Gas Leakage Detection Methods and Detection Circuits

Abstract

This application provides a gas leak detection method and detection circuit, including using a gas concentration sensor to acquire calibration electrical signals of several calibrated concentrations of the target gas, forming a concentration electrical signal calibration table; determining the linear correlation between the target gas concentration and the detection electrical signal based on the concentration electrical signal calibration table; combining the concentration electrical signal calibration table and the linear correlation to obtain the leak threshold corresponding to the gas alarm concentration; and using a gas concentration sensor to acquire the real-time detection concentration of the target gas, issuing an alarm signal when the real-time detection concentration reaches the leak threshold. This method has no destructive impact on the detection environment, generates no material loss, and has a simple structure, stable performance, and is easy to use. By checking the concentration of the target gas and whether a leak has occurred, the signal is stable, has a long service life, and the corresponding detection circuit structure is compact, facilitating installation and disassembly.

Description

Technical Field

[0001] This application belongs to the field of gas leak detection, and more specifically, relates to a gas leak detection method and detection circuit. Background Technology

[0002] Traditional gas leak detection methods generally use electrochemical methods. However, electrochemical methods are usually accompanied by chemical reactions, which inevitably alter the target environment to some extent. This can be considered a destructive detection method, and there is usually a continuous loss of some chemical substances. Summary of the Invention

[0003] The purpose of this application is to provide a gas leak detection method and detection circuit to solve the technical problem of chemical substance loss in existing gas leak detection.

[0004] To achieve the above objectives, the technical solution adopted in the embodiments of this application is as follows:

[0005] On the one hand, a method for detecting gas leaks is provided, comprising the following steps:

[0006] S100: Employs a gas concentration sensor to acquire calibration electrical signals of several calibrated concentrations of the target gas, forming a concentration electrical signal calibration table;

[0007] S200: Based on the concentration electrical signal calibration table, determine the linear correlation between the gas concentration of the target gas and the detection electrical signal;

[0008] S300: Combine the concentration electrical signal calibration table and the linear correlation to obtain the leakage threshold corresponding to the gas alarm concentration;

[0009] S400: The gas concentration sensor is used to obtain the real-time detection concentration of the target gas. When the real-time detection concentration reaches the leakage threshold, an alarm signal is issued.

[0010] In one embodiment, step S100 includes the following steps:

[0011] S110: Obtain the first calibration electrical signal corresponding to the first calibration concentration;

[0012] S120: Obtain the second calibration electrical signal corresponding to the second calibration concentration;

[0013] S130: Obtain the third calibration electrical signal corresponding to the third calibration concentration;

[0014] S140: Obtain the fourth calibration electrical signal corresponding to the fourth calibration concentration, wherein the first calibration concentration, the second calibration concentration, the third calibration concentration, and the fourth calibration concentration are all different.

[0015] In one embodiment, the first calibrated concentration has a PPM of 0%, the second calibrated concentration has a PPM of 10%, the third calibrated concentration has a PPM of 40%, and the fourth calibrated concentration has a PPM of 50%.

[0016] In one embodiment, the first calibration concentration is 0% of the range of the gas concentration sensor, the second calibration concentration is 10% of the range of the gas concentration sensor, the third calibration concentration is 40% of the range of the gas concentration sensor, and the fourth calibration concentration is 50% of the range of the gas concentration sensor.

[0017] In one embodiment, step S400 includes the following steps:

[0018] S410: The gas concentration sensor is used to acquire the initial concentration electrical signal;

[0019] S420: Uses a temperature sensor to obtain the current temperature and calculates the temperature compensation incremental electrical signal;

[0020] S430: Based on the difference between the initial concentration electrical signal and the temperature-compensated incremental electrical signal, calculate the real-time detected concentration.

[0021] In one embodiment, in step S420, the current temperature is denoted as Tmpr_TRaw, the calibration temperature as TComp_TRawBase, the difference between the current temperature and the calibration temperature as Tmpr_DltTRaw, and the temperature compensation incremental electrical signal as Sens_DltSRaw. Then:

[0022] Sens_DltSRaw=Tcomp_Coe0+Tcomp_Coe1*(Tmpr_DltTRaw)+Tcomp_Coe2*(Tmpr_DltTRaw)*(Tmpr_DltTRaw)+Tcomp_Coe3*(Tmpr_DltTRaw)*(Tmpr_DltTRaw)*(Tmpr_DltTRaw);

[0023] Among them, Tcomp_Coe0, Tcomp_Coe1, Tcomp_Coe2, and Tcomp_Coe3 are the zero-order temperature compensation coefficient, the first-order temperature compensation coefficient, the second-order temperature compensation coefficient, and the third-order temperature compensation coefficient, respectively.

[0024] In one embodiment, prior to step S100, the method further includes the following steps:

[0025] S510: At the calibration temperature, the gas concentration sensor is used to acquire the first temperature scale electrical signal corresponding to the target gas PPM being 0;

[0026] S520: At the first reference temperature, the gas concentration sensor is used to acquire the second temperature scale electrical signal corresponding to when the target gas PPM is 0;

[0027] S530: At the second reference temperature, the gas concentration sensor is used to obtain the third temperature scale electrical signal corresponding to when the target gas PPM is 0;

[0028] S540: At the third reference temperature, the gas concentration sensor is used to obtain the fourth temperature scale electrical signal corresponding to the target gas PPM being 0;

[0029] S550: Based on steps S510~S540, calculate the zero-order temperature compensation coefficient Tcomp_Coe0, the first-order temperature compensation coefficient Tcomp_Coe1, the second-order temperature compensation coefficient Tcomp_Coe2, and the third-order temperature compensation coefficient Tcomp_Coe3.

[0030] In one embodiment, after step S430, the following steps are further included:

[0031] S441: Uses a humidity sensor to obtain humidity increments;

[0032] S442: Calculate the humidity compensation amount based on the humidity increment and temperature coefficient;

[0033] S443: Based on the difference between the initial concentration electrical signal and the temperature-compensated incremental electrical signal, the PPM concentration before wet compensation is obtained;

[0034] S444: The humidity compensation amount is used to perform humidity compensation on the PPM concentration before wet compensation to obtain the real-time detection concentration.

[0035] In one embodiment, after step S444, the following steps are further included:

[0036] S451: Uses a barometric pressure sensor to obtain barometric pressure increments;

[0037] S452: Based on the pressure increment, obtain the pressure parameters;

[0038] S453: Divide the humidity-compensated real-time detection concentration by the air pressure parameter to obtain the air pressure-compensated real-time detection concentration.

[0039] In one embodiment, step S400 further includes the following step: converting the real-time detected concentration PPM value into an LFL concentration value.

[0040] On the other hand, a gas leak detection circuit is provided, comprising a thermal conductivity chip module, an operational amplifier, and a microcontroller unit connected in sequence. The thermal conductivity chip module is used to sense the concentration of a target gas in the measured environment. The microcontroller unit includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the gas leak detection method as described above and sends an alarm signal through the microcontroller unit.

[0041] The gas leak detection method and detection circuit provided in this application have at least the following beneficial effects: In electrochemical detection, electrodes or reaction reagents are continuously consumed during the detection process and need to be replaced regularly to ensure accuracy. This not only increases the cost of consumables but may also lead to detection errors due to untimely replacement. This method uses a gas concentration sensor to detect the thermal properties of the gas to form a concentration electrical signal calibration table, and then determines the linear correlation between the gas concentration and the detection electrical signal. Combining the concentration electrical signal calibration table and the linear correlation, the leakage threshold corresponding to the gas alarm concentration is obtained. Thus, when the leakage threshold is reached, real-time detection and alarm are achieved. Moreover, this method has no destructive impact on the detection environment and does not generate material loss. It is also simple in structure, stable in performance, and easy to use. By checking the concentration of the target gas and whether there is a leak, the signal is stable, the service life is long, and the corresponding detection circuit structure is compact and easy to install and disassemble. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or exemplary technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 A schematic flowchart illustrating the gas leak detection method provided in this application embodiment;

[0044] Figure 2 A circuit diagram of a power module provided in an embodiment of this application;

[0045] Figure 3 A circuit diagram of a thermal conductivity chip module provided in an embodiment of this application;

[0046] Figure 4 This is a circuit diagram of a voltage divider resistor module provided in one embodiment of this application;

[0047] Figure 5 This is a circuit diagram of an operational amplifier provided in one embodiment of this application;

[0048] Figure 6 This is a schematic diagram of a concentration electrical signal calibration table provided in an embodiment of this application;

[0049] Figure 7 This is a flowchart illustrating step S400 in one embodiment of this application;

[0050] Figure 8 This is a schematic diagram of the temperature compensation process in one embodiment of this application;

[0051] Figure 9 This is a schematic diagram of the humidity compensation process in one embodiment of this application;

[0052] Figure 10 This is a schematic diagram of the air pressure compensation process in one embodiment of this application;

[0053] Figure 11 This is a schematic diagram of the circuit connection of the thermal conductivity chip module, the voltage divider resistor module and the operational amplifier in one embodiment of this application;

[0054] Figure 12 A circuit diagram of a microcontroller unit provided in an embodiment of this application.

[0055] The main markings in the attached figures are as follows:

[0056] 100. Power supply module; 200. Thermal conductivity chip module; 300. Voltage divider resistor module; 400. Operational amplifier; 500. Microcontroller unit. Detailed Implementation

[0057] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0058] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0059] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise expressly specified. "Several" means one or more, unless otherwise expressly specified.

[0060] Throughout this specification, references to "an embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of this application. Therefore, the phrases "in one embodiment" or "in some embodiments" appear in various places throughout the specification, and not all refer to the same embodiment. Furthermore, in one or more embodiments, particular features, structures, or characteristics may be combined in any suitable manner. Example

[0061] Please see Figure 1 The gas leak detection method provided in this application embodiment will now be described. The gas leak detection method includes the following steps:

[0062] S100: A gas concentration sensor is used to acquire calibration electrical signals of several calibrated concentrations of the target gas, forming a concentration electrical signal calibration table. In some embodiments, combined with... Figure 3 , Figure 5 , Figure 11 and Figure 12 The gas concentration sensor includes a thermal conductivity chip module 200 connected in sequence. Figure 3 ), Operational amplifier 400 ( Figure 5 ) and microcontroller 500 ( Figure 12 The thermal conductivity chip module 200 senses changes in the properties of the ambient air, then uses an operational amplifier 400 to perform preliminary signal processing. The result is then fed into a microcontroller unit 500 (MCU, also known as a "single-chip microcomputer") for further processing, converting the data into user-friendly data for easy integration into various application systems. The operational amplifier 400 can be an integrated circuit (IC) signal processing IC.

[0063] S200: Based on a concentration-based electrical signal calibration table, determine the linear correlation between the target gas concentration and the detection electrical signal. The linear correlation can be positive or negative, without requiring a specific functional relationship. Generally, gas concentration and the detection electrical signal are positively correlated; however, due to the possibility of polarity reversal components in the detection circuit, they may exhibit a negative correlation. This method does not require consideration of the presence of polarity components in the detection circuit or prior knowledge of the circuit design details. It determines whether the correlation is positive or negative by analyzing multiple final output calibration electrical signals, thus obtaining the relationship between the rise and fall of gas concentration and the detection electrical signal.

[0064] S300: Combining the concentration electrical signal calibration table and linear correlation, the leakage threshold corresponding to the gas alarm concentration is obtained. For example, based on linear correlation, it is determined that the gas concentration and the detection electrical signal are positively correlated. Then, the gas alarm concentration is combined with the concentration electrical signal calibration table to calculate the corresponding detection electrical signal through interpolation. The leakage threshold can be either the gas concentration or the detection electrical signal; no specific limitation is made here. When the leakage threshold is the gas concentration, the gas alarm concentration is simply input into the gas concentration sensor, and the microcontroller unit 500 calculates the corresponding detection electrical signal. When the leakage threshold is the detection electrical signal, the operator calculates the corresponding detection electrical signal and then inputs it into the microcontroller unit 500.

[0065] S400: Employs a gas concentration sensor to acquire the real-time concentration of the target gas. When the real-time concentration reaches the leakage threshold, an alarm signal is issued. This method requires only binary judgment, greatly reducing the difficulty of detection, eliminating the need for complex calculations, reducing calculation errors, and improving detection accuracy.

[0066] In electrochemical detection, electrodes or reaction reagents are continuously consumed during the detection process, requiring periodic replacement to maintain accuracy. This not only increases consumable costs but can also lead to detection errors due to untimely replacement. This method uses a gas concentration sensor to detect gas concentration by detecting its thermal properties, forming a concentration-electrical signal calibration table to determine the linear correlation between gas concentration and the detection electrical signal. Combining the concentration-electrical signal calibration table and the linear correlation, the leakage threshold corresponding to the gas alarm concentration is obtained, thus achieving real-time detection and alarm when the leakage threshold is reached. This method has no destructive impact on the detection environment, generates no material loss, and is simple in structure, stable in performance, and easy to use. By checking the concentration of the target gas and the presence or absence of leakage, the signal is stable, has a long service life, and the corresponding detection circuit structure is compact, facilitating installation and disassembly. Furthermore, this method does not require calculating the specific functional relationship between concentration and electrical signal; it only needs to obtain the linear correlation between the two through calibration data.

[0067] In some embodiments, step S100 includes the following steps:

[0068] S110: Obtain the first calibration electrical signal SRaw1 corresponding to the first calibration concentration.

[0069] S120: Obtain the second calibration electrical signal SRaw2 corresponding to the second calibration concentration.

[0070] S130: Obtain the third calibration electrical signal SRaw3 corresponding to the third calibration concentration.

[0071] S140: Obtain the fourth calibration electrical signal SRaw4 corresponding to the fourth calibration concentration, wherein the first calibration concentration, the second calibration concentration, the third calibration concentration and the fourth calibration concentration are all different.

[0072] To obtain a linear correlation between the electrical signal and the concentration of the target gas, this method requires calibration with different calibrated concentrations of the target gas before use in leak detection. The corresponding calibrated electrical signal SRaw is then detected and compiled into a table (see [link to table]). Figure 6 This establishes a relationship between the calibration electrical signal SRaw and the concentration data of the target gas for use in data processing.

[0073] Among these methods, calibration data from more than three calibrated concentrations can more comprehensively reflect the changing patterns between gas concentration and electrical signals, more reliably eliminate random error interference, and avoid overall detection failure caused by single-point drift, thus laying the foundation for detection accuracy. Even if the sensor exhibits slight nonlinearity in local intervals, the overall trend of the four points can still reliably establish a linear correlation, eliminating the need for high-precision, high-cost components and controlling hardware costs while ensuring detection accuracy. Specifically, with only four calibrated concentrations, the linear relationship established based on these four points (such as fitting a straight line using the least squares method) allows for rapid conversion of electrical signals into concentration values ​​during real-time detection through simple linear interpolation or formula calculations, eliminating the need for complex algorithms. This simplifies data processing while ensuring the reliability of the core logic. This simplicity reduces the computational burden on the MCU and minimizes sources of error in real-time processing.

[0074] In some embodiments, the first calibration concentration is 0% PPM, accurately capturing the electrical signal reference value when there is no target gas, eliminating the influence of sensor zero-point drift or environmental background interference, and ensuring the accuracy of low-concentration leak detection. The second calibration concentration is 10% PPM, corresponding to minor leak scenarios, effectively identifying early leak states, providing data support for timely warnings, and avoiding safety risks caused by the spread of leaks. The third calibration concentration is 40% PPM, and the fourth calibration concentration is 50% PPM. These two concentrations cover the concentration range close to or reaching the leak threshold, ensuring that detection accuracy is maintained even during the escalation stage of the leak, and providing a direct reference for setting the leak threshold. Furthermore, multi-point fitting weakens the influence of local nonlinearity, making the linear correlation judgment closer to the actual detection law.

[0075] In some embodiments, the first calibration concentration is 0% of the gas concentration sensor's range, with 0% serving as the reference zero point to eliminate environmental background interference. The second calibration concentration is 10% of the gas concentration sensor's range, corresponding to early trace leaks and ensuring accuracy in low-concentration detection. The third calibration concentration is 40% of the gas concentration sensor's range, and the fourth calibration concentration is 50% of the gas concentration sensor's range. Different models of gas concentration sensors may have significantly different ranges. Setting the calibration concentration as a percentage of the range rather than an absolute value allows the same detection method to be applied to sensors of different specifications, greatly improving the method's versatility and compatibility.

[0076] It is understood that in step S100, the calibration concentration can be four groups or more, such as five or six groups, and this is not a unique limitation.

[0077] In some embodiments, combined with Figure 7 Step S400 includes the following steps:

[0078] S410: Uses a gas concentration sensor to obtain the initial concentration electrical signal.

[0079] S420: Uses a temperature sensor to obtain the current temperature and calculates the temperature compensation incremental electrical signal.

[0080] S430: The real-time detection concentration is calculated based on the difference between the initial concentration electrical signal and the temperature-compensated incremental electrical signal.

[0081] The detection principle of thermal conductivity gas sensors is based on the thermal properties of gases (such as thermal conductivity), and temperature is the core factor affecting these properties. By acquiring the current temperature in real time through a temperature sensor, the corresponding temperature-compensated incremental electrical signal (i.e., the signal error value caused by temperature deviation) is calculated, and this error is removed from the initial concentration electrical signal. This minimizes the impact of temperature on the detection results and ensures the consistency of detected concentrations under different temperature environments. Based on this, the influence of temperature on detection accuracy is eliminated, and measurement stability is improved.

[0082] In some embodiments, in step S420, the current temperature is denoted as Tmpr_TRaw, the calibration temperature as TComp_TRawBase, the difference between the current temperature Tmpr_TRaw and the calibration temperature TComp_TRawBase is denoted as Tmpr_DltTRaw, and the temperature compensation incremental electrical signal is denoted as Sens_DltSRaw. Then:

[0083] Sens_DltSRaw=Tcomp_Coe0+Tcomp_Coe1*(Tmpr_DltTRaw)+Tcomp_Coe2*(Tmpr_DltTRaw)*(Tmpr_DltTRaw)+Tcomp_Coe3*(Tmpr_DltTRaw)*(Tmpr_DltTRaw)*(Tmpr_DltTRaw).

[0084] Among them, Tcomp_Coe0, Tcomp_Coe1, Tcomp_Coe2, and Tcomp_Coe3 are the zero-order temperature compensation coefficient, the first-order temperature compensation coefficient, the second-order temperature compensation coefficient, and the third-order temperature compensation coefficient, respectively.

[0085] The effect of temperature on thermal conductivity gas sensors is not a simple linear relationship. In the low temperature range (e.g., -10℃ to 20℃), the effect of temperature change on gas thermal conductivity may be approximately linear. In the medium to high temperature range (e.g., 20℃ to 50℃), due to factors such as sensor self-heating and increased gas molecule motion, it may exhibit quadratic or cubic nonlinear characteristics (e.g., the signal deviation accelerates after the temperature rises to a certain level). A cubic polynomial (containing zero-order to cubic terms) can flexibly fit this complex nonlinear relationship through coefficients (Tcomp_Coe0 to Tcomp_Coe3). Compared to using only linear compensation (first-order term) or quadratic compensation, it can significantly reduce the compensation error in different temperature ranges, making the corrected signal closer to the electrical signal corresponding to the true concentration. This ensures that the alarm threshold judgment is based on a real and reliable signal, improving the safety factor of the entire detection system.

[0086] In some embodiments, combined with Figure 8 Before step S100, the method further includes the following steps:

[0087] S510: At the calibration temperature, a gas concentration sensor is used to acquire the first temperature calibration electrical signal corresponding to when the target gas PPM is 0.

[0088] S520: At the first reference temperature, a gas concentration sensor is used to acquire the second temperature scale electrical signal corresponding to the target gas PPM being 0.

[0089] S530: At the second reference temperature, a gas concentration sensor is used to acquire the electrical signal of the third temperature scale corresponding to the target gas PPM being 0.

[0090] S540: At the third reference temperature, a gas concentration sensor is used to acquire the electrical signal of the fourth temperature scale corresponding to when the target gas PPM is 0.

[0091] S550: Based on steps S510~S540, calculate the zero-order temperature compensation coefficient Tcomp_Coe0, the first-order temperature compensation coefficient Tcomp_Coe1, the second-order temperature compensation coefficient Tcomp_Coe2, and the third-order temperature compensation coefficient Tcomp_Coe3.

[0092] When the target gas concentration is 0, the sensor's electrical signal drift is caused only by temperature changes (eliminating interference from gas concentration). Steps S510 to S540 can generate four equations, which, when solved simultaneously, yield four temperature compensation coefficients (Tcomp_Coe0 to Tcomp_Coe3).

[0093] The initial concentration electrical signal is Sens_SRaw, and the specific code for calculating the temperature-compensated incremental electrical signal Sens_DltSRaw is as follows:

[0094] Tcomp_X = Tmpr_DltTRaw;

[0095] Usr_TComp_Polynomial_Cubic2(Tcomp_X,&Tcomp_Y);

[0096] Sens_DltSRaw = Tcomp_Y;

[0097] Sens_Raw_After_TmpComp = Sens_SRaw - Sens_DltSRaw;

[0098] uint8_t Tcomp_Flag;

[0099] float Tcomp_X;

[0100] float Tcomp_Coe0;

[0101] float Tcomp_Coe1;

[0102] float Tcomp_Coe2;

[0103] float Tcomp_Coe3;

[0104] float Tcomp_Y;

[0105] void Usr_TComp_Polynomial_Cubic2(float nbr, float *out)

[0106] {

[0107] float Temp0;

[0108] float Temp1;

[0109] if((Tcomp_Flag<4)||(TComp_TRawBase == 0)||(TComp_TRawBase==0xFFFF))

[0110] { / / if without correct parameters;

[0111] *out = 0;

[0112] return;

[0113] }

[0114] / / printf("nbr,%d,", nbr);

[0115] Temp0 = nbr*nbr*nbr;

[0116] Temp0 *= Tcomp_Coe3;

[0117] Temp1 = nbr*nbr;

[0118] Temp1 *= Tcomp_Coe2;

[0119] Temp0 += Temp1;

[0120] Temp1 = nbr;

[0121] Temp1 *= Tcomp_Coe1;

[0122] Temp0 += Temp1;

[0123] Temp0 += Tcomp_Coe0;

[0124] / / printf("Poly,%d,", tmp_A_Item);

[0125] if(Temp0>= (float)(32766.9))

[0126] {

[0127] *out = 32767;

[0128] return;

[0129] }

[0130] else if (Temp0<= (float)(-32766.9))

[0131] {

[0132] *out = -32767;

[0133] return;

[0134] }

[0135] *out = Temp0;

[0136] / / printf("return,%d,", *out);

[0137] return;

[0138] }

[0139] In some embodiments, combined with Figure 9 Following step S430, the following steps are also included:

[0140] S441: Uses a humidity sensor to obtain humidity increments. Humidity increment refers to the difference between the current humidity and the calibrated humidity. The calibrated humidity can be set to 0%.

[0141] S442: Calculate the humidity compensation amount based on the humidity increment and temperature coefficient. The temperature coefficient, Tmpr_DltTRaw, is the difference between the current temperature Tmpr_TRaw and the calibration temperature TComp_TRawBase. The effect of humidity on the thermal conductivity of a gas is not a fixed value but changes with temperature (for example, at the same humidity, the thermal conductivity of water vapor differs between high-temperature and low-temperature environments). By introducing the temperature coefficient to calculate the humidity compensation amount, the humidity compensation weight at different temperatures can be dynamically adjusted, avoiding insufficient compensation due to neglecting the interaction between temperature and humidity, and making the humidity correction more consistent with actual physical laws.

[0142] S443: The PPM concentration before wet compensation is obtained based on the difference between the initial concentration electrical signal and the temperature-compensated incremental electrical signal. Temperature compensation is performed first, followed by separate humidity compensation, making the correction logic for the two environmental factors independent. This decoupled design facilitates the separate optimization of humidity and temperature compensation parameters, reducing debugging difficulty. Simultaneously, the humidity increment is performed at the calibration temperature. First, the initial concentration electrical signal is compensated and restored to the PPM concentration before wet compensation at the calibration temperature before humidity compensation, making it more scientific and reasonable.

[0143] S444: The humidity compensation amount is used to compensate for the PPM concentration before wet-mixing to obtain the real-time detection concentration. Specifically, the real-time detection concentration = PPM concentration before wet-mixing - humidity compensation amount.

[0144] The introduction of a humidity compensation mechanism in steps S441 to S444 is a further optimization of the environmental factors for gas detection, which can effectively eliminate the interference of humidity on detection accuracy.

[0145] In one embodiment, before step S442, the calculation formula for the humidity compensation amount H_comp is first solved: H_comp = Hcomp_Coe0 + Hcomp_Coe1×Tmpr_DltTRaw + Hcomp_Coe2×H_delta + Hcomp_Coe3×Tmpr_DltTRaw×H_delta.

[0146] The specific solution process is as follows: At the calibration temperature (T0), for calibration experiments at different humidity levels (e.g., 0%, 10%, 30%, 50%), the following coefficients are fitted to obtain the humidity compensation zero-order coefficient Hcomp_Coe0 (a constant term, correcting baseline deviation), the humidity compensation temperature coefficient Hcomp_Coe1 (weighting the associated temperature parameter), the humidity compensation humidity coefficient Hcomp_Coe2 (weighting the associated humidity increment), and the humidity compensation interaction coefficient Hcomp_Coe3 (associating the cross-influence of temperature and humidity). The temperature parameter Tmpr_DltTRaw is defined as Tmpr_TRaw - T0 (i.e., the difference between the current temperature Tmpr_TRaw and the calibration temperature T0); the current humidity (H_current) is read using a humidity sensor; the humidity increment (H_delta) = current humidity H_current - calibration humidity H0 (since H0 = 0%, H_delta = H_current). The humidity compensation zero-order coefficient Hcomp_Coe0, humidity compensation temperature coefficient Hcomp_Coe1, humidity compensation humidity coefficient Hcomp_Coe2, and humidity compensation interaction coefficient Hcomp_Coe3 are obtained by solving four equations.

[0147] In some embodiments, combined with Figure 10 Following step S444, the following steps are also included:

[0148] S451: Uses a barometric pressure sensor to obtain barometric pressure increments.

[0149] S452: Based on the pressure increment, the pressure parameter is obtained. After correction by the pressure parameter, the detection values ​​in all environments are normalized to the standard pressure reference, ensuring the consistency of the alarm threshold judgment logic and avoiding safety risks caused by pressure differences. Specifically, the pressure parameter = 1 + k × pressure increment, where k is the pressure calibration coefficient.

[0150] S453: Divide the humidity-compensated real-time detection concentration by the air pressure parameter to obtain the air pressure-compensated real-time detection concentration.

[0151] Gas concentration (PPM) is essentially the number of molecules of a target gas per unit volume. However, air pressure directly affects gas volume. When air pressure decreases (e.g., at high altitudes), the gas volume expands, and the "number of molecules per unit volume" corresponding to the same number of molecules will appear artificially low (the actual concentration remains the same, but the signal appears lower). Without air pressure compensation, the same actual concentration will be converted into different PPM values ​​at different air pressures. By correcting for air pressure parameters (dividing the signal by the air pressure parameter, essentially normalizing the concentration to the standard air pressure), this "volume effect" error caused by air pressure fluctuations can be eliminated, making the detection results more closely match the true molecular density of the gas. Thus, the detection accuracy is further improved by addressing the interference of air pressure changes on gas concentration detection.

[0152] Specifically, the pressure calibration coefficient k is obtained through a pressure calibration experiment. A correlation is established between pressure increment and concentration deviation, and the pressure calibration coefficient k is finally calculated through fitting. Optionally, at the calibration pressure P0, calibration temperature, and calibration humidity, a preset concentration of target gas is selected, such as 2000 PPM methane, and an environment of 0.5 to 1.2 times the calibration pressure is simulated using a closed container with adjustable pressure. First, the detection values ​​C of the gas concentration sensor are collected at different pressures P. 测 Second, calculate the ideal concentration value C caused by changes in air pressure. 理 =C0×(P / P0), Third, according to 1+k×ΔP=C 理 / C 测 We obtain k, and use the least squares method to fit the k values ​​of multiple pressure points, taking the average or optimal fit value.

[0153] In some embodiments, step S400 further includes the following step: converting the real-time detected concentration (PPM) value into an LFL value. The LFL values ​​of different combustible gases vary significantly (e.g., hydrogen LFL is approximately 4%, ethanol LFL is approximately 3.3%), making it difficult to directly compare risks using PPM values. Converting to an LFL percentage allows for a unified measurement of risk based on its proportion relative to its lower explosive limit. Regardless of the gas, when the concentration reaches 10% of the LFL, it indicates that its explosion risk is at the same relative level (i.e., 10% away from the lower explosive limit), facilitating the establishment of a unified safety threshold.

[0154] In some embodiments, combined with Figure 2 and Figure 11 The gas concentration sensor also includes a power supply module 100, whose voltage output terminal is connected to the thermal conductivity chip module 200 to supply power to the thermal conductivity chip module 200 independently. The operational amplifier 400 and the microcontroller unit 500 can be powered by a power supply voltage provided by an external device. The external device can be an integrated component of the gas leak detection device. For example, if the gas leak detection device is integrated into an air conditioning unit, then the external device is the air conditioning unit.

[0155] In this embodiment, the thermal conductivity chip module 200 is powered separately by the power supply module 100, which effectively suppresses power coupling interference and meets the differentiated voltage requirements of the thermal conductivity chip module 200 for the operational amplifier 400 and the microcontroller unit 500. Specifically, the thermal conductivity chip module 200 is prone to generating high-frequency ripple during operation. Independent power supply can block this noise from coupling to the operational amplifier 400 and the microcontroller unit 500 through the common power supply, reducing analog signal acquisition errors. During gas leak detection, the thermal conductivity chip module 200 may experience sudden large current surges. Independent power supply can prevent load fluctuations from causing voltage drops in the microcontroller unit 500 and triggering reset faults.

[0156] In some embodiments, combined with Figure 4 and Figure 11 The gas concentration sensor also includes a voltage divider resistor module 300. The negative output terminal of the thermal conductivity chip module 200 is connected to the input terminal of the voltage divider resistor module 300, and the positive output terminal of the thermal conductivity chip module 200 is connected to the positive input terminal of the operational amplifier 400. The first output terminal of the voltage divider resistor module 300 is connected to the negative input terminal of the operational amplifier 400, the second output terminal of the voltage divider resistor module 300 is connected to the analog power input terminal of the operational amplifier 400, and the output terminal of the operational amplifier 400 is connected to the microcontroller unit 500.

[0157] In this embodiment, the thermal conductivity chip module 200 can sense the concentration of the target gas in the measured environment. When the concentration of the target gas in the measured environment changes, the thermal conductivity chip module 200 generates an electrical signal difference and outputs a differential voltage signal. The output differential voltage signal is divided by the voltage divider resistor module 300 and then input to the operational amplifier 400, where it is amplified to obtain the original signal value. The original signal value is then input to the microcontroller unit 500 for processing to obtain the detection result of whether a gas leak has occurred. This application is based on the principle of the influence of gas concentration on thermal conductivity. By detecting changes in the gas's heat transfer capacity, it can determine changes in gas concentration, which can significantly shorten the preheating process, shorten the detection time, and reduce power consumption. Unlike sensors based on electrochemical principles, it does not suffer from material loss, thus the sensor in this solution has an extremely long service life. Simultaneously, the differential voltage signal output by the thermal conductivity chip module 200 is divided by the voltage divider resistor module 300 before being input to the operational amplifier 400, ensuring that it matches the voltage processing range of the subsequent operational amplifier 400. By setting the voltage divider resistor module 300, the tiny leakage signal can be divided by the voltage divider resistor module 300 and placed in the high sensitivity range of the operational amplifier 400, thereby improving the operational amplifier 400's ability to distinguish weak leakage signals and increasing detection sensitivity.

[0158] Figure 2This is a circuit diagram of a power module 100 provided in one embodiment of this application. Figure 2 As shown, the power module 100 includes a power control chip U1 and a first capacitor C1. The first pin (IN pin) of the power control chip U1 serves as the voltage input terminal, used to connect to the power supply voltage provided by an external device. The second pin (GND pin) of the power control chip U1 is grounded, and the third pin (EN / NC pin) of the power control chip U1 serves as the enable control terminal, used to connect to the output voltage VLDO_EN regulated by an LDO (linear regulator). Therefore, the activation of the power control chip U1 can be controlled by the LDO-regulated output voltage VLDO_EN, enabling intermittent power supply to the thermal conductivity chip module 200. For example, when the LDO-regulated output voltage VLDO_EN connected to the third pin of the power control chip U1 is high, the power control chip U1 is activated, thus supplying power to the thermal conductivity chip module 200. Conversely, when the LDO-regulated output voltage VLDO_EN connected to the third pin of the power control chip U1 is low, the power control chip U1 is not activated and cannot supply power to the thermal conductivity chip module 200. The fifth pin (i.e., the OUT pin) of the power control chip U1 is connected to the thermal conductivity chip module 200 as a voltage output terminal to supply power to the thermal conductivity chip module 200. The fifth pin of the power control chip U1 is also connected to the first terminal of the first capacitor C1, and the second terminal of the first capacitor C1 is grounded. The first capacitor C1 can directly bypass high-frequency interference at the voltage output terminal to ground, preventing noise from being transmitted to subsequent circuits (i.e., the thermal conductivity chip module 200).

[0159] In this embodiment, an automotive-grade LDO device is used to convert an unstable input power supply (such as a vehicle battery) into a stable and clean output voltage, which is then connected to the power module 100. This converts fluctuating input into a precise and reliable regulated output, which is then connected to a load circuit such as the thermal conductivity chip module 200. This reduces temperature drift and prevents power supply ripple from contaminating the microvolt-level differential signal output by the thermal conductivity chip module 200.

[0160] Figure 3 This is a circuit diagram of a thermal conductivity chip module 200 provided in one embodiment of this application. Figure 3As shown, the thermal conductivity chip module 200 includes a single thermal conductivity chip U2 and a first resistor R1 connected in series. The single thermal conductivity chip U2 includes a first heat source pin HEATER1, a second heat source pin HEATER2, a positive thermistor pin TH+, and a negative thermistor pin TH-. A thermopile is connected between the positive and negative thermistor pins TH+ and TH-. The positive thermistor pin TH+ serves as the positive output terminal of the thermal conductivity chip module 200 and is connected to the positive input terminal (i.e., the SIP pin) of the operational amplifier 400. The negative thermistor pin TH- serves as the negative output terminal of the thermal conductivity chip module 200 and is connected to the input terminal of the voltage divider resistor module 300. The first heat source pin HEATER1 is grounded. The second heat source pin HEATER2 is connected to the first end of the first resistor R1. The second end of the first resistor R1 is connected to the voltage output terminal of the power supply module 100, i.e., to the fifth pin of the power control chip U1.

[0161] In this embodiment, when a specified voltage is applied between the first heat source pin HEATER1 and the second heat source pin HEATER2, a stable heat source is generated between them. Heat is transferred to the surface of the thermopile through gas molecules in the measured environment. When the concentration of the target gas in the measured environment changes, an electrical signal difference is generated between the positive electrode RTD pin TH+ and the negative electrode RTD pin TH-, and a differential signal is detected. The target gas concentration is proportional to the heat carried by the gas molecules in the measured environment.

[0162] The specified voltage can be set according to the actual application scenario. Different application scenarios correspond to different specified voltages, thereby enabling gas leak detection in different application scenarios and reducing the impact of environmental changes on the accuracy of detection results.

[0163] In this embodiment, the first resistor R1 is a voltage divider resistor connected to the fifth pin of the power control chip U1, which can perform voltage division on the power supply voltage provided by the power module 100.

[0164] Specifically, the first resistor R1 is detachably connected between the second heat source pin HEATER2 of the single thermal conductivity chip U2 and the fifth pin of the power control chip U1, thereby meeting the voltage requirements of different thermal conductivity chip modules 200. And / or, the first resistor R1 can be an adjustable resistor, which can also meet the voltage requirements of different thermal conductivity chip modules 200.

[0165] In this embodiment, the core principle of the thermal conductivity chip module 200 for detecting gas leaks is based on the physical differences in thermal conductivity of different gases. Leak identification is achieved by measuring the changes in thermal conductivity characteristics caused by changes in gas composition. Specifically, different gas molecular structures result in different thermal conductivity capabilities. The thermal conductivity of gases (such as R134a and R410A) is significantly lower than that of air. When a gas leaks, the thermal conductivity of the local gas mixture will significantly decrease due to the increase in gas concentration. The single thermal conductivity chip U2 can typically employ a Wheatstone bridge design, where two thermistors form the bridge arms, one exposed to the ambient gas (detection end) and the other sealed to the reference gas (compensation end). When a gas leaks, the heat dissipation efficiency of the detection end decreases, leading to a temperature rise, which in turn causes a change in resistance, ultimately resulting in bridge imbalance and the output of a differential voltage signal.

[0166] Figure 4 This is a circuit diagram of a voltage divider resistor module 300 provided in one embodiment of this application. Figure 4 As shown, the voltage divider resistor module 300 includes a second resistor R2, a third resistor R3, a fourth resistor R4, and a second capacitor C2. The first end of the second resistor R2 serves as the second output terminal of the voltage divider resistor module 300 and is connected to the analog power input terminal (i.e., the SVDD pin) of the operational amplifier 400. The second end of the second resistor R2 serves as the first output terminal of the voltage divider resistor module 300 and is connected to the negative input terminal (i.e., the SIN pin) of the operational amplifier 400. The negative output terminal (i.e., the negative RTD pin TH-) of the thermal conductivity chip module 200 is connected to the first end of the third resistor R3. The second end of the third resistor R3 is connected to the negative input terminal (i.e., the SIN pin) of the operational amplifier 400. The second end of the third resistor R3 is also connected to the second end of the second resistor R2, and together they are connected to the negative input terminal (i.e., the SIN pin) of the operational amplifier 400. The negative output terminal (i.e., the negative RTD pin TH-) of the thermal conductivity chip module 200 is also connected to the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is grounded. Optionally, a common-mode voltage VCM is also connected between the third resistor R3 and the fourth resistor R4. The second capacitor C2 is connected between the positive input terminal (i.e., the SIP pin) and the negative input terminal (i.e., the SIN pin) of the operational amplifier 400.

[0167] In this embodiment, the positive signal output from the positive output terminal (i.e., the positive RTD pin TH+) of the thermal conductivity chip module 200 is directly connected to the non-inverting input of the operational amplifier 400. The negative signal output from the negative output terminal (i.e., the negative RTD pin TH-) of the thermal conductivity chip module 200 is input to the inverting input of the operational amplifier 400 after being divided by the third resistor R3, forming a standard differential amplification structure. The second capacitor C2 is connected across the positive and negative input terminals of the operational amplifier 400 to form a differential low-pass filter, which can suppress high-frequency noise. The negative signal output from the negative output terminal (i.e., the negative RTD pin TH-) of the thermal conductivity chip module 200 is coupled to the SVDD pin of the operational amplifier 400 after being divided by the third resistor R3 and the second resistor R2, which can realize common-mode tracking and noise cancellation. That is, the input common-mode fluctuation can be compensated through the analog power supply pin, and the common-mode interference can be suppressed through the analog power supply signal injection. Especially in weak signal scenarios, by eliminating noise and suppressing interference, the ability to distinguish weak leakage signals can be improved, and the sensitivity of gas leakage detection can be improved.

[0168] In this embodiment, during gas leakage, the thermal conductivity chip module 200 may output a high-voltage differential signal (e.g., ±5V), exceeding the input voltage range of the operational amplifier 400 (typically ±3.3V). The voltage divider resistor module 300 can proportionally attenuate the signal, making it match the voltage processing range of the operational amplifier 400, thus preventing input saturation or damage to the operational amplifier 400. Furthermore, the thermal conductivity chip module 200 has a high output impedance; directly connecting it to the high input impedance of the operational amplifier 400 can easily cause signal reflection. The voltage divider resistor module 300 can act as a buffer layer, reducing signal distortion caused by sensor load effects. For a wide dynamic range of small leakage signals (mV level) and large leakage signals (V level), the voltage divider resistor module 300 allows adjustment of the amplification factor: for the high-voltage segment, enabling voltage division can prevent overloading of the operational amplifier 400; for the low-voltage segment, bypassing the voltage divider resistor can directly amplify weak signals, improving the resolution of weak leakage signals and increasing detection sensitivity.

[0169] Figure 5 This is a circuit diagram of an operational amplifier 400 provided in one embodiment of this application. In some embodiments, the operational amplifier 400 is an instrument-grade programmable operational amplifier 400. The instrument-grade programmable operational amplifier 400 allows for real-time gain adjustment via a digital interface without the need to replace external resistors, achieving a gain error of <0.01%, thus avoiding the accuracy loss caused by resistor temperature drift in traditional operational amplifiers.

[0170] In some embodiments, the voltage output of the power module 100 can intermittently power the thermal conductivity chip module 200. The thermal conductivity chip module 200 only requires high-current heating during the detection cycle; intermittent power supply allows it to enter a microampere-level sleep state when idle, thereby reducing power consumption and extending device lifespan. The power module 100 can be linked with the microcontroller unit 500 to achieve on-demand power supply.

[0171] Figure 12 This is a circuit diagram of a microcontroller unit 500 provided in one embodiment of this application. In some embodiments, the microcontroller unit 500 is connected to an operational amplifier 400 and is used to receive the original signal value obtained by signal amplification processing by the operational amplifier 400. The microcontroller unit 500 performs calculations on the detected original signal value to finally obtain a leakage determination result. The calculations performed by the microcontroller unit 500 on the detected original signal value to finally obtain a leakage determination result are prior art and will not be elaborated here. Example

[0172] This application provides a gas leak detection circuit, including a thermal conductivity chip module 200, an operational amplifier 400, and a microcontroller unit 500 connected in sequence. The thermal conductivity chip module 200 is used to sense the concentration of a target gas in the environment under test. The microcontroller unit 500 includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the gas leak detection method as described in any of the embodiments in the first embodiment and sends an alarm signal through the microcontroller unit 500.

[0173] The processor referred to can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0174] The memory can be an internal storage unit of the operational amplifier 400, or it can be an external storage device, such as a plug-in hard drive, SmartMedia Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the operational amplifier 400. Furthermore, the memory can include both internal storage units of the operational amplifier 400 and external storage devices. The memory is used to store the computer program and other programs and data required by the terminal device. The memory can also be used to temporarily store data that has been output or will be output.

[0175] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0176] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0177] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0178] In the embodiments provided in this application, it should be understood that the disclosed apparatus / terminal devices and methods can be implemented in other ways. For example, the apparatus / terminal device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0179] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0180] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0181] If an integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0182] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in the various method embodiments of Embodiment 1.

[0183] This application also provides a computer program product that, when run on a mobile terminal, enables the mobile terminal to implement the steps in the various method embodiments of the above embodiment 1.

[0184] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0185] The above are merely optional embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for detecting gas leaks, characterized in that: Includes the following steps: S100: Employs a gas concentration sensor to acquire calibration electrical signals of several calibrated concentrations of the target gas, forming a concentration electrical signal calibration table; S200: Based on the concentration electrical signal calibration table, determine the linear correlation between the gas concentration of the target gas and the detection electrical signal; S300: Combine the concentration electrical signal calibration table and the linear correlation to obtain the leakage threshold corresponding to the gas alarm concentration; S400: The gas concentration sensor is used to obtain the real-time detection concentration of the target gas. When the real-time detection concentration reaches the leakage threshold, an alarm signal is issued. Step S100 includes the following steps: S110: Obtain the first calibration electrical signal corresponding to the first calibration concentration; S120: Obtain the second calibration electrical signal corresponding to the second calibration concentration; S130: Obtain the third calibration electrical signal corresponding to the third calibration concentration; S140: Obtain the fourth calibration electrical signal corresponding to the fourth calibration concentration, wherein the first calibration concentration, the second calibration concentration, the third calibration concentration, and the fourth calibration concentration are all different; Wherein, the first calibrated concentration has a PPM of 0%, the second calibrated concentration has a PPM of 10%, the third calibrated concentration has a PPM of 40%, and the fourth calibrated concentration has a PPM of 50%; Alternatively, the first calibrated concentration is 0% of the range of the gas concentration sensor, the second calibrated concentration is 10% of the range of the gas concentration sensor, the third calibrated concentration is 40% of the range of the gas concentration sensor, and the fourth calibrated concentration is 50% of the range of the gas concentration sensor.

2. The gas leak detection method as described in claim 1, characterized in that: Step S400 includes the following steps: S410: The gas concentration sensor is used to acquire the initial concentration electrical signal; S420: Uses a temperature sensor to obtain the current temperature and calculates the temperature compensation incremental electrical signal; S430: Based on the difference between the initial concentration electrical signal and the temperature-compensated incremental electrical signal, calculate the real-time detected concentration.

3. The gas leak detection method as described in claim 2, characterized in that: In step S420, let the current temperature be Tmpr_TRaw, the calibration temperature be TComp_TRawBase, the difference between the current temperature and the calibration temperature be Tmpr_DltTRaw, and the temperature compensation incremental electrical signal be Sens_DltSRaw, then: Sens_DltSRaw=Tcomp_Coe0+Tcomp_Coe1*(Tmpr_DltTRaw)+Tcomp_Coe2*(Tmpr_DltTRaw)*(Tmpr_DltTRaw)+Tcomp_Coe3*(Tmpr_DltTRaw)*(Tmpr_DltTRaw)*(Tmpr_DltTRaw); Among them, Tcomp_Coe0, Tcomp_Coe1, Tcomp_Coe2, and Tcomp_Coe3 are the zero-order temperature compensation coefficient, the first-order temperature compensation coefficient, the second-order temperature compensation coefficient, and the third-order temperature compensation coefficient, respectively.

4. The gas leak detection method as described in claim 3, characterized in that: Prior to step S100, the method further includes the following steps: S510: At the calibration temperature, the gas concentration sensor is used to acquire the first temperature scale electrical signal corresponding to the target gas PPM being 0; S520: At the first reference temperature, the gas concentration sensor is used to acquire the second temperature scale electrical signal corresponding to when the target gas PPM is 0; S530: At the second reference temperature, the gas concentration sensor is used to acquire the third temperature scale electrical signal corresponding to when the target gas PPM is 0; S540: At the third reference temperature, the gas concentration sensor is used to obtain the fourth temperature scale electrical signal corresponding to the target gas PPM being 0; S550: Based on steps S510~S540, calculate the zero-order temperature compensation coefficient Tcomp_Coe0, the first-order temperature compensation coefficient Tcomp_Coe1, the second-order temperature compensation coefficient Tcomp_Coe2, and the third-order temperature compensation coefficient Tcomp_Coe3.

5. The gas leak detection method as described in claim 2, characterized in that: Following step S430, the following steps are also included: S441: Uses a humidity sensor to obtain humidity increments; S442: Calculate the humidity compensation amount based on the humidity increment and temperature coefficient; S443: Based on the difference between the initial concentration electrical signal and the temperature-compensated incremental electrical signal, the PPM concentration before wet compensation is obtained; S444: The humidity compensation amount is used to perform humidity compensation on the PPM concentration before wet compensation to obtain the real-time detection concentration.

6. The gas leak detection method as described in claim 5, characterized in that: Following step S444, the following steps are also included: S451: Uses a barometric pressure sensor to obtain barometric pressure increments; S452: Based on the pressure increment, obtain the pressure parameters; S453: Divide the humidity-compensated real-time detection concentration by the air pressure parameter to obtain the air pressure-compensated real-time detection concentration.

7. The gas leak detection method according to any one of claims 1 to 6, characterized in that: Step S400 also includes the following step: converting the real-time detected concentration PPM value into an LFL concentration value.

8. A gas leak detection circuit, characterized in that: The device includes a thermal conductivity chip module, an operational amplifier, and a microcontroller unit connected in sequence. The thermal conductivity chip module is used to sense the concentration of a target gas in the environment under test. The microcontroller unit includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the gas leak detection method as described in any one of claims 1-7 and sends an alarm signal through the microcontroller unit.

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