluorescence signal generated by the sample is efficiently transmitted through the window and received by the detection system, thus achieving high-quality optical detection compatibility under deep cryogenic conditions.

[0029] This invention is designed for ease of use. By placing the sample in a test tube and then immersing it, sample replacement is convenient and the operation is faster. This invention features a simple and compact structure, is easy to operate and install, and achieves the measurement of samples at -196℃ in a low-cost manner.

[0030] This invention integrates a Dewar flask into an accessory of a fluorescence spectrophotometer, maintaining a stable -196℃ low-temperature environment by injecting liquid nitrogen. The bottom of the Dewar flask uses a double-layer vacuum structure to encapsulate transparent quartz as an optical window, resulting in a direct optical path, low signal loss, and excellent optical performance. It also has excellent heat insulation, reducing the rate of liquid nitrogen consumption, allowing for longer experimental durations and lower operating costs.

Claims

1. A Dewar-type cryogenic measuring device for fluorescence instruments, comprising a base, a polytetrafluoroethylene positioning ring, a positioning platform, a hexagonal support column, a positioning plate, a frustum of a plate, a Dewar flask, a support cylinder, a cylinder cap, and a sample tube, characterized in that: A polytetrafluoroethylene positioning ring (12) is installed on the chassis (13). A horizontally positioned positioning platform (10) and positioning plate (7) are located above the chassis (13), and the positioning platform (10), positioning plate (7) and chassis (13) are connected by a hexagonal support column (8). A support cylinder (3) is installed on the top of the positioning plate (7), and a cylindrical cap (2) is sealed on the top of the support cylinder (3). The body of the Dewar bottle (4) passes through the positioning plate in sequence. Plate (7), positioning platform (10), a flat truncated cone (5) is installed between the body of the Dewar flask (4) and the supporting cylinder (3), the bottom mouth (41) of the Dewar flask (4) is sealed with transparent quartz using a double-layer vacuum structure, a polytetrafluoroethylene positioning ring (12) is inserted into the bottom of the Dewar flask (4), the sample tube (1) is placed inside the Dewar flask (4) after passing through the cylinder cap (2), and the lower end of the sample tube (1) is inserted into the bottom mouth (41) of the Dewar flask (4).

2. The Dewar bottle-type cryogenic measuring device for fluorescence instruments according to claim 1, characterized in that: The chassis (13) is connected to the fluorescence instrument.

3. The Dewar bottle-type cryogenic measuring device for fluorescence instruments according to claim 1, characterized in that: The polytetrafluoroethylene positioning ring (12) is surrounded by a heat insulation frame (9), the bottom of which extends to the surface of the chassis (13) and the top of which extends to the surface of the positioning platform (10).

4. The Dewar bottle-type cryogenic measuring device for fluorescence instruments according to claim 1, characterized in that: The positioning platform (10) is fixed at the chamfer of the body of the Dewar flask (4).

5. A Dewar-type cryogenic measuring device for fluorescence instruments according to claim 1, characterized in that: The Dewar flask (4) is filled with liquid nitrogen.

6. A Dewar bottle-type cryogenic measuring device for fluorescence instruments according to claim 1, characterized in that: The body of the Dewar flask (4) is coated with a heat-insulating coating.

7. A Dewar bottle-type cryogenic measuring device for fluorescence instruments according to claim 1, characterized in that: The dimensions of the cylindrical cap (2) are matched with the outer diameter of the supporting cylinder (3).

8. A Dewar bottle-type cryogenic measuring device for fluorescence instruments according to claim 1, characterized in that: O-rings (6) are provided between the Dewar bottle (4) and the positioning platform (10) and between the Dewar bottle (4) and the positioning plate (7).

9. A Dewar-type cryogenic measuring device for fluorescence instruments according to claim 1, characterized in that: The bottom opening (41) of the Dewar flask (4) is a closed structure.

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