Automatic compensation fine-tuning device and method for silicon piezoresistive pressure sensor

Abstract

The present invention discloses an automatic compensation fine-tuning device and method for a silicon piezoresistive pressure sensor. The device comprises a main controller (1), a component parameter detection module, a compensation resistor equivalent module, and a sensor accuracy test module. The main controller 1 is used to control the device parameters of the component parameter detection module, the compensation resistor equivalent module, and the sensor accuracy test module, and to read the measured values ​​of the compensation resistor equivalent module and the component parameter detection module. The component parameter detection module is used to complete parameter detection of resistors to be selected in batches. The compensation resistor equivalent module is used to equalize the equivalent resistance value output by the main controller (1). The sensor accuracy test module is used to test the sensor accuracy and provide a test environment. The present invention realizes the fine-tuning of the automatic compensation output value, thereby reducing the intensity of manual screening and the number of test cycles in the sensor fine-tuning link.

Description

Technical Field

[0001] The invention belongs to the technical field of instrument manufacturing, and relates to an automatic compensation fine-tuning device and method for a silicon piezoresistive pressure sensor. Background Art

[0002] The silicon piezoresistive pressure core is an important pressure-sensing component of the silicon piezoresistive pressure sensor, usually in the form of a Wheatstone bridge composed of four force-sensitive resistors. The main reasons why the silicon piezoresistive pressure core needs to be compensated before it can be used in engineering are as follows: 1) The resistors on the Wheatstone bridge must have the same resistance value under the same environment to ensure that the bridge output is 0 when there is no pressure. In fact, due to the limitations of the production process, there will be errors in the surface doping concentration of the force-sensitive resistor, which makes it difficult to find four completely identical force-sensitive resistors. The output offset that occurs based on this situation is called zero-point drift. 2) Since the force-sensitive resistor is a semiconductor material, its resistance value is not only linearly related to the external pressure, but also affected by temperature and will produce temperature drift. Also due to the limitations of the production process, the degree of temperature drift of the force-sensitive resistor is also different.

[0003] To overcome the problem of insufficient accuracy of the silicon pressure group pressure core caused by the above reasons, patents or papers such as "A Silicon Piezoresistive Pressure Sensor Temperature Compensation Circuit" (CN202220745706.0) provide a design method for the compensation circuit, and "A Silicon Piezoresistive Temperature Compensation Evaluation Method" (CN201410667309.6) provides a method for analyzing and automatically calculating different compensation circuit structures. However, the above methods are only developed in mathematical theory or rely on precision equipment in the laboratory. In actual engineering, due to the errors of the measurement equipment and the tolerance of the compensation resistor itself, the compensation effect of the silicon pressure group pressure core calculated according to the theoretical value is often lower than the theoretical expectation. At this time, in order to improve the actual accuracy of the core after compensation, the usual practice is to test the compensated silicon pressure group core, and manually screen and replace the resistors on the compensation circuit based on the test results, in order to use the small changes in the compensation resistor values ​​at individual compensation positions to achieve small adjustments to the sensor output value.

[0004] Traditional manual screening methods still have certain disadvantages in actual operation. One method is to directly solder components to the compensation position of the sensor circuit. When the sensor accuracy does not meet the requirements, the components are desoldered and replaced. Since repeated desoldering of the circuit board will affect the reliability of the product, the number of adjustments of this method will be limited, and it is difficult to obtain the optimal solution. Another method is to lead out the compensation position endpoint of the sensor through a test line, connect the other end of the test line to a variable resistor, use the variable resistor to complete the debugging, and then install components of equal value into the sensor. Due to the influence of the internal resistance of the test line itself, the actual compensation effect of this method will also have a slight deviation from the debugging effect. Summary of the Invention

[0005] The purpose of the present invention is to provide an automatic compensation fine-tuning device and method for a silicon piezoresistive pressure sensor. The present invention realizes the fine-tuning of the automatic compensation output value, thereby reducing the intensity of manual screening and the number of test cycles in the sensor fine-tuning link.

[0006] The technical solution of the present invention is: an automatic compensation and fine-tuning device for a silicon piezoresistive pressure sensor, comprising a main controller, a component parameter detection module, a compensation resistor equivalent module and a sensor accuracy testing module; the main controller 1 is used to control the device parameters of the component parameter detection module, the compensation resistor equivalent module and the sensor accuracy testing module, and to read the measurement values ​​of the compensation resistor equivalent module and the component parameter detection module; the component parameter detection module is used to complete parameter detection of resistors to be selected in batches; the compensation resistor equivalent module is used to equalize the equivalent resistance value output by the main controller; the sensor accuracy testing module is used to test the sensor accuracy and provide a test environment.

[0007] In the aforementioned automatic compensation and fine-tuning device for silicon piezoresistive pressure sensors, the component parameter detection module includes a multimeter II and a programmable switch electrically connected to each other; the multimeter II is electrically connected to the main controller.

[0008] In the aforementioned automatic compensation and fine-tuning device for silicon piezoresistive pressure sensors, the process of completing parameter detection of resistors to be selected in batches is as follows: a multimeter II is used to measure the parameters of several components to be selected placed in the program-controlled switch and store them in the main controller.

[0009] In the aforementioned automatic compensation fine-tuning device for the silicon piezoresistive pressure sensor, the programmable switch has a manual-automatic conversion key, a manual switching key and several installation positions for selected components. Each installation position is equipped with an indicator light. The programmable switch is turned on and off at each position by manual or automatic switching to realize the measurement of component parameters.

[0010] In the aforementioned automatic compensation and fine-tuning equipment for silicon piezoresistive pressure sensors, the compensation resistor equivalent module includes a pad fixture, a programmable constant current source, and a programmable variable resistor; the pad fixture is equipped with two sets of spring pins and test cables; the pad fixture is connected to the sensor resistance to be compensated through the spring pins, and is connected to the programmable constant current source and the programmable variable resistor through the test cables; the programmable constant current source and the programmable variable resistor are both electrically connected to the main controller.

[0011] In the aforementioned automatic compensation and fine-tuning device for the silicon piezoresistive pressure sensor, the working process of the compensation resistor equivalent module is as follows: the main controller sends the compensation parameter R1 to the programmable variable resistor. During the adjustment of the programmable variable resistor, the main controller receives the voltage value U1 and current value I1 returned by the programmable constant current source. When U1 / I1 is equal to R1, the compensation resistor equivalent module completes the equivalent work of the C1 parameter.

[0012] In the aforementioned automatic compensation and fine-tuning device for silicon piezoresistive pressure sensors, the sensor accuracy test module includes a high and low temperature chamber, a pressure control device, a sensor power supply and a multimeter I; the high and low temperature chamber, the pressure control device, the sensor power supply and the multimeter I are all electrically connected to the main controller.

[0013] The automatic compensation fine-tuning method of the aforementioned silicon piezoresistive pressure sensor automatic compensation fine-tuning device comprises the following steps:

[0014] Step 1: Empty the position of the components that need compensation and fine-tuning of the sensor to be debugged, place a pad fixture on the empty pad position, and connect the two sets of test lines on the pad fixture to the programmable constant current source and programmable variable resistor respectively;

[0015] Step 2: Place the resistors N1, N2, ..., Nn to be selected in the program-controlled switch. Based on the automatic switching instruction of the main controller or manual switching, the multimeter II measures the resistance values ​​of the selected resistors in the program-controlled switch in sequence. The measured values ​​R1, R2, ..., Rn are stored in the main controller.

[0016] Step 3: Control the high and low temperature box and the pressure control equipment to the preset temperature and pressure values ​​through the main controller, select the R1 parameter to adjust the programmable rheostat, turn on the programmable constant current source, and the programmable constant current source detects the voltage value U1 and the current value I1 and transmits the data back to the main controller. When the main controller detects that U1 / I1 is equal to R1, it stops adjusting the programmable rheostat and turns off the programmable constant current source;

[0017] Step 4: Turn on the power supply of the sensor to be debugged and multimeter I, test the sensor output accuracy, obtain the test result OUT1 and store it in the main controller;

[0018] Step 5: Repeat steps 3 and 4 until the sensor output accuracy test results OUT1, OUT2, ..., OUTn after compensation by N optional resistors are obtained;

[0019] Step 6: Use the main controller to control the high and low temperature box and pressure control equipment to the preset temperature and pressure values. Repeat steps 3 to 5. The sensor outputs the accuracy test results OUT1', OUT2', ..., OUTn'. Repeat the above steps until all temperature points that need to be calibrated are traversed.

[0020] Step 7: The main controller compares and analyzes the above multiple groups of detection results and selects components that can meet the optimal compensation results.

[0021] The advantages of the present invention are: compared with the existing technology, the present invention realizes fine adjustment of automatic compensation output value by automatically selecting appropriate components when determining the compensation position, thereby reducing the intensity of manual screening and the number of test cycles in the sensor fine-tuning link.

[0022] When a sensor is manufactured and its output accuracy is verified, if there are slight deviations from tolerance due to accumulated errors such as equipment measurement errors and component tolerances, the common practice in the past was to manually replace individual compensation electronic components within the sensor based on design and process experience. In this case, due to the limitations of sensor miniaturization, the resistor compensation positions that require fine-tuning cannot be accurately adjusted using a series or parallel connection. Only a single resistor position can be used for compensation. The parameters of the electronic components of different models are not continuous, so multiple rounds of manual replacement and testing are required to achieve performance optimization. The present invention uses a pad fixture, a programmable constant current source and a programmable variable resistor to equivalently replace the standby components in the compensation position. Firstly, it overcomes the line resistance error introduced by the current common operation of only using a variable resistor instead of the compensation position resistor. Secondly, it can complete the compensation effect test of multiple standby components in one high and low temperature cycle, saving the iterative test time of repeatedly replacing components. Thirdly, by using the interpolation algorithm embedded in the computer, the parameters of the component array composed of multiple standby components can be analyzed, the test sequence can be optimized, and the number of tests can be reduced, which is equivalent to reducing the number of iterations in previous operations. At the same time, a better compensation solution can be obtained in a shorter time.

[0023] To sum up, the present invention selects the test order of resistors through the interpolation method, rather than testing them in sequence by position, which can reduce the number of debugging times in the product compensation fine-tuning link and save debugging time; through the compensation resistor position equivalent module, it replaces the manual repetitive welding work, and can perform multiple groups of debugging and test verification in one high and low temperature cycle, thereby improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the automatic compensation fine-tuning device of the silicon piezoresistive pressure sensor.

[0025] Among them, 1-main controller, 2-high and low temperature box, 3-sensor waiting for debugging, 4-pressure control equipment, 5-soldering pad fixture, 6-programmable constant current source, 7-programmable variable resistor, 8-multimeter, 9-multimeter, 10-programmable switch. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to the accompanying drawings and examples, but they are not intended to limit the present invention.

[0027] Example 1. The compensation circuit compensation bit device automatic fine-tuning device of the present invention is composed of Figure 1 As shown, it includes a main controller, a component parameter detection module, a compensation resistance equivalent module and a sensor accuracy test module.

[0028] Main controller 1 is connected to temperature and temperature chamber 2, pressure control device 4, programmable constant current source 6, programmable rheostat 7, multimeter I 8, and multimeter II 9 via a network. Main controller 1's primary functions include controlling the parameters of temperature and temperature chamber 2, pressure control device 4, and programmable rheostat 7, and reading measurements from programmable constant current source 6 and multimeter II 9.

[0029] The component parameter detection module is used to batch-test the parameters of candidate resistors. It includes a multimeter II 9 and a programmable switch 10. This module uses the multimeter II 9 to measure the parameters of several candidate components placed within the programmable switch 10 (for example, the resistors are selected, and the multimeter II 9 measures the resistance values) and stores the values ​​in the main controller 1. The programmable switch 10 has a manual-automatic switch key, a manual shift key, and several mounting positions for candidate components. Each mounting position is equipped with an indicator light. Manual or automatic switching switches the programmable switch to on and off, enabling component parameter measurement.

[0030] The compensation resistance equivalent module is used to equalize the equivalent resistance value sent by the main controller 1, and includes a pad fixture 5, a programmable constant current source 6, and a programmable rheostat 7. The pad fixture 5 is equipped with two sets of spring pins and a test cable. The pad fixture 5 is connected to the resistance position to be compensated by the sensor through the spring pin, and is connected to the programmable constant current source 6 and the programmable rheostat 7 through the test cable. The main controller 1 sends a compensation parameter R1 to the programmable rheostat 7. During the adjustment of the programmable rheostat 7, the main controller 1 receives the voltage value U1 and current value I1 sent back by the programmable constant current source 6. When U1 / I1 is equal to R1, the compensation resistance equivalent module completes the equivalent work of the C1 parameter. Compared with directly using the resistor carried on the programmable switch for compensation debugging, this method can eliminate the internal resistance interference introduced by the pad fixture 5.

[0031] The sensor accuracy test module is used for sensor accuracy testing and providing a test environment, including a high and low temperature chamber 2, a pressure control device 4, a sensor power supply and a multimeter I8.

[0032] Specific steps for automatic compensation fine-tuning of silicon piezoresistive pressure sensor:

[0033] Step 1: Empty the positions of the components of the sensor 3 that need to be compensated and fine-tuned, place a pad fixture 5 on the empty pad positions, and connect the two sets of test lines on the pad fixture 5 to the programmable constant current source 6 and the programmable variable resistor 7 respectively;

[0034] Step 2: Place the resistors to be selected (N resistors to be selected, numbered N1, N2...Nn) in the program-controlled switch 10. According to the automatic switching instruction of the main controller 1 or through manual switching, the multimeter II 9 sequentially measures the resistance values ​​of the selected resistors in the program-controlled switch, and the measured values ​​are stored in the main controller 1 (the above measured values ​​are numbered R1, R2...Rn);

[0035] Step 3: The high and low temperature box 2 and the pressure control device 4 are controlled by the main controller 1 to adjust to the required temperature and pressure values, the R1 parameter is selected to adjust the programmable rheostat 7, and the programmable constant current source 6 is turned on. The programmable constant current source 6 detects the voltage value U1 and the current value I1 and transmits the data back to the main controller 1. When the main controller 1 detects that U1 / I1 is equal to R1, it stops adjusting the programmable rheostat 7 and turns off the programmable constant current source 6;

[0036] Step 4: Turn on the power supply of the sensor 3 to be debugged and the multimeter I8, detect the output accuracy of the sensor, obtain the detection result OUT1 and store it in the main controller 1;

[0037] Step 5: Repeat steps 3 and 4 until the sensor output accuracy test results OUT1, OUT2, ..., OUTn after compensation by N optional resistors are obtained;

[0038] Step 6: The main controller 1 controls the high and low temperature box 2 and the pressure control device 4 to adjust to the required temperature and pressure values. Repeat steps 3 to 5. The sensor outputs the accuracy test results OUT1', OUT2', ..., OUTn'. Repeat the above operation until all the temperature points that need to be calibrated are traversed.

[0039] Step 7: The main controller 1 compares and analyzes the above multiple groups of detection results and selects components that can meet the optimal compensation results.

[0040] Example 2. The operating temperature requirement of a certain type of silicon piezoresistive pressure sensor is -55°C to 200°C. According to the accuracy retest index after production, the product output should also rise by 0.07mV in the whole temperature range. At this time, according to the theoretical analysis of the design scheme of the compensation circuit, it is found that the resistance value of a certain zero adjustment compensation position can be increased by about 0.5Ω. However, due to the volume limitation of the product, only one resistance position is reserved for this compensation position, that is, the ideal resistance value cannot be obtained by series-parallel connection. It is known that the measured value of the resistance value of the resistor at this compensation position is 8.3Ω (nominal resistance 8.2Ω). Due to the limitation of the high temperature resistance requirement of the product, the series resistors that meet the requirements have similar nominal resistance values ​​of 8.2Ω, 9.1Ω, and 10.0Ω respectively. Now select 3 resistors with a nominal resistance of 8.2Ω, 5 resistors with a nominal resistance of 9.1Ω, and 2 resistors with a nominal resistance of 10.0Ω. Now take only one temperature and pressure point at 25℃, 200℃, and atmospheric pressure as an example, select a suitable resistor to complete the selection and compensation, and achieve fine-tuning of the product output value.

[0041] Implementation steps:

[0042] Step 1: Unsolder and empty the resistor position of the sensor that needs fine-tuning, clamp the empty pad with the pad fixture 5, and connect the two sets of test wires on the pad fixture 5 to the programmable constant current source 6 and the programmable variable resistor 7 respectively;

[0043] Step 2: Arrange the compensation position resistor array on the program-controlled switch and number the 10 resistors. The numbers of the resistors are shown in Table 1.

[0044] Table 1

[0045]

[0046] Step 3: The main controller 1 controls the temperature of the high and low temperature box to 25°C, and the pressure controller maintains the atmospheric pressure value;

[0047] Step 4: The main controller 1 sends a switching channel signal to the program-controlled switch 10, and the multimeter II 9 sequentially measures the resistance values ​​of the selected resistors in the program-controlled switch 10, and the measured values ​​are stored in the main controller 1;

[0048] Step 5: The main controller 1 analyzes the measured values ​​of step 4 and determines the test order of the resistor array to be selected (the main controller can choose to test from the minimum resistance value to the maximum resistance value in sequence; or use an interpolation algorithm to select the order and perform discontinuous detection);

[0049] Step 6: It is assumed here that the parameter corresponding to the first resistor in the test sequence determined in step 4 is R1. The main controller 1 controls the programmable rheostat 7 to be adjusted near 8.2Ω. At this time, the programmable constant current source 6 detects the voltage value U1 and the current value I1 and transmits the data back to the main controller 1. When the main controller 1 detects that U1 / I1=8.2 is equal, it stops adjusting the programmable rheostat 7 and turns off the programmable constant current source 6 (Note: at this time, the value of the programmable rheostat 7 is not completely equal to 8.2Ω, and the sum of the resistance of the programmable rheostat 7 and the internal resistance of the pad fixture 5 and the test line is equal to 8.2Ω); This step eliminates the line resistance error in the previous simulation compensation or test, and the deviation between the nominal resistance value and the actual resistance value of the resistor;

[0050] Step 7: Turn on the power supply of the pressure sensor and the multimeter I8, test the output accuracy of the sensor, obtain the test result OUT1 as 4.89mV and store it in the main controller 1, turn off the power supply and the multimeter I8;

[0051] Step 8: Repeat steps 6 and 7 according to the test sequence determined in step 5, and store the test results in the main controller 1;

[0052] Step 9: The main controller 1 controls the temperature of the high and low temperature box to 200°C, and the pressure controller maintains the atmospheric pressure value;

[0053] Step 10: The main controller 1 eliminates the resistors that do not meet the sensor accuracy requirements at room temperature based on all the results obtained in step 8, repeats steps 6 and 7 for the other resistors, and stores the test results in the main controller 1;

[0054] Step 11: The main controller 1 compares the obtained test results and selects the resistor that makes the sensor output most accurate.

[0055] Implementation Results: The above steps allow you to complete the compensation test of all the resistors under test at each temperature before proceeding to the next temperature point. Traditional methods require soldering the sensor's compensation resistors, testing all temperature points, and then determining if accuracy is not met. If the sensor output accuracy does not meet the requirements, another round of high and low temperature testing is required until the sensor output accuracy meets the requirements. This method eliminates the time required for repeated high and low temperature cycles, allowing debugging to be completed in a single high and low temperature cycle.

[0056] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the scope disclosed in the present invention should be covered by the protection scope of the present invention.

Claims

1. An automatic compensation and fine-tuning device for a silicon piezoresistive pressure sensor, characterized in that: The invention comprises a main controller (1), a component parameter detection module, a compensation resistor equivalent module and a sensor accuracy test module; the main controller (1) is used to control the device parameters of the component parameter detection module, the compensation resistor equivalent module and the sensor accuracy test module, and is used to read the measurement values ​​of the compensation resistor equivalent module and the component parameter detection module; the component parameter detection module is used to complete the parameter detection of the resistors to be selected in batches; the compensation resistor equivalent module is used to equalize the equivalent resistance value output by the main controller (1); the sensor accuracy test module is used to test the sensor accuracy and provide a test environment; The compensation resistor equivalent module includes a pad fixture (5), a programmable constant current source (6), and a programmable variable resistor (7); the working process of the compensation resistor equivalent module for equivalently outputting the equivalent resistance value of the main controller (1) includes: equivalently replacing the selected resistor of the compensation position by the pad fixture tooling, the programmable constant current source, and the programmable variable resistor.

2. The automatic compensation and fine-tuning device for silicon piezoresistive pressure sensors according to claim 1, characterized in that: The component parameter detection module comprises a multimeter II (9) and a program-controlled switch (10) electrically connected to each other; the multimeter II (9) is electrically connected to the main controller (1).

3. The automatic compensation and fine-tuning device for silicon piezoresistive pressure sensors according to claim 2, characterized in that: The process of completing parameter detection of the resistors to be selected in batches is as follows: using a multimeter II (9) to measure the parameters of several components to be selected placed in the program-controlled switch (10), and storing them in the main controller (1).

4. The automatic compensation and fine-tuning device for silicon piezoresistive pressure sensors according to claim 2, characterized in that: The program-controlled switch (10) has a manual-automatic conversion key, a manual switching key, and a plurality of installation positions for selected components. Each installation position is equipped with an indicator light. The program-controlled switch is switched on and off at each position by manual or automatic switching, thereby achieving measurement of component parameters.

5. The automatic compensation and fine-tuning device for silicon piezoresistive pressure sensors according to claim 1, characterized in that: The compensation resistance equivalent module comprises a pad fixture (5), a programmable constant current source (6), and a programmable variable resistor (7); the pad fixture (5) is provided with two sets of spring pins and a test cable; the pad fixture (5) is connected to the sensor resistance position to be compensated via the spring pins, and is respectively connected to the programmable constant current source (6) and the programmable variable resistor (7) via the test cable; the programmable constant current source (6) and the programmable variable resistor (7) are both electrically connected to the main controller (1).

6. The automatic compensation and fine-tuning device for silicon piezoresistive pressure sensors according to claim 5, characterized in that: The working process of the compensation resistance equivalent module is as follows: the main controller (1) sends the compensation parameter R1 to the programmable variable resistor (7). During the adjustment process of the programmable variable resistor (7), the main controller (1) receives the voltage value U1 and the current value I1 sent back by the programmable constant current source (6). When U1 / I1 is equal to R1, the compensation resistance equivalent module completes the equivalent work of the C1 parameter.

7. The automatic compensation and fine-tuning device for a silicon piezoresistive pressure sensor according to claim 1, characterized in that: The sensor accuracy test module comprises a high and low temperature box (2), a pressure control device (4), a sensor power supply and a multimeter I (8); the high and low temperature box (2), the pressure control device (4), the sensor power supply and the multimeter I (8) are all electrically connected to the main controller (1).

8. An automatic compensation fine-tuning method for an automatic compensation fine-tuning device for a silicon piezoresistive pressure sensor according to any one of claims 1 to 7, characterized in that: The steps include: Step 1: Empty the position of the components of the sensor (3) to be debugged that need compensation fine-tuning, place a pad fixture (5) at the empty pad position, and connect two sets of test wires on the pad fixture (5): one set is connected to the programmable constant current source (6), and the other set is connected to the programmable variable resistor (7); Step 2: Place the resistors N1, N2, ..., Nn to be selected in the program-controlled switch (10). According to the automatic switching instruction of the main controller (1) or through manual switching, the multimeter II (9) sequentially completes the resistance measurement of the selected resistors in the program-controlled switch. The measured values ​​R1, R2, ..., Rn are stored in the main controller (1); Step 3: The high and low temperature box (2) and the pressure control device (4) are controlled by the main controller (1) to adjust to the preset temperature and pressure values, the R1 parameter is selected to adjust the programmable variable resistor (7), and the programmable constant current source (6) is turned on. The programmable constant current source (6) detects the voltage value U1 and the current value I1 and transmits the data back to the main controller (1). When the main controller (1) detects that U1 / I1 is equal to R1, it stops adjusting the programmable variable resistor (7) and turns off the programmable constant current source (6); Step 4: Turn on the power supply of the sensor (3) to be debugged and the multimeter I (8), detect the output accuracy of the sensor, obtain the detection result OUT1 and store it in the main controller (1); Step 5: Replace R1 in step 3 with the measured values ​​R2, ..., Rn. Repeat steps 3 and 4 for each replacement until the sensor output accuracy test results OUT1, OUT2, ..., OUTn after compensation with N optional resistors are obtained. Step 6: The main controller (1) controls the high and low temperature box (2) and the pressure control device (4) to adjust the temperature and pressure to the preset values ​​at each calibration temperature point. Steps 3 to 5 are executed at each calibration temperature point, and the sensor outputs the accuracy test results OUT1', OUT2', ..., OUTn' at each calibration temperature point. Step 7: The main controller (1) compares and analyzes the accuracy test results OUT1', OUT2', ..., OUTn' at each calibration temperature point and selects the components that can meet the optimal compensation results.

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