A platinum resistance thermometric self-calibration method and related apparatus

Abstract

The present application relates to the technical field of instrument detection, and provides a platinum thermal resistance self-calibration temperature measurement method and related device, the method comprising: sending a self-calibration instruction through the obtained platinum thermal resistance line information to be calibrated; sending a disconnect instruction to the relay in the platinum thermal resistance line to be calibrated; sending the resistance value adjustment instruction corresponding to each first resistance value in the reference table to the low-temperature drift resistance card in turn, and obtaining the second resistance value of the platinum thermal resistance line to be calibrated after each time; according to the corresponding relationship and the temperature corresponding to the first resistance value, constructing the corresponding relationship between each second resistance value and temperature, obtaining the self-calibration temperature-resistance value reference table and using it for temperature measurement; after the platinum thermal resistance in the line is replaced by the low-temperature drift resistance card, the actual resistance value can be determined while the line resistance is measured, the temperature that should be measured when the line measures the second resistance value is determined, the temperature-resistance value reference table is calibrated, and the error caused by the system resistance can be ignored during subsequent temperature measurement, thereby improving the temperature measurement precision.

Description

A self-calibrated temperature measurement method and related device for platinum resistance thermometers Technical Field

[0001] This invention relates to the field of equipment temperature control technology, and in particular to a self-calibrating temperature measurement method and related device using a platinum resistance thermometer. Background Technology

[0002] When semiconductor equipment is running, the electronic components inside it generate heat. If the electronic components are in a high-temperature state for a long time, it will cause thermal deformation of the semiconductor equipment structure, thereby affecting the accuracy and causing the equipment performance to decline. Therefore, it is necessary to monitor the temperature of the electronic components.

[0003] Thermoelectric solutions currently used in temperature measurement for semiconductor equipment suffer from insufficient accuracy due to errors in the measured values ​​caused by the temperature of the components themselves. Summary of the Invention

[0004] This invention provides a self-calibrated temperature measurement method for platinum resistance thermometers, which solves the problem of insufficient temperature measurement accuracy in existing thermoelectric solutions due to errors in the measured values ​​caused by the temperature of the components in the temperature measurement system itself.

[0005] The first aspect of this invention provides a self-calibrated temperature measurement method for platinum resistance thermometers, comprising:

[0006] Obtain information about the platinum resistance thermometer circuit to be calibrated;

[0007] According to the information of the platinum resistance thermometer circuit to be calibrated, a self-calibration command is sent to the programmable switch, so that the programmable switch connects the low-temperature drift resistance card to the platinum resistance thermometer circuit to be calibrated according to the self-calibration command; and a disconnect command is sent to the platinum resistance thermometer relay in the platinum resistance thermometer circuit to be calibrated according to the information of the platinum resistance thermometer circuit to be calibrated.

[0008] Obtain the first resistance value recorded in the temperature-resistance value comparison table of platinum resistance thermometer, send the resistance adjustment command corresponding to each first resistance value to the low temperature drift resistance card in sequence, and obtain the second resistance value in the platinum resistance thermometer circuit to be calibrated after each resistance adjustment command is sent, so as to obtain the correspondence between each first resistance value and the second resistance value. The second resistance value is the total resistance value in the platinum resistance thermometer circuit to be calibrated.

[0009] Based on the correspondence between each first resistance value and the second resistance value, and the temperature corresponding to the first resistance value in the platinum resistance temperature-resistance value reference table, the correspondence between each second resistance value and the temperature is constructed to obtain the self-calibration temperature-resistance value reference table of the platinum resistance circuit to be calibrated.

[0010] Temperature measurements were performed based on the self-calibrated temperature-resistance comparison table.

[0011] Optionally, the first resistance value recorded in the platinum resistance thermometer temperature-resistance lookup table is specifically as follows:

[0012] Obtain all resistance values ​​recorded in the platinum resistance temperature-resistance value lookup table, and select a preset number of resistance values ​​at uniform intervals within the resistance value range of the platinum resistance temperature-resistance value lookup table as the first resistance value.

[0013] Optionally, based on the correspondence between each first resistance value and the second resistance value, and the temperature corresponding to each first resistance value in the platinum resistance thermometer temperature-resistance reference table, a correspondence between each second resistance value and the temperature is constructed to obtain the self-calibration temperature-resistance reference table for the platinum resistance thermometer circuit to be calibrated. Specifically:

[0014] Calculate the difference between each first resistance value and its corresponding second resistance value based on the correspondence between each first resistance value and the second resistance value, and take the average value of each difference to obtain the correction coefficient.

[0015] All resistance values ​​recorded in the platinum resistance temperature-resistance comparison table are corrected with correction factors to obtain the self-calibration temperature-resistance comparison table of the platinum resistance circuit to be calibrated.

[0016] Optionally, the step of sequentially sending the resistance adjustment commands corresponding to each first resistance value to the low-temperature drift resistor card specifically involves:

[0017] Obtain the resistance value information of each resistor card and relay in the low-temperature drift resistor card;

[0018] Calculate the state of each resistance card relay corresponding to each first resistance value based on the resistance value information of the resistance card relay;

[0019] The states of the relays corresponding to each first resistance value are sent sequentially to the low-temperature drift resistor card as resistance adjustment commands, so that the resistance values ​​of the low-temperature drift resistor card are adjusted to the respective first resistance values.

[0020] Optionally, after obtaining the self-calibration temperature-resistance comparison table of the platinum resistance thermometer circuit to be calibrated, the method further includes:

[0021] Determine if there are still platinum resistance thermometer circuits to be calibrated. If so, send a self-calibration command to the programmable switch based on the information of the platinum resistance thermometer circuit to be calibrated; otherwise, send self-calibration completion information to the host computer.

[0022] A second aspect of this application provides a platinum resistance thermometer self-calibrating temperature measuring device, comprising:

[0023] Platinum resistance thermometers, operational amplifier modules, processors, power supplies, programmable switches, and low-temperature drift resistor cards;

[0024] The platinum resistance thermometer is connected to the operational amplifier module and the programmable switch using a four-wire connection.

[0025] The operational amplifier module is connected to the processor and the platinum resistance thermometer respectively, and is used to amplify the resistance change signal of the platinum resistance thermometer.

[0026] The programmable switch is connected to the low-temperature drift resistor card, the processor, the platinum resistance thermometer, and the power supply, respectively, and is used to receive the self-calibration command from the processor and connect the low-temperature drift resistor card to the platinum resistance thermometer to be calibrated according to the self-calibration command from the processor.

[0027] The low-temperature drift resistance card is connected to the programmable switch and the processor respectively, and is used to change the resistance value in the platinum resistance circuit according to the instructions of the processor.

[0028] The power supply is connected to a programmable switch and is used to supply power to the temperature measuring device through the programmable switch.

[0029] The processor is connected to the operational amplifier module and the low-temperature drift resistor card respectively, and is used to execute the self-calibrated temperature measurement method of platinum resistance thermometer as described in any one of claims 1-5.

[0030] Optionally, the processor is specifically an STM32.

[0031] Optionally, the operational amplifier module is connected to a 4-channel ADC chip and a 16-channel multiplexer chip, and each channel of the ADC chip is connected to a platinum resistance thermometer via an operational amplifier.

[0032] A third aspect of this application provides a platinum resistance thermometer self-calibrating temperature measurement system, comprising:

[0033] The calibration information module is used to obtain information about the platinum resistance thermometer circuit to be calibrated.

[0034] The wiring instruction module is used to send a self-calibration instruction to the programmable switch according to the information of the platinum resistance thermometer circuit to be calibrated, so that the programmable switch connects the low-temperature drift resistance card to the platinum resistance thermometer circuit to be calibrated according to the self-calibration instruction; and to send a disconnection instruction to the platinum resistance thermometer relay in the platinum resistance thermometer circuit to be calibrated according to the information of the platinum resistance thermometer circuit to be calibrated.

[0035] The resistance calculation module is used to obtain the first resistance value recorded in the temperature-resistance value comparison table of platinum resistance thermometer, send the resistance adjustment command corresponding to each first resistance value to the low temperature drift resistance card in sequence, and obtain the second resistance value in the platinum resistance thermometer circuit to be calibrated after each resistance adjustment command is sent, so as to obtain the correspondence between each first resistance value and the second resistance value. The second resistance value is the total resistance value in the platinum resistance thermometer circuit to be calibrated.

[0036] The reference table calibration module is used to construct the correspondence between each second resistance value and temperature based on the correspondence between each first resistance value and the second resistance value and the temperature corresponding to the first resistance value in the platinum resistance temperature-resistance reference table, so as to obtain the self-calibration temperature-resistance reference table of the platinum resistance circuit to be calibrated.

[0037] The temperature testing module is used to perform temperature measurements based on the self-calibrated temperature-resistance comparison table.

[0038] Optionally, in the resistance calculation module, the first resistance value recorded in the platinum resistance thermometer temperature-resistance table is obtained, specifically as follows:

[0039] Obtain all resistance values ​​recorded in the platinum resistance temperature-resistance value lookup table, and select a preset number of resistance values ​​at uniform intervals within the resistance value range of the platinum resistance temperature-resistance value lookup table as the first resistance value.

[0040] As can be seen from the above technical solutions, the present invention has the following advantages: It acquires the circuit information of the platinum resistance thermometer to be calibrated; sends a self-calibration command to the programmable switch according to the circuit information, causing the programmable switch to connect the low-temperature drift resistance card to the circuit of the platinum resistance thermometer to be calibrated according to the self-calibration command; sends a disconnect command to the platinum resistance relay in the circuit of the platinum resistance thermometer to be calibrated according to the platinum resistance thermometer circuit information; acquires the first resistance value recorded in the platinum resistance thermometer temperature-resistance value lookup table, sequentially sends the resistance adjustment command corresponding to each first resistance value to the low-temperature drift resistance card, and acquires the second resistance value in the circuit of the platinum resistance thermometer to be calibrated after each transmission of the resistance adjustment command, thus obtaining the correspondence between each first resistance value and the second resistance value, where the second resistance value is the platinum resistance thermometer to be calibrated. The total resistance in the resistive circuit; based on the correspondence between each first resistance value and second resistance value, and the temperature corresponding to the first resistance value in the platinum resistance thermometer temperature-resistance reference table, a correspondence between each second resistance value and temperature is constructed to obtain a self-calibrated temperature-resistance reference table for the platinum resistance thermometer circuit to be calibrated; temperature measurement is performed based on the self-calibrated temperature-resistance reference table; after replacing the platinum resistance thermometer in the platinum resistance thermometer circuit to be calibrated with a low-temperature drift resistance card with a known accurate temperature, the first resistance value of the actual resistance value can be determined at the same time as obtaining the second resistance value of the circuit resistance measurement, and the temperature that should be measured when the circuit measures the second resistance value can be determined. The self-calibrated temperature-resistance reference table is reconstructed, and the error caused by the system resistance can be ignored in subsequent temperature measurements, thus improving the accuracy of temperature measurement. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 is the first flowchart of the self-calibrated temperature measurement method of platinum resistance thermometer.

[0043] Figure 2 is the second flowchart of the self-calibration temperature measurement method of platinum resistance thermometer;

[0044] Figure 3 is the second flowchart of the self-calibration temperature measurement method of platinum resistance thermometer;

[0045] Figure 4 shows a diagram of a platinum resistance thermometer self-calibrating temperature measurement device.

[0046] Figure 5 is a schematic diagram of the principle of a low-temperature drift resistor card;

[0047] Figure 6 is a schematic diagram of the circuit connection of the operational amplifier module;

[0048] Figure 7 shows a diagram of a platinum resistance thermometer self-calibrating temperature measurement system. Detailed Implementation

[0049] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0050] This invention provides a self-calibrated temperature measurement method for platinum resistance thermometers, which solves the problem of insufficient temperature measurement accuracy in existing thermoelectric solutions due to errors in the measured values ​​caused by the temperature of the components in the temperature measurement system itself.

[0051] The temperature measurement system uses a platinum resistance thermometer (RTD) in direct contact with the measured environment, causing the RTD's temperature to change with the environment, thus altering its resistance. The temperature of the measured environment is deduced by measuring the resistance change and using a standard temperature-resistance table for RTDs. However, changes in the resistance of components within the system, such as the operational amplifier module, can affect the signal amplification ratio. Therefore, the self-calibrating temperature measurement method using the RTD of this invention is needed to eliminate these errors.

[0052] Please refer to Figure 1, which is the first flowchart of the self-calibrated temperature measurement method of platinum resistance thermometer provided in an embodiment of the present invention.

[0053] S100, obtain information about the platinum resistance thermometer circuit to be calibrated;

[0054] It should be noted that multiple platinum resistance thermometer lines can coexist in a platinum resistance thermometer measurement system to achieve simultaneous measurement of ambient temperatures at multiple locations. Before performing temperature measurement after the temperature measurement system is started, the processor must first complete the self-calibration of all platinum resistance thermometer lines. This requires retrieving the preset platinum resistance thermometer line information from the memory, or receiving the platinum resistance thermometer line information to be calibrated from the host computer at any time when the staff needs to calibrate a specific line. This allows the processor to determine the line that needs to be self-calibrated based on the platinum resistance thermometer line information.

[0055] S200: Based on the information of the platinum resistance thermometer circuit to be calibrated, a self-calibration command is sent to the programmable switch, causing the programmable switch to connect the low-temperature drift resistance card to the platinum resistance thermometer circuit to be calibrated according to the self-calibration command; and a disconnect command is sent to the platinum resistance thermometer relay in the platinum resistance thermometer circuit to be calibrated according to the information of the platinum resistance thermometer circuit to be calibrated.

[0056] It should be noted that the programmable switch is composed of a multi-channel relay controlled by a serial port, which can control the connection and disconnection between its connected lines. In this embodiment, the programmable switch is connected to each platinum resistance thermometer line and the low-temperature drift resistance card respectively.

[0057] The processor determines the circuit that needs to be calibrated based on the platinum resistance thermometer circuit information, and then sends a self-calibration command to the programmable switch. After receiving the self-calibration command containing the information of the platinum resistance thermometer circuit to be calibrated, the programmable switch connects the low-temperature drift resistance card to the specified platinum resistance thermometer circuit. The processor then sends a disconnect command to the platinum resistance thermometer relay in the platinum resistance thermometer circuit. The platinum resistance thermometer relay can execute the disconnect command by either short-circuiting the platinum resistance thermometer or by switching the circuit connection to disconnect the platinum resistance thermometer and connect it directly to the programmable switch. By issuing the self-calibration command and the disconnect command, the low-temperature drift resistance card replaces the platinum resistance thermometer in the platinum resistance thermometer circuit to be calibrated.

[0058] S300, obtain the first resistance value recorded in the temperature-resistance value comparison table of platinum resistance thermometer, send the resistance adjustment command corresponding to each first resistance value to the low temperature drift resistance card in sequence, and obtain the second resistance value in the platinum resistance thermometer circuit to be calibrated after each resistance adjustment command is sent, and obtain the correspondence between each first resistance value and the second resistance value. The second resistance value is the total resistance value in the platinum resistance thermometer circuit to be calibrated.

[0059] It should be noted that the memory stores a standard platinum resistance thermometer temperature-resistance value lookup table. The table lists several temperatures and their corresponding resistance values ​​for the platinum resistance thermometer. In this embodiment, the first resistance value can be any of the resistance values ​​listed in the lookup table, or any resistance value within the commonly used temperature range of the temperature measurement system that falls within the table. In this embodiment, the platinum resistance thermometer selected is Pt100, which is a platinum resistance thermometer with a resistance value of 100Ω at 0℃.

[0060] The low-temperature drift resistor card consists of multiple low-temperature drift resistors with different resistance values. Each low-temperature drift resistor is connected to a relay. By controlling the on / off state of each relay, the total resistance value of the low-temperature drift resistor card can be changed. After obtaining the first resistance value, the processor calculates the state of each relay when the total resistance is the first resistance value based on the model information of the low-temperature drift resistor card. These relay states are then sent to the low-temperature drift resistor card as resistance adjustment commands, causing the low-temperature drift resistor card to adjust the relay states according to the resistance adjustment commands, thereby changing the total resistance value.

[0061] Each time a resistance adjustment command is sent, causing the total resistance of the low-temperature drift resistor card to be adjusted to the first resistance value, the processor can measure the second resistance value in the platinum resistance thermometer circuit of the temperature measurement system. This second resistance value is the total resistance value of the circuit calculated by the processor after measuring the resistance voltage. After sending multiple resistance adjustment commands, the corresponding relationship between multiple first resistance values ​​and second resistance values ​​can be obtained.

[0062] S400, based on the correspondence between each first resistance value and the second resistance value, and the temperature corresponding to the first resistance value in the platinum resistance temperature-resistance value lookup table, construct the self-calibration temperature-resistance value lookup table of the platinum resistance circuit to be calibrated.

[0063] It should be noted that when the low-temperature drift resistance card is set to the first resistance value, the second resistance value measured in the platinum resistance thermometer circuit to be calibrated is the total resistance value of the circuit. When measuring the temperature, the second resistance value is used to look up the reference table to obtain the temperature, rather than the actual first resistance value. Based on the correspondence between each first resistance value and the second resistance value, as well as the temperature corresponding to the first resistance value in the platinum resistance thermometer temperature-resistance reference table, the correspondence between each second resistance value and the temperature is obtained. This leads to the construction of a self-calibration temperature-resistance reference table for the platinum resistance thermometer circuit to be calibrated, which is equivalent to replacing the first resistance value with the corresponding second resistance value in the standard platinum resistance thermometer temperature-resistance reference table.

[0064] The resistance value of a low-temperature drift resistor is almost negligibly affected by the environment, meaning its resistance value is independent of temperature. When a low-temperature drift resistor card replaces a platinum resistance thermometer in a circuit to be calibrated, the temperature corresponding to the first resistance value set on the low-temperature drift resistor card should be the accurate temperature measured by the temperature measurement system. However, the temperature measurement system can only measure the second resistance value. Therefore, by constructing a new reference table between the second and first resistance values, the temperature measurement error caused by the resistance value in the temperature measurement system can be eliminated, ensuring the accuracy of the temperature measurement. Different platinum resistance thermometer circuits in the temperature measurement system correspond to different measured environments, and therefore each will have its own corresponding self-calibration temperature-resistance reference table.

[0065] S500 performs temperature measurement based on the self-calibrated temperature-resistance comparison table.

[0066] It should be noted that the processor stores the self-calibrated temperature-resistance comparison table corresponding to the platinum resistance circuit to be calibrated in the memory, restores the connection of the platinum resistance in each platinum resistance circuit, that is, disconnects the low temperature drift resistance card and connects the platinum resistance, and then uses the self-calibrated comparison table to perform subsequent temperature measurement tasks to achieve accurate temperature measurement.

[0067] In this embodiment, the following steps are taken: First, the circuit information of the platinum resistance thermometer to be calibrated is obtained. Then, a self-calibration command is sent to a programmable switch based on the circuit information, causing the programmable switch to connect a low-temperature drift resistor card to the platinum resistance thermometer circuit according to the self-calibration command. Next, a disconnect command is sent to the platinum resistance thermometer relay in the circuit based on the platinum resistance thermometer circuit information. Finally, the first resistance value recorded in the platinum resistance thermometer temperature-resistance value lookup table is obtained. Then, resistance adjustment commands corresponding to each first resistance value are sequentially sent to the low-temperature drift resistor card, and the second resistance value in the platinum resistance thermometer circuit after each resistance adjustment command is sent is obtained, thus establishing the correspondence between each first resistance value and the second resistance value. The second resistance value is the total resistance in the platinum resistance thermometer circuit. The system constructs a self-calibrated temperature-resistance reference table for the platinum resistance thermometer circuit based on the correspondence between the first and second resistance values ​​and the corresponding temperatures of the first resistance values ​​in the platinum resistance thermometer temperature-resistance reference table. Temperature measurements are then performed based on this self-calibrated table. By replacing the platinum resistance thermometer in the circuit with a low-temperature drift resistance card whose accurate temperature is known, the system can determine the first resistance value of the actual resistance value while simultaneously obtaining the second resistance value of the circuit. This allows the system to determine the temperature that should be measured when the circuit reaches the second resistance value, and reconstructs the self-calibrated temperature-resistance reference table. This allows the system to ignore errors caused by resistance during subsequent temperature measurements, improving the accuracy of temperature measurement.

[0068] The above is a detailed description of the first embodiment of the self-calibrated temperature measurement method of platinum resistance thermometer provided in this application. The following is a detailed description of the second embodiment of the self-calibrated temperature measurement method of platinum resistance thermometer provided in this application.

[0069] In this embodiment, a specific example of step S300 in the platinum resistance thermometer self-calibration temperature measurement method is further provided. Please refer to Figure 2. Step S300 specifically includes steps S301-S303, as detailed below:

[0070] S301, obtain all the resistance values ​​recorded in the platinum resistance temperature-resistance value comparison table, and select a preset number of resistance values ​​at uniform intervals as the first resistance value within the resistance value range of the platinum resistance temperature-resistance value comparison table.

[0071] It should be noted that the temperature-resistance value reference table for platinum resistance thermometers contains a large amount of reference data, and extracting, verifying and replacing each one would take a long time. Therefore, a preset number of resistance values ​​can be selected evenly from the reference table as the first resistance value. For example, a resistance value can be selected every 100Ω interval within the resistance range. This reduces the total number of the final first resistance values ​​while ensuring the reliability of subsequent self-calibration.

[0072] S302, Obtain the resistance value information of each resistor card relay in the low-temperature drift resistor card;

[0073] It should be noted that the low-temperature drift resistor card is composed of multiple low-temperature drift resistors with different resistance values. Each low-temperature drift resistor is connected to a relay. By controlling the on / off state of each relay, the total resistance value of the low-temperature drift resistor card can be changed. The relay state settings are different when adjusting the resistance value of different models of low-temperature drift resistor cards. The processor needs to first obtain the pre-stored low-temperature drift resistor card information in the memory to guide the subsequent relay state calculation.

[0074] S303, calculate the state of each resistance card relay corresponding to each first resistance value based on the resistance card relay resistance value information;

[0075] It should be noted that the processor calculates the combination of low-temperature drift resistors that constitute the first resistance value based on the resistance value information of the resistor card relay. For example, when the first resistance value is 123Ω, the relays that control the 100Ω, two 10Ω and three 1Ω low-temperature drift resistors are connected in series, and the other low-temperature drift resistors are disconnected, so that the total resistance value of the low-temperature drift resistor card is 123Ω.

[0076] S304, send the relay status of each resistor card corresponding to the first resistance value as a resistance adjustment command to the low temperature drift resistor card, so that the resistance value of the low temperature drift resistor card is adjusted to each of the first resistance values.

[0077] It should be noted that the state of each resistor card relay corresponding to each first resistance value is the state that all resistor card relays should maintain when the total resistance of the low-temperature drift resistor card is the first resistance value. After the states of each resistor card relay corresponding to each first resistance value are sent to the low-temperature drift resistor card as resistance adjustment commands in sequence, the drive controller in the low-temperature drift resistor card will realize the on and off of each relay according to the resistance adjustment commands.

[0078] S305, obtain the second resistance value in the platinum resistance thermometer circuit to be calibrated, the second resistance value is the total resistance value in the platinum resistance thermometer circuit to be calibrated;

[0079] S306, determine whether the status of each resistor card relay has been sent to the low-temperature drift resistor card. If not, return to step S304. If yes, obtain the correspondence between all first resistance values ​​and second resistance values.

[0080] In this embodiment, a specific implementation of step S400 is further provided. Please refer to Figure 3. Step S400 specifically includes steps S401-S403, as detailed below.

[0081] S401, calculate the difference between each first resistance value and the corresponding second resistance value according to the correspondence between each first resistance value and the second resistance value, and take the average value of each difference to obtain the correction coefficient;

[0082] It should be noted that the correction coefficient for the entire platinum resistance circuit to be calibrated is obtained by calculating the average difference between each marked resistance value as the first resistance value and the second resistance value. This correction coefficient is the difference between the representative first resistance value and the second resistance value. The number of reference values ​​in the temperature-resistance value reference table of PT100 is determined according to the detection temperature range of PT100. In this embodiment, the temperature measurement system has only 1500 resistance values ​​in the detection temperature range. The more preset numbers of marked resistance values ​​are selected and the denser the distribution, the more accurate the correction coefficient will be.

[0083] S402, correct all the resistance values ​​recorded in the platinum resistance temperature-resistance comparison table with a correction factor to obtain the self-calibration temperature-resistance comparison table of the platinum resistance circuit to be calibrated.

[0084] It should be noted that the correction factor obtained from the marked resistance value is used to correct the entire temperature-resistance reference table, eliminating the need to measure and calibrate each resistance value sequentially using a lookup table method, thus improving calibration efficiency.

[0085] S403 determines whether there is still a platinum resistance thermometer circuit to be calibrated. If so, it sends a self-calibration command to the programmable switch based on the information of the platinum resistance thermometer circuit to be calibrated; otherwise, it sends self-calibration completion information to the host computer.

[0086] It should be noted that the temperature measuring device in this embodiment has multiple platinum resistance thermometer lines to simultaneously measure the temperature of multiple electronic components, but only one low-temperature drift resistance card is set. In order to complete the calibration of each platinum resistance thermometer line, the low-temperature drift resistance card needs to be connected to each line in sequence by a programmable switch to complete the temperature-resistance comparison table calibration of each platinum resistance thermometer line. In actual implementation, multiple low-temperature drift resistance cards can be set to improve the self-calibration efficiency.

[0087] Once all platinum resistance thermometer circuits have been calibrated, it indicates that the temperature measurement system can accurately measure the temperature at the platinum resistance thermometer. The system then sends a self-calibration completion message to the host computer, allowing temperature measurement personnel to know that the temperature measurement system can now start working normally and enabling the system to be reused.

[0088] Furthermore, the method of setting the first resistance value of the low-temperature drift resistor card to the resistance value or marked resistance value recorded in the platinum resistance temperature-resistance value lookup table is as follows: calculate the relay status of the resistor card corresponding to each desired resistance value, and send the relay status of the resistor card corresponding to each desired resistance value to the low-temperature drift resistor card through the RS485 modebus RTU communication program. Control the on / off state of the relays on each low-temperature drift resistor to control the series and parallel connection between the low-temperature drift resistors, so that the total resistance of the low-temperature drift resistor card connected to the platinum resistance circuit to be calibrated is the desired resistance value.

[0089] In this embodiment, the correction coefficient of the entire reference table is obtained by calculating the preset number of first resistors and corresponding second resistors. Then, the temperature-resistance reference table is calibrated so that only a small number of resistors on the reference table need to be measured to complete the calibration of the entire reference table, thereby improving the calibration efficiency and making the temperature measurement system more repeatable.

[0090] The above is a detailed description of the second embodiment of a platinum resistance thermometer self-calibration temperature measurement method provided in this application. The following is a detailed description of a platinum resistance thermometer self-calibration temperature measurement device provided in the second aspect of this application.

[0091] Please refer to Figure 4, which is a diagram of a platinum resistance thermometer self-calibrating temperature measurement device. This embodiment provides a platinum resistance thermometer self-calibrating temperature measurement device, which is used to perform a platinum resistance thermometer self-calibrating temperature measurement method, including: a platinum resistance thermometer 10, an operational amplifier module 20, a processor 30, a power supply 40, a programmable switch 50, and a low-temperature drift resistance card 60;

[0092] The platinum resistance thermometer 10 is connected to the operational amplifier module 20 and the programmable switch 50 using a four-wire connection.

[0093] The operational amplifier module 20 is connected to the processor 30 and the platinum resistance thermometer 10 respectively, and is used to amplify the resistance change signal of the platinum resistance thermometer 10.

[0094] The programmable switch 50 is connected to the low-temperature drift resistance card 60, the processor 30, the platinum resistance thermometer 10 and the power supply 40 respectively. It is used to receive the self-calibration command from the processor 30 and connect the low-temperature drift resistance card 60 to the platinum resistance thermometer 10 to be calibrated according to the self-calibration command from the processor 30.

[0095] The low-temperature drift resistance card 60 is connected to the programmable switch 50 and the processor 30 respectively, and is used to change the resistance value in the circuit connected to the platinum resistance thermometer 10 according to the instructions of the processor 30.

[0096] In this embodiment, the low-temperature drift resistance card 60 is internally connected with high-purity silver (Ag99.99%) wires, which can minimize the resistance error caused by the wires and maximize thermal stability, so that the system can still give accurate measurement results under harsh thermal conditions.

[0097] The power supply 40 is connected to the programmable switch 50 and is used to supply power to the temperature measuring device through the programmable switch 50;

[0098] The processor 30 is connected to the operational amplifier module 20 and the low-temperature drift resistor card 60 respectively. It is used to send self-calibration commands to the programmable switch 50 and set the resistance value of the low-temperature drift resistor card 60. It also calculates the resistance value of the platinum resistance thermometer 10 according to the current in the circuit, and then converts the resistance value into the temperature of the platinum resistance thermometer 10 using a temperature-resistance conversion table.

[0099] In this embodiment, the platinum resistance thermometer 10 eliminates the error caused by wire connection through a four-wire connection method. The multi-channel platinum resistance circuit can realize the measurement of the temperature of multiple targets. The processor 30 specifically adopts an STM32. The STM32 can act according to the operation instructions of the upper-level computer. The STM32 has a corresponding control algorithm. After the temperature measuring device is started, it will perform self-calibration on each platinum resistance thermometer 10 line and store the calibrated temperature-resistance lookup table into the microcontroller. Then, the ambient temperature signal parameters can be measured by the platinum resistance thermometer 10. The processor 30 uses a lookup table method to find the corresponding temperature signal parameters in the temperature-resistance lookup table, thereby obtaining the accurate ambient temperature value.

[0100] The programmable switch 50 is composed of a serial-controlled multi-channel relay. The programmable switch 50 can control the connection and disconnection between its connected lines. During self-calibration, the low-temperature drift resistor card 60 is connected to each platinum resistance thermometer 10 to be calibrated. After self-calibration is completed, the low-temperature drift resistor card 60 can be disconnected. The programmable switch 50 is connected to the power supply 40, which specifically includes a high-precision reference voltage source and a constant current source. Its function is to keep the current flowing through the platinum resistance thermometer 10 and the low-temperature drift resistor card 60 constant. In this embodiment, the constant current value is 2mA.

[0101] Further, please refer to Figure 5, which is a schematic diagram of the low-temperature drift resistor card 60. The low-temperature drift resistor card 60 is composed of multiple low-temperature drift resistors 601 with different resistance values, ranging from 1mΩ to 500Ω. The control driver 602 changes the state of the resistor card relay 603 according to the instruction of the receiving processor 30, thereby changing the series and parallel connection relationship between each low-temperature drift resistor 601, so that the overall resistance value of the low-temperature drift resistor card 60 is the resistance value required by the instruction of the processor 30, thus realizing the self-calibration of the platinum resistance thermometer 10 circuit.

[0102] Further, please refer to Figure 6, which is a schematic diagram of the circuit connection of the operational amplifier module 20. The operational amplifier module 20 is connected to each platinum resistance thermometer 10, and each platinum resistance thermometer 10 is connected to an operational amplifier 201 to amplify the voltage signal generated by the platinum resistance thermometer 10 for signal acquisition. The operational amplifier module 20 uses a 4-channel ADC chip 202 and a 16-channel multiplexer chip 203. The 4-channel ADC chip 202 can convert up to 4 voltage signals generated by the platinum resistance thermometers 10, and the 16-channel multiplexer chip 203 can synthesize multiple acquired signals into a single output signal in a way that each input signal can be recovered, making full use of the channel signal capacity. In actual implementation, it can support up to 64 platinum resistance thermometers 10.

[0103] Please refer to Figure 7. A third aspect of this application also provides a platinum resistance thermometer self-calibrating temperature measurement system, comprising:

[0104] The calibration information module 100 is used to obtain information about the platinum resistance thermometer circuit to be calibrated.

[0105] The wiring instruction module 200 is used to send a self-calibration instruction to the programmable switch according to the information of the platinum resistance thermometer circuit to be calibrated, so that the programmable switch connects the low-temperature drift resistance card to the platinum resistance thermometer circuit to be calibrated according to the self-calibration instruction; and to send a disconnection instruction to the platinum resistance thermometer relay in the platinum resistance thermometer circuit to be calibrated according to the information of the platinum resistance thermometer circuit to be calibrated.

[0106] The resistance calculation module 300 is used to obtain the first resistance value recorded in the temperature-resistance value comparison table of platinum resistance thermometer, send the resistance adjustment command corresponding to each first resistance value to the low temperature drift resistance card in sequence, and obtain the second resistance value in the platinum resistance thermometer circuit to be calibrated after each resistance adjustment command is sent, so as to obtain the correspondence between each first resistance value and the second resistance value. The second resistance value is the total resistance value in the platinum resistance thermometer circuit to be calibrated.

[0107] The reference table calibration module 400 is used to construct the correspondence between each second resistance value and temperature based on the correspondence between each first resistance value and the second resistance value and the temperature corresponding to the first resistance value in the platinum resistance temperature-resistance reference table, so as to obtain the self-calibration temperature-resistance reference table of the platinum resistance circuit to be calibrated.

[0108] The temperature measurement module 500 is used to perform temperature measurement based on the self-calibrated temperature-resistance comparison table.

[0109] Furthermore, in the resistance calculation module 300, the first resistance value recorded in the platinum resistance thermometer temperature-resistance comparison table is obtained, specifically:

[0110] Obtain all resistance values ​​recorded in the platinum resistance temperature-resistance value lookup table, and select a preset number of resistance values ​​at uniform intervals within the resistance value range of the platinum resistance temperature-resistance value lookup table as the first resistance value.

[0111] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described apparatus and equipment can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0112] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0113] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0114] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0115] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0116] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-calibrated temperature measurement method for platinum resistance thermometers, characterized in that, include: Obtain information about the platinum resistance thermometer circuit to be calibrated; According to the information of the platinum resistance thermometer circuit to be calibrated, a self-calibration command is sent to the programmable switch, so that the programmable switch connects the low-temperature drift resistance card to the platinum resistance thermometer circuit to be calibrated according to the self-calibration command. A disconnect command is sent to the platinum resistance relay in the platinum resistance circuit to be calibrated based on the information of the platinum resistance circuit to be calibrated. Obtain the first resistance value recorded in the temperature-resistance value comparison table of platinum resistance thermometer, send the resistance adjustment command corresponding to each first resistance value to the low temperature drift resistance card in sequence, and obtain the second resistance value in the platinum resistance thermometer circuit to be calibrated after each resistance adjustment command is sent, so as to obtain the correspondence between each first resistance value and the second resistance value. The second resistance value is the total resistance value in the platinum resistance thermometer circuit to be calibrated. Based on the correspondence between each first resistance value and the second resistance value, and the temperature corresponding to the first resistance value in the platinum resistance temperature-resistance value reference table, the correspondence between each second resistance value and the temperature is constructed to obtain the self-calibration temperature-resistance value reference table of the platinum resistance circuit to be calibrated. Temperature measurement is performed based on the self-calibrated temperature-resistance reference table. Specifically, the self-calibrated temperature-resistance reference table for the platinum resistance thermometer circuit to be calibrated is obtained by constructing a correspondence between each second resistance value and temperature based on the correspondence between each first resistance value and the second resistance value, and the corresponding temperature of each first resistance value in the platinum resistance thermometer temperature-resistance reference table. This involves calculating the difference between each first resistance value and its corresponding second resistance value based on the correspondence between the first and second resistance values, taking the average of these differences to obtain a correction coefficient, and correcting all resistance values ​​recorded in the platinum resistance thermometer temperature-resistance reference table using the correction coefficient to obtain the self-calibrated temperature-resistance reference table for the platinum resistance thermometer circuit to be calibrated.

2. The self-calibrated temperature measurement method for platinum resistance thermometers according to claim 1, characterized in that, The process of obtaining the first resistance value recorded in the temperature-resistance comparison table of the platinum resistance thermometer specifically involves: obtaining all resistance values ​​recorded in the temperature-resistance comparison table of the platinum resistance thermometer, and uniformly selecting a preset number of resistance values ​​at intervals within the resistance value range of the temperature-resistance comparison table of the platinum resistance thermometer as the first resistance value.

3. The self-calibrated temperature measurement method for platinum resistance thermometers according to claim 1, characterized in that, The step of sequentially sending the resistance adjustment commands corresponding to each first resistance value to the low-temperature drift resistor card specifically involves: obtaining the resistance value information of each resistor card relay in the low-temperature drift resistor card; calculating the state of each resistor card relay corresponding to each first resistance value based on the resistance value information; sequentially sending the state of each resistor card relay corresponding to each first resistance value as a resistance adjustment command to the low-temperature drift resistor card, and sequentially adjusting the resistance value of the low-temperature drift resistor card to each first resistance value.

4. The self-calibrated temperature measurement method for platinum resistance thermometers according to claim 1, characterized in that, After obtaining the self-calibration temperature-resistance comparison table of the platinum resistance thermometer circuit to be calibrated, the method further includes: determining whether there is still a platinum resistance thermometer circuit to be calibrated; if so, sending a self-calibration command to the programmable switch according to the information of the platinum resistance thermometer circuit to be calibrated; if not, sending self-calibration completion information to the host computer.

5. A platinum resistance thermometer self-calibrating temperature measuring device, characterized in that, include: The device comprises a platinum resistance thermometer (RTD), an operational amplifier module, a processor, a power supply, a programmable switch, and a low-temperature drift resistor card. The RTD is connected to the operational amplifier module and the programmable switch using a four-wire connection. The operational amplifier module is connected to the processor and the RTD to amplify the resistance change signal of the RTD. The programmable switch is connected to the low-temperature drift resistor card, the processor, the RTD, and the power supply to receive self-calibration commands from the processor and connect the low-temperature drift resistor card to the RTD to be calibrated according to the processor's self-calibration commands. The low-temperature drift resistor card is connected to the programmable switch and the processor to change the resistance value in the RTD circuit according to the processor's commands. The power supply is connected to the programmable switch to supply power to the temperature measuring device. The processor is connected to the operational amplifier module and the low-temperature drift resistor card to execute the self-calibration temperature measurement method for the platinum resistance thermometer as described in any one of claims 1-4.

6. The self-calibrating temperature measuring device for platinum resistance thermometers according to claim 5, characterized in that, The processor is specifically an STM32.

7. The self-calibrating temperature measuring device for platinum resistance thermometers according to claim 5, characterized in that, The operational amplifier module is connected to a 4-channel ADC chip and a 16-channel multiplexer chip, and each channel of the ADC chip is connected to a platinum resistance thermometer via an operational amplifier.

8. A platinum resistance thermometer self-calibrating temperature measurement system, applied to the platinum resistance thermometer self-calibrating temperature measurement method as described in any one of claims 1-4, characterized in that, include: The calibration information module is used to obtain information about the platinum resistance thermometer circuit to be calibrated. The wiring instruction module is used to send a self-calibration instruction to the programmable switch according to the information of the platinum resistance thermometer circuit to be calibrated, so that the programmable switch connects the low-temperature drift resistance card to the platinum resistance thermometer circuit to be calibrated according to the self-calibration instruction. According to the information of the platinum resistance thermometer circuit, a disconnection command is sent to the platinum resistance relay in the platinum resistance thermometer circuit to be calibrated; the resistance calculation module is used to obtain the first resistance value recorded in the platinum resistance temperature-resistance value lookup table, send the resistance adjustment command corresponding to each first resistance value to the low temperature drift resistance card in sequence, and obtain the second resistance value in the platinum resistance thermometer circuit to be calibrated after each resistance adjustment command is sent, so as to obtain the correspondence between each first resistance value and the second resistance value, and the second resistance value is the total resistance value in the platinum resistance thermometer circuit to be calibrated; The reference table calibration module is used to construct the correspondence between each second resistance value and temperature based on the correspondence between each first resistance value and the second resistance value and the temperature corresponding to the first resistance value in the platinum resistance temperature-resistance reference table, so as to obtain the self-calibration temperature-resistance reference table of the platinum resistance circuit to be calibrated. The temperature testing module is used to perform temperature measurements based on the self-calibrated temperature-resistance comparison table.

9. The platinum resistance thermometer self-calibrating temperature measurement system according to claim 8, characterized in that, In the resistance calculation module, the first resistance value recorded in the platinum resistance temperature-resistance comparison table is obtained. Specifically, all resistance values ​​recorded in the platinum resistance temperature-resistance comparison table are obtained, and a preset number of resistance values ​​are selected evenly at intervals within the resistance value range of the platinum resistance temperature-resistance comparison table as the first resistance value.

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