Gas detection instrument prediction calibration system and method

Abstract

The invention relates to the technical field of instrument calibration, and particularly discloses a gas detection instrument prediction calibration system and method. The analysis module is used for determining a detection method of the zero drift phenomenon of the electrochemical gas sensor to be calibrated based on the use environment type; the calibration module is used for determining real-time calibration or periodic calibration of the electrochemical gas sensor in response to the occurrence of the zero drift phenomenon and the abnormal opening state of the electrochemical gas sensor; the evaluation module is used for determining the long-term zero point stability degree or the real-time signal fluctuation degree to evaluate the calibration precision according to the calibration method; the adjusting module is used for determining whether to update the environment compensation coefficient and adjust the calibration interval duration for the next calibration according to the evaluation result of the evaluation module; according to the invention, the accuracy of analyzing the use environment of the electrochemical gas sensor is improved, so that the accuracy of analyzing the zero drift phenomenon is improved, and accurate calibration is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of instrument calibration, and in particular to a gas detection instrument prediction calibration system and method. Background Art

[0002] With the rapid development of industry and the continuous improvement of environmental monitoring requirements, gas detection instruments are increasingly widely used in various fields. As the core component of gas detection instruments, the accuracy and stability of the performance of electrochemical gas sensors are crucial; however, during the operation of electrochemical gas sensors, due to the influence of various factors, their performance will decay with the increase of time and detection volume, resulting in the occurrence of zero drift. This zero drift not only affects the accuracy of gas detection, but may also bring serious consequences to industrial production, environmental monitoring and safety assurance; traditional gas detection instrument calibration methods are often relatively single and cannot adapt well to different use environments and sensor states. For example, some methods only focus on the performance changes of the sensor itself, but ignore the impact of the use environment on the sensor; although other methods take environmental factors into account, they lack comprehensive consideration of factors such as sensor usage frequency and abnormal opening state. In addition, traditional methods also have shortcomings in evaluating calibration accuracy and adjusting the calibration process, making it difficult to achieve accurate calibration and continuous performance optimization.

[0003] For example, the prior art discloses a method for self-calibrating the zero point of a catalytic gas sensor, in which a chemical coprecipitation method is used to prepare a composite sensitive material of nano-semiconductor tin dioxide, antimony pentoxide and cerium oxide. The material is subjected to aging, centrifugal solid-liquid separation, deionization washing, organic solvent dehydration, vacuum drying and heat treatment to form a sensitive material. The sensitive material is prepared into a slurry using glycerin, and a coil with a diameter of 0.018 mm is wound into a coil with a diameter of 0.2 mm using winding technology, and then welded to a standard two-pin tube socket in mid-air. The sensitive slurry is applied to the coil, and the coil is electrically heated to sinter the slurry into a small ball with a certain strength. The tube socket is sealed with a tube shell with a hole through energy storage welding to produce a gas sensor with a full range of liquefied petroleum gas (natural liquefied gas, hydrogen, organic gas) less than 10×10-6 v / V by volume fraction. It is integrated with a catalytic gas sensor, and the minimum detection limit of the catalytic gas sensor (volume fraction 50×10-6v / V) is far higher than the full-scale characteristic of this gas sensitive element. It can be considered that when the detection limit of the gas sensitive element is lower than the full-scale, the concentration of the measured gas in the environment is considered to be close to zero. At this time, the sensor zero point is adjusted by the single-chip microcomputer of the catalytic gas sensor conditioning circuit, thereby realizing the zero point self-adjustment function of the catalytic gas sensor. This method solves the problem of zero point drift of the catalytic gas sensor during long-term use, realizes the self-calibration function of the catalytic gas sensor, extends the calibration period of the catalytic gas sensor, and improves the service life of the sensor.

[0004] However, the existing technology lacks an analysis process of the use environment of the gas detection instrument, which makes the detection method for determining whether the gas detection instrument has zero drift phenomenon not accurate enough, resulting in the failure to calibrate the gas detection instrument in time, thereby causing the low accuracy of the gas detection instrument. Summary of the invention

[0005] The purpose of the present invention is to provide a gas detection instrument prediction calibration system and method, which can accurately analyze the use environment of the gas detection instrument and then select a suitable zero drift detection method, and timely calibrate the gas detection instrument to improve the use accuracy of the gas detection instrument.

[0006] To this end, the present invention provides a gas detection instrument prediction calibration system, comprising:

[0007] An acquisition module, which is used to acquire real-time data of the electrochemical gas sensor and periodically acquire the gas flow velocity and usage frequency in the use environment of the electrochemical gas sensor;

[0008] an analysis module connected to the acquisition module, for determining the type of use environment of the electrochemical gas sensor according to the average value of the gas flow velocity in the use environment of the electrochemical gas sensor acquired in several cycles and the average use frequency of the electrochemical gas sensor, and determining a detection method for the zero drift phenomenon of the electrochemical gas sensor to be calibrated based on the use environment type;

[0009] A calibration module connected to the analysis module, in response to the occurrence of a zero drift phenomenon and the electrochemical gas sensor being in an abnormally turned-on state, determines a real-time calibration or a periodic calibration for the electrochemical gas sensor;

[0010] An evaluation module, which is connected to the calibration module and is used to determine the calibration accuracy based on the long-term zero point stability or the real-time signal fluctuation according to the calibration method;

[0011] An adjustment module, which is connected to the evaluation module and is used to determine whether to update the environmental compensation coefficient for the next calibration and adjust the calibration interval according to the evaluation result of the evaluation module;

[0012] The environmental compensation coefficient is used to correct the detection error of the electrochemical gas sensor in the abnormal opening state, and the abnormal opening state includes temperature abnormality, humidity abnormality and vibration abnormality.

[0013] Furthermore, the analysis module determines that the method for detecting the zero drift phenomenon of the electrochemical gas sensor to be calibrated includes determining to detect the zero drift phenomenon by a sensor redundancy method under the condition that the use environment type of the electrochemical gas sensor is a high-frequency and high-pollution use environment, or determining to detect the zero drift phenomenon by a periodic calibration comparison method under the condition that the use environment type of the electrochemical gas sensor is a low-frequency and low-pollution use environment.

[0014] Furthermore, the analysis module determines the use environment type of the electrochemical gas sensor, including determining that the use environment type of the electrochemical gas sensor is a high-frequency and multi-pollution use environment under the condition that the average value of the gas flow velocity in the use environment of the electrochemical gas sensor collected in several cycles is greater than a preset average value and the average use frequency is greater than a preset average use frequency.

[0015] Furthermore, the calibration module determines whether to calibrate the electrochemical gas sensor in real-time or periodic manner, including determining to calibrate the electrochemical gas sensor in real-time by periodic calibration when a zero drift phenomenon is detected in the electrochemical gas sensor, or determining to calibrate the electrochemical gas sensor in real-time by periodic calibration when the electrochemical gas sensor is in an abnormally open state.

[0016] Furthermore, the evaluation module evaluates the calibration accuracy by determining the calibration accuracy based on the long-term zero point stability when calibrating with a periodic calibration method, or by determining the calibration accuracy based on the real-time signal fluctuation when calibrating with a real-time calibration method.

[0017] Furthermore, the evaluation module determines that the calibration accuracy is unqualified under the condition that the long-term zero point stability is greater than a preset stability or the real-time signal fluctuation is greater than a preset fluctuation.

[0018] Furthermore, the preset stability level is determined based on a historical average value of the long-term zero-point stability level of the electrochemical gas sensor, and the preset real-time signal fluctuation level is determined based on a historical average value of the real-time signal fluctuation level of the electrochemical gas sensor.

[0019] Furthermore, the adjustment module determines to adjust the calibration interval duration if the calibration accuracy of the periodic calibration method is unqualified, or determines to update the environmental compensation coefficient if the calibration accuracy of the real-time calibration method is unqualified.

[0020] Furthermore, the adjustment amount of the calibration interval duration is negatively correlated with the long-term zero point stability.

[0021] A method applied to the gas detection instrument prediction calibration system, comprising:

[0022] Collect real-time data of electrochemical gas sensors and periodically collect gas flow velocity and usage frequency in the environment where the electrochemical gas sensors are used;

[0023] Determine the type of use environment of the electrochemical gas sensor according to the average value of the gas flow rate in the use environment of the electrochemical gas sensor collected in several cycles and the average use frequency of the electrochemical gas sensor, and determine the detection method of the zero drift phenomenon of the electrochemical gas sensor to be calibrated based on the use environment type;

[0024] In response to the occurrence of the zero drift phenomenon and the electrochemical gas sensor being in an abnormally turned-on state, determining to perform a real-time calibration or a periodic calibration on the electrochemical gas sensor;

[0025] According to the calibration method, the calibration accuracy is evaluated by the long-term zero point stability or the real-time signal fluctuation;

[0026] Determine whether to update the environmental compensation coefficient and adjust the calibration interval for the next calibration according to the evaluation result of the evaluation module.

[0027] The beneficial effects of the present invention are as follows: in a high-frequency and multi-pollution use environment, the use of the sensor redundancy method to detect the zero drift phenomenon can fully take into account the fact that the sensor performance in such a complex environment is easily interfered by various factors. By installing redundant electrochemical gas sensors, the reliability and accuracy of the detection can be increased. Multiple sensors work simultaneously. Even in an environment with severe pollution and many interference factors, the zero drift problem of the main sensor can be discovered in time by mutual comparison. For a low-frequency and less-pollution use environment, the regular calibration comparison method is more applicable. In such a relatively stable environment, the sensor is less interfered with, and the frequency of zero drift is relatively low. By setting the calibration interval for data collection and comparison, the zero drift phenomenon can be effectively detected without increasing excessive cost and complexity. The appropriate zero drift detection method is selected according to different use environments, thereby improving the calibration accuracy and reliability of the gas detection instrument.

[0028] Furthermore, the determination of the environment type helps to predict changes in sensor performance in advance. In a high-frequency and high-pollution environment, due to the fast gas flow rate and high frequency of use, sensor aging and zero drift may occur faster. By timely determining the environment type, measures can be taken in advance, such as checking the sensor status more frequently or replacing vulnerable parts to extend the service life of the sensor. For low-frequency and less-pollution environments, although the sensor performance is relatively stable, potential failures can still be prevented through regular environmental monitoring. For example, even in a relatively stable laboratory environment, occasional abnormal conditions (such as ventilation system failure leading to abnormal gas flow rate) may affect sensor performance. By continuously monitoring the environment type, these abnormalities can be discovered in time to prevent sensor failures caused by environmental changes. Under different environment types, the gas flow rate and frequency of use will have different degrees of impact on the sensor's detection results. After accurately dividing the environment type, corresponding compensation measures can be taken for these influencing factors. The above method improves the accuracy of the analysis process of the use environment of the gas detection instrument to improve the accuracy of the detection method selection for whether the gas detection instrument has zero drift, thereby improving the use accuracy of the gas detection instrument.

[0029] Furthermore, when zero drift is detected, a periodic calibration method is used. This is a relatively systematic and comprehensive calibration method. Periodic calibration can adjust multiple key parameters of the sensor, such as the zero point and range, so as to effectively correct the zero drift problem caused by long-term use or accumulation of environmental factors. For example, after a period of operation, the sensor may have zero drift due to electrode aging or electrolyte changes. Periodic calibration can use standard gases and precise calibration processes to restore the zero point and range of the sensor to an accurate state, thereby ensuring the accuracy of subsequent test results. For electrochemical gas sensors that are abnormally turned on in extreme environments, the real-time calibration method can respond quickly and perform calibration. Extreme environments may cause significant interference to the initial state of the sensor. For example, if the sensor is turned on in an environment with high temperature, high humidity or high concentration of toxic gases, its output signal may have a large deviation. Real-time calibration can quickly adjust the working parameters of the sensor according to the environmental conditions and the actual output of the sensor within a short period of time after the sensor is turned on, so that the sensor can adapt to the environment as soon as possible and provide relatively accurate detection results, avoiding false detection caused by initial deviations, and determining that the sensor is in an abnormally turned-on state in extreme environments and performing real-time calibration. This is in consideration of the significant impact of extreme environments on sensors and detection results. In emergency situations such as chemical production, fire scenes, or toxic gas leaks, sensors often need to work in extremely harsh environments. If they cannot be calibrated in time, the erroneous output of the sensor may delay the rescue time or lead to incorrect safety decisions. By distinguishing between zero drift and abnormal opening, the calibration method can be selected to prevent misjudgment and missed judgment. If the same calibration method is used for all situations, it may lead to untimely calibration in some emergency situations, or excessive calibration on zero drift problems and waste of resources. The above method improves the accuracy of the analysis process of the use environment of the gas detection instrument to improve the accuracy of the selection of the detection method for whether the gas detection instrument has zero drift phenomenon, thereby improving the accuracy of the use of the gas detection instrument.

[0030] Furthermore, by setting specific evaluation parameters for different calibration methods, the calibration effect can be accurately measured. For the periodic calibration method, the long-term zero-point stability reflects the stability of the sensor over a long period of time, ensuring that it can maintain an accurate zero point throughout the calibration interval. For the real-time calibration method, the real-time signal fluctuation focuses on the immediate performance of the sensor in a dynamic environment, ensuring that it can respond promptly to a rapidly changing environment and maintain a stable output. Setting clear preset stability and preset fluctuation makes the determination of calibration accuracy more objective and strict. Only when the long-term zero-point stability is less than or equal to the preset stability, and the real-time signal fluctuation is less than the preset fluctuation, the calibration accuracy is determined to be qualified. This helps to avoid detection errors caused by insufficient calibration and improve the accuracy and reliability of gas detection instruments. When the accuracy of the periodic calibration method is unqualified, adjust the calibration. The calibration interval can dynamically optimize the calibration frequency according to actual conditions. If the long-term zero-point stability does not meet the requirements, it may mean that the current calibration interval is too long, and the performance changes of the sensor accumulate too much between two calibrations, resulting in a decrease in accuracy. By shortening the calibration interval, the sensor can be calibrated more frequently, and problems such as zero drift can be corrected in time to improve the long-term stability of the sensor. For the real-time calibration method, updating the environmental compensation coefficient when the accuracy is unqualified can better adapt to different working environments. By re-evaluating these factors and updating the compensation coefficient, the sensor can detect gas concentration more accurately under various environmental conditions, thereby improving the effect of real-time calibration. The above method improves the accuracy of the environmental analysis process of the gas detection instrument to improve the accuracy of the detection method selection for whether the gas detection instrument has zero drift, thereby improving the accuracy of the use of the gas detection instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of the structure of a gas detection instrument prediction and calibration system according to an embodiment of the present invention;

[0032] Figure 2 It is a working flow chart of the analysis module of the prediction and calibration system of the gas detection instrument in the embodiment of the present invention;

[0033] Figure 3 It is a working flow chart of the adjustment module of the prediction and calibration system of the gas detection instrument in the embodiment of the present invention;

[0034] Figure 4 The present invention is a flowchart of a method for applying a predictive calibration system for a gas detection instrument in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0039] like Figure 1-3 As shown, Figure 1 A schematic diagram of the structure of a gas detection instrument prediction and calibration system according to an embodiment of the present invention; Figure 2 It is a working flow chart of the analysis module of the prediction and calibration system of the gas detection instrument in the embodiment of the present invention; Figure 3 The following is a flowchart of the adjustment module of the prediction and calibration system of the gas detection instrument in the embodiment of the present invention.

[0040] This embodiment provides a gas detection instrument prediction calibration system, including:

[0041] An acquisition module, which is used to acquire real-time data of the electrochemical gas sensor and periodically acquire the gas flow velocity and usage frequency in the use environment of the electrochemical gas sensor;

[0042] an analysis module connected to the acquisition module, for determining the type of use environment of the electrochemical gas sensor according to the average value of the gas flow velocity in the use environment of the electrochemical gas sensor acquired in several cycles and the average use frequency of the electrochemical gas sensor, and determining a detection method for the zero drift phenomenon of the electrochemical gas sensor to be calibrated based on the use environment type;

[0043] A calibration module connected to the analysis module, in response to the occurrence of a zero drift phenomenon and the electrochemical gas sensor being in an abnormally turned-on state, determines a real-time calibration or a periodic calibration for the electrochemical gas sensor;

[0044] An evaluation module, which is connected to the calibration module and is used to determine the calibration accuracy based on the long-term zero point stability or the real-time signal fluctuation according to the calibration method;

[0045] An adjustment module, which is connected to the evaluation module and is used to determine whether to update the environmental compensation coefficient for the next calibration and adjust the calibration interval according to the evaluation result of the evaluation module;

[0046] The environmental compensation coefficient is used to correct the detection error of the electrochemical gas sensor in the abnormal opening state, and the abnormal opening state includes temperature abnormality, humidity abnormality and vibration abnormality.

[0047] Optionally, the real-time data of the electrochemical gas sensor in this embodiment includes but is not limited to "real-time usage environment temperature data, real-time usage environment humidity data and real-time vibration data of the electrochemical gas sensor", and the periodic collection of the gas flow velocity and usage frequency in the electrochemical gas sensor usage environment includes but is not limited to collecting the gas flow velocity and usage frequency in the electrochemical gas sensor usage environment 25 times.

[0048] Specifically, the analysis module determines the detection method of the zero drift phenomenon of the electrochemical gas sensor to be calibrated, including determining to detect the zero drift phenomenon by the sensor redundancy method under the condition that the use environment type of the electrochemical gas sensor is a high-frequency and high-pollution use environment, or determining to detect the zero drift phenomenon by the periodic calibration comparison method under the condition that the use environment type of the electrochemical gas sensor is a low-frequency and low-pollution use environment.

[0049] Optionally, the calibration interval duration described in the present embodiment can be determined based on the average interval of the historical calibration time points of the electrochemical gas sensor. The sensor redundancy method for detecting zero drift phenomenon in the present embodiment includes installing redundant electrochemical gas sensors in a high-frequency and multi-pollution use environment, and simultaneously starting all electrochemical gas sensors (including redundant sensors) for data collection. The collected data includes the electrical signal output by the sensor, and this electrical signal is related to the detected gas concentration. For example, for an electrochemical sensor for detecting carbon monoxide, it will output a corresponding current signal based on the concentration of carbon monoxide. The collected data is the change of these current signals over time, and the data of the main sensor (the sensor used for detection in normal operation) is compared with the data of the redundant sensor. Ideally, when there is no zero drift, these sensors are in the same environment and the detected data should be similar. If zero drift occurs, the data of the main sensor and the redundant sensor will be different. For example, suppose the main sensor and the redundant sensor have the same detection output signal for a certain gas in the initial state, but over time, the output signal of the main sensor begins to deviate from the normal range due to zero drift, while the redundant sensor has no zero drift or the drift is small, so the output signal is still within the normal range. By comparing this difference, it can be preliminarily determined that the main sensor has a zero drift.

[0050] Optionally, the periodic calibration comparison method for detecting the zero drift phenomenon described in this embodiment includes determining the time point for data collection according to a set periodic calibration interval. For example, data collection can be set once a week, month or quarter. At each collection time point, multiple data collections are performed at predetermined time intervals to obtain a more accurate average value. At the collection time point, the electrochemical gas sensor is placed in a normal use environment to detect the gas in the environment, and the gas concentration data displayed by the instrument is recorded. The gas concentration data collected each time is compared with the initial calibration data. The initial calibration data is used as a reference value to determine whether the instrument has a zero drift phenomenon. If the display value of the instrument in pure air changes significantly compared to the zero value of the initial calibration, there may be a zero drift phenomenon. In addition to comparing with the reference value, it is also necessary to analyze the trend of the gas concentration data over time. If the data shows a trend of gradually deviating from the initial value, and this trend is continuous, then it can be determined that the instrument has a zero drift.

[0051] In the above embodiments, in a high-frequency and multi-pollution use environment, the use of sensor redundancy method to detect zero drift phenomenon can fully take into account the situation that sensor performance in such a complex environment is easily interfered by multiple factors. By installing redundant electrochemical gas sensors, the reliability and accuracy of detection can be increased. Multiple sensors work at the same time. Even in an environment with severe pollution and many interference factors, the zero drift problem of the main sensor can be discovered in time by mutual comparison. For a low-frequency and less-pollution use environment, the regular calibration comparison method is more applicable. In such a relatively stable environment, the sensor is less interfered with, and the frequency of zero drift phenomenon is relatively low. Setting the calibration interval for data collection and comparison can effectively detect the zero drift phenomenon without increasing excessive cost and complexity. The appropriate zero drift detection method is selected according to different use environments, thereby improving the calibration accuracy and reliability of the gas detection instrument.

[0052] Specifically, the analysis module determines the type of the use environment of the electrochemical gas sensor, including determining that the type of the use environment of the electrochemical gas sensor is a high-frequency and high-pollution use environment under the condition that the average value of the gas flow velocity in the use environment of the electrochemical gas sensor collected over several cycles is greater than a preset average value and the average use frequency is greater than a preset average use frequency, or determines that the type of the use environment of the electrochemical gas sensor is a low-frequency and low-pollution use environment under the condition that the average value of the gas flow velocity in the use environment of the electrochemical gas sensor collected over several cycles is less than or equal to a preset average value.

[0053] Optionally, the value range of the preset average value in this embodiment is set to 1m / s-1.8m / s, and the value of the preset average value is preferably 1.2m / s. The preset usage frequency is determined according to the service life of the electrochemical gas sensor. For example, the nominal service life of a sensor is two years, and this life can be achieved under normal usage frequency (such as 10 detections per day), then the preset usage frequency is 10 times / day.

[0054] In the above embodiment, the determination of the environment type helps to predict the change of sensor performance in advance. In a high-frequency and high-pollution environment, due to the fast gas flow rate and high frequency of use, the aging and zero drift of the sensor may occur faster. By timely determining the environment type, measures can be taken in advance, such as checking the sensor status more frequently or replacing vulnerable parts to extend the service life of the sensor. For a low-frequency and less-pollution environment, although the sensor performance is relatively stable, potential failures can still be prevented through regular environmental monitoring. For example, even in a relatively stable laboratory environment, occasional abnormal conditions (such as abnormal gas flow rate caused by a ventilation system failure) may affect the sensor performance. By continuously monitoring the environment type, these abnormalities can be discovered in time to prevent sensor failures caused by environmental changes. Under different environment types, the gas flow rate and frequency of use will have different degrees of impact on the sensor's detection results. After accurately dividing the environment type, corresponding compensation measures can be taken for these influencing factors. The above method improves the accuracy of the analysis process of the use environment of the gas detection instrument to improve the accuracy of the detection method selection for whether the gas detection instrument has zero drift, thereby improving the use accuracy of the gas detection instrument.

[0055] Specifically, the calibration module determines whether to calibrate the electrochemical gas sensor in real time or in periodic manner, including determining to calibrate the electrochemical gas sensor in real time by periodic calibration method when zero drift is detected in the electrochemical gas sensor, or determining to calibrate the electrochemical gas sensor in real time by periodic calibration method when the electrochemical gas sensor is in an abnormally open state.

[0056] Optionally, the calibration by periodic method described in the present embodiment includes placing the electrochemical gas sensor in a pure background gas (such as clean air or nitrogen) environment, stabilizing the sensor for a period of time, generally 10 to 30 minutes, allowing the sensor to adapt to the environment and reach a stable initial state, and then recording the output signal of the sensor at this time, which should be a zero signal. If it is not zero, the output signal is reset to zero by adjusting the zero offset of the sensor (usually by a calibration circuit or software algorithm inside the instrument), and the standard gas of known concentration is passed into the sensor in turn, and the flow rate is controlled within a suitable range, generally determined according to the instructions of the sensor, such as 100-200 ml per minute. After passing the standard gas, wait for the sensor output signal to stabilize, and record the output signal value corresponding to each standard gas concentration. By comparing the actual output signal with the theoretical output signal (calculated according to the sensitivity of the sensor and the standard gas concentration), adjusting the gain or other relevant parameters of the sensor, an accurate corresponding relationship is established between the output of the sensor and the standard gas concentration, and all data in the calibration process are recorded in detail, including the standard gas concentration, the sensor output signal, the environmental parameters, the zero point and the range adjustment parameters, etc. After completing the calibration, introduce the standard gas again for verification to ensure that the output signal of the sensor meets expectations, that is, the zero point is stable within the allowable range and the range accuracy meets the requirements. If the verification fails, the calibration process needs to be repeated.

[0057] Optionally, the calibration by the real-time calibration method described in this embodiment includes real-time and continuous acquisition of the output signal of the electrochemical gas sensor, while monitoring the working environment parameters of the sensor (such as temperature, humidity and air pressure), and quickly judging whether the sensor is in an abnormally open state or whether zero drift occurs through the built-in algorithm. For example, a zero drift threshold is set. If the output signal of the sensor deviates from the zero point by more than this threshold, it is judged that zero drift occurs. For the abnormal open state, it can be judged by monitoring whether the environmental parameters are within the normal range and the output signal characteristics when the sensor is started. Once it is determined that calibration is required, first, according to the real-time monitored environmental parameters, the influence of environmental factors on the output signal of the sensor is calculated to obtain the environmental compensation coefficient. For example, according to the temperature-signal change model (this model can be obtained through preliminary experiments or data analysis), the signal offset caused by the temperature change is calculated. If the temperature rises by 10°C, the corresponding signal change value is calculated according to the model to provide a compensation basis for subsequent calibration, and the output signal of the sensor is adjusted in real time through software algorithms or hardware circuits (such as adjustable elements in digital signal processors or analog circuits). If it is a zero point drift, adjust the signal offset to restore the zero point to the normal range; if it is a range change, adjust the signal gain. For example, if the zero point drifts upward by 0.1mV, calibrate the zero point by subtracting the 0.1mV offset; if it is found that the signal gain decreases for some reason, increase the gain according to the calculation result to restore the normal range.

[0058] Optionally, the extreme environment described in this embodiment includes but is not limited to "high temperature environment, high humidity environment and high vibration environment". The judgment of high temperature environment, high humidity environment and high vibration environment includes comparing the real-time temperature data, real-time humidity data and real-time vibration data of the electrochemical gas sensor with their corresponding preset values ​​respectively. If they are higher than the preset values, it is determined to be a high temperature environment, high humidity environment and high vibration environment. The preset temperature data may preferably be 1.1 times the average value of the historical working environment temperature of the electrochemical gas sensor, the preset humidity data may preferably be 1.2 times the average value of the historical working environment humidity of the electrochemical gas sensor, and the preset vibration data may preferably be 1.3 times the historical working environment vibration data of the electrochemical gas sensor.

[0059] In the above embodiment, when the zero drift phenomenon is detected, a periodic calibration method is used. This is a relatively systematic and comprehensive calibration method. The periodic calibration can adjust multiple key parameters of the sensor, such as the zero point and range, so as to effectively correct the zero drift problem caused by long-term use or accumulation of environmental factors. For example, after a period of operation, the sensor may have zero drift due to electrode aging or electrolyte changes. The periodic calibration can use standard gases and precise calibration processes to restore the zero point and range of the sensor to an accurate state, thereby ensuring the accuracy of subsequent test results. For electrochemical gas sensors that are abnormally turned on in extreme environments, the real-time calibration method can respond quickly and perform calibration. Extreme environments may cause significant interference to the initial state of the sensor. For example, if the sensor is turned on in an environment with high temperature, high humidity or high concentration of toxic gases, its output signal may have a large deviation. Real-time calibration can quickly adjust the working parameters of the sensor according to the environmental conditions and the actual output of the sensor within a short period of time after the sensor is turned on, so that the sensor can adapt to the environment as soon as possible and provide relatively accurate detection results, avoiding false detection caused by initial deviations, and determining that the sensor is in an abnormally turned-on state in extreme environments and performing real-time calibration. This is in consideration of the significant impact of extreme environments on sensors and detection results. In emergency situations such as chemical production, fire scenes, or toxic gas leaks, sensors often need to work in extremely harsh environments. If they cannot be calibrated in time, the erroneous output of the sensor may delay the rescue time or lead to incorrect safety decisions. By distinguishing between zero drift and abnormal opening, the calibration method can be selected to prevent misjudgment and missed judgment. If the same calibration method is used for all situations, it may lead to untimely calibration in some emergency situations, or excessive calibration on zero drift problems and waste of resources. The above method improves the accuracy of the analysis process of the use environment of the gas detection instrument to improve the accuracy of the selection of the detection method for whether the gas detection instrument has zero drift phenomenon, thereby improving the accuracy of the use of the gas detection instrument.

[0060] Specifically, the evaluation module evaluates the calibration accuracy by determining the long-term zero point stability when calibrating with a periodic calibration method, or by determining the real-time signal fluctuation when calibrating with a real-time calibration method.

[0061] Specifically, the evaluation module determines that the calibration accuracy is unqualified under the condition that the long-term zero point stability is greater than the preset stability or the real-time signal fluctuation is greater than the preset fluctuation. The evaluation module determines that the calibration accuracy is qualified under the condition that the long-term zero point stability is less than or equal to the preset stability or the real-time signal fluctuation is less than the preset fluctuation.

[0062] Optionally, the long-term zero point stability determination process described in this embodiment includes that after periodic calibration, the standard deviation of the value detected at the zero point of the electrochemical gas sensor within a calibration interval is the long-term zero point stability, and the preset stability is the historical average of the long-term zero point stability of the electrochemical gas sensor. The real-time signal fluctuation determination process includes continuously collecting the output signal value of the sensor within a period of time (for example, 3 minutes) during the real-time calibration process, and calculating the range and average of the collected output signal values. The real-time signal fluctuation is the ratio of the range to the average value, and the preset real-time signal fluctuation is the historical average of the real-time signal fluctuation of the electrochemical gas sensor.

[0063] Specifically, the adjustment module determines whether to adjust the calibration process, including determining to adjust the calibration process under the condition that the calibration accuracy is unqualified, and the adjustment module determines not to adjust the calibration process under the condition that the calibration accuracy is qualified.

[0064] Specifically, the adjustment module determines to adjust the calibration interval for the next calibration if the calibration accuracy of the periodic calibration method is unqualified, or determines to update the environmental compensation coefficient for the next calibration if the calibration accuracy of the real-time calibration method is unqualified.

[0065] Specifically, the adjustment module determines to adjust the calibration interval duration with the adjustment coefficient under the condition that the calibration interval duration for the next calibration is adjusted, and the adjustment module determines to re-evaluate the impact of environmental factors on the sensor under the condition that the environmental compensation coefficient for the next calibration is updated.

[0066] Optionally, the adjustment coefficient in this embodiment has a value range of 0.82-0.97, and the value of the adjustment coefficient is preferably 0.88. The re-evaluation of the impact of environmental factors on the sensor includes testing the sensor under different temperature environments (different temperature data, humidity data, and vibration data) through experiments and data analysis, and observing the change law of the sensor output signal. If it is found that the actual signal change is significantly different from the theoretical change calculated based on the existing environmental compensation coefficient, it is necessary to refit the environment-signal change curve and update the environmental compensation coefficient. The existing environmental compensation coefficient can be determined according to an experimental method. Under a relatively stable and known environmental condition (such as a laboratory environment where temperature, humidity, and vibration can be precisely controlled), the sensor is calibrated using a standard gas. By comparing the actual output signal of the sensor with the theoretical signal corresponding to the standard gas concentration, an initial environmental compensation coefficient is calculated. For example, in an environment with a temperature of 25°C, a humidity of 50%, and no vibration, the sensor is tested with a 100ppm standard gas. If the actual output signal of the sensor is a signal corresponding to 90ppm, then the environmental compensation coefficient can be initially set to 100 / 90≈1.11.

[0067] In the above embodiment, by setting specific evaluation parameters for different calibration methods, the calibration effect can be accurately measured. For the periodic calibration method, the long-term zero-point stability reflects the stability of the sensor over a long period of time, ensuring that it can maintain an accurate zero point throughout the entire calibration interval. For the real-time calibration method, the real-time signal fluctuation level focuses on the instantaneous performance of the sensor in a dynamic environment, ensuring that it can respond to a rapidly changing environment in a timely manner and maintain a stable output. Setting clear preset stability levels and preset fluctuation levels makes the determination of calibration accuracy more objective and strict. Only when the long-term zero-point stability is less than or equal to the preset stability level, and the real-time signal fluctuation level is less than the preset fluctuation level, is the calibration accuracy determined to be qualified? This helps to avoid detection errors caused by insufficient calibration and improve the accuracy and reliability of gas detection instruments. When the accuracy of the periodic calibration method is unqualified, adjust The calibration interval can dynamically optimize the calibration frequency according to actual conditions. If the long-term zero-point stability does not meet the requirements, it may mean that the current calibration interval is too long, and the performance changes of the sensor accumulate too much between two calibrations, resulting in a decrease in accuracy. By shortening the calibration interval, the sensor can be calibrated more frequently, and problems such as zero-point drift can be corrected in time to improve the long-term stability of the sensor. For the real-time calibration method, updating the environmental compensation coefficient when the accuracy is unqualified can better adapt to different working environments. By re-evaluating these factors and updating the compensation coefficient, the sensor can detect gas concentration more accurately under various environmental conditions, thereby improving the effect of real-time calibration. The above method improves the accuracy of the environmental analysis process of the gas detection instrument to improve the accuracy of the detection method selection for whether the gas detection instrument has zero-point drift, thereby improving the accuracy of the use of the gas detection instrument.

[0068] like Figure 4 As shown, Figure 4 The present invention is a flowchart of a method for applying a predictive calibration system for a gas detection instrument in an embodiment of the present invention.

[0069] Specifically, a method applied to the gas detection instrument prediction calibration system includes:

[0070] Step S1, collecting real-time data of the electrochemical gas sensor and periodically collecting the gas flow velocity and usage frequency in the use environment of the electrochemical gas sensor;

[0071] Step S2, determining the use environment type of the electrochemical gas sensor according to the average value of the gas flow rate in the use environment of the electrochemical gas sensor collected in several cycles and the average use frequency of the electrochemical gas sensor, and determining a detection method for the zero drift phenomenon of the electrochemical gas sensor to be calibrated based on the use environment type;

[0072] Step S3, in response to the occurrence of the zero drift phenomenon and the electrochemical gas sensor being in an abnormally turned-on state, determining a real-time calibration or a periodic calibration for the electrochemical gas sensor;

[0073] Step S4, determining, according to the calibration method, to evaluate the calibration accuracy by the long-term zero point stability or the real-time signal fluctuation degree;

[0074] Step S5, determining whether to update the environmental compensation coefficient and adjust the calibration interval for the next calibration according to the evaluation result of the evaluation module.

[0075] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A gas detection instrument prediction calibration system, characterized in that: include: An acquisition module, which is used to acquire real-time data of the electrochemical gas sensor and periodically acquire the gas flow velocity and usage frequency in the use environment of the electrochemical gas sensor; an analysis module connected to the acquisition module, for determining the type of use environment of the electrochemical gas sensor according to the average value of the gas flow velocity in the use environment of the electrochemical gas sensor acquired in several cycles and the average use frequency of the electrochemical gas sensor, and determining a detection method for the zero drift phenomenon of the electrochemical gas sensor to be calibrated based on the use environment type; A calibration module connected to the analysis module, in response to the occurrence of a zero drift phenomenon and the electrochemical gas sensor being in an abnormally turned-on state, determines a real-time calibration or a periodic calibration for the electrochemical gas sensor; An evaluation module, which is connected to the calibration module and is used to determine the calibration accuracy based on the long-term zero point stability or the real-time signal fluctuation according to the calibration method; An adjustment module, which is connected to the evaluation module and is used to determine whether to update the environmental compensation coefficient for the next calibration and adjust the calibration interval according to the evaluation result of the evaluation module; The environmental compensation coefficient is used to correct the detection error of the electrochemical gas sensor in the abnormal opening state, and the abnormal opening state includes temperature abnormality, humidity abnormality and vibration abnormality.

2. The gas detection instrument prediction and calibration system according to claim 1, characterized in that: The analysis module determines the detection method of the zero drift phenomenon of the electrochemical gas sensor to be calibrated, including determining to detect the zero drift phenomenon by the sensor redundancy method under the condition that the use environment type of the electrochemical gas sensor is a high-frequency and high-pollution use environment, or determining to detect the zero drift phenomenon by the periodic calibration comparison method under the condition that the use environment type of the electrochemical gas sensor is a low-frequency and low-pollution use environment.

3. The gas detection instrument prediction and calibration system according to claim 2, characterized in that: The analysis module determines the use environment type of the electrochemical gas sensor, including determining that the use environment type of the electrochemical gas sensor is a high-frequency and multi-pollution use environment under the condition that the average value of the gas flow rate in the use environment of the electrochemical gas sensor collected in several cycles is greater than a preset average value and the average use frequency is greater than a preset average use frequency.

4. The gas detection instrument prediction and calibration system according to claim 3, characterized in that: The calibration module determines whether to calibrate the electrochemical gas sensor in real time or in periodic manner, including determining to calibrate the electrochemical gas sensor in periodic manner when zero drift is detected in the electrochemical gas sensor, or determining to calibrate the electrochemical gas sensor in real time when the electrochemical gas sensor is in an abnormally open state.

5. The gas detection instrument prediction and calibration system according to claim 4, characterized in that: The evaluation module evaluates the calibration accuracy by determining the long-term zero point stability under the condition of calibration by a periodic calibration method, or by determining the real-time signal fluctuation under the condition of calibration by a real-time calibration method.

6. The gas detection instrument prediction and calibration system according to claim 5, characterized in that: The evaluation module determines that the calibration accuracy is unqualified under the condition that the long-term zero point stability is greater than a preset stability or the real-time signal fluctuation is greater than a preset fluctuation.

7. The gas detection instrument prediction and calibration system according to claim 6, characterized in that: The preset stability level is determined based on the historical average of the long-term zero-point stability level of the electrochemical gas sensor, and the preset real-time signal fluctuation level is determined based on the historical average of the real-time signal fluctuation level of the electrochemical gas sensor.

8. The gas detection instrument prediction and calibration system according to claim 7, characterized in that: The adjustment module determines to adjust the calibration interval duration if the calibration accuracy of the periodic calibration method is unqualified, or determines to update the environmental compensation coefficient if the calibration accuracy of the real-time calibration method is unqualified.

9. The gas detection instrument prediction and calibration system according to claim 8, characterized in that: The adjustment amount of the calibration interval duration is negatively correlated with the long-term zero point stability.

10. A method for the predictive calibration system of a gas detection instrument according to any one of claims 1 to 9, characterized in that: include: Collect real-time data of electrochemical gas sensors and periodically collect gas flow velocity and usage frequency in the environment where the electrochemical gas sensors are used; Determine the type of use environment of the electrochemical gas sensor according to the average value of the gas flow rate in the use environment of the electrochemical gas sensor collected in several cycles and the average use frequency of the electrochemical gas sensor, and determine the detection method of the zero drift phenomenon of the electrochemical gas sensor to be calibrated based on the use environment type; In response to the occurrence of the zero drift phenomenon and the electrochemical gas sensor being in an abnormally turned-on state, determining to perform a real-time calibration or a periodic calibration on the electrochemical gas sensor; According to the calibration method, the calibration accuracy is evaluated by the long-term zero point stability or the real-time signal fluctuation; Determine whether to update the environmental compensation coefficient and adjust the calibration interval for the next calibration according to the evaluation result of the evaluation module.

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