A high-precision temperature sensor calibration method in a cryogenic environment

Abstract

The application relates to the technical field of temperature measurement, in particular to a high-precision temperature sensor calibration method under a deep cooling environment. The method comprises the following steps: inserting a reference thermometer and a temperature sensor to be calibrated into a test cavity which is constructed in advance; adjusting the temperature inside the test cavity to a first preset temperature, and measuring a first standard temperature and a first test temperature; adopting a recursive algorithm to calculate a set temperature sequence, adjusting the temperature inside the test cavity according to the set temperature sequence, and measuring a standard temperature sequence and a test temperature sequence; fitting a temperature error function according to the standard temperature sequence and the test temperature sequence; and embedding the temperature error function into the temperature sensor to be calibrated, and calibrating the measurement value of the temperature sensor to be calibrated. The set temperature sequence is autonomously generated, and the calibration of the temperature sensor under the deep cooling environment is realized.

Description

Technical Field

[0001] This invention relates to the field of temperature measurement technology, specifically a method for calibrating a high-precision temperature sensor in a cryogenic environment. Background Technology

[0002] Cryogenic environments generally refer to environments with temperatures ranging from 77 Kelvin to 233 Kelvin. In fields such as aerospace, superconductivity research, and low-temperature physics, temperature monitoring in cryogenic environments has a decisive impact on system safety and experimental accuracy. Therefore, high-precision temperature sensors with excellent low-temperature stability and measurement reliability are required. However, the measurement results of temperature sensors in cryogenic environments are easily affected by nonlinear factors such as heat leakage from the sensor signal wires, leading to parameter distortion. Currently, the mainstream temperature sensor calibration method uses static isothermal point-by-point calibration, which involves placing a reference thermometer and the temperature sensor to be calibrated in an isothermal test chamber, recording the deviation values ​​at preset discrete temperature points, and generating a piecewise linear correction table. This method has the following drawbacks:

[0003] First, it suffers from poor dynamic adaptability. Piecewise linear correction tables cannot capture the complex nonlinear error variations of sensors over a wide temperature range. Second, calibration efficiency is low. Different temperature sensors, due to differences in application, principle, and manufacturing process, inevitably have high-precision and low-precision temperature zones. Current technology fails to adaptively distinguish between these zones, employing a uniformly distributed approach with numerous static calibration points, leading to low efficiency. Third, calibration results are significantly affected by heat leakage from signal cables. In cryogenic environments, heat leakage from sensor signal cables can cause signal distortion.

[0004] Therefore, there is an urgent need to propose an intelligent calibration method that can autonomously generate the optimal temperature test sequence, reduce the impact of heat leakage from signal wires, and accurately capture nonlinear errors in cryogenic environments. Summary of the Invention

[0005] (1) Technical problems to be solved

[0006] The purpose of this invention is to provide a high-precision temperature sensor calibration method for cryogenic environments. During the calibration process, the method autonomously generates the optimal temperature test sequence, reduces the influence of heat leakage from the signal wires, and accurately captures the nonlinear error of temperature measurement in cryogenic environments, thereby improving the calibration effect.

[0007] (2) Technical solution

[0008] To achieve the above objectives, the present invention provides a high-precision temperature sensor calibration method for cryogenic environments, the method comprising the following steps:

[0009] S1, insert the reference thermometer and the temperature sensor to be calibrated into the pre-built test chamber.

[0010] S2, adjust the internal temperature of the test chamber to a preset first temperature; measure the internal temperature of the test chamber using a reference thermometer and a temperature sensor to be calibrated, and transmit the measurements to the central processing unit via a wireless transmission device to obtain the first standard temperature and the first test temperature.

[0011] S3. Based on the first temperature, the first standard temperature, and the first test temperature, a set temperature sequence is calculated using a recursive algorithm. The internal temperature of the test chamber is adjusted sequentially according to the set temperature sequence. The test results of the reference thermometer and the temperature sensor to be calibrated are read through a wireless transmission device to obtain the standard temperature sequence and the test temperature sequence.

[0012] S4. The temperature error function is obtained by fitting the standard temperature sequence and the test temperature sequence; the temperature error function is then embedded into the temperature sensor to be calibrated, and the measured values ​​of the temperature sensor to be calibrated are calibrated.

[0013] Furthermore, the test chamber employs an adaptive temperature regulation algorithm to maintain a uniform temperature at different spatial locations within the test chamber, which can be adjusted according to a set value.

[0014] Further, the method of calculating a set temperature sequence using a recursive algorithm based on a first temperature, a first standard temperature, and a first test temperature, adjusting the internal temperature of the test chamber sequentially according to the set temperature sequence, and reading the test results of a reference thermometer and a temperature sensor to be calibrated via a wireless transmission device to obtain a standard temperature sequence and a test temperature sequence includes:

[0015] S31, the loop flag Set to 1.

[0016] S32, according to the Standard temperature, the The test temperature was calculated to obtain the first Error; the first The formula for calculating the error is:

[0017] ;

[0018] in, Indicates the first Standard temperature Indicates the first Test temperature, Indicates the first error.

[0019] S33, according to the Error, first Temperature calculation yields the first temperature.

[0020] S34, adjust the internal temperature of the test chamber to the first Temperature; the internal temperature of the test chamber is measured using a reference thermometer and a temperature sensor to be calibrated, and transmitted wirelessly to the central processing unit to obtain the result. Standard temperature and the Test temperature.

[0021] S35, The value is increased by 1; steps S32 to S35 are repeated until... The value reaches N Finally, the first standard temperature was obtained up to the [number missing]. N Standard temperature, first test temperature to the... N Test temperature; N This indicates the pre-set maximum number of measurements; The value is 1 to N Integer variables.

[0022] S36, from the first standard temperature to the second N Standard temperature combinations yield a standard temperature sequence; the first test temperature is then set to the next... N The test temperature combination yields the test temperature sequence.

[0023] Furthermore, the statement based on the first Error, first Temperature calculation yields the first Temperature methods include:

[0024] The first Error compared to a pre-set first error threshold Compare, if the first If the error is greater than the first error threshold, then the first formula is used to calculate the... Temperature; if the first If the error is less than or equal to the first error threshold, then the second formula is used to calculate the first error. temperature.

[0025] The first formula is:

[0026] ;

[0027] in, Indicates the first temperature, Indicates the first temperature, This indicates the upper limit of the pre-set constant temperature step.

[0028] The second formula is:

[0029] ;

[0030] in, Represents the calculated first... Temperature gradient.

[0031] Furthermore, the first The method for calculating temperature gradients is as follows:

[0032] The third formula is used to calculate the first... Temperature gradient; the third formula is: ;

[0033] in, This indicates a pre-set second error threshold; This indicates the lower limit of the pre-set constant temperature step.

[0034] Furthermore, the method for obtaining the temperature error function by fitting the standard temperature sequence and the test temperature sequence includes:

[0035] According to the first standard temperature to the... N Standard temperature, first test temperature to the... N The test temperature calculation yielded the first calculation error up to the [missing value]. N Calculation error; where the first The formula for calculating the error is:

[0036] ;

[0037] in, Indicates the first Calculation error; the first calculation error is transferred to the second... N The calculation error combination yields the calculation error sequence.

[0038] Using the test temperature sequence as the independent variable and the calculated error sequence as the dependent variable, a temperature error function is obtained by fitting.

[0039] Furthermore, the method for fitting the temperature error function using the test temperature sequence as the independent variable and the calculated error sequence as the dependent variable includes:

[0040] Construct a fitting function; the fitting function is expressed as:

[0041] ;

[0042] in, Represents the fitted function. This indicates the measured value of the temperature sensor to be calibrated, in Kelvin. Represents the cubic nonlinear coefficients. Represents the second-order nonlinear coefficients. Represents linear coefficients. This indicates the zero-point offset.

[0043] Using the test temperature sequence as the independent variable and the calculation error sequence as the dependent variable, a fitting algorithm was used to obtain the result. , , , The optimal values ​​are denoted as follows: , , , .

[0044] according to , , , The temperature error function is obtained, and the temperature error function is:

[0045] ;

[0046] in, This represents the temperature error function.

[0047] Furthermore, the step involves using the test temperature sequence as the independent variable and the calculated error sequence as the dependent variable, and then employing a fitting algorithm to obtain the result. , , , The optimal values ​​are denoted as follows: , , , The methods include:

[0048] Construct an optimization objective function; the optimization objective function is:

[0049] ;

[0050] With the objective function being minimized and pre-set constraints in place, the particle swarm optimization algorithm is used to calculate the optimal value. , , , The optimal values ​​are denoted as follows: , , , .

[0051] Furthermore, the method for calibrating the measured values ​​of the temperature sensor to be calibrated by embedding the temperature error function into the temperature sensor to be calibrated includes:

[0052] A temperature error function is built into the temperature sensor to be calibrated, and the calibration temperature is calculated based on the measured value of the temperature sensor. The formula for calculating the calibration temperature is as follows:

[0053] ;

[0054] in, Indicates the calibration temperature.

[0055] (3) Beneficial effects

[0056] Compared with the prior art, the beneficial effects of the present invention are:

[0057] 1. Wireless transmission reduces the impact of heat leakage from signal wires, thus improving calibration accuracy.

[0058] 2. Based on the first temperature, the first standard temperature, and the first test temperature, a recursive algorithm is used to calculate the set temperature sequence. The internal temperature of the test chamber is then adjusted sequentially according to this set temperature sequence. The test results from the reference thermometer and the temperature sensor to be calibrated are read via a wireless transmission device to obtain the standard temperature sequence and the test temperature sequence. This method overcomes the inefficiency caused by setting static calibration points by autonomously generating the optimal temperature test sequence.

[0059] 3. Using the test temperature sequence as the independent variable and the calculated error sequence as the dependent variable, a temperature error function is obtained by fitting. This fitting function can adaptively capture the complex nonlinear error characteristics under cryogenic conditions. Attached Figure Description

[0060] Figure 1 This is a flowchart of a high-precision temperature sensor calibration method under cryogenic conditions according to Embodiment 1 of the present invention. Detailed Implementation

[0061] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] Before providing examples, it is necessary to describe the application scenarios of this invention. This embodiment is applied to the calibration of temperature sensors in cryogenic environments. During the calibration process, it autonomously generates the optimal temperature test sequence, reduces the impact of heat leakage from signal wires, and accurately captures nonlinear temperature measurement errors in cryogenic environments.

[0063] Example 1: As Figure 1As shown, this embodiment provides a high-precision temperature sensor calibration method for cryogenic environments, the method comprising the following steps:

[0064] S1, insert the reference thermometer and the temperature sensor to be calibrated into the pre-built test chamber.

[0065] S2, adjust the internal temperature of the test chamber to a preset first temperature; measure the internal temperature of the test chamber using a reference thermometer and a temperature sensor to be calibrated, and transmit the measurements to the central processing unit via a wireless transmission device to obtain the first standard temperature and the first test temperature.

[0066] S3. Based on the first temperature, the first standard temperature, and the first test temperature, a set temperature sequence is calculated using a recursive algorithm. The internal temperature of the test chamber is adjusted sequentially according to the set temperature sequence. The test results of the reference thermometer and the temperature sensor to be calibrated are read through a wireless transmission device to obtain the standard temperature sequence and the test temperature sequence.

[0067] S4. The temperature error function is obtained by fitting the standard temperature sequence and the test temperature sequence; the temperature error function is then embedded into the temperature sensor to be calibrated, and the measured values ​​of the temperature sensor to be calibrated are calibrated.

[0068] For example, a reference thermometer and the temperature sensor to be calibrated are inserted parallel to each other into the axial core region of the test chamber, resulting in a coaxial mounting structure free from thermal conduction interference. A stable temperature field with uniform temperature is achieved through a vacuum insulation layer and thermal shielding design. By adjusting the insertion depth of the reference thermometer and the temperature sensor to be calibrated, it is ensured that the sensing ends of the reference thermometer and the temperature sensor to be calibrated are located in the core temperature field region of the test chamber. The reference thermometer is a thermometer that has undergone traceability verification by a higher-level authority and is capable of measuring the true temperature value.

[0069] The internal temperature of the cavity is adjusted to a preset first temperature using a liquid nitrogen cooling system. Temperature data simultaneously measured by a reference thermometer and the temperature sensor to be calibrated is transmitted in real-time to the central processing unit via a wireless transmission device to obtain the first standard temperature and the first test temperature. The wireless transmission method eliminates errors caused by heat leakage from the wires in traditional methods. All temperature data in this embodiment are in Kelvin.

[0070] Based on the numerical relationship between the first temperature, the first standard temperature, and the first test temperature, a set temperature sequence is dynamically calculated using a recursive algorithm. During the calculation of the set temperature sequence, the measurement results from the reference thermometer and the temperature sensor to be calibrated are fed back to the recursive algorithm for calculation. The internal temperature of the test chamber is adjusted sequentially according to the generated set temperature sequence, and the measurement results from the reference thermometer and the temperature sensor to be calibrated are acquired in real time via wireless transmission, ultimately yielding the standard temperature sequence and the test temperature sequence.

[0071] Based on the numerical relationship between the standard temperature sequence and the test temperature sequence, a temperature error function is fitted. The internal calibration program of the temperature sensor to be calibrated is then written according to the temperature error function, resulting in a calibrated temperature sensor with a built-in error compensation mechanism, enabling automatic correction of measured values.

[0072] Furthermore, the test chamber employs an adaptive temperature regulation algorithm to maintain a uniform temperature at different spatial locations within the test chamber, which can be adjusted according to a set value.

[0073] For example, based on the thermodynamic distribution characteristics of the test chamber, an adaptive temperature control algorithm monitors the axial and radial temperature gradients of the chamber in real time. The power of the multi-segment heaters and the refrigerant flow rate are dynamically adjusted based on the gradient data, ensuring that the temperature uniformity at different spatial locations is stabilized within ±0.05 Kelvin. Based on the externally input set temperature sequence, a feedforward-feedback composite control algorithm rapidly responds to temperature adjustment commands, achieving precise tracking of the setpoint.

[0074] Further, the method of calculating a set temperature sequence using a recursive algorithm based on a first temperature, a first standard temperature, and a first test temperature, adjusting the internal temperature of the test chamber sequentially according to the set temperature sequence, and reading the test results of a reference thermometer and a temperature sensor to be calibrated via a wireless transmission device to obtain a standard temperature sequence and a test temperature sequence includes:

[0075] S31, the loop flag Set to 1.

[0076] S32, according to the Standard temperature, the The test temperature was calculated to obtain the first Error; the first The formula for calculating the error is:

[0077] ;

[0078] in, Indicates the first Standard temperature Indicates the first Test temperature, Indicates the first error.

[0079] S33, according to the Error, first Temperature calculation yields the first temperature.

[0080] S34, adjust the internal temperature of the test chamber to the first Temperature; the internal temperature of the test chamber is measured using a reference thermometer and a temperature sensor to be calibrated, and transmitted wirelessly to the central processing unit to obtain the result. Standard temperature and the Test temperature.

[0081] S35, The value is increased by 1; steps S32 to S35 are repeated until... The value reaches N Finally, the first standard temperature was obtained up to the [number missing]. N Standard temperature, first test temperature to the... N Test temperature; N This indicates the pre-set maximum number of measurements; The value is 1 to N Integer variables.

[0082] S36, from the first standard temperature to the second N Standard temperature combinations yield a standard temperature sequence; the first test temperature is then set to the next... N The test temperature combination yields the test temperature sequence.

[0083] For example, the preset upper limit for the number of measurements is 100. If a high level of accuracy is required for the final calibration result, a larger upper limit for the number of measurements can be set, but this will consume more computing power. If a lower level of accuracy is required for the final calibration result, a smaller upper limit for the number of measurements can be set, which will consume less computing power.

[0084] Furthermore, the statement based on the first Error, first Temperature calculation yields the first Temperature methods include:

[0085] The first Error compared to a pre-set first error threshold Compare, if the first If the error is greater than the first error threshold, then the first formula is used to calculate the... Temperature; if the first If the error is less than or equal to the first error threshold, then the second formula is used to calculate the first error. temperature.

[0086] The first formula is:

[0087] ;

[0088] in, Indicates the first temperature, Indicates the first temperature, This indicates the upper limit of the pre-set constant temperature step.

[0089] The second formula is:

[0090] ;

[0091] in, Represents the calculated first... Temperature gradient.

[0092] For example, based on the comparison between the error value at the current temperature point and a first error threshold, a temperature adjustment strategy is dynamically selected to achieve efficient calibration. When the... When the error exceeds the first error threshold, it indicates that the temperature sensor exhibits significant distortion in this temperature range. This suggests that the temperature sensor itself is unsuitable for measuring this temperature range, and therefore, further computational effort should be avoided. The next temperature point is generated based on the upper limit of the constant temperature step, quickly locating the critical transition zone requiring fine-tuning by significantly traversing the distortion temperature range. When the... When the error is less than or equal to the first error threshold, it indicates that the temperature sensor has entered a critical transition zone requiring fine calibration. This is based on the dynamically calculated... The temperature step generates the next temperature point.

[0093] Furthermore, the first The method for calculating temperature gradients is as follows:

[0094] The third formula is used to calculate the first... Temperature gradient; the third formula is: ;

[0095] in, This indicates a pre-set second error threshold; This indicates the lower limit of the pre-set constant temperature step.

[0096] For example, establish the first Error and the first The mapping function of the temperature step. When the... When the error is between the second error threshold and the first error threshold, the first... Temperature gradient follows the first The error changes continuously and linearly. When the... When the error is less than or equal to the second error threshold, the lower limit of the constant temperature step is used as the step size.

[0097] Furthermore, the method for obtaining the temperature error function by fitting the standard temperature sequence and the test temperature sequence includes:

[0098] According to the first standard temperature to the... NStandard temperature, first test temperature to the... N The test temperature calculation yielded the first calculation error up to the [missing value]. N Calculation error; where the first The formula for calculating the error is:

[0099] ;

[0100] in, Indicates the first Calculation error; the first calculation error is transferred to the second... N The calculation error combination yields the calculation error sequence.

[0101] Using the test temperature sequence as the independent variable and the calculated error sequence as the dependent variable, a temperature error function is obtained by fitting.

[0102] Furthermore, the method for fitting the temperature error function using the test temperature sequence as the independent variable and the calculated error sequence as the dependent variable includes:

[0103] Construct a fitting function; the fitting function is expressed as:

[0104] ;

[0105] in, Represents the fitted function. This indicates the measured value of the temperature sensor to be calibrated, in Kelvin. Represents the cubic nonlinear coefficients. Represents the second-order nonlinear coefficients. Represents linear coefficients. This indicates the zero-point offset.

[0106] Using the test temperature sequence as the independent variable and the calculation error sequence as the dependent variable, a fitting algorithm was used to obtain the result. , , , The optimal values ​​are denoted as follows: , , , .

[0107] according to , , , The temperature error function is obtained, and the temperature error function is:

[0108] ;

[0109] in, This represents the temperature error function.

[0110] For example, a mathematical mapping model, i.e., a fitting function, is established with the measured value of the temperature sensor to be calibrated as input and the error value as output. Through extensive experiments and physical laws, it is found that the error value and the measured value of the temperature sensor to be calibrated exhibit an approximately cubic nonlinear relationship. Based on this, the fitting function is expressed as a cubic polynomial. In this cubic polynomial, This represents the cubic nonlinear coefficient, expressed in Kelvin to the power of -2. This represents the quadratic nonlinear coefficient, expressed in Kelvin to the power of -1. Represents linear coefficients, dimensionless. This represents the zero-point offset, measured in Kelvin. Based on the principle of minimizing the fitting residual, an optimization algorithm iteratively calculates the numerical solutions of the polynomial coefficients to obtain the optimal combination of coefficients that best matches the fitted curve with the distribution of error data points. The polynomial function expression is then reconstructed based on this coefficient combination, yielding a temperature error function that accurately describes the nonlinear error behavior of the sensor under calibration in a cryogenic environment. This function can accept any measured value as input and outputs the corresponding error compensation amount in real time.

[0111] Furthermore, the step involves using the test temperature sequence as the independent variable and the calculated error sequence as the dependent variable, and then employing a fitting algorithm to obtain the result. , , , The optimal values ​​are denoted as follows: , , , The methods include:

[0112] Construct an optimization objective function; the optimization objective function is:

[0113] ;

[0114] With the objective function being minimized and pre-set constraints in place, the particle swarm optimization algorithm is used to calculate the optimal value. , , , The optimal values ​​are denoted as follows: , , , .

[0115] Furthermore, the method for calibrating the measured values ​​of the temperature sensor to be calibrated by embedding the temperature error function into the temperature sensor to be calibrated includes:

[0116] A temperature error function is built into the temperature sensor to be calibrated, and the calibration temperature is calculated based on the measured value of the temperature sensor. The formula for calculating the calibration temperature is as follows:

[0117] ;

[0118] in, Indicates the calibration temperature.

[0119] For example, a temperature error function is written into the non-volatile memory of the temperature sensor to be calibrated via a programming interface, resulting in an embedded hardware structure with self-calibration capabilities. The measured values ​​of the temperature sensor to be calibrated, acquired in real time by the sensor, are input into the temperature error function for calculation, yielding the error compensation amount corresponding to the current temperature point. Based on the arithmetic logic of "subtracting the error compensation amount from the measured value of the temperature sensor to be calibrated," the built-in microprocessor performs the subtraction operation in real time to obtain the true value of the calibrated physical temperature. This true value is used to replace the original signal output, resulting in the calibration temperature that eliminates cryogenic nonlinearity errors, thus achieving online self-calibration without external intervention.

[0120] Finally, it should be noted that although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-precision temperature sensor calibration method in a cryogenic environment, characterized by, The method comprises the following steps: S1, inserting a reference thermometer and a temperature sensor to be calibrated into a pre-constructed test cavity; S2, adjusting the temperature inside the test cavity to a pre-set first temperature; measuring the temperature inside the test cavity by the reference thermometer and the temperature sensor to be calibrated respectively, and transmitting the test results to the central processing unit through the wireless transmission device to obtain a first standard temperature and a first test temperature; S3, calculating a set temperature sequence according to the first temperature, the first standard temperature and the first test temperature by using a recursive algorithm, adjusting the temperature inside the test cavity according to the set temperature sequence in turn, and reading the test results of the reference thermometer and the temperature sensor to be calibrated through the wireless transmission device to obtain a standard temperature sequence and a test temperature sequence; S4, fitting a temperature error function according to the standard temperature sequence and the test temperature sequence; and calibrating the measurement value of the temperature sensor to be calibrated by embedding the temperature error function into the temperature sensor to be calibrated. The method for calculating the set temperature sequence according to the first temperature, the first standard temperature and the first test temperature by using the recursive algorithm, adjusting the temperature inside the test cavity according to the set temperature sequence in turn, and reading the test results of the reference thermometer and the temperature sensor to be calibrated through the wireless transmission device to obtain the standard temperature sequence and the test temperature sequence comprises: S31, set the cycle flag to 1; S32, according to the first standard temperature, the first test temperature, the first error; the first error is calculated according to the following formula: ； wherein, represents the standard temperature, represents the test temperature, represents the error; S33, according to the first error, the first temperature calculation of the first temperature; S34, adjusting the temperature inside the test chamber to the first temperature; measuring the temperature inside the test chamber by a reference thermometer and the temperature sensor to be calibrated respectively, and transmitting to the central processing unit by a wireless transmission device to obtain the first standard temperature and the first test temperature; S35, The value is increased by 1; steps S32 to S35 are repeated until... The value reaches N Finally, the first standard temperature was obtained up to the [number missing]. N Standard temperature, first test temperature to the... N Test temperature; N This indicates the pre-set maximum number of measurements; The value is 1 to N Integer variables; S36, from the first standard temperature to the second N Standard temperature combinations yield a standard temperature sequence; the first test temperature is then set to the next... N The test temperature combination yields the test temperature sequence.

2. The method of calibrating a high-precision temperature sensor in a cryogenic environment of claim 1, wherein, The test cavity adopts an adaptive temperature adjustment algorithm, so that the temperature at different spatial positions in the test cavity is uniform and can be adjusted according to the set value.

3. A high-precision temperature sensor calibration method in a cryogenic environment as claimed in claim 2, characterized in that, The method according to the first error, the first temperature calculation of the first The method of calculating the temperature comprises: The first Error compared to a pre-set first error threshold Compare, if the first If the error is greater than the first error threshold, then the first formula is used to calculate the... Temperature; if the first If the error is less than or equal to the first error threshold, then the second formula is used to calculate the first error. temperature; The first formula is: ； wherein, represents the temperature, represents the temperature, represents the upper limit of a constant temperature step set in advance; The second formula is: ； wherein, represents the calculated first temperature step.

4. A high-precision temperature sensor calibration method in a cryogenic environment as claimed in claim 3, characterized in that, The first The temperature step is calculated by: The third formula is used to calculate the first temperature step temperature steps; the third formula is: ； wherein represents a pre-set second error threshold value; represents a pre-set lower limit of constant temperature step.

5. A high-precision temperature sensor calibration method in a cryogenic environment as claimed in claim 4, characterized in that, The method for fitting the temperature error function according to the standard temperature sequence and the test temperature sequence comprises: According to the first standard temperature to the... N Standard temperature, first test temperature to the... N The test temperature calculation yielded the first calculation error up to the [missing value]. N Calculation error; where the first The formula for calculating the error is: ； wherein, denotes the calculating errors; calculating the first error to the N combining the calculation errors to obtain a calculation error sequence; Taking the test temperature sequence as the independent variable and the calculation error sequence as the dependent variable, the temperature error function is fitted.

6. A high-precision temperature sensor calibration method in a cryogenic environment as claimed in claim 5, characterized in that, The method for fitting the temperature error function by taking the test temperature sequence as the independent variable and the calculation error sequence as the dependent variable comprises: Constructing a fitting function; the fitting function is expressed as: ； wherein represents the fitting function, represents the measured value of the temperature sensor to be calibrated in Kelvin; represents the cubic non-linear coefficient, represents the quadratic non-linear coefficient, represents the linear coefficient, represents the zero-point offset; Taking the test temperature sequence as the independent variable and the calculation error sequence as the dependent variable, the optimal value of the fitting algorithm is fitted to obtain , , , The optimal value is recorded as , , , ; According to , , , a temperature error function is obtained, which is: ； wherein denotes the temperature error function.

7. A high-precision temperature sensor calibration method in a cryogenic environment as claimed in claim 6, characterized in that, The method for obtaining the optimal value of the calculation error sequence with the test temperature sequence as the independent variable and the calculation error sequence as the dependent variable by using a fitting algorithm is fitted to obtain 、 、 、 The optimal value of the calculation error sequence with the test temperature sequence as the independent variable and the calculation error sequence as the dependent variable by using a fitting algorithm is fitted to obtain 、 、 、 The method comprises the following steps: Constructing an optimization objective function; the optimization objective function is: ； With the optimization objective function value minimum as the goal, with the pre-set constraint condition as the constraint, the particle swarm optimization algorithm is used to calculate the optimal value of 、 、 、 , which are respectively recorded as 、 、 、 .

8. A high-precision temperature sensor calibration method in a cryogenic environment as claimed in claim 7, characterized in that, The method for calibrating the measurement value of the temperature sensor to be calibrated by embedding the temperature error function into the temperature sensor to be calibrated comprises: The temperature error function is embedded into the temperature sensor to be calibrated, and a calibrated temperature is calculated according to the measurement value of the temperature sensor to be calibrated; the calculation formula of the calibrated temperature is: ； wherein represents the calibration temperature.

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