A gas detection instrument predictive calibration system and method

Abstract

This invention relates to the field of instrument calibration technology, specifically disclosing a predictive calibration system and method for gas detection instruments. The system includes: a data acquisition module; an analysis module for determining a detection method for zero-point drift of an electrochemical gas sensor to be calibrated based on the type of operating environment; a calibration module for determining whether to perform real-time or periodic calibration of the electrochemical gas sensor in response to the occurrence of zero-point drift and the electrochemical gas sensor being in an abnormal on-state; an evaluation module for assessing calibration accuracy based on long-term zero-point stability or real-time signal fluctuation according to the calibration method; and an adjustment module for determining whether to update the environmental compensation coefficient and adjust the calibration interval based on the evaluation results of the evaluation module. This invention improves the accuracy of zero-point drift analysis by enhancing the accuracy of environmental analysis of the electrochemical gas sensor, thereby achieving precise calibration.

Description

Technical Field

[0001] This invention relates to the field of instrument calibration technology, and in particular to a predictive calibration system and method for gas detection instruments. Background Technology

[0002] With the rapid development of industry and the increasing demands for environmental monitoring, gas detection instruments are being used more and more widely in various fields. As a core component of gas detection instruments, the accuracy and stability of electrochemical gas sensors are crucial. However, during operation, the performance of electrochemical gas sensors degrades with time and increased detection volume due to various factors, leading to zero-point drift. This zero-point drift not only affects the accuracy of gas detection but can also have serious consequences for industrial production, environmental monitoring, and safety assurance. Traditional calibration methods for gas detection instruments are often relatively simplistic and cannot adequately adapt to different operating environments and sensor conditions. For example, some methods focus only on changes in the sensor's own performance, ignoring the impact of the operating environment; others, while considering environmental factors, lack comprehensive consideration of factors such as sensor usage frequency and abnormal operating states. Furthermore, traditional methods are also insufficient in evaluating calibration accuracy and adjusting the calibration process, making it difficult to achieve precise calibration and continuous performance optimization.

[0003] For example, a catalytic gas sensor zero-point self-calibration method is disclosed in the prior art. A composite sensitive material of nano-semiconductor tin dioxide, antimony pentoxide and cerium oxide is prepared by chemical co-precipitation. The material is aged, centrifuged for solid-liquid separation, deionized and washed, dehydrated with organic solvent, vacuum dried and heat-treated to form a sensitive material. The sensitive material is prepared into a slurry using glycerol. A coil with a diameter of 0.018 mm is wound into a coil with a diameter of 0.2 mm using a winding technique and suspended and welded to a standard two-pronged tube socket. The sensitive slurry is applied to the coil. The coil is heated by electricity to burn the slurry into a small ball with a certain strength. The tube socket is sealed with a perforated shell by energy storage welding to produce a gas-sensitive element with a full scale range of less than 10 × 10-6 V / V for liquefied petroleum gas (natural liquefied gas, hydrogen, organic gas). By integrating it with a catalytic gas sensor, and taking advantage of the fact that the detection limit of the catalytic gas sensor (volume fraction 50×10-6v / V) is much higher than the full scale of this gas sensing element, it can be assumed that when the detection limit of the gas sensing element is lower than the full scale, the concentration of the gas being measured in the environment is close to zero. At this time, the microcontroller of the conditioning circuit of the catalytic gas sensor adjusts the zero point of the sensor, thereby realizing the zero-point self-calibration function of the catalytic gas sensor. This method solves the zero-point drift problem of the catalytic gas sensor during long-term use, realizes the self-calibration function of the catalytic gas sensor, extends the calibration cycle of the catalytic gas sensor, and improves the service life of the sensor.

[0004] However, existing technologies lack analysis of the operating environment of gas detectors, resulting in inaccurate selection of detection methods to determine whether gas detectors are experiencing zero-point drift. This leads to the inability to calibrate gas detectors in a timely manner, resulting in low accuracy of gas detectors. Summary of the Invention

[0005] The purpose of this invention is to provide a predictive calibration system and method for gas detection instruments, which can accurately analyze the operating environment of gas detection instruments, select appropriate zero-point drift detection methods, and calibrate gas detection instruments in a timely manner, thereby improving the accuracy of gas detection instruments.

[0006] Therefore, the present invention provides a gas detection instrument prediction and calibration system, comprising:

[0007] The data acquisition module is used to acquire real-time data from the electrochemical gas sensor and periodically acquire gas flow velocity and usage frequency in the environment in which the electrochemical gas sensor is used.

[0008] An analysis module, connected to the acquisition module, is used to determine the operating environment type of the electrochemical gas sensor based on the average gas flow velocity collected over several cycles in the operating environment of the electrochemical gas sensor, and the average operating frequency of the electrochemical gas sensor, and to determine a detection method for the zero-point drift phenomenon of the electrochemical gas sensor to be calibrated based on the operating environment type.

[0009] The calibration module, which is connected to the analysis module, determines whether to perform real-time or periodic calibration of the electrochemical gas sensor in response to the occurrence of zero-point drift and the abnormal activation state of the electrochemical gas sensor.

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

[0011] An adjustment module, which is connected to the evaluation module, is used to determine whether to update the environmental compensation coefficient and adjust the calibration interval based on the evaluation results of the evaluation module.

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

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

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

[0015] Furthermore, the calibration module determines whether to perform real-time or periodic calibration of the electrochemical gas sensor, including determining to calibrate using a periodic calibration method when a zero-point drift phenomenon is detected in the electrochemical gas sensor, or determining to calibrate using a real-time calibration method when the electrochemical gas sensor is in an abnormal on state.

[0016] Furthermore, the evaluation module evaluates the calibration accuracy by determining the long-term zero-point stability under the condition of calibration using a periodic calibration method, or by determining the real-time signal fluctuation under the condition of calibration using a real-time calibration method.

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

[0018] Furthermore, the preset stability level is determined based on the historical average value of the long-term zero-point stability of the electrochemical gas sensor, and the preset real-time signal fluctuation level is determined based on the 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 when the calibration accuracy of the periodic calibration method is unqualified, or determines to update the environmental compensation coefficient when 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 for use in the gas detection instrument prediction calibration system, comprising:

[0022] Collect real-time data from the electrochemical gas sensor and periodically collect gas flow velocity and usage frequency in the environment in which the electrochemical gas sensor is used;

[0023] The method for detecting zero-point drift of the electrochemical gas sensor is determined based on the average gas flow velocity collected over several cycles in the operating environment of the electrochemical gas sensor and the average usage frequency of the electrochemical gas sensor.

[0024] In response to the occurrence of zero-point drift and the abnormal activation state of the electrochemical gas sensor, determine whether to perform real-time or periodic calibration of the electrochemical gas sensor.

[0025] The calibration accuracy is assessed based on either long-term zero-point stability or real-time signal fluctuation, depending on the calibration method.

[0026] Based on the evaluation results of the evaluation module, it is determined whether to update the environmental compensation coefficient and adjust the calibration interval for the next calibration.

[0027] The beneficial effects of this invention are as follows: In high-frequency, high-pollution environments, the sensor redundancy method for detecting zero-point drift fully considers the susceptibility of sensor performance to various interferences in such complex environments. By installing redundant electrochemical gas sensors, the reliability and accuracy of detection can be increased. Multiple sensors operating simultaneously, even in heavily polluted environments with numerous interfering factors, can promptly detect zero-point drift issues in the main sensor through mutual comparison. For low-frequency, low-pollution environments, the periodic calibration and comparison method is more suitable. In such relatively stable environments, sensors experience less interference, and the frequency of zero-point drift is relatively low. Setting calibration intervals for data collection and comparison allows for effective detection of zero-point drift without increasing costs or complexity. Selecting appropriate zero-point drift detection methods based on different operating environments improves the calibration accuracy and reliability of gas detection instruments.

[0028] Furthermore, determining the environmental type helps predict changes in sensor performance in advance. In high-frequency, high-pollution environments, due to the high gas flow rate and frequent use, sensor aging and zero-point drift may occur more quickly. By timely determining the environmental type, measures can be taken in advance, such as checking the sensor status more frequently or replacing vulnerable parts, to extend the sensor's lifespan. For low-frequency, low-pollution environments, although 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 anomalies (such as ventilation system failures causing abnormal gas flow rates) may affect sensor performance. By continuously monitoring the environmental type, these anomalies can be detected in a timely manner, preventing sensor failures caused by environmental changes. Under different environmental types, gas flow rates and usage frequencies will have varying degrees of impact on sensor detection results. After accurately classifying the environmental type, corresponding compensatory measures can be taken for these influencing factors. The above methods improve the accuracy of the analysis process of the gas detection instrument's operating environment, thereby improving the accuracy of the detection method selection for whether the gas detection instrument exhibits zero-point drift, and ultimately improving the accuracy of the gas detection instrument's operation.

[0029] Furthermore, when zero-point drift is detected, a periodic calibration method is employed. This is a relatively systematic and comprehensive calibration approach. Periodic calibration can adjust multiple key parameters of the sensor, such as its zero point and range, thereby effectively correcting zero-point drift caused by prolonged use or the accumulation of environmental factors. For example, after a period of operation, the sensor may experience zero-point drift due to electrode aging or changes in the electrolyte. Periodic calibration can utilize standard gases and precise calibration procedures to restore the sensor's zero point and range to an accurate state, ensuring the accuracy of subsequent detection results. For electrochemical gas sensors that are abnormally activated under extreme environments, the real-time calibration method can respond quickly and perform calibration. Extreme environments may significantly interfere with the initial state of the sensor. For instance, activating the sensor in environments with high temperature, high humidity, or high concentrations of toxic gases may result in significant deviations in its output signal. Real-time calibration allows for rapid adjustment of sensor operating parameters based on environmental conditions and actual output shortly after sensor activation. This enables the sensor to adapt to the environment quickly and provide relatively accurate detection results, avoiding erroneous detections due to initial deviations. It also identifies abnormal activation states in extreme environments and performs real-time calibration. This is crucial considering the significant impact of extreme environments on sensors and detection results. In emergencies such as chemical production, fire scenes, or toxic gas leaks, sensors often need to operate in extremely harsh conditions. Failure to calibrate promptly could delay rescue efforts or lead to incorrect safety decisions due to erroneous sensor outputs. By differentiating between zero-point drift and abnormal activation, the calibration method can prevent misjudgments and missed detections. Applying the same calibration method to all situations could result in delayed calibration in emergency situations or over-calibration and wasted resources on zero-point drift issues. These methods improve the accuracy of environmental analysis of gas detection instruments, enhance the precision of selecting detection methods for zero-point drift, and ultimately improve the overall accuracy of gas detection instruments.

[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 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 degree focuses on the immediate performance of the sensor in a dynamic environment, ensuring that it can respond in a timely manner to a rapidly changing environment and maintain a stable output. By setting clear preset stability and preset fluctuation degrees, the determination of calibration accuracy becomes more objective and strict. Only when the long-term zero stability is less than or equal to the preset stability and the real-time signal fluctuation degree is less than the preset fluctuation degree, 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 the gas detection instrument. When the accuracy of the periodic calibration method is unqualified, adjusting the calibration interval duration can dynamically optimize the calibration frequency according to the actual situation. If the long-term zero stability does not meet the requirements, it may mean that the current calibration interval duration 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 duration, the sensor can be calibrated more frequently to promptly correct problems such as zero drift and 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 the gas concentration more accurately under various environmental conditions and improve the effect of real-time calibration. By the above methods, the accuracy of the analysis process of the gas detection instrument's usage environment is improved, the accuracy of the detection method selection for whether the gas detection instrument has a zero drift phenomenon is improved, and thus the usage accuracy of the gas detection instrument is improved. Description of the Drawings

[0031] Figure 1 It is a schematic structural diagram of the gas detection instrument prediction calibration system in an embodiment of the present invention;

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

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

[0034] Figure 4 It is a working flowchart of the method applied to the gas detection instrument prediction calibration system in an embodiment of the present invention. Detailed Embodiments

[0035] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Furthermore, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0039] like Figure 1-3 As shown, Figure 1 This is a schematic diagram of the gas detection instrument prediction and calibration system in an embodiment of the present invention; Figure 2 This is a flowchart illustrating the workflow of the analysis module of the gas detection instrument prediction and calibration system in an embodiment of the present invention. Figure 3 This is a flowchart illustrating the workflow of the gas detection instrument prediction calibration system adjustment module in an embodiment of the present invention.

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

[0041] The data acquisition module is used to acquire real-time data from the electrochemical gas sensor and periodically acquire gas flow velocity and usage frequency in the environment in which the electrochemical gas sensor is used.

[0042] An analysis module, connected to the acquisition module, is used to determine the operating environment type of the electrochemical gas sensor based on the average gas flow velocity collected over several cycles in the operating environment of the electrochemical gas sensor, and the average operating frequency of the electrochemical gas sensor, and to determine the detection method for the zero-point drift phenomenon of the electrochemical gas sensor to be calibrated based on the operating environment type.

[0043] The calibration module, which is connected to the analysis module, determines whether to perform real-time or periodic calibration of the electrochemical gas sensor in response to the occurrence of zero-point drift and the abnormal activation state of the electrochemical gas sensor.

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

[0045] An adjustment module, which is connected to the evaluation module, is used to determine whether to update the environmental compensation coefficient and adjust the calibration interval based on the evaluation results of the evaluation module.

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

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

[0048] Specifically, the analysis module determines the detection method for zero-point drift of the electrochemical gas sensor to be calibrated, including determining the detection method of zero-point drift by sensor redundancy when the electrochemical gas sensor is used in a high-frequency, high-pollution environment, or determining the detection method of periodic calibration comparison when the electrochemical gas sensor is used in a low-frequency, low-pollution environment.

[0049] Optionally, the calibration interval in this embodiment can be determined based on the average interval of the historical calibration time points of the electrochemical gas sensor. The zero-point drift detection method described in this embodiment includes installing redundant electrochemical gas sensors in a high-frequency, high-pollution environment, and simultaneously activating all electrochemical gas sensors (including redundant sensors) to collect data. The collected data includes the electrical signals output by the sensors, which are related to the detected gas concentration. For example, for an electrochemical sensor that detects carbon monoxide, it will output a corresponding current signal based on the carbon monoxide concentration. The collected data is the change of these current signals over time. The data from the main sensor (the sensor used for detection in normal operation) is compared with the data from the redundant sensors. Ideally, without zero-point drift, these sensors should detect similar data because they are in the same environment. If zero-point drift occurs, the data from the main sensor and the redundant sensor will differ. For example, suppose the main sensor and the redundant sensor initially output the same signal for a certain gas. However, as time goes on, the output signal of the main sensor begins to deviate from the normal range due to zero-point drift, while the output signal of the redundant sensor remains within the normal range because it has not experienced zero-point drift or has only a small degree of drift. By comparing this difference, it can be preliminarily determined that the main sensor has experienced zero-point drift.

[0050] Optionally, the zero-point drift detection method described in this embodiment includes determining the data acquisition time point according to the set periodic calibration interval. For example, data acquisition can be set to be performed weekly, monthly, or quarterly. At each acquisition time point, multiple data acquisitions are performed at predetermined time intervals to obtain a more accurate average value. At the acquisition time point, the electrochemical gas sensor is placed in a normal operating environment to detect the gas in the environment and record the gas concentration data displayed by the instrument. The gas concentration data acquired 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-point drift phenomenon. If the value displayed by the instrument in pure air changes significantly compared with the initial calibration zero-point value, a zero-point drift phenomenon may exist. In addition to comparing with the reference value, it is also necessary to analyze the trend of 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-point drift.

[0051] In the above embodiments, in high-frequency, high-pollution environments, the sensor redundancy method for detecting zero-point drift fully considers the susceptibility of sensor performance to various interferences in such complex environments. By installing redundant electrochemical gas sensors, the reliability and accuracy of detection can be increased. Multiple sensors operating simultaneously, even in heavily polluted environments with numerous interfering factors, can promptly detect zero-point drift issues in the main sensor through mutual comparison. For low-frequency, low-pollution environments, the periodic calibration and comparison method is more suitable. In such relatively stable environments, sensors experience less interference, and the frequency of zero-point drift is relatively low. Setting calibration intervals for data collection and comparison allows for effective detection of zero-point drift without increasing costs or complexity. Selecting appropriate zero-point drift detection methods based on different operating environments improves the calibration accuracy and reliability of gas detection instruments.

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

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

[0054] In the above embodiments, determining the environmental type helps to predict changes in sensor performance in advance. In high-frequency, high-pollution environments, due to the high gas flow rate and high usage frequency, sensor aging and zero-point drift may occur more quickly. By timely determining the environmental type, measures can be taken in advance, such as checking the sensor status more frequently or replacing vulnerable parts, to extend the sensor's service life. For low-frequency, low-pollution environments, although 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 anomalies (such as ventilation system failure leading to abnormal gas flow rate) may affect sensor performance. By continuously monitoring the environmental type, these anomalies can be detected in time, preventing sensor failures caused by environmental changes. Under different environmental types, the gas flow rate and usage frequency will have different degrees of impact on the sensor's detection results. After accurately classifying the environmental type, corresponding compensation measures can be taken for these influencing factors. The above method improves the accuracy of the analysis process of the gas detection instrument's operating environment, thereby improving the accuracy of the detection method selection for whether the gas detection instrument has zero-point drift, and ultimately improving the accuracy of the gas detection instrument's operation.

[0055] Specifically, the calibration module determines whether to perform real-time or periodic calibration of the electrochemical gas sensor, including determining to perform periodic calibration when zero-point drift is detected in the electrochemical gas sensor, or determining to perform real-time calibration when the electrochemical gas sensor is in an abnormal on state.

[0056] Optionally, the periodic calibration method described in this embodiment includes placing the electrochemical gas sensor in a pure background gas environment (such as clean air or nitrogen) to allow the sensor to stabilize for a period of time, typically 10-30 minutes, allowing the sensor to adapt to the environment and reach a stable initial state. The sensor's output signal is then recorded; this signal should be the zero-point signal. If it is not zero, the zero-point offset of the sensor is adjusted (usually through the instrument's internal calibration circuit or software algorithm) to bring the output signal to zero. Standard gases of known concentrations are sequentially introduced into the sensor, with the flow rate controlled within an appropriate range, generally determined according to the sensor's instruction manual, such as 100-200 ml per minute. After introducing the standard gases, the sensor output signal is allowed to stabilize, and the output signal values ​​corresponding to each standard gas concentration are recorded. By comparing the actual output signal with the theoretical output signal (calculated based on the sensor's sensitivity and the standard gas concentration), the sensor's gain or other relevant parameters are adjusted to establish an accurate correspondence between the sensor's output and the standard gas concentration. All data during the calibration process are recorded in detail, including standard gas concentration, sensor output signal, environmental parameters, zero-point and range adjustment parameters, etc. After calibration, standard gas is introduced again for verification to ensure that the sensor's output signal meets expectations, i.e., the zero point is stable within the allowable range and the measurement accuracy meets the requirements. If the verification fails, the calibration process needs to be repeated.

[0057] Optionally, the real-time calibration method described in this embodiment includes continuously acquiring the output signal of the electrochemical gas sensor in real time, while simultaneously monitoring the sensor's operating environmental parameters (such as temperature, humidity, and air pressure). A built-in algorithm quickly determines whether the sensor is in an abnormal operating state or experiencing zero-point drift. For example, a zero-point drift threshold is set; if the sensor's output signal deviates from zero by more than this threshold, it is considered to have zero-point drift. For abnormal operating states, this can be determined by monitoring whether environmental parameters are within the normal range and the characteristics of the sensor's output signal at startup. Once calibration is determined, the environmental compensation coefficient is first calculated based on the real-time monitored environmental parameters to determine the impact of environmental factors on the sensor's output signal. For example, based on a temperature-signal change model (which can be obtained through prior experiments or data analysis), the signal offset caused by temperature changes is calculated. If the temperature increases by 10°C, the corresponding signal change value is calculated according to the model, providing a compensation basis for subsequent calibration. The sensor's output signal is then adjusted in real time using software algorithms or hardware circuits (such as adjustable components in digital signal processors or analog circuits). If it is zero-point drift, adjust the signal offset to restore the zero point to the normal range; if it is 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 the signal gain is found to have decreased for some reason, increase the gain according to the calculation results to restore the normal range.

[0058] Optionally, the extreme environments described in this embodiment include, but are not limited to, "high temperature environment, high humidity environment, and high vibration environment". The determination 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. If the values ​​are higher than the preset values, the environment is determined to be a high temperature environment, a high humidity environment, and a high vibration environment. The preset temperature data is preferably 1.1 times the average value of the historical operating environment temperature of the electrochemical gas sensor, the preset humidity data is preferably 1.2 times the average value of the historical operating environment humidity of the electrochemical gas sensor, and the preset vibration data is preferably 1.3 times the historical operating environment vibration data of the electrochemical gas sensor.

[0059] In the above embodiments, a periodic calibration method is used when zero-point drift is detected. This is a relatively systematic and comprehensive calibration method. Periodic calibration can adjust multiple key parameters of the sensor, such as zero point and range, thereby effectively correcting zero-point drift caused by long-term use or the accumulation of environmental factors. For example, after a period of operation, the sensor may experience zero-point drift due to electrode aging or changes in electrolyte. Periodic calibration can use standard gases and precise calibration procedures to restore the sensor's zero point and range to an accurate state, ensuring the accuracy of subsequent detection results. For electrochemical gas sensors that are abnormally turned on under 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, turning on the sensor in an environment with high temperature, high humidity, or high concentration of toxic gases may result in a large deviation in its output signal. Real-time calibration allows for rapid adjustment of sensor operating parameters based on environmental conditions and actual output shortly after sensor activation. This enables the sensor to adapt to the environment quickly and provide relatively accurate detection results, avoiding erroneous detections due to initial deviations. It also identifies abnormal activation states in extreme environments and performs real-time calibration. This is crucial considering the significant impact of extreme environments on sensors and detection results. In emergencies such as chemical production, fire scenes, or toxic gas leaks, sensors often need to operate in extremely harsh conditions. Failure to calibrate promptly could delay rescue efforts or lead to incorrect safety decisions due to erroneous sensor outputs. By differentiating between zero-point drift and abnormal activation, the calibration method can prevent misjudgments and missed detections. Applying the same calibration method to all situations could result in delayed calibration in emergency situations or over-calibration and wasted resources on zero-point drift issues. These methods improve the accuracy of environmental analysis of gas detection instruments, enhance the precision of selecting detection methods for zero-point drift, and ultimately improve the overall accuracy of gas detection instruments.

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

[0061] Specifically, the evaluation module determines that the calibration accuracy is unqualified if the long-term zero-point stability is greater than the preset stability or the real-time signal fluctuation is greater than the preset fluctuation, and determines that the calibration accuracy is qualified if 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 in this embodiment includes determining the long-term zero-point stability by the standard deviation of the values ​​detected at the zero point of the electrochemical gas sensor within a calibration interval after periodic calibration. 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 values ​​of the sensor over a period of time (e.g., 3 minutes) during real-time calibration, calculating the range and average of the collected output signal values, and the real-time signal fluctuation is the ratio of the range to the average. 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 adjusting the calibration process if the calibration accuracy is unacceptable, and not adjusting the calibration process if the calibration accuracy is acceptable.

[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 an adjustment coefficient when it determines to adjust the calibration interval duration for the next calibration, and determines to re-evaluate the impact of environmental factors on the sensor when it determines to update the environmental compensation coefficient for the next calibration.

[0066] Optionally, in this embodiment, the adjustment coefficient is set to a value range of 0.82-0.97, and preferably 0.88. The reassessment 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 pattern of the sensor output signal. If a large deviation is found between the actual signal change and 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 by experimental methods. Under relatively stable and known environmental conditions (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, humidity of 50%, and no vibration, the sensor is tested with a standard gas of 100 ppm. If the actual output signal of the sensor is the signal corresponding to 90 ppm, then the environmental compensation coefficient can be initially set as 100 / 90≈1.11.

[0067] In the above embodiments, by setting specific evaluation parameters for different calibration methods, the calibration effect can be accurately measured. For periodic calibration methods, long-term zero-point stability reflects the stability of the sensor over a longer period, ensuring that it maintains an accurate zero point throughout the entire calibration interval. For real-time calibration methods, real-time signal fluctuation focuses on the sensor's immediate performance in dynamic environments, ensuring that it can respond promptly to rapidly changing environments and maintain stable output. Setting clear preset stability and fluctuation levels makes the determination of calibration accuracy more objective and rigorous. Only when the long-term zero-point stability is less than or equal to the preset stability level, and the real-time signal fluctuation is less than the preset fluctuation level, is the calibration accuracy considered qualified. This helps avoid detection errors caused by insufficient calibration, improving the accuracy and reliability of gas detection instruments. When the accuracy of the periodic calibration method is unqualified, adjustments are made. The calibration interval can be dynamically optimized based on actual conditions. If the long-term zero-point stability does not meet requirements, it may mean that the current calibration interval is too long, and the sensor's performance changes accumulate too much between two calibrations, leading to 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, improving the long-term stability of the sensor. For real-time calibration methods, updating the environmental compensation coefficient when the accuracy is unacceptable can better adapt to different working environments. By re-evaluating these factors and updating the compensation coefficient, the sensor can more accurately detect gas concentration under various environmental conditions, improving the effect of real-time calibration. The above methods improve the accuracy of the analysis process of the gas detection instrument's operating environment, thereby improving the accuracy of the detection method selection for whether the gas detection instrument has zero-point drift, and ultimately improving the accuracy of the gas detection instrument.

[0068] like Figure 4 As shown, Figure 4 This is a flowchart illustrating the process of a method applied to a gas detection instrument prediction and calibration system in an embodiment of the present invention.

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

[0070] Step S1: Collect real-time data from the electrochemical gas sensor and periodically collect gas flow velocity and usage frequency in the operating environment of the electrochemical gas sensor.

[0071] Step S2: Determine the usage environment type of the electrochemical gas sensor based on the average gas flow velocity collected over several cycles in the operating environment of the electrochemical gas sensor, and the average usage frequency of the electrochemical gas sensor; and determine the detection method for the zero-point drift phenomenon of the electrochemical gas sensor to be calibrated based on the usage environment type.

[0072] Step S3: In response to the occurrence of zero drift and the abnormal activation state of the electrochemical gas sensor, determine whether to perform real-time calibration or periodic calibration of the electrochemical gas sensor.

[0073] Step S4: Determine whether to evaluate the calibration accuracy based on the long-term zero-point stability or the real-time signal fluctuation, according to the calibration method.

[0074] Step S5: Based on the evaluation results of the evaluation module, determine whether to update the environmental compensation coefficient and adjust the calibration interval for the next calibration.

[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 implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A gas detection instrument predictive calibration system, comprising: include: The data acquisition module is used to acquire real-time data from the electrochemical gas sensor and periodically acquire gas flow velocity and usage frequency in the environment in which the electrochemical gas sensor is used. An analysis module, connected to the acquisition module, is used to determine the operating environment type of the electrochemical gas sensor based on the average gas flow velocity collected over several cycles in the operating environment of the electrochemical gas sensor, and the average operating frequency of the electrochemical gas sensor, and to determine a detection method for the zero-point drift phenomenon of the electrochemical gas sensor to be calibrated based on the operating environment type. The calibration module, which is connected to the analysis module, determines whether to perform real-time or periodic calibration of the electrochemical gas sensor in response to the occurrence of zero-point drift and the abnormal activation state of the electrochemical gas sensor. An evaluation module, which is connected to the calibration module, is used to determine the calibration accuracy by long-term zero-point stability or real-time signal fluctuation according to the calibration method. An adjustment module, which is connected to the evaluation module, is used to determine whether to update the environmental compensation coefficient and adjust the calibration interval based on the evaluation results of the evaluation module. The environmental compensation coefficient is used to correct the detection error of the electrochemical gas sensor under the abnormal opening state, which includes abnormal temperature, abnormal humidity, and abnormal vibration.

2. The gas detection instrument predictive calibration system of claim 1, wherein, The analysis module determines the detection method for zero-point drift of the electrochemical gas sensor to be calibrated, including determining the detection method of zero-point drift by sensor redundancy under the condition that the electrochemical gas sensor is used in a high-frequency and high-pollution environment, or determining the detection method of periodic calibration comparison under the condition that the electrochemical gas sensor is used in a low-frequency and low-pollution environment.

3. The gas detection instrument predictive calibration system of claim 2, wherein, The analysis module determines the operating environment type of the electrochemical gas sensor by determining that the average gas flow velocity in the operating environment of the electrochemical gas sensor collected over several cycles is greater than a preset average value and the average usage frequency is greater than a preset average usage frequency.

4. The gas detection instrument predictive calibration system of claim 3, wherein, The calibration module determines whether to perform real-time or periodic calibration for the electrochemical gas sensor, including determining to perform periodic calibration when zero-point drift is detected in the electrochemical gas sensor, or determining to perform real-time calibration when the electrochemical gas sensor is in an abnormal on state.

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

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

7. The gas detection instrument predictive calibration system of claim 6, wherein, The preset stability level is determined based on the historical average value of the long-term zero-point stability of the electrochemical gas sensor, and the preset fluctuation level is determined based on the historical average value of the real-time signal fluctuation of the electrochemical gas sensor.

8. The gas detection instrument predictive calibration system of claim 7, wherein, The adjustment module determines to adjust the calibration interval duration when the calibration accuracy of the periodic calibration method is unqualified, or determines to update the environmental compensation coefficient when the calibration accuracy of the real-time calibration method is unqualified.

9. The gas detection instrument predictive calibration system of claim 8, wherein, The adjustment amount of the calibration interval duration is negatively correlated with the long-term zero-point stability.

10. A method for applying the gas detection instrument prediction calibration system according to any one of claims 1-9, characterized in that, include: Collect real-time data from the electrochemical gas sensor and periodically collect gas flow velocity and usage frequency in the environment in which the electrochemical gas sensor is used; The method for detecting zero-point drift of the electrochemical gas sensor is determined based on the average gas flow velocity collected over several cycles in the operating environment of the electrochemical gas sensor and the average usage frequency of the electrochemical gas sensor. In response to the occurrence of zero-point drift and the abnormal activation state of the electrochemical gas sensor, determine whether to perform real-time or periodic calibration of the electrochemical gas sensor. The calibration accuracy is assessed based on either long-term zero-point stability or real-time signal fluctuation, depending on the calibration method. Based on the evaluation results of the evaluation module, it is determined whether to update the environmental compensation coefficient and adjust the calibration interval for the next calibration.

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