A method and system for tracing the source of isothermal pressure

Abstract

This invention relates to the field of pressure measurement technology, specifically a method and system for tracing isothermal pressure. The method includes acquiring the measured wireless pressure recorder; heating a dry isothermal chamber using an air bath dry isothermal control method, causing the temperature of the dry isothermal chamber to sequentially reach and stabilize at a certain value. N A target temperature value is obtained. N A set temperature environment is established; under each set temperature environment, the actual pressure value inside the dry constant temperature chamber is gradually brought closer to the preset standard pressure value using a standard pressure source; during the process of the actual pressure value gradually approaching the preset standard pressure value, samples are obtained. N A set of temperature-pressure deviation data; for N A hierarchical fitting process is performed on a set of temperature-pressure deviation data to obtain the temperature-pressure compensation curve of the wireless pressure recorder under test. This invention achieves calibration of the wireless pressure recorder under test at different temperatures through fitting calculations.

Description

Technical Field

[0001] This invention relates to the field of pressure measurement technology, specifically a constant temperature pressure traceability method and system. Background Technology

[0002] Wireless pressure recorders are widely used for the calibration and verification of pressure parameters in thermal sterilization equipment. During sterilization, the sterilization equipment is under high temperature and high pressure, and the wireless pressure recorder is placed directly in this environment to measure the pressure. However, according to the measurement principle of wireless pressure recorders, their pressure sensors experience temperature drift at different temperatures, resulting in deviations between the measured values ​​and the true values ​​at the same pressure but different temperatures. Therefore, the calibration of wireless pressure recorders requires obtaining their pressure measurement errors at different temperatures, establishing a compensation relationship between temperature and pressure deviations, and using this information to correct the pressure measurement values ​​in actual use.

[0003] The existing calibration method involves placing a wireless pressure recorder inside the device cavity, controlling the temperature within the cavity to a pre-set standard temperature point, and waiting for the temperature field to fully stabilize. Then, a standard pressure value is applied to the cavity using a standard pressure source. The pressure reading from the wireless pressure recorder is then read, and the pressure deviation is calculated. Finally, multiple pressure deviations are fitted to corresponding standard temperature points to obtain a temperature-pressure compensation curve. However, this method has the following technical problems: the standard pressure source typically applies the standard pressure value to the cavity by filling and venting gas. This filling and venting process inevitably causes temperature fluctuations within the cavity, resulting in the temperature deviating from the pre-set standard temperature point when the pressure reading from the wireless pressure recorder is read. If the standard temperature point is still used for fitting, the temperature-pressure compensation curve will inevitably be distorted. If the actual temperature value is collected during the temperature fluctuation within the equipment cavity and directly used for fitting, the temperature fluctuation data and pressure deviation data collected at each standard temperature point are limited to a local range near that temperature point. The variation patterns within these local data and the overall variation patterns across temperature points have scale differences. If the two are mixed and fitted indiscriminately, the local fluctuation characteristics will be submerged by the overall trend, or the overall trend will be interfered with by the local fluctuations. It will be difficult to obtain a compensation curve that accurately reflects the pressure measurement error across the entire temperature range.

[0004] Therefore, it is necessary to provide a constant temperature pressure traceability method that can overcome the above-mentioned technical limitations, achieve accurate acquisition of temperature-pressure compensation curves, and thus enable the calibration of wireless pressure recorders at different temperatures. Summary of the Invention

[0005] The purpose of this invention is to provide a constant temperature pressure traceability method and system to enable the calibration of wireless pressure recorders at different temperatures.

[0006] To achieve the above objectives, the present invention provides a constant temperature pressure traceability method, the method comprising the following steps:

[0007] S1, acquire the wireless pressure recorder under test; acquire the constant temperature pressure traceability device, which consists of a dry constant temperature chamber and a standard pressure source; place the wireless pressure recorder under test inside the dry constant temperature chamber.

[0008] S2, according to the preset N To achieve the target temperature value, an air bath dry constant temperature control method is used to heat the dry constant temperature cavity, causing the temperature of the dry constant temperature cavity to sequentially reach and stabilize at the target temperature value. N A target temperature value is obtained. N A set temperature environment.

[0009] S3, under each set temperature environment, the actual pressure value inside the dry constant temperature chamber is gradually brought closer to the preset standard pressure value using a standard pressure source; during the process of the actual pressure value gradually approaching the preset standard pressure value, the actual temperature value, actual pressure value, and pressure value measured by the wireless pressure recorder under test are synchronously collected at each sampling point according to a preset sampling period; the deviation between the pressure value measured by the wireless pressure recorder under test and the actual pressure value at each sampling point is calculated and recorded as the pressure deviation value; the actual temperature value and pressure deviation value under each set temperature environment are combined to obtain... N Each temperature-pressure deviation data set corresponds to a set of temperature conditions. M The actual temperature value and pressure deviation value at each sampling point M The number of data points in the set is preset.

[0010] S4, for N A stratified fitting process is performed on a set of temperature-pressure deviation data to obtain the temperature-pressure compensation curve of the wireless pressure recorder under test; the temperature-pressure compensation curve reflects the pressure measurement error of the wireless pressure recorder under test at different temperatures.

[0011] Furthermore, the method for obtaining the constant temperature and pressure traceability device, wherein the constant temperature and pressure traceability device comprises a dry constant temperature chamber and a standard pressure source, includes: A constant temperature and pressure traceability device is provided; the dry constant temperature chamber is equipped with a heating element, an air circulation element, a temperature sensor, and a temperature controller; the measuring end of the temperature sensor is set at the placement position of the wireless pressure recorder under test in the dry constant temperature chamber, and the temperature controller is connected to the heating element; the standard pressure source is sealed and connected to the dry constant temperature chamber through a pressure source interface reserved on the wall of the dry constant temperature chamber, and the pressure inside the dry constant temperature chamber is adjusted by filling and venting gas into the dry constant temperature chamber.

[0012] Furthermore, the statement based on the preset...N To achieve the target temperature value, an air bath dry constant temperature control method is used to heat the dry constant temperature cavity, causing the temperature of the dry constant temperature cavity to sequentially reach and stabilize at the target temperature value. N A target temperature value is obtained. N One method for setting a temperature environment includes: The temperature sensor collects the current temperature value at the location of the wireless pressure recorder under test inside the dry constant temperature chamber in real time and feeds it back to the temperature controller. The temperature controller adjusts the heating power of the heating element according to the difference between the current temperature value and the target temperature value, using a gradual approach to the target temperature control process, so that the temperature of the dry constant temperature chamber reaches and stabilizes at the target temperature value. The air circulation element drives the air circulation within the chamber, ensuring a uniform temperature distribution within the dry constant temperature chamber. When the temperature fluctuation of the dry constant temperature chamber within a preset time does not exceed a preset temperature fluctuation threshold, it is determined that the temperature of the dry constant temperature chamber has stabilized at the target temperature value. This process is repeated sequentially for the... N For each of the target temperature values, a temperature control process is performed to progressively approximate the target value, resulting in the... N A set temperature environment.

[0013] Furthermore, the aforementioned N The method for obtaining the temperature-pressure compensation curve of the tested wireless pressure recorder by performing hierarchical fitting on a set of temperature-pressure deviation data includes: Each N The sets of temperature-pressure deviation data are sequentially denoted as the first set to the second set. N Data set.

[0014] structure First-level objective function to The objective function of the first layer is expressed as: ; in, The value is 1 to Integer variables between; The value is 1 to Integer variables between; For the first The first in the data set The actual temperature value of each sampling point; For the first The first in the data set Pressure deviation values ​​at each sampling point; , , , These are the first coefficient, the second coefficient, the third coefficient, and the fourth coefficient, respectively.

[0015] Constructing the second-level objective function The objective function of the second layer is expressed as: .

[0016] Construct the optimization objective function The optimization objective function is expressed as: ; in, This indicates the pre-set combined weights. The value is greater than 0.5 and less than 1.

[0017] The objective function is minimized, and the particle swarm optimization algorithm is used to calculate the result. , , , The optimal values ​​are denoted as follows: , , , ;according to , , , The temperature-pressure compensation curve of the wireless pressure recorder under test is obtained.

[0018] Furthermore, the aforementioned according to , , , Methods for obtaining the temperature-pressure compensation curve of the wireless pressure recorder under test include: according to , , , The temperature-pressure compensation curve of the tested wireless pressure recorder was obtained by fitting; the temperature-pressure compensation curve of the tested wireless pressure recorder is as follows: ; in, Indicates temperature. This indicates the pressure measurement error.

[0019] Based on the same inventive concept, this invention also provides a constant temperature and pressure traceability system, the system comprising: The data reading module is used to acquire the wireless pressure recorder under test; acquire the constant temperature pressure traceability device, which consists of a dry constant temperature chamber and a standard pressure source; and place the wireless pressure recorder under test inside the dry constant temperature chamber.

[0020] The temperature environment construction module, connected to the data reading module, is used to construct a temperature environment based on preset parameters. N To achieve the target temperature value, an air bath dry constant temperature control method is used to heat the dry constant temperature cavity, causing the temperature of the dry constant temperature cavity to sequentially reach and stabilize at the target temperature value. N A target temperature value is obtained. N A set temperature environment.

[0021] The data sampling module, connected to the temperature environment construction module, is used to gradually approximate the actual pressure value inside the dry constant temperature chamber to a preset standard pressure value using a standard pressure source under each set temperature environment. During this process, the actual temperature value, actual pressure value, and pressure value measured by the wireless pressure recorder under test are synchronously collected at each sampling point according to a preset sampling period. The deviation between the pressure value measured by the wireless pressure recorder under test and the actual pressure value at each sampling point is calculated and recorded as the pressure deviation value. The actual temperature value and pressure deviation value under each set temperature environment are combined to obtain... N Each temperature-pressure deviation data set corresponds to a set of temperature conditions. M The actual temperature value and pressure deviation value at each sampling point M The number of data points in the set is preset.

[0022] The fitting module, connected to the data sampling module, is used to... N A stratified fitting process is performed on a set of temperature-pressure deviation data to obtain the temperature-pressure compensation curve of the wireless pressure recorder under test; the temperature-pressure compensation curve reflects the pressure measurement error of the wireless pressure recorder under test at different temperatures.

[0023] Furthermore, the data reading module includes: A constant temperature and pressure traceability device construction module is used to acquire the constant temperature and pressure traceability device; the dry constant temperature chamber is equipped with a heating element, an air circulation element, a temperature sensor, and a temperature controller; the measuring end of the temperature sensor is set at the placement position of the wireless pressure recorder under test in the dry constant temperature chamber, and the temperature controller is connected to the heating element; the standard pressure source is sealed and connected to the dry constant temperature chamber through a pressure source interface reserved on the wall of the dry constant temperature chamber, and the pressure inside the dry constant temperature chamber is adjusted by filling and venting gas into the dry constant temperature chamber.

[0024] Furthermore, the temperature environment construction module includes: A temperature approximation module is used to collect the current temperature value at the location of the wireless pressure recorder under test inside the dry constant temperature chamber in real time via the temperature sensor and feed it back to the temperature controller. The temperature controller adjusts the heating power of the heating element according to the difference between the current temperature value and the target temperature value, using a gradual temperature control process to approach the target value, so that the temperature of the dry constant temperature chamber reaches and stabilizes at the target temperature value. The air circulation element drives the air circulation within the chamber to ensure uniform temperature distribution within the dry constant temperature chamber. When the temperature fluctuation of the dry constant temperature chamber within a preset time does not exceed a preset temperature fluctuation threshold, it is determined that the temperature of the dry constant temperature chamber has stabilized at the target temperature value. This process is repeated sequentially for the... N For each of the target temperature values, a temperature control process is performed to progressively approximate the target value, resulting in the... N A set temperature environment.

[0025] Furthermore, the fitting module includes: The objective function construction module is optimized to respectively convert the objective function into a function that constructs the objective function. N The sets of temperature-pressure deviation data are sequentially denoted as the first set to the second set. N Data set.

[0026] structure First-level objective function to The objective function of the first layer is expressed as: ; in, The value is 1 to Integer variables between; The value is 1 to Integer variables between; For the first The first in the data set The actual temperature value of each sampling point; For the first The first in the data set Pressure deviation values ​​at each sampling point; , , , These are the first coefficient, the second coefficient, the third coefficient, and the fourth coefficient, respectively.

[0027] Constructing the second-level objective function The objective function of the second layer is expressed as: .

[0028] Construct the optimization objective function The optimization objective function is expressed as: ; in, This indicates the pre-set combined weights. The value is greater than 0.5 and less than 1.

[0029] The optimization calculation module, connected to the optimization objective function construction module, is used to calculate the optimal value of the optimization objective function using the particle swarm optimization algorithm. , , , The optimal values ​​are denoted as follows: , , , ;according to , , , The temperature-pressure compensation curve of the wireless pressure recorder under test is obtained.

[0030] Furthermore, the optimization calculation module includes: Output module, used to determine the output based on , , , The temperature-pressure compensation curve of the tested wireless pressure recorder was obtained by fitting; the temperature-pressure compensation curve of the tested wireless pressure recorder is as follows: ; in, Indicates temperature. This indicates the pressure measurement error.

[0031] Compared with the prior art, the beneficial effects of the present invention are: By synchronously collecting actual temperature and pressure deviation values ​​at a preset sampling period during the process of gradually approximating the preset standard pressure value under each set temperature environment, each set of temperature-pressure deviation data contains both local temperature fluctuation information under that set temperature environment and, together with the data sets of other set temperature environments, constitutes the overall deviation distribution across the temperature zone. Thus, through hierarchical fitting, a temperature-pressure compensation curve that takes into account both local fluctuation characteristics and overall change trends is obtained across the entire temperature range, thereby achieving the calibration of the wireless pressure recorder at different temperatures. Attached Figure Description

[0032] Figure 1 This is a flowchart of a constant temperature pressure traceability method according to Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the module composition of a constant temperature and pressure traceability system according to Embodiment 2 of the present invention. Detailed Implementation

[0033] 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.

[0034] Before providing examples, it is necessary to describe the application scenario of the present invention, which is applied to calibrating the pressure measurement values ​​of a wireless pressure recorder under a combined temperature-pressure field in a closed cavity.

[0035] Example 1: As Figure 1 As shown, this embodiment provides a method for isothermal pressure traceability, the method including the following steps: S1, acquire the wireless pressure recorder under test; acquire the constant temperature pressure traceability device, which consists of a dry constant temperature chamber and a standard pressure source; place the wireless pressure recorder under test inside the dry constant temperature chamber.

[0036] S2, according to the preset N To achieve the target temperature value, an air bath dry constant temperature control method is used to heat the dry constant temperature cavity, causing the temperature of the dry constant temperature cavity to sequentially reach and stabilize at the target temperature value. N A target temperature value is obtained. N A set temperature environment.

[0037] S3, under each set temperature environment, the actual pressure value inside the dry constant temperature chamber is gradually brought closer to the preset standard pressure value using a standard pressure source; during the process of the actual pressure value gradually approaching the preset standard pressure value, the actual temperature value, actual pressure value, and pressure value measured by the wireless pressure recorder under test are synchronously collected at each sampling point according to a preset sampling period; the deviation between the pressure value measured by the wireless pressure recorder under test and the actual pressure value at each sampling point is calculated and recorded as the pressure deviation value; the actual temperature value and pressure deviation value under each set temperature environment are combined to obtain... N Each temperature-pressure deviation data set corresponds to a set of temperature conditions. M The actual temperature value and pressure deviation value at each sampling point M The number of data points in the set is preset.

[0038] S4, for N A stratified fitting process is performed on a set of temperature-pressure deviation data to obtain the temperature-pressure compensation curve of the wireless pressure recorder under test; the temperature-pressure compensation curve reflects the pressure measurement error of the wireless pressure recorder under test at different temperatures.

[0039] For example, a wireless pressure recorder under test is acquired. This wireless pressure recorder is used for pressure monitoring in a thermal sterilization apparatus. To calibrate the wireless pressure recorder, it needs to be placed within the dry constant-temperature chamber of a constant-temperature pressure traceability device. The constant-temperature pressure traceability device consists of a dry constant-temperature chamber providing the temperature environment and a standard pressure source providing the pressure environment.

[0040] Based on the operating temperature range of the wireless pressure recorder under test during the actual sterilization process, preset... N One target temperature value, N The value is 5, with five target temperature values ​​being 30℃, 60℃, 90℃, 120℃, and 150℃ respectively. An air bath dry-type constant temperature control method is adopted, using air as the heating medium. Heating elements heat the dry-type constant temperature chamber, and an air circulation element drives the air circulation within the chamber, ensuring a uniform temperature distribution. The temperature of the dry-type constant temperature chamber is controlled to sequentially reach and stabilize at 30℃, 60℃, 90℃, 120℃, and 150℃, resulting in five set temperature environments. The temperature fluctuation within each set temperature environment does not exceed a preset temperature fluctuation threshold within a preset time period, with the temperature fluctuation threshold being ±0.3℃.

[0041] Under each set temperature environment, gas is injected or vented into the dry constant-temperature chamber using a standard pressure source, gradually bringing the actual pressure value inside the chamber closer to a preset standard pressure value of 300 kPa. During this gradual pressure approach, the injection and venting operations within the chamber cause slight fluctuations in the actual temperature value near the target temperature. Instead of waiting for the temperature to stabilize completely, the actual temperature value, actual pressure value, and pressure value measured by the wireless pressure recorder under test are simultaneously collected at each sampling point according to a preset sampling period of 1 second. The sampling points are arranged in chronological order of collection time. The unit for the actual temperature value is °C, the unit for the actual pressure value is kPa, and the unit for the pressure value measured by the wireless pressure recorder under test is kPa. The deviation between the pressure value measured by the wireless pressure recorder and the actual pressure value at each sampling point is calculated and recorded as the pressure deviation value. The unit for the pressure deviation value is kPa. The actual temperature values ​​collected under each set temperature environment were combined with the corresponding pressure deviation values ​​to obtain 5 sets of temperature-pressure deviation data. Each set of temperature-pressure deviation data corresponds to the actual temperature values ​​and pressure deviation values ​​of the first 200 sampling points during the charging and discharging process under the set temperature environment. M The value is greater than 150, and in this embodiment it is 200. M The principle for determining the value is: M It should be large enough that the front M Each sampling point should include the operating condition where the temperature recovers to a completely stable state.

[0042] A stratified fitting process was performed on five sets of temperature-pressure deviation data. The stratified fitting consisted of two levels: the first level performed local fitting within each set of temperature-pressure deviation data to preserve the pressure deviation changes corresponding to minor temperature fluctuations caused by inflation and deflation under that set temperature environment; the second level fitted the overall trend across the five sets of temperature-pressure deviation data to ensure the continuity of the deviation curve across the entire temperature range of 30℃ to 150℃. It is worth noting that the first and second levels of fitting were not performed independently, but rather weighted and incorporated into a unified optimization objective function for global fitting. The resulting temperature-pressure compensation curve of the tested wireless pressure recorder reflects the pressure measurement error of the tested wireless pressure recorder at different temperatures within the range of 30℃ to 150℃. When the tested wireless pressure recorder measures pressure values ​​during subsequent actual sterilization processes, the corresponding pressure measurement error can be obtained from the temperature-pressure compensation curve based on the current temperature and corrected accordingly.

[0043] Furthermore, the method for obtaining the constant temperature and pressure traceability device, wherein the constant temperature and pressure traceability device comprises a dry constant temperature chamber and a standard pressure source, includes: A constant temperature and pressure traceability device is provided; the dry constant temperature chamber is equipped with a heating element, an air circulation element, a temperature sensor, and a temperature controller; the measuring end of the temperature sensor is set at the placement position of the wireless pressure recorder under test in the dry constant temperature chamber, and the temperature controller is connected to the heating element; the standard pressure source is sealed and connected to the dry constant temperature chamber through a pressure source interface reserved on the wall of the dry constant temperature chamber, and the pressure inside the dry constant temperature chamber is adjusted by filling and venting gas into the dry constant temperature chamber.

[0044] For example, a constant temperature and pressure traceability device is obtained. The constant temperature and pressure traceability device consists of a dry constant temperature chamber and a standard pressure source. The dry constant temperature chamber is a cylindrical sealed cavity. The inner cavity is made of a thermally conductive material with a thermal conductivity of not less than 200 W / (m·K). Insulation material, specifically aluminum silicate fiber cotton, with a thickness of 30 mm, is filled between the inner cavity and the outer shell to reduce heat loss from the cavity to the external environment. The dry constant temperature chamber is equipped with a heating element, an air circulation element, a temperature sensor, and a temperature controller. The heating element is a TEC semiconductor thermoelectric cooler, symmetrically distributed on both sides of the inner wall of the dry constant temperature chamber, which can heat and cool the air inside the chamber. The air circulation element is an axial flow fan located at the rear of the dry constant temperature chamber, used to drive the air circulation within the chamber, making the temperature more uniform throughout the chamber. The temperature sensor is a platinum resistance temperature sensor, with its measuring end fixed inside the dry constant temperature chamber at the location where the wireless pressure recorder under test is placed. The placement location is in the center of the bottom of the dry constant temperature chamber, ensuring that the temperature value measured by the sensor matches the actual ambient temperature of the wireless pressure recorder. The temperature controller is electrically connected to the heating element. The temperature controller receives the temperature signal from the temperature sensor and adjusts the heating power of the heating element according to a preset control strategy. The standard pressure source is an external benchtop pressure controller, which is sealed to the dry constant temperature chamber via a pressure source interface pre-installed on the chamber wall. The pressure source interface is a stainless steel pipe connector that penetrates the side wall of the dry constant temperature chamber and is sealed to the chamber wall with a perfluoroelastomer rubber sealing ring, capable of withstanding temperatures up to 180°C. The standard pressure source regulates the pressure inside the dry constant temperature chamber by injecting or venting nitrogen gas. Nitrogen is an inert gas and does not react with the wireless pressure recorder under test inside the chamber.

[0045] Furthermore, the statement based on the preset... N To achieve the target temperature value, an air bath dry constant temperature control method is used to heat the dry constant temperature cavity, causing the temperature of the dry constant temperature cavity to sequentially reach and stabilize at the target temperature value. N A target temperature value is obtained. N One method for setting a temperature environment includes: The temperature sensor collects the current temperature value at the location of the wireless pressure recorder under test inside the dry constant temperature chamber in real time and feeds it back to the temperature controller. The temperature controller adjusts the heating power of the heating element according to the difference between the current temperature value and the target temperature value, using a gradual approach to the target temperature control process, so that the temperature of the dry constant temperature chamber reaches and stabilizes at the target temperature value. The air circulation element drives the air circulation within the chamber, ensuring a uniform temperature distribution within the dry constant temperature chamber. When the temperature fluctuation of the dry constant temperature chamber within a preset time does not exceed a preset temperature fluctuation threshold, it is determined that the temperature of the dry constant temperature chamber has stabilized at the target temperature value. This process is repeated sequentially for the... N For each of the target temperature values, a temperature control process is performed to progressively approximate the target value, resulting in the...N A set temperature environment.

[0046] For example, during the temperature regulation process of the dry constant temperature chamber, a platinum resistance temperature sensor collects the current temperature value at the location where the wireless pressure recorder under test is placed inside the dry constant temperature chamber. The placement location is the central area of ​​the bottom of the dry constant temperature chamber. The temperature sensor feeds back the collected current temperature value to the temperature controller. The temperature controller adjusts the heating power of the TEC semiconductor thermoelectric cooler using a temperature control process that gradually approaches the target temperature value based on the difference between the current temperature value and the target temperature value. Taking a target temperature value of 150°C as an example, the temperature controller first calculates the difference between the current temperature value and 150°C. When the current temperature value is less than 150°C and the difference is greater than 10°C, the TEC semiconductor thermoelectric cooler is rapidly heated at 80% of the rated power. When the difference falls within 10°C, the heating power is gradually reduced by 15% of the rated power for every 2°C decrease in the difference, so that the temperature inside the chamber gradually approaches 150°C, avoiding temperature overshoot caused by continuous heating at full power. An axial fan continuously drives the air circulation within the chamber throughout the temperature control process, ensuring a uniform temperature distribution within the dry constant-temperature chamber. Once the temperature of the dry constant-temperature chamber enters the range of 150℃ ± 0.3℃, the temperature controller continuously monitors the temperature fluctuation within the chamber over 30 seconds. When the fluctuation does not exceed the preset temperature fluctuation threshold of ± 0.3℃, the temperature of the dry constant-temperature chamber is considered to have stabilized at 150℃. This process is repeated sequentially for each of the five target temperature values: 30℃, 60℃, 90℃, 120℃, and 150℃, resulting in five set temperature environments. The temperature uniformity of each set temperature environment does not exceed ± 0.3℃.

[0047] Furthermore, the aforementioned N The method for obtaining the temperature-pressure compensation curve of the tested wireless pressure recorder by performing hierarchical fitting on a set of temperature-pressure deviation data includes: Each N The sets of temperature-pressure deviation data are sequentially denoted as the first set to the second set. N Data set.

[0048] structure First-level objective function to The objective function of the first layer is expressed as: ; in, The value is 1 to Integer variables between; The value is 1 to Integer variables between; For the first The first in the data set The actual temperature value of each sampling point; For the first The first in the data set Pressure deviation values ​​at each sampling point; , , , These are the first coefficient, the second coefficient, the third coefficient, and the fourth coefficient, respectively.

[0049] Constructing the second-level objective function The objective function of the second layer is expressed as: .

[0050] Construct the optimization objective function The optimization objective function is expressed as: ; in, This indicates the pre-set combined weights. The value is greater than 0.5 and less than 1.

[0051] The objective function is minimized, and the particle swarm optimization algorithm is used to calculate the result. , , , The optimal values ​​are denoted as follows: , , , ;according to , , , The temperature-pressure compensation curve of the wireless pressure recorder under test is obtained.

[0052] For example, the five sets of temperature-pressure deviation data are sequentially designated as the first to the fifth data sets. The first data set corresponds to 200 sampling points collected under a set temperature of 30°C, the second data set corresponds to 200 sampling points collected under a set temperature of 60°C, the third data set corresponds to 200 sampling points collected under a set temperature of 90°C, the fourth data set corresponds to 200 sampling points collected under a set temperature of 120°C, and the fifth data set corresponds to 200 sampling points collected under a set temperature of 150°C. Taking the first data set as an example, under a set temperature of 30°C, as a standard pressure source injects nitrogen into the dry constant temperature chamber to gradually approach 300 kPa from atmospheric pressure, the actual temperature value inside the chamber fluctuates slightly due to the inflation operation. Among the 200 sampling points, the actual temperature value of the first sampling point is 30.08°C, the pressure value measured by the wireless pressure recorder is 296.7 kPa, the actual pressure value is 297.1 kPa, and the calculated pressure deviation value is -0.4 kPa. Two points are worth noting in this process: First, after the dry-type thermostatic chamber reaches the set temperature environment through the operation of the temperature controller, the actual pressure value inside the dry-type thermostatic chamber is gradually brought closer to the preset standard pressure value through a standard pressure source. During this process, the temperature controller ceases operation. This is to avoid additional thermodynamic interference caused by the temperature controller's operation. Second, the actual pressure value is measured by a higher-precision, calibrated pressure recorder integrated with the standard pressure source. Third, the pressure deviation is calculated by subtracting the actual pressure value from the pressure value measured by the wireless pressure recorder under test. Data from other sampling points will not be elaborated further.

[0053] Construct five first-level objective functions. Taking the first data set as an example, The construction method is as follows: Substitute the actual temperature values ​​of the first to the 200th sampling points in the first data set into the cubic polynomial one by one. Summing up the 200 absolute values ​​yields... The first-level objective function reflects the sum of the fitting biases of the cubic polynomial to all sampling points under a single set temperature environment. A cubic polynomial is used in the first-level objective function because it achieves the best fitting effect in historical data.

[0054] Then, construct the second-level objective function. The second-level objective function takes the mean temperature and mean deviation of each data set as the processing object, reflecting the degree of fit of the cubic polynomial to the overall deviation trend among the five set temperature environments, and ensuring the continuity of the deviation curve across the entire temperature range of 30℃ to 150℃.

[0055] Construct the optimization objective function The objective function is constructed by weighting the first-level and second-level objective functions. The weights are then combined. The value is 0.7. The value of 0.7 is chosen because the temperature range between the five set temperature environments reaches 120℃, while the temperature fluctuation range within each set temperature environment caused by charging and discharging does not exceed ±1.5℃. The accuracy of the overall fitting across the temperature range has a greater impact on the usability of the compensation curve. Therefore, the second-level objective function plays a dominant role in optimizing the objective function; at the same time, the combined weights... The value of 0.7 also retains a weight of 0.3 for the first-level objective function, avoiding the local fitting bias being ignored due to the second-level objective function completely dominating, thus taking into account both local fluctuation characteristics and overall trend. The larger the value, the higher the weight of the overall trend of change in the objective function and the lower the weight of local fluctuation features.

[0056] To optimize the objective function The objective is to minimize the value, and the particle swarm optimization algorithm is used to calculate the result. , , , The optimal value is determined. In the particle swarm optimization algorithm, the number of particles is set to 50, and the maximum number of iterations is set to 1000. The calculation yields... , , , .

[0057] Furthermore, the aforementioned according to , , , Methods for obtaining the temperature-pressure compensation curve of the wireless pressure recorder under test include: according to , , , The temperature-pressure compensation curve of the tested wireless pressure recorder was obtained by fitting; the temperature-pressure compensation curve of the tested wireless pressure recorder is as follows: ; in, Indicates temperature. This indicates the pressure measurement error.

[0058] For example, the temperature-pressure compensation curve of the tested wireless pressure recorder is obtained as follows: .

[0059] in, Temperature is expressed in °C. This indicates the pressure measurement error, expressed in kPa. When the wireless pressure recorder under test measures the pressure value during the subsequent actual sterilization process, the ambient temperature value of the recorder should be substituted into the value. Obtain the corresponding pressure measurement error from the temperature-pressure compensation curve. Subtract the pressure value measured by the recorder This yields the corrected pressure value. The temperature range in the temperature-pressure compensation curve of the wireless pressure recorder under test is 30℃ to 150℃.

[0060] Example 2: Based on the same inventive concept, such as Figure 2 As shown, this embodiment also provides a constant temperature and pressure traceability system, the system comprising: The data reading module is used to acquire the wireless pressure recorder under test; acquire the constant temperature pressure traceability device, which consists of a dry constant temperature chamber and a standard pressure source; and place the wireless pressure recorder under test inside the dry constant temperature chamber.

[0061] The temperature environment construction module, connected to the data reading module, is used to construct a temperature environment based on preset parameters. N To achieve the target temperature value, an air bath dry constant temperature control method is used to heat the dry constant temperature cavity, causing the temperature of the dry constant temperature cavity to sequentially reach and stabilize at the target temperature value. N A target temperature value is obtained. N A set temperature environment.

[0062] The data sampling module, connected to the temperature environment construction module, is used to gradually approximate the actual pressure value inside the dry constant temperature chamber to a preset standard pressure value using a standard pressure source under each set temperature environment. During this process, the actual temperature value, actual pressure value, and pressure value measured by the wireless pressure recorder under test are synchronously collected at each sampling point according to a preset sampling period. The deviation between the pressure value measured by the wireless pressure recorder under test and the actual pressure value at each sampling point is calculated and recorded as the pressure deviation value. The actual temperature value and pressure deviation value under each set temperature environment are combined to obtain... N Each temperature-pressure deviation data set corresponds to a set of temperature conditions. M The actual temperature value and pressure deviation value at each sampling point M The number of data points in the set is preset.

[0063] The fitting module, connected to the data sampling module, is used to... NA stratified fitting process is performed on a set of temperature-pressure deviation data to obtain the temperature-pressure compensation curve of the wireless pressure recorder under test; the temperature-pressure compensation curve reflects the pressure measurement error of the wireless pressure recorder under test at different temperatures.

[0064] Furthermore, the data reading module includes: A constant temperature and pressure traceability device construction module is used to acquire the constant temperature and pressure traceability device; the dry constant temperature chamber is equipped with a heating element, an air circulation element, a temperature sensor, and a temperature controller; the measuring end of the temperature sensor is set at the placement position of the wireless pressure recorder under test in the dry constant temperature chamber, and the temperature controller is connected to the heating element; the standard pressure source is sealed and connected to the dry constant temperature chamber through a pressure source interface reserved on the wall of the dry constant temperature chamber, and the pressure inside the dry constant temperature chamber is adjusted by filling and venting gas into the dry constant temperature chamber.

[0065] Furthermore, the temperature environment construction module includes: A temperature approximation module is used to collect the current temperature value at the location of the wireless pressure recorder under test inside the dry constant temperature chamber in real time via the temperature sensor and feed it back to the temperature controller. The temperature controller adjusts the heating power of the heating element according to the difference between the current temperature value and the target temperature value, using a gradual temperature control process to approach the target value, so that the temperature of the dry constant temperature chamber reaches and stabilizes at the target temperature value. The air circulation element drives the air circulation within the chamber to ensure uniform temperature distribution within the dry constant temperature chamber. When the temperature fluctuation of the dry constant temperature chamber within a preset time does not exceed a preset temperature fluctuation threshold, it is determined that the temperature of the dry constant temperature chamber has stabilized at the target temperature value. This process is repeated sequentially for the... N For each of the target temperature values, a temperature control process is performed to progressively approximate the target value, resulting in the... N A set temperature environment.

[0066] Furthermore, the fitting module includes: The objective function construction module is optimized to respectively convert the objective function into a function that constructs the objective function. N The sets of temperature-pressure deviation data are sequentially denoted as the first set to the second set. N Data set.

[0067] structure First-level objective function to The objective function of the first layer is expressed as: ; in, The value is 1 to Integer variables between; The value is 1 to Integer variables between; For the first The first in the data set The actual temperature value of each sampling point; For the first The first in the data set Pressure deviation values ​​at each sampling point; , , , These are the first coefficient, the second coefficient, the third coefficient, and the fourth coefficient, respectively.

[0068] Constructing the second-level objective function The objective function of the second layer is expressed as: .

[0069] Construct the optimization objective function The optimization objective function is expressed as: ; in, This indicates the pre-set combined weights. The value is greater than 0.5 and less than 1.

[0070] The optimization calculation module, connected to the optimization objective function construction module, is used to calculate the optimal value of the optimization objective function using the particle swarm optimization algorithm. , , , The optimal values ​​are denoted as follows: , , , ;according to , , , The temperature-pressure compensation curve of the wireless pressure recorder under test is obtained.

[0071] Furthermore, the optimization calculation module includes: Output module, used to determine the output based on , , , The temperature-pressure compensation curve of the tested wireless pressure recorder was obtained by fitting; the temperature-pressure compensation curve of the tested wireless pressure recorder is as follows: ; in, Indicates temperature. This indicates the pressure measurement error.

[0072] It should be noted that the specific methods by which each module performs operations in the system described in the above embodiments have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0073] 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 method of constant temperature pressure traceability, characterized in that, The method includes the following steps: S1, acquire the wireless pressure recorder under test; acquire the constant temperature pressure traceability device, which consists of a dry constant temperature chamber and a standard pressure source; place the wireless pressure recorder under test inside the dry constant temperature chamber; S2, according to the preset N To achieve the target temperature value, an air bath dry constant temperature control method is used to heat the dry constant temperature cavity, causing the temperature of the dry constant temperature cavity to sequentially reach and stabilize at the target temperature value. N A target temperature value is obtained. N A set temperature environment; S3, under each set temperature environment, the actual pressure value inside the dry constant temperature chamber is gradually brought closer to the preset standard pressure value using a standard pressure source; during the process of the actual pressure value gradually approaching the preset standard pressure value, the actual temperature value, actual pressure value, and pressure value measured by the wireless pressure recorder under test are synchronously collected at each sampling point according to a preset sampling period; the deviation between the pressure value measured by the wireless pressure recorder under test and the actual pressure value at each sampling point is calculated and recorded as the pressure deviation value; the actual temperature value and pressure deviation value under each set temperature environment are combined to obtain... N Each temperature-pressure deviation data set corresponds to a set of temperature conditions. M The actual temperature value and pressure deviation value at each sampling point M The number of data points in the set is preset; S4, for N A hierarchical fitting is performed on a set of temperature-pressure deviation data to obtain the temperature-pressure compensation curve of the wireless pressure recorder under test; the temperature-pressure compensation curve reflects the pressure measurement error of the wireless pressure recorder under test at different temperatures. The pair N The method for obtaining the temperature-pressure compensation curve of the tested wireless pressure recorder by performing hierarchical fitting on a set of temperature-pressure deviation data includes: Each N The sets of temperature-pressure deviation data are sequentially denoted as the first set to the second set. N Data set; structure First-level objective function to The objective function of the first layer is expressed as: ； in, The value is 1 to Integer variables between; The value is 1 to Integer variables between; For the first The first in the data set The actual temperature value of each sampling point; For the first The first in the data set Pressure deviation values ​​at each sampling point; , , , These are the first coefficient, the second coefficient, the third coefficient, and the fourth coefficient, respectively. Constructing the second-level objective function The objective function of the second layer is expressed as: ； Construct the optimization objective function The optimization objective function is expressed as: ； in, This indicates the pre-set combined weights. The value is greater than 0.5 and less than 1; The objective function is minimized, and the particle swarm optimization algorithm is used to calculate the result. , , , The optimal values ​​are denoted as follows: , , , ;according to , , , The temperature-pressure compensation curve of the wireless pressure recorder under test is obtained.

2. The isothermal pressure traceability method as described in claim 1, characterized in that, The method for obtaining the constant temperature and pressure traceability device, wherein the constant temperature and pressure traceability device consists of a dry constant temperature chamber and a standard pressure source, includes: A constant temperature and pressure traceability device is provided; the dry constant temperature chamber is equipped with a heating element, an air circulation element, a temperature sensor, and a temperature controller; the measuring end of the temperature sensor is set at the placement position of the wireless pressure recorder under test in the dry constant temperature chamber, and the temperature controller is connected to the heating element; the standard pressure source is sealed and connected to the dry constant temperature chamber through a pressure source interface reserved on the wall of the dry constant temperature chamber, and the pressure inside the dry constant temperature chamber is adjusted by filling and venting gas into the dry constant temperature chamber.

3. The isothermal pressure traceability method as described in claim 2, characterized in that, According to the preset N To achieve the target temperature value, an air bath dry constant temperature control method is used to heat the dry constant temperature cavity, causing the temperature of the dry constant temperature cavity to sequentially reach and stabilize at the target temperature value. N A target temperature value is obtained. N One method for setting a temperature environment includes: The temperature sensor collects the current temperature value at the location of the wireless pressure recorder under test inside the dry constant temperature chamber in real time and feeds it back to the temperature controller. The temperature controller adjusts the heating power of the heating element according to the difference between the current temperature value and the target temperature value, using a gradual approach to the target temperature control process, so that the temperature of the dry constant temperature chamber reaches and stabilizes at the target temperature value. The air circulation element drives the air circulation within the chamber, ensuring a uniform temperature distribution within the dry constant temperature chamber. When the temperature fluctuation of the dry constant temperature chamber within a preset time does not exceed a preset temperature fluctuation threshold, it is determined that the temperature of the dry constant temperature chamber has stabilized at the target temperature value. This process is repeated sequentially for the... N For each of the target temperature values, a temperature control process is performed to progressively approximate the target value, resulting in the... N A set temperature environment.

4. The isothermal pressure traceability method as described in claim 1, characterized in that, According to , , , Methods for obtaining the temperature-pressure compensation curve of the wireless pressure recorder under test include: according to , , , The temperature-pressure compensation curve of the tested wireless pressure recorder was obtained by fitting; the temperature-pressure compensation curve of the tested wireless pressure recorder is as follows: ； in, Indicates temperature. This indicates the pressure measurement error.

5. A constant temperature and pressure traceability system, characterized in that, The system includes: The data reading module is used to acquire the wireless pressure recorder under test; acquire the constant temperature pressure traceability device, which consists of a dry constant temperature chamber and a standard pressure source; and place the wireless pressure recorder under test inside the dry constant temperature chamber. The temperature environment construction module, connected to the data reading module, is used to construct a temperature environment based on preset parameters. N To achieve the target temperature value, an air bath dry constant temperature control method is used to heat the dry constant temperature cavity, causing the temperature of the dry constant temperature cavity to sequentially reach and stabilize at the target temperature value. N A target temperature value is obtained. N A set temperature environment; The data sampling module, connected to the temperature environment construction module, is used to gradually approximate the actual pressure value inside the dry constant temperature chamber to a preset standard pressure value using a standard pressure source under each set temperature environment. During this process, the actual temperature value, actual pressure value, and pressure value measured by the wireless pressure recorder under test are synchronously collected at each sampling point according to a preset sampling period. The deviation between the pressure value measured by the wireless pressure recorder under test and the actual pressure value at each sampling point is calculated and recorded as the pressure deviation value. The actual temperature value and pressure deviation value under each set temperature environment are combined to obtain... N Each temperature-pressure deviation data set corresponds to a set of temperature conditions. M The actual temperature value and pressure deviation value at each sampling point M The number of data points in the set is preset; The fitting module, connected to the data sampling module, is used to... N A hierarchical fitting is performed on a set of temperature-pressure deviation data to obtain the temperature-pressure compensation curve of the wireless pressure recorder under test; the temperature-pressure compensation curve reflects the pressure measurement error of the wireless pressure recorder under test at different temperatures. The fitting module includes: The objective function construction module is optimized to respectively convert the objective function into a function that constructs the objective function. N The sets of temperature-pressure deviation data are sequentially denoted as the first set to the second set. N Data set; structure First-level objective function to The objective function of the first layer is expressed as: ； in, The value is 1 to Integer variables between; The value is 1 to Integer variables between; For the first The first in the data set The actual temperature value of each sampling point; For the first The first in the data set Pressure deviation values ​​at each sampling point; , , , These are the first coefficient, the second coefficient, the third coefficient, and the fourth coefficient, respectively. Constructing the second-level objective function The objective function of the second layer is expressed as: ； Construct the optimization objective function The optimization objective function is expressed as: ； in, This indicates the pre-set combined weights. The value is greater than 0.5 and less than 1; The optimization calculation module, connected to the optimization objective function construction module, is used to calculate the optimal value of the optimization objective function using the particle swarm optimization algorithm. , , , The optimal values ​​are denoted as follows: , , , ;according to , , , The temperature-pressure compensation curve of the wireless pressure recorder under test is obtained.

6. The constant temperature and pressure traceability system as described in claim 5, characterized in that, The data reading module includes: A constant temperature and pressure traceability device construction module is used to acquire the constant temperature and pressure traceability device; the dry constant temperature chamber is equipped with a heating element, an air circulation element, a temperature sensor, and a temperature controller; the measuring end of the temperature sensor is set at the placement position of the wireless pressure recorder under test in the dry constant temperature chamber, and the temperature controller is connected to the heating element; the standard pressure source is sealed and connected to the dry constant temperature chamber through a pressure source interface reserved on the wall of the dry constant temperature chamber, and the pressure inside the dry constant temperature chamber is adjusted by filling and venting gas into the dry constant temperature chamber.

7. The constant temperature pressure traceability system as described in claim 6, characterized in that, The temperature environment construction module includes: A temperature approximation module is used to collect the current temperature value at the location of the wireless pressure recorder under test inside the dry constant temperature chamber in real time via the temperature sensor and feed it back to the temperature controller. The temperature controller adjusts the heating power of the heating element according to the difference between the current temperature value and the target temperature value, using a gradual temperature control process to approach the target value, so that the temperature of the dry constant temperature chamber reaches and stabilizes at the target temperature value. The air circulation element drives the air circulation within the chamber to ensure uniform temperature distribution within the dry constant temperature chamber. When the temperature fluctuation of the dry constant temperature chamber within a preset time does not exceed a preset temperature fluctuation threshold, it is determined that the temperature of the dry constant temperature chamber has stabilized at the target temperature value. This process is repeated sequentially for the... N For each of the target temperature values, a temperature control process is performed to progressively approximate the target value, resulting in the... N A set temperature environment.

8. The constant temperature pressure traceability system as described in claim 5, characterized in that, The optimization calculation module includes: Output module, used to determine the output based on , , , The temperature-pressure compensation curve of the tested wireless pressure recorder was obtained by fitting; the temperature-pressure compensation curve of the tested wireless pressure recorder is as follows: ； in, Indicates temperature. This indicates the pressure measurement error.

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