A method for online calibration of temperature sensors inside equipment

Abstract

The present invention discloses and provides a method for online calibration of the internal temperature sensor of a device. The method is simple and accurate, and online calibration can be achieved without removing the temperature sensor on the device. The present invention includes the following steps: ① calibrating the calibration temperature sensor of the external calibration device; ② installing a calibration temperature module on each heat-insulating temperature measuring module; ③ setting the temperatures of the upper temperature measuring box, the lower temperature measuring box, and the heating plate to be consistent; ④ a host computer is communicatively connected to the main control board, the host computer continuously collects the temperature values ​​of the upper product temperature sensor and the lower product temperature sensor at intervals, and the main control board also continuously collects the temperature values ​​of the calibration temperature sensor at intervals; ⑤ the host computer and the main control board have the same temperature value collection frequency and collection time points, calculate the temperature difference collected by the calibration temperature sensor, the upper product temperature sensor, and the lower product temperature sensor at each time point, and determine anomalies. The present invention is applied to the technical field of methods for online calibration of the internal temperature sensor of a device.

Description

Technical Field

[0001] The present invention relates to a method for calibrating a temperature sensor, and in particular to a method for online calibration of a temperature sensor inside a device. Background Art

[0002] With the development of science and technology, the development of smart wearable devices is also changing with each passing day. The equipment produced by various manufacturers is becoming more and more intelligent, and various wearable devices are adding more and more functions. Traditional Bluetooth headsets, watches, etc., commonly used functions are voice calls, time management, sports and health, etc. The temperature detection function is now gradually becoming popular in some consumer electronic products. For these electronic products, they are generally produced in factories through assembly and testing on the assembly line. Therefore, the temperature test also needs to be tested by automated equipment.

[0003] Traditional temperature testing typically involves submerging the product or sensor under test in constant-temperature water to verify that its performance meets requirements. For external water tanks, it's more convenient to use a higher-precision Fluke temperature sensor to monitor the product, ensuring that the product's temperature indicators meet design requirements. This method, involving water, places high demands on testing and can also be slow in calibration efficiency, making it less suitable for assembly line production.

[0004] However, for some automated temperature measurement equipment on the assembly line, how can we always ensure that the temperature sensors in the equipment are accurate? This requires a solution that can perform online detection or calibration directly on the machine.

[0005] In temperature testing of some products with low temperature requirements, it is relatively convenient to remove the temperature sensor from the machine and calibrate it externally. However, for some high-precision temperature measurement equipment, due to the limitations of various insulation structures, it is difficult to remove the temperature sensor from the machine and calibrate it offline. How to ensure that the temperature sensor in the equipment does not drift over time, or that some contact pressure factors of the test machine cause stress on the sensor, thereby affecting the accuracy of the temperature measurement data, is a more difficult problem to solve. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for online calibration of a temperature sensor inside a device. The method is simple and accurate and can achieve online calibration without removing the temperature sensor from the device.

[0007] The technical solution adopted by the present invention is: the present invention is a method for online calibration of the temperature sensor inside the device, which uses an external calibration device to perform online calibration on the temperature sensor inside the device, the external calibration device includes a main control board 1 and a plurality of calibration temperature measurement modules 2, each of the calibration temperature measurement modules 2 includes a calibration product simulation part 3 and calibration temperature measurement sensors 4, 4' respectively arranged on the upper and lower sides of the calibration product simulation part 3, the calibration temperature measurement sensors 4, 4' are connected to the main control board 1 through signal lines; the device includes a plurality of heat preservation temperature measurement modules 5, each of the heat preservation temperature measurement modules 5 includes an upper temperature measuring box 6 and a lower temperature measuring box 7. The lower end of the upper temperature measuring box 6 and the upper end of the lower temperature measuring box 7 are respectively provided with an upper product temperature sensor 8 and a lower product temperature sensor 9. When the device performs a temperature test, the test product is placed between the upper temperature measuring box 6 and the lower temperature measuring box 7. After the upper temperature measuring box 6 and the lower temperature measuring box 7 are closed, the upper product temperature sensor 8 at the lower end of the upper temperature measuring box 6 and the lower product temperature sensor 9 at the upper end of the lower temperature measuring box 7 are respectively abutted against the upper and lower surfaces of the test product. The upper temperature measuring box 6 is also provided with a heating plate for heating the test product. The method includes the following steps:

[0008] ① Calibrate the calibration temperature sensor 4 of the external calibration device;

[0009] ② Each of the heat-insulating temperature measuring modules 5 is equipped with a calibration temperature measuring module 2, and the upper product temperature measuring sensor 8 at the lower end of the upper temperature measuring box 6 and the lower product temperature measuring sensor 9 at the upper end of the lower temperature measuring box 7 are respectively arranged opposite to the calibration temperature measuring sensors 4 and 4' on the upper and lower sides of the calibration product simulation piece 3;

[0010] ③ The temperatures of the upper temperature measuring box 6, the lower temperature measuring box 7 and the heating plate are set to be consistent;

[0011] ④ The host computer is in communication with the main control board 1, and the host computer continuously collects the temperature values ​​of the upper product temperature sensor 8 and the lower product temperature sensor 9 at intervals, and the main control board 1 also continuously collects the temperature values ​​of the verification temperature sensors 4, 4' at intervals;

[0012] ⑤ The temperature value collection frequency and collection time point of the host computer and the main control board 1 are the same. The temperature difference collected by the verification temperature sensor 4 and the product temperature sensor 8 at each time point is calculated. If the temperature difference is greater than the set value, it is judged that the upper product temperature sensor 8 and the lower product temperature sensor 9 in the corresponding insulation temperature measurement module 5 are abnormal, and the product temperature sensor 8 needs to be replaced.

[0013] Furthermore, the calibration temperature sensor 4, 4' includes a PCB board, and the PCB board is provided with two temperature measuring elements; there is a PCB board on the upper and lower sides of the calibration product simulation part 3 in the calibration temperature measurement module 2, one is embedded in it near the upper surface of the calibration product simulation part 3, and the other is embedded in it near the lower surface of the calibration product simulation part 3, and then they are sealed together for waterproofing and installed together.

[0014] Furthermore, the temperature measuring element is a TMP117 temperature sensor.

[0015] Further, in step ①, the main instruments required for calibrating the calibration temperature sensor 4 of the external calibration device are: Fluke 7008 constant temperature water bath, Fluke 1524 thermometer, and two Fluke 5611 high-precision temperature probes; the method for calibrating the calibration temperature sensors 4, 4' of the external calibration device is: placing the calibration temperature measurement module 2 and the standard sensor of Fluke 5611 together in the Fluke 7008 constant temperature water bath, controlling the temperature of the Fluke 7008 constant temperature water bath to rise from 25°C to 40°C, and the computer terminal continuously collects the data read by the calibration temperature measurement module 2 And the data read by the Fluke 1524 temperature meter, and finally the data obtained by the calibration temperature measurement module 2 is linearly fitted with the data measured by the Fluke 5611 high-precision temperature measurement probe to obtain the gain offset of each calibration temperature sensor 4, 4', that is, the calibration coefficient of each calibration temperature sensor 4, 4', and the calibration coefficient is stored in the read-only memory EEPROM inside each calibration temperature sensor 4, 4', and can be directly called when used later, thereby ensuring that the temperature measured by the calibration temperature sensor 4, 4' can be as close as possible to the temperature measurement data of the Fluke standard sensor.

[0016] The beneficial effects of the present invention are as follows: compared with some current temperature-related test fixtures, most of which mainly use direct temperature measurement with temperature sensors, and the method used is mainly to put them into constant temperature water, constant temperature oil, or a constant temperature box for testing, and then install them into the product for direct use after the test. There are currently very few products that have temperature sensors installed in them to test some thermal parameters, such as thermal resistance, etc., so there are even fewer corresponding equipment to test these products. For some products with low test accuracy, this is mainly achieved through a constant temperature box. The present invention is aimed at the temperature test requirements with very high accuracy. At present, we require that the temperature measurement accuracy of the insulation box where the product is located reaches plus or minus 0.01°C. After dynamic balance, the temperature control accuracy can reach ±0.1°C. So after the machine equipment has been used for a few months, whether the temperature measurement accuracy is good or not.

[0017] The temperature control accuracy can still meet the requirements. At this time, it is necessary to test and calibrate the sensors in the machine equipment. Due to the design of the thermal insulation structure, the machine will be relatively large. The traditional method of removing the sensor and recalibrating it in a constant temperature water bath is not practical and will waste manpower, time and material costs. Therefore, this online calibration solution was designed and developed. It performs very well in actual use and can ensure that the temperature sensor of the machine fluctuates within plus or minus 0.1. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a connection diagram of the temperature measurement module for calibration of the present invention;

[0019] Figure 2 This is the calibration diagram of the temperature measurement module;

[0020] Figure 3 This is a detection and calibration block diagram of the present invention when used on an assembly line machine;

[0021] Figure 4 This is a schematic diagram of the relative positions of the upper and lower calibration temperature sensors of the calibration temperature measurement module and the upper and lower product temperature sensors inside the machine box after the calibration temperature measurement module is installed in the machine. DETAILED DESCRIPTION

[0022] The present invention adopts an external calibration device to perform online calibration on the temperature sensor inside the equipment, which specifically includes the following steps:

[0023] ① Calibrate the calibration temperature sensors 4, 4' of the external calibration device;

[0024] ② Each of the heat-insulating temperature measuring modules 5 is equipped with a calibration temperature measuring module 2, and the upper product temperature measuring sensor 8 at the lower end of the upper temperature measuring box 6 and the lower product temperature measuring sensor 9 at the upper end of the lower temperature measuring box 7 are respectively arranged opposite to the calibration temperature measuring sensors 4 and 4' on the upper and lower sides of the calibration product simulation piece 3;

[0025] ③ The temperatures of the upper temperature measuring box 6, the lower temperature measuring box 7 and the heating plate are set to be consistent;

[0026] ④ The host computer is in communication with the main control board 1, and the host computer continuously collects the temperature values ​​of the upper product temperature sensor 8 and the lower product temperature sensor 9 at intervals, and the main control board 1 also continuously collects the temperature values ​​of the verification temperature sensors 4, 4' at intervals;

[0027] ⑤ The temperature value collection frequency and collection time point of the host computer and the main control board 1 are the same, and the temperature difference collected by the verification temperature sensor 4, 4', the upper product temperature sensor 8 and the lower product temperature sensor 9 at each time point is calculated. If the temperature difference is greater than the set value, it is judged that the upper product temperature sensor 8 and the lower product temperature sensor 9 in the corresponding insulation temperature measurement module 5 are abnormal, and the product temperature sensor 8 needs to be replaced.

[0028] like Figure 1 As shown, this solution has 32 temperature measurement module units, which are connected to the main control board via a 2.5-meter communication cable to realize temperature data collection and communication with the host computer. The calibration temperature measurement module 2 contains two PCB boards, one embedded near the top surface and one near the bottom surface, and then sealed together for waterproofing.

[0029] like Figure 2 As shown, this solution requires calibration of the temperature measurement module first, that is, calibration of the accuracy. The main instruments required to calibrate the calibration temperature sensors 4, 4' of the external calibration device are: Fluke 7008 constant temperature water bath, Fluke 1524 thermometer, and two Fluke 5611 high-precision temperature probes; the method for calibrating the calibration temperature sensors 4, 4' of the external calibration device is: put the calibration temperature measurement module 2 and the standard sensor of Fluke 5611 into the Fluke 7008 constant temperature water bath together, control the temperature of the Fluke 7008 constant temperature water bath to rise from 25°C to 40°C, and the computer terminal continuously collects the calibration temperature data. The data read by the verification temperature measurement module 2 and the data read by the Fluke 1524 temperature measuring meter are finally linearly fitted with the data obtained by the verification temperature measurement module 2 and the data measured by the Fluke 5611 high-precision temperature measuring probe to obtain the gain offset of each of the verification temperature sensors 4, 4', that is, the calibration coefficient of each of the verification temperature sensors 4, 4'. The calibration coefficient is stored in the read-only memory EEPROM inside each of the verification temperature sensors 4, 4', and can be directly called when used later, thereby ensuring that the temperature measured by the verification temperature sensors 4, 4' can be as close as possible to the temperature measurement data of the Fluke standard sensor.

[0030] like Figure 4As shown, inside the machine, after the temperature measurement module is installed, the upper and lower temperature sensors of the temperature measurement module are positioned relative to the upper and lower temperature sensors inside the machine box. The verification temperature sensors 4 and 4' comprise a PCB board equipped with two TMP117 temperature sensors. Therefore, the upper product temperature sensor 8 affixed to the upper temperature measurement box 6 can simultaneously detect two temperature sets, Fixture BC1 and Fixture BC2, on its upper and lower surfaces. The lower product temperature sensor 9 affixed to the lower temperature measurement box 7 can simultaneously detect two temperature sets, Fixture FC1 and Fixture FC2, on its upper and lower surfaces. The verification temperature sensors 4 and 4' on the upper surface of the calibration product dummy 3 can simultaneously detect two temperature sets, AT BC1 and AT BC2, on its upper and lower surfaces. The verification temperature sensors 4 and 4' on the lower surface of the calibration product dummy 3 can simultaneously detect two temperature sets, FT BC1 and FT BC2, on its upper and lower surfaces. In addition, a heating plate for heating the test product is provided in the upper temperature measuring box 6 , and the heating plate is located below the calibration product simulation part 3 .

[0031] like Figure 3 As shown in the figure, 32 temperature measurement modules are connected to the machine through a 2.5-meter communication line. All temperature measurement modules are installed in an insulation box. At the same time, the water tank of the upper box, the water tank of the lower box, and the internal heating plate are all set to 25.0℃. In theory, when everything stabilizes, a dynamic balance will be reached. At this time, the host computer will continuously collect the temperature value of the temperature sensor in the box on the machine side, and the external board will also collect the temperature value of the upper and lower temperature sensors in the temperature measurement module.

[0032] The present invention also includes a storage box for calibration product simulation parts. The main control board 1 is arranged in the storage box. When no calibration operation is required, the calibration temperature measurement module 2 can be placed in the storage box for storage.

[0033] Theoretically, since the upper and lower boxes are both set to 25.0°C, the temperature measured by the temperature measurement module will also be 25.0°C. The actual test process requires maintaining a stable test for 90 minutes, continuously collecting temperature data at various locations, and ultimately generating a summary table containing the temperature values ​​collected at each location, all of which are temperature values ​​after adding calibration parameters. The following table shows the data from the detection module test on the machine design after one month of use: According to the data in the table, the temperature measurement accuracy of most channels meets the accuracy requirements after the difference algorithm is used. However, in Slot 7 indicated in the bold frame, one set of temperature difference is greater than 0.1°C, and another set of temperature difference is close to -0.1°C. In this case, it is necessary to replace the channel in time to avoid abnormal temperature measurement accuracy even though the temperature value of the product tested in this channel is normal.

[0034] Although the embodiments of the present invention are described with practical solutions, they do not limit the meaning of the present invention. For those skilled in the art, it is obvious to modify the implementation scheme and combine it with other solutions based on this description.

Claims

1. A method for online calibration of a temperature sensor inside a device, wherein an external calibration device is used to perform online calibration on the temperature sensor inside the device, wherein the external calibration device comprises a main control board (1) and a plurality of calibration temperature measurement modules (2), each of the calibration temperature measurement modules (2) comprising a calibration product simulation component (3) and calibration temperature measurement sensors (4, 4') respectively arranged above and below the calibration product simulation component (3), wherein the calibration temperature measurement sensors (4, 4') are connected to the main control board (1) via a signal line; the device comprises a plurality of heat-insulating temperature measurement modules (5), each of the heat-insulating temperature measurement modules (5) comprising an upper temperature measurement box (6) and a lower temperature measurement box ( 7), the lower end of the upper temperature measuring box (6) and the upper end of the lower temperature measuring box (7) are respectively provided with an upper product temperature measuring sensor (8) and a lower product temperature measuring sensor (9), when the device performs temperature testing, the test product is placed between the upper temperature measuring box (6) and the lower temperature measuring box (7), after the upper temperature measuring box (6) and the lower temperature measuring box (7) are closed, the upper product temperature measuring sensor (8) at the lower end of the upper temperature measuring box (6) and the lower product temperature measuring sensor (9) at the upper end of the lower temperature measuring box (7) are respectively abutted against the upper and lower surfaces of the test product, and a heating plate for heating the test product is further provided in the upper temperature measuring box (6), characterized in that: The method comprises the following steps: ① calibrating the calibration temperature sensor (4, 4') of the external calibration device; ② Each of the heat-insulating temperature measurement modules (5) is equipped with a calibration temperature measurement module (2), and the upper product temperature measurement sensor (8) at the lower end of the upper temperature measurement box (6) and the lower product temperature measurement sensor (9) at the upper end of the lower temperature measurement box (7) are respectively arranged relative to the calibration temperature measurement sensors (4, 4') at the upper and lower ends of the calibration product simulation component (3); ③ The temperatures of the upper temperature measuring box (6), the lower temperature measuring box (7), and the heating plate are set to be consistent; ④ The host computer is in communication connection with the main control board (1), the host computer continuously collects the temperature values ​​of the upper product temperature sensor (8) and the lower product temperature sensor (9) at intervals, and the main control board (1) also continuously collects the temperature values ​​of the calibration temperature sensors (4, 4') at intervals; ⑤ The temperature value acquisition frequency and acquisition time points of the host computer and the main control board (1) are the same, and the temperature difference collected by the verification temperature sensor (4, 4') and the product temperature sensor (8) at each time point is calculated. If the temperature difference is greater than a set value, it is determined that the product temperature sensor (8) in the corresponding heat preservation temperature measurement module (5) has an abnormality and needs to be replaced.

2. The method for online calibration of a temperature sensor inside a device according to claim 1, characterized in that: The calibration temperature sensor (4, 4') comprises a PCB board, and the PCB board is provided with two temperature measuring elements; the calibration product simulation part (3) in the calibration temperature measurement module (2) has one PCB board on the upper and lower sides, one PCB board is embedded near the upper surface of the calibration product simulation part (3), and the other is embedded near the lower surface of the calibration product simulation part (3), and then the two are sealed together for waterproofing and assembled together.

3. The method for online calibration of a temperature sensor inside a device according to claim 2, wherein: The temperature measuring element is a TMP117 temperature sensor.

4. The method for online calibration of a temperature sensor inside a device according to claim 1, wherein: In step ①, the main instruments required for calibrating the calibration temperature sensor (4, 4') of the external calibration device are: Fluke 7008 constant temperature water bath, Fluke 1524 thermometer, and two Fluke 5611 high-precision temperature probes; the method for calibrating the calibration temperature sensor (4, 4') of the external calibration device is as follows: placing the calibration temperature module (2) and the standard sensor of Fluke 5611 together in the Fluke 7008 constant temperature water bath, controlling the temperature of the Fluke 7008 constant temperature water bath to rise from 25°C to 40°C, and continuously collecting the data read by the calibration temperature module (2) and the Fluke 5611 standard sensor. The data read by the Fluke 1524 temperature meter is finally linearly fitted with the data obtained by the calibration temperature measurement module (2) and the temperature measurement data of the Fluke 5611 high-precision temperature measurement probe, so as to obtain the gain offset of each calibration temperature sensor (4, 4'), that is, the calibration coefficient of each calibration temperature sensor (4, 4'), and the calibration coefficient is stored in the read-only memory (EEPROM) inside each calibration temperature sensor (4, 4'). It can be directly called when used later, thereby ensuring that the temperature measured by the calibration temperature sensor (4, 4') can be as close as possible to the temperature measurement data of the Fluke standard sensor.

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