Temperature sensor and calibration method thereof

Abstract

The invention belongs to the technical field of sensor calibration, discloses a temperature sensor and a calibration method thereof, and aims to gradually measure and correct temperature deviation by setting a plurality of temperature calibration points, so that the calibration in the whole measuring range is more accurate. The multi-point calibration method can effectively reduce the measurement error of a single temperature point and improve the overall precision. According to the invention, when the temperature deviation exceeds the preset range, multi-parameter correction is carried out according to the response time and the nonlinear error of the sensor. The automatic adjustment mechanism ensures that the sensor can adapt to error changes in different environments, and the intelligence and self-adaptability of calibration are enhanced. According to the method, the response time of the sensor can be analyzed by recording the time of collecting data each time, so that calibration not only stays on the data precision, but also the dynamic performance of the sensor can be evaluated, and the response efficiency of the whole system is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of sensor calibration, and in particular relates to a temperature sensor and a calibration method thereof. Background Art

[0002] With the continuous development of science and technology, high-precision temperature sensors have been widely used in various industrial and scientific research fields. As a device that can convert temperature changes into electrical signals, temperature sensors are of great significance for temperature monitoring and control. However, in practical applications, temperature sensors may be affected by various factors, such as temperature fluctuations, electromagnetic interference, etc., resulting in deviations in measurement results. Therefore, it is particularly important to accurately calibrate the temperature sensor.

[0003] Traditional temperature sensor calibration methods mainly include direct calibration and multi-parameter calibration using a high-precision data acquisition system. The direct calibration method is simple and easy to use, but may be affected by the accuracy of the standard thermometer and environmental factors. The multi-parameter calibration method collects data from the sensor at different temperature points and uses algorithms to process and analyze the data to improve the accuracy of the calibration. However, the existing multi-parameter calibration methods have some limitations in actual operation, such as the selection of calibration points and the optimization of data processing algorithms. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings of low accuracy and limited applicability, and to provide a temperature sensor and a calibration method thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: In a first aspect, the present invention provides a temperature sensor calibration method, comprising the following steps: Place the temperature sensor in a preset standard temperature source and set several temperature calibration points according to the range and accuracy requirements of the temperature sensor; Start the standard temperature source and stabilize the temperature at the first calibration point; After the temperature sensor becomes stable, collect data from the temperature sensor several times within a preset time, and record the time of each collection; Process the data collected from the temperature sensor to obtain data for a stable time period as the final reading of the calibration point; Compare the final reading with the temperature of the standard temperature source to obtain the temperature deviation, and compare the temperature deviation with the preset range. If the temperature deviation is within the preset range, calibrate the next calibration point until all calibration points are calibrated; If the temperature deviation is outside the preset range, the response time and nonlinear error of the temperature sensor are obtained according to the time of each acquisition, and multi-parameter correction is performed on the temperature sensor according to the response time and nonlinear error of the temperature sensor.

[0006] A further improvement of the present invention is that when the temperature sensor is placed in a preset standard temperature source, if the preset standard temperature source is a constant temperature bath, the temperature sensor is installed on a bracket in the constant temperature bath so that the temperature sensor sensing head is immersed in the liquid in the constant temperature bath, and the temperature sensor sensing head does not contact the wall and / or bottom of the constant temperature bath.

[0007] A further improvement of the present invention is that the set calibration points of several temperatures are evenly distributed within the measurement linear range of the temperature sensor.

[0008] A further improvement of the present invention is that the standard for temperature stabilization at the first calibration point is as follows: Maintain the temperature of the standard temperature source so that the fluctuation of the standard temperature source is less than a preset threshold and lasts for a required time, then the temperature of the standard temperature source is considered to be stable.

[0009] A further improvement of the present invention is that the specific method for processing the data collected from the temperature sensor is as follows: Preset moving average window size; According to the preset moving average window size, calculate the average value of all data in each moving average window; According to the average value of all data in each moving average window, the stable time period of each moving average window is obtained, and according to the stable time of each moving average window, the data stable interval is determined; Obtain the mean or median value of the data within the data stability interval as the final reading of the calibration point.

[0010] A further improvement of the present invention is that the specific method for calculating the average value of all data in each window is as follows:

[0011] in, is the average value of all data in each window, For time point The original data value, is the number of data in the moving average window.

[0012] A further improvement of the present invention is that the specific method of obtaining the average value or median value of the data within the data stability interval as the final reading of the calibration point is as follows: The calculation method for the average value of data within the data stability interval is as follows:

[0013] The calculation method for the median value of the data within the data stability interval is as follows:

[0014] in, is the final reading for this calibration point, is the length of the data stability interval, is the starting time point of the data stability interval, The end time point of the data stability interval.

[0015] A further improvement of the present invention is that the temperature deviation is calculated as follows: Temperature deviation = final reading - temperature of the standard temperature source.

[0016] In a second aspect, the present invention provides a temperature sensor, characterized in that it includes a sensor integrated head, the sensor integrated head is connected to the sensor sensing head, and the sensor integrated head is provided with a sensor mounting bolt and an integrated head mounting bolt.

[0017] A further improvement of the present invention is that the integrated head mounting bolts are arranged obliquely.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention measures and corrects the temperature deviation step by step by setting multiple temperature calibration points, so that the calibration within the entire range is more accurate. This multi-point calibration method can effectively reduce the error of single temperature point measurement and improve the overall accuracy. When the temperature deviation exceeds the preset range, the present invention performs multi-parameter correction according to the response time and nonlinear error of the sensor. This automatic adjustment mechanism ensures that the sensor can adapt to the error changes in different environments, and enhances the intelligence and adaptability of the calibration. By recording the time of each data collection, the present invention can analyze the response time of the sensor, so that the calibration not only stays on the data accuracy, but also can evaluate the dynamic performance of the sensor and improve the response efficiency of the overall system. The present invention collects temperature data in the stable stage for many times, and performs averaging or filtering processing to ensure the stability and reliability of the final reading, thereby reducing the influence of short-term fluctuations or random errors. The present invention detects the temperature deviation at each calibration point and compares it with the preset range. The robustness of the calibration is further improved through multi-parameter correction, ensuring that even if the sensor has a large error, it can be effectively compensated. The present invention not only calibrates the temperature through multi-parameter correction, but also corrects the response characteristics and nonlinear errors of the sensor, so that the sensor has better performance in a wider range of application scenarios. In conclusion, the present invention overcomes the shortcomings of traditional calibration methods in terms of accuracy and adaptability through multi-point calibration, automatic error processing and multi-parameter correction, and provides a more efficient and accurate calibration solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a flow chart of the present invention; Figure 2 It is a structural diagram of the temperature sensor of the present invention; Among them, 1. Sensor integrated head; 2. Sensor sensing head; 3. Sensor mounting bolts; 4. Integrated head mounting bolts. DETAILED DESCRIPTION

[0020] In order to further understand the content of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0021] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] See also Figure 1 , a temperature sensor calibration method, comprising the following steps: S1, place the temperature sensor in a preset standard temperature source, and set several temperature calibration points according to the range and accuracy requirements of the temperature sensor.

[0023] S2, start the standard temperature source and stabilize the temperature at the first calibration point.

[0024] S3, after the temperature sensor becomes stable, data of the temperature sensor is collected several times within a preset time, and the time of each collection is recorded.

[0025] S4, processing the data collected from the temperature sensor to obtain data in a stable time period as the final reading of the calibration point.

[0026] S5, comparing the final reading with the temperature of the standard temperature source to obtain a temperature deviation, comparing the temperature deviation with a preset range, and if the temperature deviation is within the preset range, calibrating the next calibration point until all calibration points are calibrated.

[0027] S6, if the temperature deviation is outside the preset range, the response time and nonlinear error of the temperature sensor are obtained according to the time of each acquisition, and multi-parameter correction is performed on the temperature sensor according to the response time and nonlinear error of the temperature sensor.

[0028] See also Figure 2 A temperature sensor includes a sensor integrated head 1, the sensor integrated head 1 is connected to a sensor sensing head 2, and the sensor integrated head 1 is provided with a sensor mounting bolt 3 and an integrated head mounting bolt 4. The integrated head mounting bolt 4 is arranged obliquely.

[0029] Embodiment 1: A method for calibrating a temperature sensor, comprising the following steps: Step 1: Make sure the temperature sensor is in good condition and not damaged; prepare a standard temperature source: including a constant temperature bath or a high-precision thermometer; prepare data recording equipment: a laptop and corresponding data acquisition software; prepare necessary tools: screwdriver, wrench.

[0030] Step 2: Ensure that the calibration environment temperature is stable to avoid the influence of airflow and humidity on the calibration results; turn off the equipment that may affect the calibration.

[0031] Step 3: Fix the temperature sensor in the standard temperature source to ensure good contact between the sensor and the standard temperature source.

[0032] Step 4: Set several temperature calibration points according to the range and accuracy requirements of the temperature sensor.

[0033] Step 5: Start the standard temperature source and wait for the temperature to stabilize at the first calibration point.

[0034] Step 6. When the temperature stabilizes, start the high-precision data acquisition system and use high-precision data acquisition equipment to continuously collect sensor readings at least once per second for more than 5 minutes to ensure data stability and reliability. At the same time, use a high-precision timer to record the exact time of each reading for subsequent time series analysis. Use moving average filtering technology to process the collected data and select the data in the middle stable time period as the final reading of the calibration point.

[0035] Step 7: Compare the readings of the temperature sensor with those of the standard temperature source and calculate the temperature deviation.

[0036] Step 8. If the temperature deviation is within the allowable range, calibrate the next calibration point. If the deviation exceeds the allowable range, check whether the sensor is installed correctly. Not only consider the temperature deviation, but also monitor the response time and nonlinear error of the sensor. Through the multi-parameter correction algorithm, comprehensively adjust the sensor performance.

[0037] Step 9: Repeat steps 5 to 8 until all calibration points are calibrated.

[0038] Step 10: Record the sensor reading, standard temperature source reading and deviation at each calibration point in a table.

[0039] Step 11: Analyze the calibration data and evaluate the performance of the sensor; adjust the sensor parameters according to the calibration results to improve the measurement accuracy; write a calibration report to summarize the calibration process and results.

[0040] Embodiment 2: Step 1: Place the temperature sensor in a preset standard temperature source and set several temperature calibration points according to the range and accuracy requirements of the temperature sensor.

[0041] Among them, first choose a suitable installation position for the temperature sensor to ensure that the temperature sensor will not be interfered with by external environmental factors; if a constant temperature bath is used, the temperature sensor should be installed on a bracket inside the constant temperature bath so that the sensing head of the temperature sensor is completely immersed in the liquid in the constant temperature bath, while preventing the temperature sensor from contacting the wall and / or bottom of the constant temperature bath.

[0042] When setting the calibration points, base it on the full range of the temperature sensor and ensure that the calibration points cover the operating temperature range of the temperature sensor. If the range of the temperature sensor is -50°C to 150°C, select -50°C, 0°C, 25°C, 50°C, 75°C, 100°C, 125°C and 150°C as calibration points. These calibration points should be evenly distributed over the entire range of the temperature sensor, especially within the linear range of the temperature sensor. In addition, the accuracy level of the temperature sensor needs to be considered, and calibration points should be selected to meet or exceed the accuracy requirements of the sensor.

[0043] Step 2: Start the standard temperature source and stabilize the temperature at the first calibration point.

[0044] Among them, the temperature stability of the standard temperature source depends on the heating or cooling rate of the standard temperature source and the response time of the temperature sensor; if the first calibration point is 0℃, it is necessary to monitor the display of the standard temperature source until the temperature fluctuation of the standard temperature source is less than ±0.1℃ and remains within this range for at least 10 minutes, which indicates that the temperature of the standard temperature source has stabilized.

[0045] Step 3: After the temperature sensor becomes stable, collect data from the temperature sensor several times within a preset time, and record the time of each collection.

[0046] Among them, when the temperature is stable, the high-precision data acquisition system is started, and the high-precision data acquisition equipment is used to continuously collect the readings of the sensor at a frequency of at least once per second for more than 5 minutes to ensure the stability and reliability of the data; at the same time, a high-precision timer is used to record the exact time of each reading for subsequent time series analysis; the moving average filtering technology is used to process the collected data, and the data of the intermediate stable time period is selected as the final reading of the calibration point. The steps of processing the collected data using the moving average filtering technology include: The first step is to preset the moving average window size, that is, the number of data in the moving average window ,The window size will affect the filtering effect and usually needs to be determined based on the data characteristics and noise level.

[0047] The second step is to calculate the average value of all data in each moving average window according to the preset moving average window size. The specific method is as follows:

[0048] in, is the average value of all data in each window, For time point The original data value, is the number of data in the moving average window.

[0049] The third step is to obtain the stable time period of each moving average window based on the average value of all data in each moving average window, and determine the data stability interval based on the stable time of each moving average window. This is usually done by observing the range of change of the moving average, that is, looking for a continuous data segment with the smallest fluctuation.

[0050] The fourth step is to obtain the average value or median value of the data within the data stability interval as the final reading of the calibration point. The calculation method of the average value of the data within the data stability interval is as follows:

[0051] The calculation method for the median value of the data within the data stability interval is as follows:

[0052] in, is the final reading for this calibration point, is the length of the data stability interval, is the starting time point of the data stability interval, The end time point of the data stability interval.

[0053] Step 4: Process the data collected from the temperature sensor and obtain the data of the stable time period as the final reading of the calibration point. The final reading of the temperature sensor is compared with the reading of the standard temperature source; if the reading of the standard temperature source is 0℃ and the reading of the temperature sensor is 0.2℃, the deviation is 0.2℃; record the temperature deviation value of each calibration point, which is crucial for the subsequent temperature sensor performance evaluation and calibration coefficient adjustment; the temperature deviation is calculated using a simple subtraction formula: temperature deviation = sensor reading - standard temperature source reading.

[0054] Step 5: Compare the final reading with the temperature of the standard temperature source to obtain the temperature deviation, and compare the temperature deviation with the preset range. If the temperature deviation is within the preset range, calibrate the next calibration point until all calibration points are calibrated. For each calibration point, temperature stabilization, data collection, deviation calculation, and temperature sensor adjustment when necessary need to be performed; if 8 calibration points are set, the whole process needs to be repeated 8 times; each repetition must ensure that the temperature sensor reaches a stable state at the new calibration point, and then perform data collection and deviation analysis.

[0055] Step six, if the temperature deviation is outside the preset range, the response time and nonlinear error of the temperature sensor are obtained according to the time of each acquisition, and multi-parameter correction is performed on the temperature sensor according to the response time and nonlinear error of the temperature sensor.

[0056] Step 7: Create a detailed log sheet to record all relevant information for each calibration point. Analyze the recorded data to evaluate the performance of the sensor; calculate the average deviation and standard deviation of all calibration points to understand the overall accuracy and stability of the sensor; based on these analysis results, adjust the sensor's calibration factor to reduce deviation and improve measurement accuracy.

[0057] The present invention uses moving average filtering technology to process the collected data. The effectiveness of this step is that it can significantly reduce the impact of random noise on the data, thereby improving the stability and reliability of the data. In actual operation, the temperature sensor reading may be affected by various external factors, such as temperature fluctuations, electromagnetic interference, etc., which may cause data fluctuations and affect the accuracy of calibration. Through the moving average filtering technology, these random noises can be filtered out and only the data within the stable time period is retained. The advantage of doing so is that the final calibration point reading is more accurate and can better reflect the true performance of the temperature sensor, thereby improving the accuracy of the entire calibration process.

[0058] The present invention uses a multi-parameter correction algorithm to adjust the sensor. The effectiveness of this step lies in that it can comprehensively consider multiple performance indicators of the sensor, such as temperature deviation, response time and nonlinear error, so as to achieve a more comprehensive and accurate calibration. In actual operation, the performance of the temperature sensor may be affected by many factors, and the adjustment of a single parameter may not completely solve the problem. Through the multi-parameter correction algorithm, multiple parameters of the sensor can be adjusted at the same time to achieve the best calibration effect. The advantage of this is that the calibrated sensor can measure the temperature more accurately, thereby improving the accuracy and reliability of the entire measurement system.

[0059] The present invention can reduce the impact of random noise on data, improve the stability and reliability of data, and comprehensively consider multiple performance indicators of the sensor to achieve more comprehensive and accurate calibration. The implementation of these steps helps to improve the performance of the sensor and ensure the accuracy and reliability of the measurement system.

[0060] Finally, it should be noted that the above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0061] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A temperature sensor calibration method, characterized in that: The following steps are involved: Place the temperature sensor in a preset standard temperature source and set several temperature calibration points according to the range and accuracy requirements of the temperature sensor; Start the standard temperature source and stabilize the temperature at the first calibration point; After the temperature sensor becomes stable, collect data from the temperature sensor several times within a preset time, and record the time of each collection; Process the data collected from the temperature sensor to obtain data for a stable time period as the final reading of the calibration point; Compare the final reading with the temperature of the standard temperature source to obtain the temperature deviation, and compare the temperature deviation with the preset range. If the temperature deviation is within the preset range, calibrate the next calibration point until all calibration points are calibrated; If the temperature deviation is outside the preset range, the response time and nonlinear error of the temperature sensor are obtained according to the time of each acquisition, and multi-parameter correction is performed on the temperature sensor according to the response time and nonlinear error of the temperature sensor.

2. A temperature sensor calibration method according to claim 1, characterized in that: When the temperature sensor is placed in a preset standard temperature source, if the preset standard temperature source is a constant temperature bath, the temperature sensor is installed on a bracket in the constant temperature bath so that the temperature sensor sensing head is immersed in the liquid in the constant temperature bath, and the temperature sensor sensing head does not contact the wall and / or bottom of the constant temperature bath.

3. A temperature sensor calibration method according to claim 1, characterized in that: The set calibration points of several temperatures are evenly distributed within the measurement linear range of the temperature sensor.

4. A temperature sensor calibration method according to claim 1, characterized in that: The criteria for temperature stabilization at the first calibration point are as follows: Maintain the temperature of the standard temperature source so that the fluctuation of the standard temperature source is less than a preset threshold and lasts for a required time, then the temperature of the standard temperature source is considered to be stable.

5. A temperature sensor calibration method according to claim 1, characterized in that: The specific method for processing the data collected from the temperature sensor is as follows: Preset moving average window size; According to the preset moving average window size, calculate the average value of all data in each moving average window; According to the average value of all data in each moving average window, the stable time period of each moving average window is obtained, and according to the stable time of each moving average window, the data stable interval is determined; Obtain the mean or median value of the data within the data stability interval as the final reading of the calibration point.

6. A temperature sensor calibration method according to claim 5, characterized in that: The specific method for calculating the average value of all data in each window is as follows: in, is the average value of all data in each window, For time point The original data value, is the number of data in the moving average window.

7. A temperature sensor calibration method according to claim 5, characterized in that: The specific method for obtaining the average or median value of the data within the data stability interval as the final reading of the calibration point is as follows: The calculation method for the average value of data within the data stability interval is as follows: The calculation method for the median value of the data within the data stability interval is as follows: in, is the final reading for this calibration point, is the length of the data stability interval, is the starting time point of the data stability interval, The end time point of the data stability interval.

8. A temperature sensor calibration method according to claim 1, characterized in that: The temperature deviation is calculated as follows: Temperature deviation = final reading - temperature of the standard temperature source.

9. A temperature sensor, characterized in that: The sensor integrated head (1) comprises a sensor integrated head (1), the sensor integrated head (1) is connected to a sensor sensing head (2), and a sensor mounting bolt (3) and an integrated head mounting bolt (4) are provided on the sensor integrated head (1).

10. A temperature sensor according to claim 9, characterized in that: The integrated head mounting bolts (4) are set at an angle.

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