Wavelength correction method, correction device and detection device of gas detection optical module

Abstract

The invention discloses a wavelength correction method and device for a gas detection optical module and a detection device. The wavelength correction method for the gas detection optical module comprises the following steps: determining a temperature scanning range and a temperature scanning step length; a temperature scanning monitoring step: adjusting the working temperature of the gas detection optical module according to the temperature scanning range and the temperature scanning step length, and obtaining a photoelectric curve through a photoelectric detector; repeatedly executing the temperature scanning monitoring step until an absorption peak appears in the photoelectric curve; the working temperature of the gas detection optical module is fixed, and current scanning monitoring is carried out; and determining whether the absorption peak deviates from the central position of the photoelectric curve, and if the absorption peak deviates from the central position of the photoelectric curve, adjusting the current scanning range until the absorption peak is located at the central position of the photoelectric curve. According to the technical scheme provided by the invention, the working wavelength range of the gas detection optical module is monitored and corrected in real time, and the accuracy of gas concentration detection is improved.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of gas concentration detection, and in particular to a wavelength correction method, correction device, and detection device for a gas detection optical module. Background Art

[0002] Laser methane sensors are a common gas concentration detection device, typically using tunable semiconductor laser absorption spectroscopy (TDLAS) as its detection principle. This technology utilizes the wavelength tuning properties of semiconductor lasers and the selective absorption of specific wavelengths of laser light by methane gas to detect gas concentration. Specifically, the attenuation of laser light intensity as it passes through the methane gas being measured follows the Lambert-Beer law, which states that the component being measured absorbs light of a specific wavelength, and the absorption intensity is proportional to the component's concentration. By measuring the attenuation of the laser light after passing through methane gas, the methane concentration can be calculated.

[0003] Laser methane sensors are widely used in gas safety monitoring, but their measurement accuracy is affected by a variety of factors. As the laser ages, the sensor hardware wears out, or it operates under complex or harsh conditions for extended periods, variations in the laser's drive current can cause changes in the laser's scanning wavelength range, reducing sensor accuracy and even causing sensor failure. This necessitates recalibrating the mapping between emission wavelength and drive current.

[0004] In actual applications, laser methane sensors are usually factory-set with parameters. During the measurement process, algorithms and general rules are used to compensate for the effects of environmental factors. Alternatively, a known concentration of the measured gas is used to find the laser drive current when light absorption occurs, thereby recalibrating the mapping relationship between the characteristic absorption light wavelength and the drive current to correct the laser scanning wavelength range. Although the above methods can achieve positive results, the compensation algorithm can only achieve a certain degree of correction and cannot reach the preset state. Manual correction is required during recalibration, and when the wavelength drift is too large, it exceeds the current scanning range, and the direction of the absorption peak shift is uncertain. The operation is complicated and cannot achieve real-time correction. Therefore, a method is needed to monitor the changes in the sensor's scanning wavelength range in real time and calibrate the sensor's wavelength. Summary of the Invention

[0005] The embodiments of the present invention provide a wavelength correction method, correction device, and detection device for a gas detection optical module to achieve real-time monitoring and correction of the operating wavelength range of the gas detection optical module and improve the accuracy of gas concentration detection.

[0006] According to one aspect of the present invention, a wavelength calibration method for a gas detection optical module is provided, comprising:

[0007] Determine the temperature scanning range and temperature scanning step;

[0008] Temperature scanning monitoring step; the temperature scanning monitoring step includes adjusting the operating temperature of the gas detection optical module according to the temperature scanning range and the temperature scanning step, and obtaining a photoelectric curve through a photoelectric detector;

[0009] Repeating the temperature scanning monitoring step until an absorption peak appears in the photoelectric curve;

[0010] Fixing the operating temperature of the gas detection optical module, adjusting the operating current of the gas detection optical module, and obtaining a photoelectric curve through a photodetector to perform current scanning monitoring;

[0011] Determine whether the absorption peak deviates from the center position of the photoelectric curve. If the absorption peak deviates from the center position of the photoelectric curve, adjust the current scanning range until the absorption peak is located at the center position of the photoelectric curve to achieve wavelength correction of the gas detection light module and obtain a calibrated photoelectric curve.

[0012] Optionally, in the temperature scanning monitoring step, the operating current of the gas detection optical module is scanned according to a preset current scanning range, each execution of the temperature scanning monitoring step corresponds to a current scanning cycle, and the operating temperature of the gas detection optical module remains unchanged;

[0013] Adjusting the operating temperature of the gas detection optical module according to the temperature scanning range and the temperature scanning step, and obtaining a photoelectric curve through a photoelectric detector, including:

[0014] determining an operating temperature of the gas detection optical module during a previous current scanning cycle;

[0015] determining the operating temperature of the gas detection optical module in the current current scanning cycle according to the operating temperature in the previous current scanning cycle and the temperature scanning step;

[0016] Determining whether the operating temperature of the current current scanning cycle exceeds the temperature scanning range;

[0017] If not, adjusting the operating temperature of the gas detection light module to the operating temperature of the current current scanning period, controlling the operating current of the gas detection light module to scan according to the preset current scanning range, and generating an electrical signal according to the detected laser by a photodetector to obtain the photoelectric curve;

[0018] If it exceeds, the operating temperature of the gas detection light module is adjusted to the starting temperature of the temperature scanning range, and the operating current of the gas detection light module is controlled to scan according to the preset current scanning range, and the photoelectric curve is obtained by generating an electrical signal according to the detected laser through the photodetector.

[0019] Optionally, in the temperature scanning monitoring step, the operating current of the gas detection optical module is a DC driving current; each execution of the temperature scanning monitoring step corresponds to a temperature scanning cycle;

[0020] Adjusting the operating temperature of the gas detection optical module according to the temperature scanning range and the temperature scanning step, and obtaining a photoelectric curve through a photoelectric detector, including:

[0021] driving the gas detection optical module by a DC driving current, and gradually changing the operating temperature of the gas detection optical module according to the temperature scanning step within the temperature scanning range;

[0022] The laser light emitted by the gas detection optical module is detected by a photoelectric detector, and an electrical signal is generated according to the detected laser light to obtain the photoelectric curve.

[0023] Optionally, fixing the operating temperature of the gas detection optical module includes:

[0024] The operating temperature of the gas detection optical module is fixed to the temperature at which an absorption peak appears in the temperature scanning monitoring step.

[0025] Optionally, fixing the operating temperature of the gas detection optical module includes:

[0026] Determining whether a difference between a temperature at which an absorption peak appears in the temperature scanning monitoring step and a rated operating temperature of the gas detection optical module is less than a preset temperature difference;

[0027] If it is less than, fixing the operating temperature of the gas detection optical module to the rated operating temperature of the gas detection optical module;

[0028] If it is greater than or equal to, the operating temperature of the gas detection optical module is fixed to the temperature at which the absorption peak appears in the temperature scanning monitoring step.

[0029] Optionally, adjusting the current scanning range until the absorption peak is located at the center of the photoelectric curve includes:

[0030] The difference between the end scanning current and the start scanning current is kept unchanged, and the start scanning current is adjusted until the absorption peak is located at the center of the photoelectric curve.

[0031] Optionally, the difference between the end scan current and the start scan current is kept unchanged, and before adjusting the start scan current, the following steps are further included:

[0032] Determining the number of signal collection points of the photodetector in a single current scanning cycle;

[0033] According to the number of signal collection points in a single current scanning cycle, the number of signal collection points located at the center of the photoelectric curve is determined;

[0034] Determining the number of points at which the absorption peak deviates from the center position according to the number of points at which the absorption peak is located on the photoelectric curve and the number of signal collection points located at the center position of the photoelectric curve;

[0035] The adjusted target starting scanning current is determined based on the current starting scanning current, the difference between the ending scanning current and the starting scanning current, the number of signal collection points in a single current scanning cycle, and the number of deviation points of the absorption peak relative to the center position.

[0036] Optionally, after obtaining the calibrated photoelectric curve, the following steps are further included:

[0037] Determine the gas concentration of the gas to be measured based on the calibrated photoelectric curve;

[0038] Determining whether the gas concentration of the gas to be measured exceeds a first preset concentration threshold;

[0039] If it exceeds, the alarm device is controlled to give an alarm prompt; if it does not exceed, the process returns to the temperature scanning and monitoring step.

[0040] And / or, after repeatedly performing the temperature scanning monitoring step until an absorption peak appears in the photoelectric curve, the method further includes:

[0041] Determine the preliminary gas concentration of the gas to be measured based on the photoelectric curve where the absorption peak appears;

[0042] Determining whether the preliminary gas concentration of the gas to be measured exceeds a second preset concentration threshold;

[0043] If it exceeds, the current scanning monitoring step is executed; if it does not exceed, the process returns to execute the temperature scanning monitoring step.

[0044] According to another aspect of the present invention, a wavelength correction device for a gas detection optical module is provided, comprising:

[0045] a temperature control module, configured to obtain a temperature scanning range and a temperature scanning step, and to adjust the operating temperature of the gas detection optical module according to the temperature scanning range and the temperature scanning step in a temperature scanning monitoring step;

[0046] A photoelectric curve acquisition module is used to obtain a photoelectric curve through a photoelectric detector in the temperature scanning monitoring step;

[0047] The temperature control module is further configured to fix the operating temperature of the gas detection optical module after performing the temperature scanning monitoring step multiple times until an absorption peak appears in the photoelectric curve;

[0048] a current control module, configured to adjust the operating current of the gas detection optical module after fixing the operating temperature of the gas detection optical module to perform current scanning monitoring, wherein the photoelectric curve acquisition module is further configured to obtain a photoelectric curve through a photoelectric detector during the current scanning monitoring step;

[0049] The judgment module is used to determine whether the absorption peak deviates from the center position of the photoelectric curve. The current control module is also used to adjust the current scanning range when the absorption peak deviates from the center position of the photoelectric curve until the absorption peak is located at the center position of the photoelectric curve, so as to achieve wavelength correction of the gas detection light module and obtain a calibrated photoelectric curve.

[0050] According to another aspect of the present invention, a gas concentration detection device is provided, comprising a gas detection optical module, a photodetector, a thermoelectric cooler, and the wavelength correction device for the gas detection optical module according to any embodiment of the present invention.

[0051] The technical solution provided by the embodiment of the present invention performs wide-range wavelength scanning through temperature scanning. When the wavelength offset is large and the offset direction is unknown, wide-range wavelength scanning can facilitate finding the absorption peak. After finding the absorption peak, the current scanning range is adjusted so that the absorption peak is located at the center of the photoelectric curve, thereby realizing the correction of the current scanning range, thereby completing the wavelength drift correction, and thereby improving the accuracy of gas concentration detection.

[0052] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0054] Figure 1 Schematic diagram of three photoelectric curves obtained by a laser methane sensor provided in the related art during normal operation;

[0055] Figure 2 This is a schematic diagram of a single photoelectric curve obtained by another laser methane sensor provided in the related art during normal operation;

[0056] Figure 3 yes Figure 2 An enlarged schematic diagram of the forward absorption peak of the absorption peak in the photoelectric curve shown;

[0057] Figure 4 This is a schematic diagram comparing methane absorption curves obtained by scanning wavelengths of a laser methane sensor provided in the related art at different offset levels;

[0058] Figure 5 This is a flow chart of a wavelength calibration method for a gas detection optical module provided by an embodiment of the present invention;

[0059] Figure 6 This is a schematic diagram of a scanning wavelength range obtained under different current scanning ranges provided in the related art;

[0060] Figure 7 is a schematic diagram of a scanning wavelength range obtained at different operating temperatures provided by an embodiment of the present invention;

[0061] Figure 8 This is a flow chart of another wavelength calibration method for a gas detection optical module provided by an embodiment of the present invention;

[0062] Figure 9 This is a schematic diagram of the change in scanning wavelength of a gas detection optical module during a wavelength calibration process of temperature scanning monitoring combined with current scanning monitoring provided by an embodiment of the present invention;

[0063] Figure 10 This is a flow chart of another wavelength calibration method for a gas detection optical module provided by an embodiment of the present invention;

[0064] Figure 11 This is another schematic diagram of the change in scanning wavelength of a gas detection optical module during a wavelength calibration process of temperature scanning monitoring combined with current scanning monitoring provided by an embodiment of the present invention;

[0065] Figure 12 This is a schematic diagram of an absorption peak position correction process in a current scanning detection step provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0066] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0067] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0068] As the background technology, laser methane sensor is a common gas concentration detection device. Figure 1 This is a schematic diagram of three photoelectric curves obtained by a laser methane sensor in normal operation provided in the related art. Figure 1 The horizontal axis represents the number of times the photodetector in the laser methane sensor collects signals, while the vertical axis represents the amplitude of the electrical signal (e.g., voltage or current) converted by the photodetector based on the detected laser light, i.e., the signal data collected by the photodetector. When the laser light emitted by the laser in the laser methane sensor passes through methane gas, the methane molecules absorb the laser energy corresponding to their characteristic absorption peak (absorption wavelength of 1653.7 nm), resulting in a decrease in the intensity of the transmitted light. The photodetector measures the change in light intensity, and based on the Lambert-Beer law, the methane gas concentration can be inferred by comparing the laser energy attenuation. Modulating the laser's scanning wavelength is typically achieved by adjusting the laser's operating current. The laser is fed an operating current superimposed with a periodic signal, such as a low-frequency sawtooth wave or triangular wave, causing the wavelength of the laser light emitted by the laser to repeatedly scan near the center frequency of the absorption spectrum. As the laser passes through the methane gas to be measured, an absorption spectrum within a certain frequency range is obtained.

[0069] Figure 2 This is a schematic diagram of a single photoelectric curve obtained by another laser methane sensor provided in the related art during normal operation. Figure 3 yes Figure 2 The forward absorption peak type magnified schematic diagram of the absorption peak in the photoelectric curve shown is shown in FIG. Figure 2 and Figure 3 , when calculating the methane absorbance, it is necessary to fit the baseline first. Figure 2 The data at positions a1 and a3 are linearly fitted to obtain baseline fitting data, and then the methane absorption peak at position a3 is peak fitted to obtain absorption peak fitting data. Finally, the absorbance value of methane gas is obtained by subtracting the absorption peak data from the baseline fitting data corresponding to the absorption peak position, and then the methane concentration result is calculated. Figure 3 The curve a31 shown is a positive absorption peak-type curve obtained by subtracting the absorption peak-type data from the baseline fitting data corresponding to the absorption peak position.

[0070] However, once the scanning wavelength of the laser drifts, the position of the absorption peak in the photoelectric curve will shift, which will lead to inaccurate fitting baseline data and large deviations in the calculated gas concentration results. When the absorption peak position shifts out of the scanning wavelength range of the laser, the laser methane sensor will fail and be unable to work. Existing laser methane sensors only consider the changes in scanning wavelength affected by general environmental factors such as temperature, humidity, and pressure, and use corresponding algorithms to compensate for them. However, in actual use, the sensor will face more complex and unpredictable challenges, such as damage to the hardware structure inside the sensor, changes in the physical properties of electronic components (such as aging of the laser, decreased sensitivity of the photodetector, etc.), and long-term exposure to extreme or harsh environmental conditions (such as high temperature, low temperature, high humidity, strong electromagnetic interference, etc.), which may cause the scanning wavelength range of the laser methane sensor to change.

[0071] Figure 4 This is a comparative diagram of methane absorption curves obtained by scanning wavelengths of a laser methane sensor provided in the related art at different offset levels. The horizontal axis is the scanning wavelength and the vertical axis is the electrical signal amplitude. The normal scanning wavelength range (the scanning wavelength range without offset) of the laser methane sensor is 1653.4nm~1654.0nm (the absorption wavelength of methane gas is 1653.7nm±0.3nm). Figure 4 Curve #1 in the middle is the methane absorption curve obtained when the laser methane sensor is scanning the wavelength range normally. The absorption peak is located at the center of curve #1. Figure 4 Curve #2 in the middle represents the methane absorption curve with a shifted scanning wavelength. It can be observed that the position of the absorption peak on the methane absorption curve has changed. In this state, the absorption peak parameters (such as peak value and half-width) may change accordingly. During concentration inversion, general rules are usually used to perform algorithm compensation and calibration. Figure 4The middle curve #3 indicates that the absorption wavelength of methane gas is at the critical point of the scanning wavelength range. In this state, the parameters of the complete absorption peak cannot be calculated, which will lead to inaccurate concentration inversion results and abnormal sensor operation. Figure 4 The middle curve #4 indicates that the methane absorption wavelength is outside the scanning wavelength range. At this time, the absorption peak parameters cannot be detected for concentration inversion, and the sensor is working abnormally.

[0072] In view of this, an embodiment of the present invention provides a wavelength calibration method for a gas detection optical module. Figure 5 This is a flow chart of a wavelength calibration method for a gas detection optical module provided by an embodiment of the present invention, with reference to Figure 5 , the wavelength calibration method of the gas detection optical module includes:

[0073] S110 , determining a temperature scanning range and a temperature scanning step.

[0074] Specifically, the gas detection optical module is located in the gas concentration detection device, and the gas concentration detection device includes a gas detection optical module, a photoelectric detector and a thermoelectric cooler (TEC). Among them, the gas detection optical module can be a semiconductor laser for emitting laser; the thermoelectric cooler is used to control the operating temperature of the gas detection optical module; the photoelectric detector is used to detect the laser emitted by the gas detection optical module, and convert the optical signal into an electrical signal according to the photoelectric response of the detected laser. Among them, the temperature scanning range can be understood as the temperature adjustment range of the operating temperature of the gas detection optical module, and the temperature scanning step can be understood as the temperature adjustment amplitude each time the operating temperature of the gas detection optical module is adjusted. The temperature scanning range and the temperature scanning step can be set according to actual conditions. The gas concentration detection device can be used to detect methane gas.

[0075] S120, temperature scanning monitoring step; the temperature scanning monitoring step includes adjusting the operating temperature of the gas detection optical module according to the temperature scanning range and the temperature scanning step, and obtaining a photoelectric curve through a photoelectric detector; repeating the temperature scanning monitoring step until an absorption peak appears in the photoelectric curve.

[0076] Specifically, in the temperature scanning monitoring step, the operating current of the gas detection optical module can be changed within a preset current scanning range, and a photoelectric curve is obtained each time the operating temperature is adjusted. Alternatively, in the temperature scanning monitoring step, the operating current of the gas detection optical module can be a DC current, and the laser operating temperature is scanned once within the temperature scanning range according to the temperature scanning step, and a photoelectric curve is obtained accordingly. The photoelectric curve can be understood as a curve in which the photocurrent signal changes with time based on the photocurrent signal at different moments. Among them, the photocurrent signal is obtained by detecting the laser signal passing through the gas to be measured through a photodetector. The wavelength corresponding to the absorption peak in the photoelectric curve is the absorption wavelength of the laser by the gas to be measured. In an embodiment of the present invention, a temperature scanning method with a larger temperature tuning coefficient is used to perform a large-scale wavelength scan. When the scanning wavelength range has a large offset and the offset direction is unknown, a large-scale wavelength scan can facilitate finding the absorption peak, and can achieve fast and accurate wavelength drift correction, thereby greatly improving the accuracy and long-term stability of the gas concentration detection device during use.

[0077] S130 , fixing the operating temperature of the gas detection optical module, adjusting the operating current of the gas detection optical module, and obtaining a photoelectric curve through a photoelectric detector to perform current scanning monitoring.

[0078] S140. Determine whether the absorption peak deviates from the center position of the photoelectric curve. If the absorption peak deviates from the center position of the photoelectric curve, adjust the current scanning range of the gas detection light module until the absorption peak is located at the center position of the photoelectric curve to achieve wavelength correction of the gas detection light module and obtain a calibrated photoelectric curve.

[0079] Specifically, the laser emits lasers of different wavelengths at different working currents. After finding the absorption peak, the current scanning monitoring step is performed. The current scanning monitoring step includes: fixing the working temperature of the gas detection light module to the temperature at which the absorption peak can appear in the photoelectric curve, adjusting the working current of the gas detection light module according to the preset current scanning step within the preset current scanning range, completing a current scan, and obtaining the photoelectric curve corresponding to the current current scanning cycle through the photoelectric detector; wherein, the current scanning range can be understood as the working current range of the laser when periodically detecting the concentration of the gas to be measured, and the working current of the laser increases or decreases within the working current range. One change corresponds to obtaining a photoelectric curve. The method of obtaining the photoelectric curve can refer to the above description. Figure 2 and Figure 3The description of is omitted here. The preset current scanning range can be the rated operating current range of the laser; determine whether the absorption peak in the photoelectric curve is located at the center of the photoelectric curve. If not, it means that the scanning wavelength of the laser has drifted and needs to be corrected. Adjust the current scanning range of the laser, that is, adjust the operating current range, obtain the photoelectric curve again, and determine the position of the absorption peak in the photoelectric curve; repeat the current scanning monitoring steps until the absorption peak is located at the center of the photoelectric curve, thereby realizing the correction of the scanning wavelength range of the gas detection optical module and obtaining the calibrated photoelectric curve.

[0080] In the related art, current scanning is generally used for calibration, but the current scanning tuning coefficient is small and the calibration range is insufficient. Figure 6 This is a schematic diagram of a scanning wavelength range obtained under different current scanning ranges provided in the related art, such as Figure 6 As shown, the operating current range of the laser is 20mA-60mA, the full-range current scanning wavelength is 0.4nm, and the current tuning coefficient is 0.01nm / mA. During the methane gas monitoring process, the laser is under normal working conditions and periodically scans according to the current scanning range of 30mA-50mA. If the position of the absorption peak in the photoelectric curve shifts, the current scanning range of the laser is adjusted (the operating current range of the laser) and the laser wavelength is drift-corrected so that the position of the absorption peak returns to the center position in the photoelectric curve. However, there is a problem that the current scanning tuning coefficient is small and the correction range is insufficient.

[0081] Figure 7 is a schematic diagram of a scanning wavelength range obtained at different operating temperatures provided by an embodiment of the present invention, Figure 7 The current scanning range corresponding to the different scanning wavelength bands is the same, and the wavelength change range corresponding to the scanning current is 0.4nm. Among them, the scanning wavelength bands c1 to c10 are the scanning wavelength ranges corresponding to the operating temperatures of the laser at 52℃, 54℃, 56℃, 58℃, 60℃, 62℃, 64℃, 66℃, 68℃, and 70℃, respectively. When the temperature range changes from 52℃ to 70℃, the wavelength change value corresponding to the wavelength emitted by the laser driven by the same working current is 1.8nm (1654.95nm-0.4nm-1652.75nm), and the temperature tuning coefficient can reach 0.1nm / ℃. Therefore, temperature scanning can achieve a wide range of wavelength scanning.

[0082] The wavelength correction method for a gas detection optical module provided in an embodiment of the present invention uses temperature scanning to perform a wide-range wavelength scan. When the wavelength shift is large and the direction of the shift is unknown, this wide-range wavelength scan facilitates finding the absorption peak. Once the absorption peak is found, the current scanning range is adjusted to center the absorption peak on the photoelectric curve. This corrects the current scanning range, thereby completing wavelength drift correction and improving the accuracy of gas concentration detection. This method enables rapid and accurate wavelength drift correction, significantly improving the accuracy and long-term stability of laser methane sensors during use.

[0083] Figure 8 This is a flow chart of another wavelength calibration method for a gas detection optical module provided by an embodiment of the present invention. Figure 8 , a wavelength calibration method for a gas detection optical module includes:

[0084] S210: Determine the temperature scanning range and the temperature scanning step size.

[0085] S220. Obtain the operating temperature of the gas detection optical module in the previous current scanning cycle; wherein, in the temperature scanning monitoring step, the operating current of the gas detection optical module is scanned according to a preset current scanning range, and each temperature scanning monitoring step executed corresponds to a current scanning cycle, and the operating temperature of the gas detection optical module remains unchanged.

[0086] S230 : Determine the operating temperature of the gas detection optical module in the current current scanning cycle according to the operating temperature and the temperature scanning step length in the previous current scanning cycle.

[0087] S240, determining whether the operating temperature of the current current scanning cycle exceeds the temperature scanning range; if not, executing step S250; if exceeded, executing step S260.

[0088] S250, adjust the operating temperature of the gas detection light module to the operating temperature of the current current scanning cycle, control the operating current of the gas detection light module to scan according to the preset current scanning range, and generate an electrical signal according to the detected laser through the photoelectric detector to obtain a photoelectric curve.

[0089] S260, adjusting the operating temperature of the gas detection light module to the starting temperature of the temperature scanning range, controlling the operating current of the gas detection light module to scan according to the preset current scanning range, and generating an electrical signal according to the detected laser through the photodetector to obtain a photoelectric curve.

[0090] S270 , determining whether an absorption peak appears in the photoelectric curve; if so, executing step S290 ; if not, executing step S280 .

[0091] S280: Take the current current scanning cycle as the previous current scanning cycle, and return to step S220.

[0092] S290, fixing the operating temperature of the gas detection optical module, adjusting the current scanning range of the gas detection optical module, and obtaining a photoelectric curve through a photoelectric detector to perform current scanning monitoring.

[0093] S2100, determine whether the absorption peak deviates from the center position of the photoelectric curve. If so, execute step S2110; if not, return to execute step S290.

[0094] S2110 , determining that wavelength calibration of the gas detection optical module is completed, obtaining a calibrated photoelectric curve, and obtaining the concentration of the gas to be measured based on the calibrated photoelectric curve.

[0095] Specifically, in the temperature scanning monitoring step, the operating current of the gas detection optical module is scanned according to the preset current scanning range. Each temperature scanning monitoring step executed corresponds to a current scanning cycle, and the operating temperature of the gas detection optical module remains unchanged. The temperature scanning monitoring step is repeatedly executed within the temperature scanning range. If an absorption peak with a wavelength of 1653.7 nm does not appear in the photoelectric curve from the starting temperature to the ending temperature of the temperature scanning range, it means that there is no gas to be measured in the environment, and the temperature scanning monitoring is restarted from the starting temperature. If the gas to be measured is detected in the temperature scanning step, current scanning monitoring is performed to adjust the current scanning range until the absorption peak is located at the center of the photoelectric curve, thereby achieving calibration of the absorption peak position.

[0096] refer to Figure 9 The upper curve d in the figure is the scanning wavelength band corresponding to multiple current scanning cycles, and the lower curve t is the operating temperature curve of the laser in each current scanning cycle. Figure 9 The scanning wavelength segments of the seven current scanning cycles d1 to d7 are shown as an example. d1 to d4 are the scanning wavelength segments obtained in the temperature scanning monitoring step. The operating temperature of the laser is constantly changing, resulting in the laser scanning wavelength range constantly climbing while the current scanning range (the laser operating current range) remains unchanged; d5 to d7 are the scanning wavelength segments obtained in the current scanning monitoring step. The laser scanning wavelength range is gradually corrected while the laser operating temperature remains unchanged.

[0097] like Figure 9As shown, the operating temperature of the laser is continuously scanned within the temperature scanning range. For example, the temperature scanning range is 60°C to 66°C, the temperature scanning step is 2°C, and the starting temperature is 60°C. When methane gas is monitored, it indicates that an absorption peak with a wavelength of 1653.7nm appears in the photoelectric curve. As shown in the scanning wavelength segment d4, when the operating temperature of the laser is 66°C, the scanning wavelength range of the laser includes the absorption wavelength of 1653.7nm of methane gas, and an absorption peak appears in the obtained photoelectric curve. After finding the absorption peak, determine whether the absorption peak in the photoelectric curve is located at the center of the photoelectric curve. If not, it means that the scanning wavelength of the laser still needs to be calibrated. Fix the operating temperature of the laser ( Figure 9 The operating temperature of the laser is fixed to the rated operating temperature of the laser, such as 65°C), the current scanning range of the laser is adjusted, and the current scanning monitoring is performed to obtain the photoelectric curve corresponding to the scanning wavelength band d5. Again, it is determined whether the absorption peak in the photoelectric curve corresponding to the scanning wavelength band d5 is located at the center of the photoelectric curve. If not, it means that the scanning wavelength of the laser still needs to be calibrated. Continue to adjust the current scanning range of the laser until the absorption peak is located at the center of the photoelectric curve. Record the current operating current range of the laser and use it as the calibrated current scanning range. Drive the laser according to the calibrated current scanning range so that the laser wavelength range emitted by the laser meets the target scanning wavelength range. Then, the calibrated photoelectric curve can be obtained through the photodetector.

[0098] The wavelength correction method provided by an embodiment of the present invention includes, in the temperature scanning monitoring step: determining the operating temperature of the gas detection light module in the previous current scanning cycle; determining the operating temperature of the gas detection light module in the current current scanning cycle based on the operating temperature and temperature scanning step of the previous current scanning cycle; judging whether the operating temperature of the current current scanning cycle exceeds the temperature scanning range; if not, adjusting the operating temperature of the gas detection light module to the operating temperature of the current current scanning cycle, and controlling the operating current of the gas detection light module to scan according to a preset current scanning range, and generating an electrical signal according to the detected laser through a photoelectric detector to obtain a photoelectric curve; if exceeded, adjusting the operating temperature of the gas detection light module to the starting temperature of the temperature scanning range, and controlling the operating current of the gas detection light module to scan according to the preset current scanning range, and generating an electrical signal according to the detected laser through a photoelectric detector to obtain a photoelectric curve. A wide range of wavelength scanning is performed by temperature scanning. When the wavelength shift is large and the direction of the shift is unknown, a wide range of wavelength scanning can facilitate finding the absorption peak. After finding the absorption peak, the current scanning range is adjusted so that the absorption peak is located at the center of the photoelectric curve, thereby correcting the current scanning range and completing the wavelength drift correction, thereby improving the accuracy of gas concentration detection.

[0099] Figure 10 This is a flow chart of another wavelength calibration method for a gas detection optical module provided by an embodiment of the present invention. Figure 10 , a wavelength calibration method for a gas detection optical module includes:

[0100] S310: Determine the temperature scanning range and the temperature scanning step size.

[0101] S320. Drive the gas detection optical module by a DC driving current, and gradually change the operating temperature of the gas detection optical module according to the temperature scanning step within the temperature scanning range; wherein, in the temperature scanning monitoring step, the operating current of the gas detection optical module is a DC driving current; each temperature scanning monitoring step executed corresponds to a temperature scanning cycle.

[0102] S330 , detecting the laser light emitted by the gas detection optical module through a photoelectric detector, generating an electrical signal according to the detected laser light, and obtaining a photoelectric curve.

[0103] S340, determining whether an absorption peak appears in the photoelectric curve corresponding to the current temperature scanning period; if so, executing step S350; if not, returning to executing step S320.

[0104] S350, fixing the operating temperature of the gas detection optical module, controlling the operating current of the gas detection optical module to gradually change within the current scanning range, and obtaining a photoelectric curve through a photoelectric detector to perform current scanning monitoring.

[0105] S360, determine whether the absorption peak deviates from the center position of the photoelectric curve, if so, execute step S380; if not, execute step S370.

[0106] S370 , adjusting the current scanning range of the gas detection optical module, and returning to step S350 .

[0107] S380: Determine whether the wavelength calibration of the gas detection optical module is completed, obtain a calibrated photoelectric curve, and obtain the concentration of the gas to be measured based on the calibrated photoelectric curve.

[0108] Specifically, in the temperature scanning monitoring step, the operating current of the gas detection optical module is a DC driving current; each execution of the temperature scanning monitoring step corresponds to a temperature scanning cycle. Figure 11 This is another schematic diagram of the change in scanning wavelength of a gas detection optical module during wavelength calibration of temperature scanning monitoring combined with current scanning monitoring provided by an embodiment of the present invention. Figure 11In the figure, e1~d4 are the scanning wavelength bands obtained in the temperature scanning monitoring step. The working current of the laser remains unchanged (the working current of the laser is fixed at ImA, and I is a current value within the rated working current range of the laser). The working temperature of the laser continues to increase, resulting in a continuous increase in the laser wavelength; d5~d7 are the scanning wavelength bands obtained in the current scanning monitoring step. When the working temperature of the laser remains unchanged, the scanning wavelength range of the laser is gradually corrected.

[0109] During the temperature scanning detection process, the temperature scanning range is relatively large, for example, the temperature scanning range is 18°C, so that the scanning wavelength range emitted by the laser can include the absorption wavelength of methane gas, 1653.7nm. It is in a state of continuous monitoring. When methane gas is detected, an absorption peak of methane appears in the photoelectric curve, as shown in the scanning wavelength segment e4 (it should be noted that the scanning wavelength segment in the present invention does not have an absorption peak. The peak type in the scanning wavelength segment is used to indicate that an absorption peak appears in the photoelectric curve corresponding to the scanning wavelength segment. The position of the peak type in the scanning wavelength segment corresponds to the position of the absorption peak in the photoelectric curve); then stop the temperature scanning detection, fix the operating temperature of the laser, ( Figure 11 The operating temperature of the laser is fixed at T°C, where T is the laser temperature when the absorption peak wavelength is currently scanned. At the same time, current scanning monitoring is started. The current scanning range during the first current scanning monitoring can be the rated operating current range of the laser, and the photoelectric curve corresponding to the scanning wavelength range f1 is obtained.

[0110] After finding the absorption peak, determine whether the absorption peak in the photoelectric curve is located at the center of the photoelectric curve. If not, it means that the scanning wavelength of the laser still needs to be calibrated. Adjust the current scanning range of the laser, perform current scanning monitoring, and obtain the photoelectric curve corresponding to the scanning wavelength segment f2. Determine again whether the absorption peak in the photoelectric curve corresponding to the scanning wavelength segment f2 is located at the center of the photoelectric curve. If not, it means that the scanning wavelength of the laser still needs to be calibrated. Continue to adjust the current scanning range of the laser until the absorption peak is located at the center of the photoelectric curve. Record the current operating current range of the laser and use it as the calibrated current scanning range. Drive the laser according to the calibrated current scanning range so that the laser wavelength range emitted by the laser meets the target scanning wavelength range. Then, the calibrated photoelectric curve can be obtained through the photodetector.

[0111] The wavelength correction method provided by an embodiment of the present invention includes a temperature scanning monitoring step, which includes: driving a gas detection optical module with a direct current drive current, and gradually varying the operating temperature of the gas detection optical module according to the temperature scanning step size within a temperature scanning range; detecting laser light emitted by the gas detection optical module with a photodetector, and generating an electrical signal based on the detected laser light to obtain a photoelectric curve. This temperature scanning method performs a wide-range wavelength scan. When the wavelength shift is large and the direction of the shift is unknown, this wide-range wavelength scan facilitates finding the absorption peak. Once the absorption peak is found, the current scanning range is adjusted so that the absorption peak is centered on the photoelectric curve, thereby correcting the current scanning range and completing wavelength drift correction, thereby improving the accuracy of gas concentration detection.

[0112] Based on the above embodiments, optionally, in step S130, step S290 and step S350, fixing the operating temperature of the gas detection light module includes: fixing the operating temperature of the gas detection light module to the temperature when the absorption peak appears in the temperature scanning monitoring step.

[0113] On the basis of the above embodiments, optionally, in step S130, step S290 and step S350, the operating temperature of the gas detection light module is fixed, including: judging whether the difference between the temperature when the absorption peak appears in the temperature scanning monitoring step and the rated operating temperature of the gas detection light module is less than a preset temperature difference; if it is greater than or equal to, then the operating temperature of the gas detection light module is fixed to the temperature when the absorption peak appears in the temperature scanning monitoring step; if it is less than, then the operating temperature of the gas detection light module is fixed to the rated operating temperature of the gas detection light module, so that the laser operates at the rated operating temperature during the current scanning detection process, which is beneficial to improving the service life of the laser.

[0114] Based on the above embodiments, optionally, in step S140, step S290 and step S370, the current scanning range of the gas detection optical module is adjusted, including: keeping the difference between the end scanning current and the start scanning current unchanged, and adjusting the size of the start scanning current.

[0115] Furthermore, the difference between the termination scan current and the starting scan current is kept constant, and before adjusting the starting scan current, the method further includes: determining the number of signal acquisition points of the photodetector in a single current scan cycle; determining the number of signal acquisition points located at the center of the photoelectric curve based on the number of signal acquisition points in the single current scan cycle; determining the number of points where the absorption peak deviates from the center based on the number of points of the absorption peak in the photoelectric curve and the number of signal acquisition points located at the center of the photoelectric curve; and determining the adjusted target starting scan current based on the current starting scan current, the difference between the termination scan current and the starting scan current, the number of signal acquisition points in a single current scan cycle, and the number of points where the absorption peak deviates from the center. The method further includes determining the adjusted target starting scan current based on the current starting scan current, the difference between the termination scan current and the starting scan current, the number of signal acquisition points in a single current scan cycle, and the number of points where the absorption peak deviates from the center based on the following formula:

[0116] Target starting scan current = current starting current value - (scan current interval value / number of scan points per unit cycle) * number of offset points from current position to center position. The current starting current value is the current starting scan current. The scan current interval value is the difference between the ending scan current and the starting scan current.

[0117] For example, Figure 12 This is a schematic diagram of the absorption peak position correction process in the current scanning detection step provided by an embodiment of the present invention, with reference to Figure 12 In current scan monitoring, if the number of scan points (signal acquisition points) per unit cycle is 330, the center of the photoelectric curve is at point 165. If the peak of the current absorption peak is at point 33 of the current scan cycle, it is 132 points lower than the center of the photoelectric curve. In this case, the starting scan current of the current scan range needs to be reduced to the target starting scan current. The target starting scan current is calculated as: target starting scan current = current starting current value - (current scan interval value / number of scan points per unit cycle) * number of offset points from the current position to the center position.

[0118] The technical solution provided by the embodiment of the present invention determines the adjusted target starting scanning current based on the current starting scanning current, the difference between the ending scanning current and the starting scanning current, the number of signal acquisition points in a single current scanning cycle, and the number of deviation points of the absorption peak relative to the center position. The position of the absorption peak in the photoelectric curve can be calibrated by adjusting the current scanning range once, thereby simplifying the wavelength correction method of the gas detection optical module.

[0119] Based on the above embodiments, after obtaining the calibrated photoelectric curve, the method may further include: determining the gas concentration of the gas to be measured based on the calibrated photoelectric curve; determining whether the gas concentration of the gas to be measured exceeds a first preset concentration threshold; if so, controlling an alarm device to issue an alarm prompt; if not, returning to the temperature scanning and monitoring step. The first preset concentration threshold may be set based on actual conditions, and the alarm device may provide an alarm in at least one of audible, visual, and textual form.

[0120] In the embodiment of the present invention, the gas concentration of the gas to be measured after calibration is used to determine whether to trigger the alarm device to issue an alarm prompt, thereby improving the accuracy of the alarm device in issuing an alarm prompt.

[0121] Based on the above embodiments, optionally, after repeating the temperature scanning monitoring step until an absorption peak appears in the photoelectric curve, the method further includes: determining a preliminary gas concentration of the gas to be measured based on the photoelectric curve where the absorption peak appears; determining whether the preliminary gas concentration of the gas to be measured exceeds a second preset concentration threshold; if so, executing the current scanning monitoring step; if not, returning to executing the temperature scanning monitoring step. The second preset concentration threshold can be set according to actual conditions, and the alarm device can provide an alarm in at least one of audible, visual, and textual forms.

[0122] In the embodiment of the present invention, before the current scanning detection step, the preliminary gas concentration of the gas to be tested obtained in the temperature scanning monitoring step is used to determine whether to trigger the alarm device to issue an alarm prompt, so as to reduce the negative impact caused by the gas to be tested.

[0123] An embodiment of the present invention also provides a wavelength correction device for a gas detection optical module, comprising: a temperature control module, used to obtain a temperature scanning range and a temperature scanning step, and adjust the operating temperature of the gas detection optical module according to the temperature scanning range and the temperature scanning step in the temperature scanning monitoring step; a photoelectric curve acquisition module, used to obtain a photoelectric curve through a photodetector in the temperature scanning monitoring step; the temperature control module is also used to fix the operating temperature of the gas detection optical module after performing the temperature scanning monitoring step multiple times until an absorption peak appears in the photoelectric curve; a current control module, used to adjust the operating current of the gas detection optical module for current scanning monitoring after fixing the operating temperature of the gas detection optical module, and the photoelectric curve acquisition module is also used to obtain a photoelectric curve through a photodetector in the current scanning monitoring step; a judgment module, used to determine whether the absorption peak deviates from the center position of the photoelectric curve, and the current control module is also used to adjust the current scanning range when the absorption peak deviates from the center position of the photoelectric curve until the absorption peak is located at the center position of the photoelectric curve, so as to achieve wavelength correction of the gas detection optical module and obtain a calibrated photoelectric curve.

[0124] An embodiment of the present invention further provides a gas concentration detection device, comprising a gas detection optical module, a photoelectric detector, a thermoelectric cooler, and a wavelength correction device for the gas detection optical module. The gas detection optical module may be a semiconductor laser for emitting laser light; the thermoelectric cooler is used to control the operating temperature of the gas detection optical module; the photodetector is used to detect the laser light emitted by the gas detection optical module and convert the optical signal into an electrical signal based on a photoelectric response to the detected laser light. The wavelength correction device for the gas detection optical module is electrically connected to the gas detection optical module, the thermoelectric cooler, and the photodetector, and is used to execute the wavelength correction method for the gas detection optical module described in any embodiment of the present invention. The gas concentration detection device may be a laser methane sensor for detecting the concentration of methane; the gas concentration detection device may also be a sensor for detecting the concentration of other gases.

[0125] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A wavelength calibration method for a gas detection optical module, characterized in that: include: Determine the temperature scanning range and temperature scanning step; Temperature scanning monitoring step; the temperature scanning monitoring step includes adjusting the operating temperature of the gas detection optical module according to the temperature scanning range and the temperature scanning step, and obtaining a photoelectric curve through a photoelectric detector; Repeating the temperature scanning monitoring step until an absorption peak appears in the photoelectric curve; Fixing the operating temperature of the gas detection optical module, adjusting the operating current of the gas detection optical module, and obtaining a photoelectric curve through a photodetector to perform current scanning monitoring; Determine whether the absorption peak deviates from the center position of the photoelectric curve. If the absorption peak deviates from the center position of the photoelectric curve, adjust the current scanning range until the absorption peak is located at the center position of the photoelectric curve to achieve wavelength correction of the gas detection light module and obtain a calibrated photoelectric curve.

2. The wavelength calibration method for a gas detection optical module according to claim 1, characterized in that: In the temperature scanning monitoring step, the operating current of the gas detection optical module is scanned according to a preset current scanning range. Each execution of the temperature scanning monitoring step corresponds to a current scanning cycle, and the operating temperature of the gas detection optical module remains unchanged. Adjusting the operating temperature of the gas detection optical module according to the temperature scanning range and the temperature scanning step, and obtaining a photoelectric curve through a photoelectric detector, including: determining an operating temperature of the gas detection optical module during a previous current scanning cycle; determining the operating temperature of the gas detection optical module in the current current scanning cycle according to the operating temperature in the previous current scanning cycle and the temperature scanning step; Determining whether the operating temperature of the current current scanning cycle exceeds the temperature scanning range; If not, adjusting the operating temperature of the gas detection light module to the operating temperature of the current current scanning period, controlling the operating current of the gas detection light module to scan according to the preset current scanning range, and generating an electrical signal according to the detected laser by a photodetector to obtain the photoelectric curve; If it exceeds, the operating temperature of the gas detection light module is adjusted to the starting temperature of the temperature scanning range, and the operating current of the gas detection light module is controlled to scan according to the preset current scanning range, and the photoelectric curve is obtained by generating an electrical signal according to the detected laser through the photodetector.

3. The wavelength calibration method for a gas detection optical module according to claim 1, characterized in that: In the temperature scanning monitoring step, the operating current of the gas detection optical module is a DC driving current; each temperature scanning monitoring step performed corresponds to a temperature scanning cycle; Adjusting the operating temperature of the gas detection optical module according to the temperature scanning range and the temperature scanning step, and obtaining a photoelectric curve through a photoelectric detector, including: driving the gas detection optical module by a DC driving current, and gradually changing the operating temperature of the gas detection optical module according to the temperature scanning step within the temperature scanning range; The laser light emitted by the gas detection optical module is detected by a photoelectric detector, and an electrical signal is generated according to the detected laser light to obtain the photoelectric curve.

4. The wavelength calibration method for a gas detection optical module according to claim 1, wherein: The fixing of the operating temperature of the gas detection optical module comprises: The operating temperature of the gas detection optical module is fixed to the temperature at which an absorption peak appears in the temperature scanning monitoring step.

5. The wavelength calibration method for a gas detection optical module according to claim 1, characterized in that: The fixing of the operating temperature of the gas detection optical module comprises: Determining whether a difference between a temperature at which an absorption peak appears in the temperature scanning monitoring step and a rated operating temperature of the gas detection optical module is less than a preset temperature difference; If it is less than, fixing the operating temperature of the gas detection optical module to the rated operating temperature of the gas detection optical module; If it is greater than or equal to, the operating temperature of the gas detection optical module is fixed to the temperature at which the absorption peak appears in the temperature scanning monitoring step.

6. The wavelength calibration method for a gas detection optical module according to claim 1, characterized in that: Adjusting the current scanning range until the absorption peak is located at the center of the photoelectric curve includes: The difference between the end scanning current and the start scanning current is kept unchanged, and the start scanning current is adjusted until the absorption peak is located at the center of the photoelectric curve.

7. The wavelength calibration method for a gas detection optical module according to claim 6, characterized in that: Keep the difference between the end scan current and the start scan current unchanged. Before adjusting the start scan current, the following steps are also included: Determining the number of signal collection points of the photodetector in a single current scanning cycle; According to the number of signal collection points in a single current scanning cycle, the number of signal collection points located at the center of the photoelectric curve is determined; Determining the number of points at which the absorption peak deviates from the center position according to the number of points at which the absorption peak is located on the photoelectric curve and the number of signal collection points located at the center position of the photoelectric curve; The adjusted target starting scanning current is determined based on the current starting scanning current, the difference between the ending scanning current and the starting scanning current, the number of signal collection points in a single current scanning cycle, and the number of deviation points of the absorption peak relative to the center position.

8. The wavelength calibration method for a gas detection optical module according to claim 1, wherein: After obtaining the calibrated photoelectric curve, it also includes: Determine the gas concentration of the gas to be measured based on the calibrated photoelectric curve; Determining whether the gas concentration of the gas to be measured exceeds a first preset concentration threshold; If it exceeds, the alarm device is controlled to give an alarm prompt; if it does not exceed, the process returns to the temperature scanning and monitoring step; And / or, after repeatedly performing the temperature scanning monitoring step until an absorption peak appears in the photoelectric curve, the method further includes: Determine the preliminary gas concentration of the gas to be measured based on the photoelectric curve where the absorption peak appears; Determining whether the preliminary gas concentration of the gas to be measured exceeds a second preset concentration threshold; If it exceeds, the current scanning monitoring step is executed; if it does not exceed, the process returns to execute the temperature scanning monitoring step.

9. A wavelength correction device for a gas detection optical module, characterized in that: include: a temperature control module, configured to obtain a temperature scanning range and a temperature scanning step, and to adjust the operating temperature of the gas detection optical module according to the temperature scanning range and the temperature scanning step in a temperature scanning monitoring step; A photoelectric curve acquisition module is used to obtain a photoelectric curve through a photoelectric detector in the temperature scanning monitoring step; The temperature control module is further configured to fix the operating temperature of the gas detection optical module after performing the temperature scanning monitoring step multiple times until an absorption peak appears in the photoelectric curve; a current control module, configured to adjust the operating current of the gas detection optical module after fixing the operating temperature of the gas detection optical module to perform current scanning monitoring, wherein the photoelectric curve acquisition module is further configured to obtain a photoelectric curve through a photoelectric detector during the current scanning monitoring step; The judgment module is used to determine whether the absorption peak deviates from the center position of the photoelectric curve. The current control module is also used to adjust the current scanning range when the absorption peak deviates from the center position of the photoelectric curve until the absorption peak is located at the center position of the photoelectric curve, so as to achieve wavelength correction of the gas detection light module and obtain a calibrated photoelectric curve.

10. A gas concentration detection device, characterized in that: The invention comprises a gas detection optical module, a photoelectric detector, a thermoelectric cooler and the wavelength correction device of the gas detection optical module according to claim 9.

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