Liquid level calibration method and device for low-temperature liquid nitrogen biological container based on temperature variation

Abstract

The invention discloses a liquid level calibration method and device for a low-temperature liquid nitrogen biological container based on temperature variation, and the method comprises the steps: setting different liquid levels in a liquid nitrogen barrel, measuring and calculating the resistance values of a first lead and a second lead corresponding to each liquid level according to resistance measurement equipment, and forming a liquid level resistance value corresponding table; different resistors are arranged in the liquid nitrogen barrel, the resistance value is measured, when the measured resistance value is larger than a preset threshold value range, the measured resistance value or the adjusted resistance value is converted into an electric signal through resistance measuring equipment, the electric signal is transmitted to a data processing system, and the data processing system calculates the liquid level resistance value according to a liquid level resistance value corresponding table. The liquid level distance is reflected by measuring the resistance value, accuracy and stability of liquid level measurement are improved, fine adjustment of liquid level measurement can be achieved by adjusting the position of the wire through the floating circular ring, and sensitivity and accuracy of measurement are enhanced by setting the resistance value difference.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid level calibration, and in particular to a method and device for calibrating the liquid level of a low-temperature liquid nitrogen biological container based on temperature variation. Background Art

[0002] In the fields of cryobiology, medical preservation, and materials science, liquid nitrogen, as an important coolant, is widely used in the preservation of biological samples and cryogenic processing of materials. However, accurate measurement and control of the liquid level in the liquid nitrogen container is crucial to the success of these applications. Accurate measurement of the liquid level is not only related to the safe preservation of biological samples, but also affects the consistency and efficiency of material processing. Traditional liquid level measurement methods, such as water level gauges or float switches, often fail in cryogenic liquid nitrogen environments due to low temperatures and cannot meet the needs of accurate measurement.

[0003] Some technologies that attempt to use electrical methods for liquid level measurement, such as capacitive or resistive liquid level sensors, have solved the measurement problem in low-temperature environments to a certain extent, but there are still many shortcomings. Capacitive liquid level sensors are easily affected by changes in ambient temperature and dielectric constant of the medium, resulting in unstable measurement accuracy. Resistive liquid level sensors may cause changes in resistance due to direct contact between the wire and liquid nitrogen. This change is not only related to the liquid level, but also closely related to the temperature and purity of the liquid nitrogen and the material properties of the wire, thereby increasing the complexity of the measurement.

[0004] In order to improve the accuracy and stability of liquid level measurement, researchers began to explore liquid level calibration methods based on temperature changes. Liquid nitrogen is an ultra-low temperature liquid with extremely low temperature and relatively stable temperature, but the liquid level in the liquid nitrogen container may fluctuate due to external factors (such as taking liquid nitrogen, ambient temperature changes, etc.). This fluctuation not only affects the efficiency of liquid nitrogen use, but may also cause damage to biological samples or materials stored in liquid nitrogen. Therefore, it is particularly important to develop a method that can accurately measure and calibrate the liquid level in a liquid nitrogen container. Summary of the invention

[0005] The present application provides a method and device for calibrating the liquid level of a low-temperature liquid nitrogen biological container based on temperature changes. The liquid level distance is reflected by measuring the resistance value, thereby improving the accuracy and stability of the liquid level measurement. The liquid level measurement can be fine-tuned by adjusting the position of the wire through a floating ring. The operation is simple and quick. The measured resistance value can be accurately converted into the liquid level distance through a pre-set liquid level-resistance value correspondence table. The setting of the resistance value difference enhances the sensitivity and accuracy of the measurement.

[0006] The present application provides a method for calibrating the liquid level of a low-temperature liquid nitrogen biological container based on temperature variation, comprising: S101, setting different liquid levels in the liquid nitrogen barrel, measuring and calculating the resistance value of the first wire and the second wire corresponding to each liquid level using a resistance measuring device, and forming a liquid level resistance value correspondence table; S102, setting different resistors in the liquid nitrogen barrel and measuring the resistance values. When the measured resistance value is greater than a preset threshold range, the floating ring is rotated counterclockwise to increase the length of the first wire and the second wire immersed in the liquid nitrogen, that is, to reduce the resistance; when the measured resistance value is less than the preset threshold range, the floating ring is rotated clockwise to reduce the length of the first wire and the second wire immersed in the liquid nitrogen, that is, to increase the resistance; S103, converting the measured resistance value or the adjusted resistance value into an electrical signal through a resistance measuring device, transmitting the electrical signal to a data processing system, and the data processing system calculates and compares the received electrical signal according to a liquid level resistance value corresponding table to obtain a current liquid level distance; A floating ring is also provided in the liquid nitrogen barrel, a conductive rod is fixedly provided at the center of the floating ring, a support rod is movably installed at the center of the conductive rod, the conductive rod is sleeved on the support rod, and the top and bottom of the support rod are fixedly connected to the top and bottom of the liquid nitrogen barrel respectively; The conductive rod is provided with a third conductive wire, and two ends of the third conductive wire are respectively provided on both sides of the conductive rod and are movably connected with the first conductive wire and the second conductive wire, and the first conductive wire and the second conductive wire are connected with the resistance measuring device.

[0007] Preferably, the first wire is movably arranged on one side of the conductive rod close to the vacuum head, and the first wire extends from the side of the conductive rod close to the vacuum head to the top of the liquid nitrogen barrel far away from the vacuum head; the second wire is movably arranged on the other side of the conductive rod far away from the vacuum head, and the second wire extends from the other side of the conductive rod far away from the vacuum head to the top of the liquid nitrogen barrel close to the vacuum head; the projections of the first wire and the second wire in the x-axis direction are distributed in parallel, and the projections of the first wire and the second wire in the y-axis direction are cross-distributed.

[0008] Preferably, the method for setting different liquid levels further comprises: S201, an auxiliary barrel is fixedly arranged in the liquid nitrogen barrel, and the liquid nitrogen in the liquid nitrogen barrel is quantitatively extracted and input by using the auxiliary barrel, and several groups of dynamic data of the liquid level drop process and the liquid level rise process are measured; S202, according to the measured several groups of dynamic data, the measured several groups of data are input into the value selection model, and the value selection model selects one group of data from the several groups of data as the corresponding relationship between the liquid level value and the resistance value finally selected according to the built-in algorithm; S203, establishing a liquid level resistance value comparison table according to the correspondence between the liquid level value and the resistance value finally selected; S204, measuring the resistance value, comparing the measured resistance value with the liquid level resistance value comparison table, and obtaining liquid level data.

[0009] Preferably, the value selection model is a weighted value selection model, which calculates the weighted average value according to the built-in weighted average formula, and the weighted average value = , is the weight of the i-th group of data, is the mean value of the ith group of data, and n is the number of data groups.

[0010] Preferably, the method for quantitatively extracting and inputting liquid nitrogen in the liquid nitrogen barrel in step S201 further includes: S301, setting an auxiliary pipe in the liquid nitrogen barrel, and using the auxiliary pipe to extract or input liquid nitrogen in the liquid nitrogen barrel; S302, extracting or inputting liquid nitrogen in the liquid nitrogen barrel according to the set auxiliary tube, and detecting the resistance after the extraction or input is completed; S303, constructing a query table according to the obtained resistance detection result, and comparing and weighting the constructed query table to obtain a resistance liquid level query table; S304, measuring the resistance value, comparing the measured resistance value with the resistance liquid level query table, and obtaining liquid level data.

[0011] Preferably, the interior of the support rod is configured as a hollow structure, and an auxiliary tube is formed after an extension tube is fixedly installed on the support rod. The auxiliary tube is fixedly arranged inside the liquid nitrogen barrel through a bracket, and the bracket is fixedly installed inside the liquid nitrogen barrel. The auxiliary tube is L-shaped, and the auxiliary tube consists of a main tube and an extension tube. The main tube is a support rod with a hollow structure. A rotating device is fixedly arranged on the auxiliary tube, and the main tube and the extension tube are driven to rotate circumferentially in the liquid nitrogen barrel by starting the rotating device.

[0012] Preferably, the method for setting the conductive rod further comprises: a support frame is fixedly set on the floating ring, the conductive rod is fixedly set on the support frame, and the height of the conductive rod is greater than the height of the floating ring.

[0013] Preferably, the minimum installation height of the conductive rod is calculated so that the height of the conductive rod is greater than the height of the floating ring. The minimum installation height of the conductive rod is H2, H2>H1+ΔH, wherein the height of the floating ring is measured as H1, and the maximum liquid level fluctuation range of the liquid nitrogen is determined to be ΔH according to the use conditions of the liquid nitrogen container.

[0014] Preferably, the interior of the floating ring is a hollow structure, and the hollow structure is used to make the floating ring float on the liquid nitrogen.

[0015] The present application also provides a liquid level calibration device for a low-temperature liquid nitrogen biological container based on temperature changes, comprising: a floating ring, a conductive rod fixedly arranged at the center of the floating ring, a support rod movably installed at the center of the conductive rod, the conductive rod is sleeved on the support rod, the top and bottom of the support rod are respectively fixedly connected to the top and bottom of the liquid nitrogen barrel, a third wire is arranged on the conductive rod, two ends of the third wire are respectively arranged on both sides of the conductive rod, and are movably connected to the first wire and the second wire, and the first wire and the second wire are connected to a resistance measuring device.

[0016] One or more technical solutions provided in the present application have at least the following technical effects or advantages: the liquid level distance is reflected by measuring the resistance value, thereby improving the accuracy and stability of the liquid level measurement; the liquid level measurement can be fine-tuned by adjusting the position of the third wire through the floating ring, and the operation is simple and quick; the measured resistance value can be accurately converted into the liquid level distance through the pre-set liquid level-resistance value correspondence table; the setting of the resistance value difference enhances the sensitivity and accuracy of the measurement, so that even if there is a slight change in the liquid level, it can be reflected by the change in the resistance value; the adjustment mechanism of the floating ring makes the fine adjustment of the liquid level simple and quick; only the floating ring needs to be rotated to change the immersion length of the third wire, thereby adjusting the resistance value; By measuring multiple sets of dynamic data during the process of liquid level recovery and decrease, a more accurate liquid level resistance value comparison table between the liquid level and the resistance value R is established, so that the measured liquid level is more accurate. 3-5 cm of liquid nitrogen is quantitatively extracted and input through the auxiliary barrel 160, and multiple sets of liquid level dynamic data are measured. The measured change data are input into the model, and the model selects and averages the values ​​to obtain the corresponding relationship between the final liquid level value and the resistance value. By measuring multiple sets of dynamic data during the process of liquid level recovery and decrease, and establishing the corresponding relationship with the resistance value R, the liquid level can be measured more accurately, and the measurement error caused by the fluctuation of the liquid nitrogen liquid level can be reduced. The model selects and averages the measured change data to obtain a more stable corresponding relationship between the liquid level value and the resistance value, thereby improving the reliability of the measurement result. By using an L-shaped auxiliary tube for rotation and extraction operations, setting a waiting time of N seconds and weighting processing, the liquid level change in the liquid nitrogen barrel is made more uniform, thereby improving the accuracy of resistance measurement. The uniformity of liquid level change can be quantified by comparing the liquid level height difference in different directions, and the accuracy of resistance measurement can be quantified by comparing the deviation between the weighted average resistance value and the true value; Reducing the amount of liquid nitrogen entering between the support rod and the conductive rod and reducing the impact of liquid nitrogen on the conductive rod makes the resistance measurement more accurate. By increasing the height of the conductive rod, a liquid nitrogen isolation space is formed, which effectively prevents the direct impact of liquid nitrogen on the conductive rod. The increased height of the conductive rod ensures that even if the liquid nitrogen level fluctuates, it will not contact the conductive rod, thereby maintaining the stable conductivity of the conductive rod, improving the accuracy of resistance measurement, and reducing measurement errors caused by the influence of liquid nitrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic flow chart of a method for calibrating the liquid level of a low-temperature liquid nitrogen biological container based on temperature variation of the present invention; Figure 2 It is a structural schematic diagram of a liquid level calibration device of a low-temperature liquid nitrogen biological container based on temperature variation of the present invention; Figure 3 is a top view of the calibration device of the present invention; Figure 4 A schematic diagram of a process for setting different liquid levels according to an embodiment of the present invention; Figure 5 This is a schematic structural diagram of an auxiliary barrel according to an embodiment of the present invention; Figure 6 It is a schematic diagram of the process of setting the auxiliary pipe according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of the auxiliary pipe according to an embodiment of the present invention; Figure 8 It is a schematic diagram of the structure of a support frame according to an embodiment of the present invention.

[0018] In the figure: 100, first conductor; 110, second conductor; 120, support rod; 130, conductive rod; 140, floating ring; 150, third conductor; 160, auxiliary barrel; 170, liquid nitrogen barrel; 180, vacuum head; 190, rotating device; 200, auxiliary pipe; 210, main pipe; 220, extension pipe; 230, support frame; 240, liquid level line. DETAILED DESCRIPTION

[0019] To facilitate the understanding of the present invention, the present application will be described more comprehensively below with reference to the relevant drawings; the drawings show preferred embodiments of the present invention, but the present invention can be implemented in many different forms and is not limited to the embodiments described herein; on the contrary, the purpose of providing these embodiments is to enable a more thorough and comprehensive understanding of the disclosed content of the present invention.

[0020] It should be noted that the terms “vertical”, “horizontal”, “up”, “down”, “left”, “right” and similar expressions used in this document are only for illustrative purposes and do not represent the only implementation method.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs; the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the term "and / or" used herein includes any and all combinations of one or more related listed items.

[0022] Embodiment 1: Figure 2 and Figure 3 It is a structural schematic diagram of a liquid level calibration device of a low-temperature liquid nitrogen biological container based on temperature change according to an embodiment of the present invention, comprising: a floating ring 140, which is a hollow ring and floats on liquid nitrogen and is arranged in a liquid nitrogen barrel 170, a conductive rod 130 is fixedly arranged at the center of the floating ring 140, a support rod 120 is movably installed at the center of the conductive rod 130, the conductive rod 130 is sleeved on the support rod 120, the top and bottom of the support rod 120 are respectively fixedly connected to the top and bottom of the liquid nitrogen barrel 170, and the support rod 120 enhances the stability of the floating ring 140 and reduces the left and right shaking of the floating ring 140.

[0023] The conductive rod 130 is provided with a third conductive wire 150, and the two ends of the third conductive wire 150 are respectively arranged on both sides of the conductive rod 130, and are movably connected with the first conductive wire 100 and the second conductive wire 110, and the movably connected is realized by a sliding contact. The movably connected means that as the liquid level changes, the third conductive wire 150 on the conductive rod 130 can maintain contact with the first conductive wire 100 and the second conductive wire 110 to form a continuous circuit. The first conductive wire 100 is movably arranged on one side of the conductive rod 130 close to the vacuum head 180, and the first conductive wire 150 is movably connected to the first conductive wire 100 and the second conductive wire 110. 00 extends from one side of the conductive rod 130 close to the vacuum head 180 to the top of the liquid nitrogen barrel 170 far away from the vacuum head 180, the second conductive wire 110 is movably arranged on the other side of the conductive rod 130 far away from the vacuum head 180, the second conductive wire 110 extends from the other side of the conductive rod 130 far away from the vacuum head 180 to the top of the liquid nitrogen barrel 170 close to the vacuum head 180, the projections of the first conductive wire 100 and the second conductive wire 110 in the x-axis direction are parallelly distributed, and the projections of the first conductive wire 100 and the second conductive wire 110 in the y-axis direction are cross-distributed.

[0024] The resistance of the first wire 100 and the second wire 110 is measured by connecting the first wire 100 and the second wire 110 to a resistance measuring device, and the resistance measuring device converts the measured resistance value into an electrical signal, which is then transmitted to a data processing and display system for display.

[0025] like Figure 1As shown, the steps of the liquid level calibration method of the low-temperature liquid nitrogen biological container based on temperature change are as follows: S101, setting different liquid levels in the liquid nitrogen barrel 170, measuring and calculating the resistance values ​​of the first wire 100 and the second wire 110 corresponding to each liquid level using a resistance measuring device, and forming a liquid level resistance value correspondence table; Before starting the measurement, adjust the liquid level to the lowest point, and use the lowest point of the liquid level as the starting point of the measurement. Start the resistance measuring device to measure the resistance value between the first wire 100 and the second wire 110, and record the measured resistance value. Gradually increase the liquid level by 1 cm each time to ensure that the liquid level increase process is smooth and without fluctuations. Measure the resistance value of the new liquid level obtained after each increase of 1 cm, and record the resistance value at each liquid level in the table in turn to form a one-to-one correspondence with the corresponding liquid level height. Check the resistance value at each liquid level to ensure that they are correctly matched with the corresponding liquid level height, and organize them to form a liquid level-resistance value correspondence table.

[0026] In some embodiments, a resistance measuring device is used to set different liquid levels, measure and calculate the resistance values ​​of the first wire 100 (L1) and the second wire 110 (L2) corresponding to each liquid level, and form a liquid level-resistance value correspondence table. The liquid level is adjusted to the lowest point, assuming it is 0 cm, as the starting point of the measurement, and the resistance measuring device is started to measure the resistance value between L1 and L2. The measurement result is 10Ω, which is recorded in the record table: "Liquid level height: 0 cm, resistance value: 10Ω". The liquid level is gradually increased by 1 cm each time to ensure that the liquid level increase process is smooth and without fluctuations. When the liquid level increases to 1 cm, the resistance value between L1 and L2 is measured again, and the measurement result is 10.5Ω, which is recorded in the record table: "Liquid level height: 1 cm, resistance value: 10.5Ω". The liquid level is continued to increase to 2 cm, and the resistance value is measured. The result is 11Ω, which is recorded: "Liquid level height: 2 cm, resistance value: 11Ω". By analogy, each time the liquid level is increased by 1 cm, a resistance value measurement is performed and the result is recorded to form a liquid level-resistance value correspondence table.

[0027] S102, setting different resistances and measuring the resistance values. When the measured resistance value is greater than a preset threshold range, the floating ring 140 is rotated counterclockwise to increase the length of the first wire 100 and the second wire 110 immersed in liquid nitrogen, that is, the resistance is reduced; when the measured resistance value is less than the preset threshold range, the floating ring 140 is rotated clockwise to reduce the length of the first wire 100 and the second wire 110 immersed in liquid nitrogen, that is, the resistance is increased; Specifically, the first wire 100 and the second wire 110 are set to different resistance values, namely, a large resistor and a small resistor, and the ratio range of the large resistor to the small resistor is 2:1 to 3:1. The error during resistance measurement is reduced by setting the ratio range of the large resistor to the small resistor. The resistance value of L1 is set to 100Ω, and L1 is a large resistor. According to the ratio range of the large resistor to the small resistor being 2:1 to 3:1, the resistance value of L2 is between 33.33Ω (100Ω / 3) and 50Ω (100Ω / 2), and the resistance value of L2 is set to 40Ω. One end of the third wire 150 of L1 is connected to one input end of the resistance measuring device, and one end of the third wire 150 of L2 is connected to the other input end of the resistance measuring device, and the different set resistances are measured.

[0028] When the measured resistance value R is greater than the preset value, the measured liquid level will be lower than the actual liquid level. On the contrary, when the measured resistance value R is less than the preset value, the measured liquid level will be higher than the actual liquid level. The resistance greater than the preset value and less than the preset value are adjusted. When the resistance value R is greater than the preset value, the adjustment is made by turning the floating ring 140 left. Turning the floating ring 140 left will reduce the effective length of the resistor and increase the conductive part of the wire in the liquid nitrogen. The resistance value R decreases and gradually approaches the preset value. When the resistance value R is less than the preset value, the adjustment is made by turning the floating ring 140 right. Turning the floating ring 140 right will increase the effective length of the resistor and reduce the conductive part of the wire in the liquid nitrogen. As a result, the resistance value R increases and gradually approaches the preset value.

[0029] S103, converting the measured resistance value or the adjusted resistance value into an electrical signal through a resistance measuring device, transmitting the electrical signal to a data processing system, and the data processing system calculates and compares the received electrical signal according to a liquid level resistance value corresponding table to obtain a current liquid level distance; Furthermore, a resistance measuring device is used to convert the measured resistance value or the adjusted resistance value into an electrical signal. The converted electrical signal is an analog signal. The analog signal is a continuously changing signal, and its amplitude, frequency or phase can represent the size of the resistance value. The converted electrical signal is transmitted to the data processing system. The data processing system processes and calculates the received electrical signal according to a pre-established liquid level resistance value correspondence table. The electrical signal received by the data processing system is converted into a resistance value, and then by comparing the resistance value with the resistance value in the correspondence table, the system calculates the current liquid level distance. The calculated liquid level distance is displayed on the display screen of the data processing system, which is convenient for observing and recording the liquid level distance. The display screen is an LED display screen.

[0030] The technical solution in the above-mentioned embodiment of the present application has at least the following technical effects or advantages: the liquid level distance is reflected by measuring the resistance value, which improves the accuracy and stability of the liquid level measurement. The liquid level measurement can be fine-tuned by adjusting the position of the wire through the floating ring 140. The operation is simple and quick. The measured resistance value can be accurately converted into the liquid level distance through the pre-set liquid level-resistance value correspondence table. The setting of the resistance value difference enhances the sensitivity and accuracy of the measurement, so that even if there is a slight change in the liquid level, it can be reflected by the change in the resistance value. The adjustment mechanism of the floating ring 140 makes the fine-tuning of the liquid level simple and quick. The immersion length of the wire can be changed by rotating the floating ring 140, thereby adjusting the resistance value.

[0031] Embodiment 2: Based on the fact that measuring static data in embodiment 1 may lead to errors, this embodiment sets an auxiliary barrel 160 inside the liquid nitrogen barrel 170, quantitatively extracts liquid nitrogen from the auxiliary barrel 160, and measures multiple sets of dynamic data of the liquid level rising and falling processes. The dynamic data makes the measured liquid level more accurate.

[0032] like Figure 4 and Figure 5 As shown, the method for setting different liquid levels also includes: S201, the auxiliary barrel 160 is fixedly arranged in the liquid nitrogen barrel 170, and the liquid nitrogen in the liquid nitrogen barrel 170 is quantitatively extracted and input by using the auxiliary barrel 160 to measure several groups of dynamic data of the liquid level drop process and the liquid level rise process; Specifically, the auxiliary barrel 160 is fixedly arranged inside the liquid nitrogen barrel 170, and the bottom of the auxiliary barrel 160 is an open structure. The bottom of the auxiliary barrel 160 is connected with the inside of the liquid nitrogen barrel 170. By quantitatively extracting 3-5 cm of liquid nitrogen from the top of the auxiliary barrel 160 and setting a 3-5 cm height range, the 3-5 cm height range can produce obvious liquid level fluctuations, so that multiple sets of dynamic data can be measured.

[0033] Use a liquid nitrogen pump to extract liquid nitrogen from the auxiliary barrel 160. When the height of the liquid nitrogen extracted by the liquid nitrogen pump is set to 3 cm, first measure the resistance at the initial liquid level value, then use the liquid nitrogen pump to extract the liquid nitrogen in the liquid nitrogen barrel 170, and use the resistance measuring device to measure the value of the resistance at the liquid level after the liquid nitrogen is extracted. Re-input the extracted liquid nitrogen into the liquid nitrogen barrel 170. After the input is completed, use the resistance measuring device to measure the value of the resistance at the liquid level; when the height of the liquid nitrogen extracted by the liquid nitrogen pump is set to 4 cm, measure the resistance at the initial liquid level value, use the liquid nitrogen pump to extract the liquid nitrogen in the liquid nitrogen barrel 170, and use the resistance measuring device to measure the value of the resistance at the liquid level after the liquid nitrogen is extracted. The value of the resistance under the liquid level is measured, the extracted liquid nitrogen is re-input into the liquid nitrogen barrel 170, and the value of the resistance under the liquid level is measured by a resistance measuring device after the input is completed; when the height of the liquid nitrogen extracted by the liquid nitrogen pump is set to 5 cm, the resistance under the initial liquid level value is measured, the liquid nitrogen in the liquid nitrogen barrel 170 is extracted by a liquid nitrogen pump, and the value of the resistance under the liquid level is measured by a resistance measuring device after the liquid nitrogen is extracted, and the extracted liquid nitrogen is re-input into the liquid nitrogen barrel 170, and the value of the resistance under the liquid level is measured by a resistance measuring device after the input is completed; the multiple groups of dynamic data measured above are recorded, and the recorded data include the range and boundary value of the data.

[0034] S202, according to the measured several groups of dynamic data, the measured several groups of data are input into the value selection model, and the value selection model selects one group of data from the several groups of data as the corresponding relationship between the liquid level value and the resistance value finally selected according to the built-in algorithm; Furthermore, the several groups of data obtained by measurement are cleaned to remove abnormal values ​​or obviously erroneous data points, and the processed groups of data are input into the weighted value selection model. The average value and median value of each group of data are calculated according to the built-in average algorithm and median algorithm in the weighted value selection model; weights are assigned according to the fluctuation range, measurement accuracy and representativeness of each group of data. The smaller the fluctuation range, the more stable the data, the larger the weight, the higher the measurement accuracy, the more reliable the data, the larger the weight, the more representative the data of the actual liquid level change, and the larger the weight. The weighted average formula is used to calculate the weighted average value, and the weighted average value = ,in, is the weight of the i-th group of data, is the average value of the i-th group of data, n is the number of data groups, and the calculated weighted average value is compared with the average value and median. If the data is relatively stable as a whole and the fluctuation range is small, the weighted average value is selected as the final result; if the data is particularly stable and representative, the average value or median of the group is selected as the final result. When the weighted average value is slightly different from the average value of a group of data, the average value of the group is selected as the final result. After the weighted value selection model is processed, the corresponding relationship between the final selected liquid level value and the resistance value is output.

[0035] S203, establishing a liquid level resistance value comparison table according to the correspondence between the liquid level value and the resistance value finally selected; S204, measuring the resistance value, comparing the measured resistance value with the liquid level resistance value comparison table, and obtaining liquid level data; Furthermore, the obtained resistance values ​​are compared one by one with the liquid level resistance value comparison table, and the corresponding liquid level data are found in the liquid level resistance value corresponding table.

[0036] The technical solution in the above-mentioned embodiment of the present application has at least the following technical effects or advantages: by measuring multiple sets of dynamic data in the process of liquid level recovery and decrease, a more accurate liquid level resistance value comparison table between the liquid level and the resistance value R is established, so that the measured liquid level is more accurate, and 3-5 cm of liquid nitrogen is quantitatively extracted and input through the auxiliary barrel 160, and multiple sets of liquid level dynamic data are measured, and the measured change data are input into the model. The model selects and averages the values ​​to obtain the final correspondence between the liquid level value and the resistance value. By measuring multiple sets of dynamic data in the process of liquid level recovery and decrease, and establishing a correspondence with the resistance value R, the liquid level can be measured more accurately, and the measurement error caused by the fluctuation of the liquid nitrogen liquid level is reduced. The measured change data is selected and averaged by the model, and a more stable correspondence between the liquid level value and the resistance value can be obtained, thereby improving the reliability of the measurement results.

[0037] Embodiment 3: Based on the fact that the auxiliary barrel 160 in Embodiment 2 causes uneven changes in the liquid nitrogen level when extracting or inputting liquid nitrogen, the liquid nitrogen level changes significantly in the direction close to the auxiliary barrel 160, but not significantly in the direction away from the auxiliary barrel 160. In this embodiment, an L-shaped auxiliary pipe 200 is provided. By rotating the L-shaped auxiliary pipe 200, the auxiliary pipe 200 extracts liquid nitrogen from different directions in the liquid nitrogen barrel 170, so that the auxiliary pipe 200 can make the liquid nitrogen level change more uniform and balanced when extracting or inputting liquid nitrogen.

[0038] like Figure 6 and Figure 7 As shown, the method for quantitatively extracting and inputting the liquid nitrogen in the liquid nitrogen barrel 170 in step S201 also includes: S301, an auxiliary pipe 200 is arranged in the liquid nitrogen barrel 170, and the liquid nitrogen in the liquid nitrogen barrel 170 is extracted or input using the auxiliary pipe 200; Further, the interior of the support rod 120 is set to a hollow structure, and an auxiliary pipe 200 is formed after an extension pipe 220 is fixedly installed on the support rod 120. The auxiliary pipe 200 is fixedly arranged in the liquid nitrogen barrel 170 through a bracket, and the bracket is fixedly installed in the liquid nitrogen barrel 170. The auxiliary pipe 200 is L-shaped, and the auxiliary pipe 200 is composed of a main pipe 210 and an extension pipe 220. The main pipe 210 is a support rod 120 with a hollow structure. A rotating device is fixedly arranged on the auxiliary pipe 200, and preset angle parameters and speed parameters are input into the rotating device, wherein the preset angle parameters and speed parameters are obtained through experiments, so that liquid nitrogen in different directions in the liquid nitrogen barrel 170 can be evenly extracted. The main pipe 210 and the extension pipe 220 are driven to rotate circumferentially in the liquid nitrogen barrel 170 by starting the rotating device. The extension pipe 220 rotates circumferentially in the liquid nitrogen barrel 170 so that the extension pipe 220 can extract or input liquid nitrogen in different directions, so that the liquid level of liquid nitrogen in the liquid nitrogen barrel 170 changes evenly.

[0039] S302, extracting or inputting liquid nitrogen in the liquid nitrogen barrel 170 according to the auxiliary pipe 200, and detecting the resistance after the extraction or input is completed; Specifically, a liquid nitrogen pump is used to repeatedly extract or input the liquid nitrogen in the liquid nitrogen barrel 170 through the auxiliary pipe 200, and the number and amount of extraction and input of liquid nitrogen are obtained by experiment. The parameters of the liquid nitrogen pump are set according to the experimental data. Each time the liquid nitrogen barrel 170 is extracted or input through the auxiliary pipe 200, the resistance measuring device measures the resistance. Before using the resistance measuring device to measure the resistance, wait for 10 seconds to keep the liquid nitrogen level extracted or input by the liquid nitrogen pump uniform, so as to avoid the influence of liquid nitrogen level fluctuation on the measured resistance. The measured results are recorded, and the measurement is repeated multiple times. Before each measurement, the above-mentioned rotation, extraction and waiting operations are performed to make the conditions of each measurement consistent, so as to improve the accuracy and reliability of the measurement.

[0040] S303, constructing a query table according to the obtained resistance detection result, and comparing and weighting the constructed query table to obtain a resistance liquid level query table; Furthermore, the liquid surface resistance values ​​in the liquid nitrogen barrel 170 obtained by multiple measurements are recorded and organized into a set of ordered data sets, the data in the data sets are compared, the measured resistance values ​​are compared one by one, and the resistance values ​​with similar measured values ​​are retained. The resistance values ​​of the liquid surface in the liquid nitrogen barrel 170 with similar measured values ​​are kept at a relatively stable level, thereby reducing the errors caused by abnormal conditions; weights are assigned according to the number of measurements, the stability of the measured values, and the measurement conditions, and the organized measurement data and the corresponding weights are input into Python using the data processing software Python. Python processes the input data and weights according to the weighted average formula, calculates the weighted average resistance value, outputs the compared and weighted resistance value, and the output resistance value and the liquid nitrogen level constitute a resistance level query table.

[0041] S304, measuring the resistance value, comparing the measured resistance value with the resistance liquid level query table, and obtaining liquid level data.

[0042] The technical solution in the above-mentioned embodiment of the present application has at least the following technical effects or advantages: by using the L-shaped auxiliary tube 200 to perform rotation and extraction operations, and setting the waiting time N seconds and weighting processing, the liquid level change in the liquid nitrogen barrel 170 is more uniform, thereby improving the accuracy of resistance measurement. The uniformity of the liquid level change can be quantified by comparing the liquid level height difference in different directions, and the accuracy of the resistance measurement can be quantified by comparing the deviation between the weighted average resistance value and the true value.

[0043] Embodiment 4: Based on the conductive rod 130 fixedly provided at the center of the floating ring 140 in Embodiment 1, the floating ring 140 and the conductive rod 130 are at the same height when viewed from the side. When the floating ring 140 moves up and down according to the liquid level, liquid nitrogen will enter between the support rod 120 and the conductive rod 130. There is an intermolecular force between the support rod 120 and the conductive rod 130, which affects the conductivity of the conductive rod 130, and further affects the resistance measurement of the measuring equipment.

[0044] like Figure 8 As shown, the method for setting the conductive rod 130 further includes: A support frame 230 is fixedly arranged on the floating ring 140, and a conductive rod 130 is fixedly arranged on the support frame 230; specifically, a support frame 230 is fixedly arranged on the floating ring 140, and the conductive rod 130 is fixedly installed on the support frame 230. From the perspective of the front view, the height of the conductive rod 130 is greater than the height of the floating ring 140, and the minimum installation height of the conductive rod 130 is H2, H2>H1+ΔH, wherein the height of the floating ring 140 is measured as H1, and according to the use conditions of the liquid nitrogen container, the maximum liquid level fluctuation range of the liquid nitrogen is determined to be ΔH. When the floating ring 140 floats according to the liquid nitrogen level, it can prevent the liquid nitrogen from entering between the support rod 120 and the conductive rod 130 due to the fluctuation of the floating ring 140, thereby reducing the influence of the liquid nitrogen on the conductivity of the conductive rod 130. Different liquid levels are set, and the resistance value corresponding to each liquid level is measured and calculated to form a liquid level resistance value correspondence table. Then, the resistance is measured using a resistance measuring device, and the corresponding liquid level is found in the liquid level resistance value correspondence table according to the measured resistance.

[0045] The technical solutions in the above-mentioned embodiments of the present application have at least the following technical effects or advantages: reducing the entry of liquid nitrogen between the support rod 120 and the conductive rod 130, reducing the influence of liquid nitrogen on the conductive rod 130, making the measurement of resistance more accurate, and forming a liquid nitrogen isolation space by increasing the installation height of the conductive rod 130, which effectively prevents the direct influence of liquid nitrogen on the conductive rod 130. The increased height of the conductive rod 130 ensures that even if the liquid nitrogen level fluctuates, it will not contact the conductive rod 130, thereby maintaining the stable conductivity of the conductive rod 130, improving the accuracy of resistance measurement, and reducing the measurement error caused by the influence of liquid nitrogen.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for calibrating the liquid level of a low-temperature liquid nitrogen biological container based on temperature variation, characterized in that: include: S101, setting different liquid levels in the liquid nitrogen barrel (170), measuring and calculating the resistance value of the first wire (100) and the second wire (110) corresponding to each liquid level using a resistance measuring device, and forming a liquid level resistance value correspondence table; S102, different resistors are arranged in the liquid nitrogen barrel (170), and the resistance values ​​are measured. When the measured resistance value is greater than a preset threshold range, the floating ring (140) is rotated counterclockwise to increase the length of the first wire (100) and the second wire (110) immersed in the liquid nitrogen, that is, the resistance is reduced; when the measured resistance value is less than the preset threshold range, the floating ring (140) is rotated clockwise to reduce the length of the first wire (100) and the second wire (110) immersed in the liquid nitrogen, that is, the resistance is increased; S103, converting the measured resistance value or the adjusted resistance value into an electrical signal through a resistance measuring device, transmitting the electrical signal to a data processing system, and the data processing system calculates and compares the received electrical signal according to a liquid level resistance value corresponding table to obtain a current liquid level distance; A floating ring (140) is further provided in the liquid nitrogen barrel (170), a conductive rod (130) is fixedly provided at the center of the floating ring (140), a support rod (120) is movably installed at the center of the conductive rod (130), the conductive rod (130) is sleeved on the support rod (120), and the top and bottom of the support rod (120) are respectively fixedly connected to the top and bottom of the liquid nitrogen barrel (170); A wire (150) is arranged on the conductive rod (130), two ends of the wire (150) are respectively arranged on both sides of the conductive rod (130) and are movably connected to a first wire (100) and a second wire (110), and the first wire (100) and the second wire (110) are connected to a resistance measuring device.

2. The method for calibrating the liquid level of a low-temperature liquid nitrogen biological container based on temperature variation according to claim 1, characterized in that: The first wire (100) is movably arranged on one side of a conductive rod (130) close to a vacuum head (180), the first wire (100) extends from one side of the conductive rod (130) close to the vacuum head (180) to the top of a liquid nitrogen barrel (170) away from the vacuum head (180), the second wire (110) is movably arranged on the other side of the conductive rod (130) away from the vacuum head (180), the second wire (110) extends from the other side of the conductive rod (130) away from the vacuum head (180) to the top of the liquid nitrogen barrel (170) close to the vacuum head (180), the projections of the first wire (100) and the second wire (110) in the x-axis direction are parallel, and the projections of the first wire (100) and the second wire (110) in the y-axis direction are cross-distributed.

3. The method for calibrating the liquid level of a low-temperature liquid nitrogen biological container based on temperature variation according to claim 1, characterized in that: The method for setting different liquid levels also includes: S201, a supplementary barrel (160) is fixedly arranged in the liquid nitrogen barrel (170), and liquid nitrogen in the liquid nitrogen barrel (170) is quantitatively extracted and input by using the supplementary barrel (160), so as to measure several groups of dynamic data of the liquid level drop process and the liquid level rise process; S202, according to the measured several groups of dynamic data, the measured several groups of data are input into the value selection model, and the value selection model selects one group of data from the several groups of data as the corresponding relationship between the liquid level value and the resistance value finally selected according to the built-in algorithm; S203, establishing a liquid level resistance value comparison table according to the correspondence between the liquid level value and the resistance value finally selected; S204, measuring the resistance value, comparing the measured resistance value with the liquid level resistance value comparison table, and obtaining liquid level data.

4. The method for calibrating the liquid level of a low-temperature liquid nitrogen biological container based on temperature variation according to claim 3, characterized in that: The value selection model is a weighted value selection model. The weighted value selection model calculates the weighted average value according to the built-in weighted average formula. The weighted average value = ,in, is the weight of the i-th group of data, is the mean value of the ith group of data, and n is the number of data groups.

5. The method for calibrating the liquid level of a low-temperature liquid nitrogen biological container based on temperature variation according to claim 3, characterized in that: The method for quantitatively extracting and inputting liquid nitrogen from the liquid nitrogen barrel (170) in step S201 further includes: S301, disposing an auxiliary pipe (200) in the liquid nitrogen barrel (170), and using the auxiliary pipe (200) to extract or input liquid nitrogen in the liquid nitrogen barrel (170); S302, extracting or inputting liquid nitrogen in the liquid nitrogen barrel (170) according to the provided auxiliary tube (200), and detecting the resistance after the extraction or input is completed; S303, constructing a query table according to the obtained resistance detection result, and comparing and weighting the constructed query table to obtain a resistance liquid level query table; S304, measuring the resistance value, comparing the measured resistance value with the resistance liquid level query table, and obtaining liquid level data.

6. The method for calibrating the liquid level of a low-temperature liquid nitrogen biological container based on temperature variation according to claim 5, characterized in that: The interior of the support rod (120) is configured to have a hollow structure. An extension tube (220) is fixedly mounted on the support rod (120) to form an auxiliary tube (200). The auxiliary tube (200) is fixedly mounted inside the liquid nitrogen barrel (170) via a bracket. The bracket is fixedly mounted inside the liquid nitrogen barrel (170). The auxiliary tube (200) is L-shaped. The auxiliary tube (200) is composed of a main tube (210) and an extension tube (220). The main tube (210) is a support rod (120) with a hollow structure. A rotating device is fixedly mounted on the auxiliary tube (200). By starting the rotating device, the main tube (210) and the extension tube (220) are driven to rotate in a circumferential direction inside the liquid nitrogen barrel (170).

7. The method for calibrating the liquid level of a low-temperature liquid nitrogen biological container based on temperature variation according to claim 1, characterized in that: The method for arranging the conductive rod (130) further comprises: a support frame (230) is fixedly arranged on the floating ring (140), the conductive rod (130) is fixedly arranged on the support frame (230), and the height of the conductive rod (130) is greater than the height of the floating ring (140).

8. The method for calibrating the liquid level of a low-temperature liquid nitrogen biological container based on temperature variation according to claim 7, characterized in that: The minimum installation height of the conductive rod (130) is calculated so that the height of the conductive rod (130) is greater than the height of the floating ring (140). The minimum installation height of the conductive rod (130) is H2, and H2>H1+ΔH. The height of the floating ring (140) is measured to be H1. According to the use conditions of the liquid nitrogen container, the maximum liquid level fluctuation range of the liquid nitrogen is determined to be ΔH.

9. The method for calibrating the liquid level of a low-temperature liquid nitrogen biological container based on temperature variation according to claim 7, characterized in that: The interior of the floating ring (140) is a hollow structure, and the hollow structure is used to make the floating ring (140) float on liquid nitrogen.

10. A liquid level calibration device for a low-temperature liquid nitrogen biological container based on temperature variation, applied to a liquid level calibration method for a low-temperature liquid nitrogen biological container based on temperature variation as claimed in any one of claims 1 to 9, characterized in that: include: A floating ring (140), wherein a conductive rod (130) is fixedly arranged at the center of the floating ring (140), a support rod (120) is movably installed at the center of the conductive rod (130), the conductive rod (130) is sleeved on the support rod (120), the top and bottom of the support rod (120) are respectively fixedly connected to the top and bottom of a liquid nitrogen barrel (170), a third wire (150) is arranged on the conductive rod (130), two ends of the third wire (150) are respectively arranged on both sides of the conductive rod (130), and are movably connected to a first wire (100) and a second wire (110), and the first wire (100) and the second wire (110) are connected to a resistance measuring device.

Images