Anti-interference detection method of infrared methane sensor and infrared methane sensor

Abstract

The invention provides an anti-interference detection method for an infrared methane sensor, comprising the following steps: S1, powering on a dual-channel infrared methane sensor; S2, acquiring a signal AD value of a measurement channel and a signal AD value of a reference channel; S3, selecting a reference signal AD baseline: calculating a fluctuation value Δ1 of the reference signal AD value within a T time; when 0≦Δ1≦X1, and the mutation value of the reference signal AD value is Δ2, the baseline within the T time before the mutation is generated is used as the reference signal AD baseline; S4, comparing the magnitude of a change X2 of the reference channel with Δ2; when X2>Δ2, determining that interference gas intervenes to interfere with the detection of methane concentration, and obtaining a methane concentration measurement value, correcting the methane concentration measurement value by a reference AD ​​algorithm, and obtaining an actual methane concentration value; when X2≤Δ2, the methane concentration measurement value is the actual methane concentration value; the invention also proposes that the infrared methane sensor can effectively avoid the interference of interference gas on the detection of methane concentration.

Description

Technical Field

[0001] The present invention relates to the field of methane concentration detection, and in particular to an anti-interference detection method of an infrared methane sensor and an infrared methane sensor. Background Art

[0002] The infrared methane sensor is a sensor used to detect methane concentration. Compared with other types of gas sensors such as electrochemical, catalytic combustion and semiconductor, it is increasingly widely used due to its high reliability, high precision, good selectivity, anti-poisoning, long life, little environmental impact and independence on oxygen. However, according to the "National Standard of the People's Republic of China - GB15322.1-2019" and "National Standard of the People's Republic of China - GB / T 34004-2017", it was found in the anti-gas interference performance test that the infrared methane sensor cannot avoid the interference of acetic acid and / or ethanol. The reason is that the infrared absorption peak of methane (3.3-3.4μm) is within the wavelength range of the infrared absorption peak of the interfering gases acetic acid and ethanol.

[0003] In order to solve the above problems, patent CN 111982850A discloses a sensor array for infrared anti-acetic acid interference detection device and method, which specifically utilizes the characteristic that catalytic combustion sensors are non-responsive to acetic acid, and solves the influence of acetic acid interference on infrared methane sensors by combining infrared methane sensors and catalytic combustion sensors for detection. However, due to the high operating temperature and high current consumption of the catalytic combustion sensor, the power consumption of the entire device is high, and the integration of two sensors leads to a complex structure and high cost. Summary of the invention

[0004] The present invention aims to provide an anti-interference detection method of an infrared methane sensor and an infrared methane sensor, which can effectively avoid the interference of at least one interfering gas of acetic acid and ethanol on the detection of methane concentration.

[0005] The present invention provides an anti-interference detection method for an infrared methane sensor, comprising the following steps:

[0006] S1. Start powering on and initialize the dual-channel infrared methane sensor;

[0007] S2. Obtaining the measurement signal AD value of the measurement channel and the reference signal AD value of the reference channel; wherein the absorption peak wavelength of the measurement channel is the absorption peak wavelength of methane, the absorption peak wavelength of the reference channel is the absorption peak wavelength of the interference gas, the absorption peak wavelength range of the interference gas covers the absorption peak wavelength of methane gas, and the absorption peak wavelength of the reference channel is outside the absorption peak wavelength of methane;

[0008] S3, select the reference signal AD baseline: calculate the fluctuation value Δ1 of the reference signal AD value within T time; when 0≦Δ1≦X1, and the mutation value of the reference signal AD value is Δ2, the baseline within T time before the mutation is generated as the reference signal AD baseline; wherein X1 is the upper limit AD value of the stable fluctuation of the reference channel in the air;

[0009] S4. Compare the change X2 of the reference channel with Δ2; when X2>Δ2, it is determined that there is interference gas interfering with the detection of methane concentration, and the methane concentration measurement value is obtained, and the methane concentration measurement value is corrected by referring to the AD algorithm to obtain the actual value of the methane concentration; when X2≤Δ2, it is determined that there is no interference gas interfering with the methane detection, and the methane concentration measurement value at this time is the actual value of the methane concentration.

[0010] Furthermore, the interfering gas is acetic acid and / or ethanol.

[0011] Further, in step S4, when it is determined that there is no interfering gas interfering with methane detection,

[0012] Calculate the methane concentration measurement value according to formula (1);

[0013]

[0014] in, is the measured AD value of methane in the measurement channel, and f1 is the methane concentration calibration function.

[0015] Further, in step S4, when it is determined that there is interference gas interfering with methane detection, the specific method of correcting the methane concentration measurement value by referring to the AD algorithm is as follows:

[0016] S401, according to the 5% LEL low limit warning setting value, different known concentrations of interference gases are introduced into the reference channel, and the influence of the change amount of the measurement channel relative to the air environment ΔT and the influence of the change amount of the reference channel relative to the air environment ΔR are obtained respectively, and the relationship between ΔT and ΔR is obtained by least squares fitting: ΔT=f2(ΔR);

[0017] S402, calculating the actual value of the methane concentration according to formula (2);

[0018]

[0019] in, T 总信号量 is the total signal AD value of the measurement channel, R 干扰气信号量 is the signal AD value of the interference gas of the reference channel, T 干扰气干扰量 is the signal AD value of the interference gas interference quantity of the measurement channel, R 干扰气信号量is the signal AD value of the interference gas in the measurement channel, f1 is the methane concentration calibration function, and f2 is the interference amount calibration function of the interference gas.

[0020] Further, in step S2, the absorption peak wavelength of the measurement channel is 3.3-3.4 μm; and the absorption peak wavelength of the reference channel is 3.6-4 μm.

[0021] The present invention also provides an infrared methane sensor, comprising:

[0022] A power-on unit, used to initialize the dual-channel infrared methane sensor;

[0023] An acquisition unit, used to acquire a measurement signal AD value of a measurement channel and a reference signal AD value of a reference channel; wherein the absorption peak wavelength of the measurement channel is the absorption peak wavelength of methane, the absorption peak wavelength of the reference channel is the absorption peak wavelength of the interference gas, the absorption peak wavelength range of the interference gas covers the absorption peak wavelength of the methane gas, and the absorption peak wavelength of the reference channel is outside the absorption peak wavelength of methane;

[0024] A baseline selection unit is used to calculate the fluctuation value Δ1 of the reference signal AD value within T time; when 0≦Δ1≦X1, and the mutation value of the reference signal AD value is Δ2, the baseline within T time before the mutation is generated as the reference signal AD baseline; wherein X1 is the upper limit AD value of the stable fluctuation of the reference channel in the air;

[0025] The comparison unit is used to compare the change X2 of the reference channel with Δ2; when X2>Δ2, it is judged that there is interference gas interfering with the detection of methane concentration, and the methane concentration measurement value is obtained, and the methane concentration measurement value is corrected by referring to the AD algorithm to obtain the actual value of the methane concentration; when X2≤Δ2, it is judged that there is no interference gas interfering with the methane detection, and the methane concentration measurement value at this time is the actual value of the methane concentration.

[0026] Furthermore, the comparison unit also includes an alarm module, which is used to control the infrared methane sensor to issue a methane leakage alarm when the actual value of the methane concentration is greater than 0.

[0027] The present invention also proposes an infrared methane sensor, comprising a sensor body and a filter membrane; the sensor body is used in the above-mentioned anti-interference detection method of an infrared methane sensor; the filter membrane is arranged on the sensor body to filter out acetic acid and / or ethanol in the gas entering the sensor body.

[0028] Furthermore, the filter membrane includes activated carbon fiber cotton.

[0029] Furthermore, the filter membrane also includes a waterproof and breathable membrane arranged on both sides of the activated carbon fiber cotton.

[0030] Compared with the prior art, the technical solution provided by the embodiment of the present invention has the following beneficial effects:

[0031] Based on the characteristic that the absorption peak wavelength range of the interference gas covers the absorption peak wavelength of the gas methane to be detected, the present invention sets the absorption peak wavelengths of the measurement channel and the reference channel to the absorption peak wavelength of methane and the absorption peak wavelength of the interference gas respectively, and sets the absorption peak wavelength of the reference channel to be outside the absorption peak wavelength of methane, so as to effectively judge whether there is interference from interference gases such as acetic acid or ethanol when detecting methane. At the same time, under the condition of the 5% LEL low limit warning setting value, the change amount of the interference gas in the reference channel can be calibrated to correct and obtain the true concentration of methane when the acetic acid or ethanol interference gas intervenes, thereby greatly improving the false alarm caused by the interference gas in the detection of methane concentration, without the need to set up other functional hardware. In addition, the infrared methane sensor provided by the present invention can directly and effectively filter out the acetic acid and ethanol interference gases in a low concentration environment because a filter membrane is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of a flow chart of an anti-interference detection method of an infrared methane sensor in a certain embodiment of the present invention;

[0033] Figure 2 The AD value variation curve of the measurement channel T and the reference channel R when there is only methane gas in a certain embodiment of the present invention;

[0034] Figure 3 The AD value variation curve of the measurement channel T and the reference channel R when there is only acetic acid gas in a certain embodiment of the present invention;

[0035] Figure 4 is a curve showing the change of AD values ​​of the measurement channel T and the reference channel R when there is both acetic acid gas and methane gas in one embodiment of the present invention;

[0036] Figure 5 is a curve showing the change of methane concentration over time when no correction is made for acetic acid interference in an embodiment of the present invention;

[0037] Figure 6 is a curve showing the change of methane concentration over time after correction of acetic acid interference in a certain embodiment of the present invention;

[0038] Figure 7 The influence curve of methane on the reference channel and the measurement channel of the sensor in a certain embodiment of the present invention;

[0039] Figure 8 The influence curve of acetic acid on the reference channel and the measurement channel of the sensor in a certain embodiment of the present invention;

[0040] Fig. 9 This is a schematic diagram of the explosion structure of an infrared methane sensor in a certain embodiment of the present invention;

[0041] Among them, 1. upper waterproof and breathable membrane; 2. activated carbon fiber cotton; 3. lower waterproof and breathable membrane; 4. air chamber; 5. air chamber protective film; 6. infrared probe; 7. circuit board. DETAILED DESCRIPTION

[0042] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0043] Please refer to Figure 1 , an embodiment of the present invention provides an anti-interference detection method for an infrared methane sensor, comprising the following steps:

[0044] S1. Start powering on and initializing the dual-channel infrared methane sensor.

[0045] Exemplarily, in step S1, after the infrared methane sensor is initialized for 5 minutes, the measurement signal AD value and the reference signal AD value are measured normally.

[0046] S2. Obtain the measurement signal AD value of the measurement channel and the reference signal AD value of the reference channel; wherein, the absorption peak wavelength of the measurement channel is the absorption peak wavelength of methane, the absorption peak wavelength of the reference channel is the absorption peak wavelength of the interfering gas, the absorption peak wavelength range of the interfering gas covers the absorption peak wavelength of methane gas, and the absorption peak wavelength of the reference channel is outside the absorption peak wavelength of methane.

[0047] In step S2, the measurement channel can detect the signal AD values ​​of methane, ethanol and / or acetic acid at the same time, while the reference channel can only detect the signal AD values ​​of ethanol and / or acetic acid.

[0048] S3. Select the reference signal AD baseline: calculate the fluctuation value Δ1 of the reference signal AD value within T time; when 0≦Δ1≦X1, and the mutation value of the reference signal AD value is Δ2, the baseline within T time before the mutation is generated as the reference signal AD baseline; wherein X1 is the upper limit AD value of the stable fluctuation of the reference channel in the air;.

[0049] S4. Compare the change X2 of the reference channel with Δ2; when X2>Δ2, it is determined that there is interference gas interfering with the detection of methane concentration, and the methane concentration measurement value is obtained, and the methane concentration measurement value is corrected by referring to the AD algorithm to obtain the actual value of the methane concentration; when X2≤Δ2, it is determined that there is no interference gas interfering with the methane detection, and the methane concentration measurement value at this time is the actual value of the methane concentration.

[0050] Specifically, in step S4, when it is determined that there is no interfering gas interfering with methane detection, the methane concentration measurement value is calculated according to formula (1);

[0051]

[0052] in, is the measured AD value of methane in the measurement channel, and f1 is the methane concentration calibration function.

[0053] Illustratively, in this embodiment, the interfering gas is acetic acid.

[0054] In some preferred embodiments, when the actual value of the methane concentration is greater than 0, the infrared methane concentration sensor sends out a methane leakage alarm, which may be an audible and / or visual alarm.

[0055] Specifically, in step S4, when it is determined that there is interference gas interfering with methane detection, the specific method of correcting the methane concentration measurement value by referring to the AD algorithm is as follows:

[0056] S402, according to the 5% LEL low limit warning setting value, different known concentrations of interference gases are introduced into the reference channel, and the influence of the change amount of the measurement channel relative to the air environment ΔT and the influence of the change amount of the reference channel relative to the air environment ΔR are obtained respectively, and the relationship between ΔT and ΔR is obtained by least squares fitting: ΔT=f2(ΔR);

[0057] S403, calculating the actual value of the methane concentration according to formula (2);

[0058]

[0059] in, T 总信号量 is the total signal AD value of the measurement channel, R 干扰气信号量 is the signal AD value of the interference gas of the reference channel, T 干扰气干扰量 is the signal AD value of the interference gas interference quantity of the measurement channel, R 干扰气信号量 is the signal AD value of the interference gas in the measurement channel, and f2 is the interference quantity calibration function of the interference gas.

[0060] For example, reference Figures 2 to 4In this embodiment, the influence of acetic acid on the change of the measurement channel relative to the air environment ΔT1, ΔT2, ΔT3 and ΔT4, and the influence of the change of the reference channel relative to the air environment ΔR1, ΔR2, ΔR3 and ΔR4 are tested in the air environment and A, 2A, 3A and 4A concentration environments respectively; the relationship between ΔT and ΔR is obtained by least squares fitting: ΔT=f2(ΔR), and the influence of acetic acid interference gas on the measurement channel can be calculated according to the change of the reference channel, and then in the process of calculating the methane concentration, the interference of acetic acid interference gas is removed to obtain the actual value of the methane concentration; f1 is the methane concentration calibration function, which is obtained by fitting the standard concentration curve.

[0061] Figure 5 is the curve of methane concentration changing with time when no correction for acetic acid interference is made. Figure 5 It can be seen that different concentrations of acetic acid (2000PPM, 4000PPM and 6000PPM) will interfere with the detection of methane concentration to varying degrees; Figure 6 This is the change curve of methane concentration over time after correction for acetic acid interference, where the concentration of acetic acid is 6000PPM; Figure 5 and Figure 6 It can be seen that this embodiment can effectively eliminate the interference of acetic acid on the methane concentration detection by correcting the methane concentration detection.

[0062] Figure 7 The influence curve of methane on the reference channel and measurement channel of the sensor; by comparing the AD values ​​of the measurement channel and reference channel signals due to the methane concentration, it can be seen that: methane has a greater influence on the AD value of the measurement channel signal, that is, the measurement channel signal has a greater response to the methane concentration, and the methane signal can be detected; methane has a smaller influence on the AD value of the reference channel signal, that is, the reference channel signal has a smaller response to the methane concentration, and the methane signal cannot be detected; Figure 8 is the influence curve of acetic acid on the reference channel and measurement channel of the sensor; Figure 8 It can be seen that acetic acid has a greater impact on the measurement channel and the AD value of the measurement channel signal, that is, the measurement channel and the reference channel have a greater response to the methane concentration, and the signal detection of acetic acid interference can be realized.

[0063] Specifically, in step S2, the absorption peak wavelength of the measurement channel is 3.3-3.4 μm; the absorption peak wavelength of the reference channel is 3.6-4 μm.

[0064] Illustratively, in this embodiment, the absorption peak wavelength of the measurement channel is 3.4 μm; and the absorption peak wavelength of the reference channel is 3.9 μm.

[0065] The present invention also provides an infrared methane sensor, comprising:

[0066] A power-on unit, used to initialize the dual-channel infrared methane sensor;

[0067] An acquisition unit, used to acquire a measurement signal AD value of a measurement channel and a reference signal AD value of a reference channel; wherein the absorption peak wavelength of the measurement channel is the absorption peak wavelength of methane, the absorption peak wavelength of the reference channel is the absorption peak wavelength of the interference gas, the absorption peak wavelength range of the interference gas covers the absorption peak wavelength of the methane gas, and the absorption peak wavelength of the reference channel is outside the absorption peak wavelength of methane;

[0068] A baseline selection unit is used to calculate the fluctuation value Δ1 of the reference signal AD value within T time; when 0≦Δ1≦X1, and the mutation value of the reference signal AD value is Δ2, the baseline within T time before the mutation is generated as the reference signal AD baseline; wherein X1 is the upper limit AD value of the stable fluctuation of the reference channel in the air;

[0069] The comparison unit is used to compare the change X2 of the reference channel with Δ2; when X2>Δ2, it is judged that there is interference gas interfering with the detection of methane concentration, and the methane concentration measurement value is obtained, and the methane concentration measurement value is corrected by referring to the AD algorithm to obtain the actual value of the methane concentration; when X2≤Δ2, it is judged that there is no interference gas interfering with the methane detection, and the methane concentration measurement value at this time is the actual value of the methane concentration.

[0070] In some preferred embodiments, the comparison unit further includes an alarm module for controlling the infrared methane sensor to issue a methane leakage alarm when the actual value of the methane concentration is greater than 0.

[0071] Fig. 9 An infrared methane sensor in another embodiment of the present invention comprises a sensor body and a filter membrane; wherein the sensor body is used to implement the above-mentioned anti-interference detection method of an infrared methane sensor; the filter membrane is arranged on the sensor body to filter out acetic acid and / or ethanol in the gas entering the sensor body.

[0072] Specifically, in this embodiment, the sensor body includes a circuit board 7, and an infrared probe 6 and an air chamber 4 arranged on the upper surface of the circuit board 7; the air chamber 4 is a hollow structure, and an opening is provided at the bottom of the air chamber 4, which is isolated from the circuit board 7 by an air chamber protective film 5, and an air inlet is opened at the top of the air chamber 4; the filter membrane is arranged at the top of the air chamber 4, completely covering the air inlet, and is used to filter out acetic acid and / or ethanol in the gas entering the air inlet.

[0073] Exemplarily, in this embodiment, the filter membrane includes activated carbon fiber cotton 2; waterproof and breathable membranes are respectively provided on the upper and lower sides of the activated carbon fiber cotton 2, specifically an upper waterproof and breathable membrane 1 and a lower waterproof and breathable membrane 3; the filter membrane is located at the top of the air chamber 4 and completely covers the air inlet of the air chamber 4, and is connected to the air chamber 4 by glue.

[0074] When the infrared methane sensor in this embodiment is working, the gas enters the gas chamber through the filter membrane and the waterproof breathable membrane; if the gas is mixed with acetic acid and / or ethanol gas, the acetic acid and / or ethanol gas is adsorbed and filtered by the activated carbon fiber cotton, so that the acetic acid and / or ethanol gas cannot pass through the activated carbon fiber cotton to reach the sensing area of ​​the infrared methane sensor, thereby not interfering with the normal operation of the infrared methane sensor; in addition, since the activated carbon fiber cotton does not adsorb methane, methane will reach the sensing area of ​​the infrared methane sensor and will not affect the detection accuracy and sensitivity of the infrared methane sensor.

[0075] For matters not mentioned above, the prior art applies.

[0076] In this document, the directional words such as front, back, top, and bottom are defined by the positions of the components in the drawings and the positions of the components relative to each other, and are only for the sake of clarity and convenience in expressing the technical solution. It should be understood that the use of the directional words should not limit the scope of protection claimed in this application.

[0077] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An anti-interference detection method for an infrared methane sensor, characterized in that: The steps include: S1. Start powering on and initialize the dual-channel infrared methane sensor; S2. Obtaining the measurement signal AD value of the measurement channel and the reference signal AD value of the reference channel; wherein the absorption peak wavelength of the measurement channel is the absorption peak wavelength of methane, the absorption peak wavelength of the reference channel is the absorption peak wavelength of the interference gas, the absorption peak wavelength range of the interference gas covers the absorption peak wavelength of methane gas, and the absorption peak wavelength of the reference channel is outside the absorption peak wavelength of methane; S3, select the reference signal AD baseline: calculate the fluctuation value Δ1 of the reference signal AD value within T time; when 0≤Δ1≤X1, and the mutation value of the reference signal AD value is Δ2, the baseline within T time before the mutation is generated as the reference signal AD baseline; wherein X1 is the upper limit AD value of the stable fluctuation of the reference channel in the air; S4, comparing the change X2 of the reference channel with Δ2; when X2>Δ2, it is determined that there is interference gas interfering with the detection of methane concentration, and the methane concentration measurement value is obtained, and the methane concentration measurement value is corrected by referring to the AD algorithm to obtain the actual value of the methane concentration; when X2≤Δ2, it is determined that there is no interference gas interfering with the methane detection, and the methane concentration measurement value at this time is the actual value of the methane concentration; When it is determined that there is no interfering gas interfering with methane detection, the methane concentration measurement value is calculated according to formula (1): in, is the measured AD value of methane in the measurement channel, and f1 is the methane concentration calibration function; When it is determined that there is interference gas interfering with methane detection, the specific method of correcting the methane concentration measurement value by referring to the AD algorithm is as follows: S401, according to the 5% LEL low limit warning setting value, different known concentrations of interference gases are introduced into the reference channel, and the influence of the change amount of the measurement channel relative to the air environment ΔT and the influence of the change amount of the reference channel relative to the air environment ΔR are obtained respectively, and the relationship between ΔT and ΔR is obtained by least squares fitting: ΔT=f2(ΔR); S402. Calculate the actual value of the methane concentration according to formula (2): in, T 总信号量 is the total signal AD value of the measurement channel, R 干扰气信号量 is the signal AD value of the interference gas of the reference channel, T 干扰气干扰量 is the signal AD value of the interference gas interference quantity of the measurement channel, R 干扰气信号量 is the signal AD value of the interference gas in the measurement channel, f1 is the methane concentration calibration function, and f2 is the interference amount calibration function of the interference gas.

2. The anti-interference detection method of an infrared methane sensor according to claim 1 is characterized in that: The interfering gas is acetic acid and / or ethanol.

3. The anti-interference detection method of an infrared methane sensor according to claim 1 is characterized in that: In step S2, the absorption peak wavelength of the measurement channel is 3.3-3.4 μm; the absorption peak wavelength of the reference channel is 3.6-4 μm.

4. An infrared methane sensor for implementing the anti-interference detection method of the infrared methane sensor according to any one of claims 1 to 3, characterized in that: include: A power-on unit, used to initialize the dual-channel infrared methane sensor; An acquisition unit, used to acquire a measurement signal AD value of a measurement channel and a reference signal AD value of a reference channel; wherein the absorption peak wavelength of the measurement channel is the absorption peak wavelength of methane, the absorption peak wavelength of the reference channel is the absorption peak wavelength of the interference gas, the absorption peak wavelength range of the interference gas covers the absorption peak wavelength of the methane gas, and the absorption peak wavelength of the reference channel is outside the absorption peak wavelength of methane; A baseline selection unit is used to calculate the fluctuation value Δ1 of the reference signal AD value within T time; when 0≦Δ1≦X1, and the mutation value of the reference signal AD value is Δ2, the baseline within T time before the mutation is generated as the reference signal AD baseline; wherein X1 is the upper limit AD value of the stable fluctuation of the reference channel in the air; The comparison unit is used to compare the change X2 of the reference channel with Δ2; when X2>Δ2, it is judged that there is interference gas interfering with the detection of methane concentration, and the methane concentration measurement value is obtained, and the methane concentration measurement value is corrected by referring to the AD algorithm to obtain the actual value of the methane concentration; when X2≤Δ2, it is judged that there is no interference gas interfering with the methane detection, and the methane concentration measurement value at this time is the actual value of the methane concentration.

5. The infrared methane sensor according to claim 4, characterized in that: The comparison unit also includes an alarm module, which is used to control the infrared methane sensor to issue a methane leakage alarm when the actual value of the methane concentration is greater than 0.

6. An infrared methane sensor for implementing the anti-interference detection method of the infrared methane sensor according to any one of claims 1 to 3, characterized in that: The sensor comprises a sensor body and a filter membrane. The filter membrane is arranged on the sensor body and is used for filtering out acetic acid and / or ethanol in the gas entering the sensor body.

7. The infrared methane sensor according to claim 6, characterized in that: The filter membrane includes activated carbon fiber cotton.

8. The infrared methane sensor according to claim 7, characterized in that: The filter membrane also includes waterproof and breathable membranes arranged on both sides of the activated carbon fiber cotton.

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