Infrared multi-channel gas detection method and gas sensor

Abstract

This invention discloses an infrared multi-channel gas detection method and a gas sensor. The gas detection method mainly includes: calibrating the infrared multi-channel gas sensor using first, second, and third target gases to obtain a fitting function of the concentration of each target gas and the ratio of the absorbance of each target gas in its corresponding measurement channel and reference channel, as well as a fitting function of the ratio of the absorbance of each target gas in its corresponding measurement channel and reference channel and the interference absorbance of each target gas in other measurement channels. Interference correction is then applied to the target gas in each measurement channel to obtain the true concentration of each target gas. This invention utilizes the characteristic of a blackbody light source that can radiate a wider wavelength range to design the infrared wavelength of multi-component target gases, minimizing cross-interference between components. Furthermore, an anti-interference detection method is used to eliminate interference between the component gases, thereby improving the detection accuracy of each component of the target gas.

Description

Technical Field

[0001] This invention relates to the field of infrared gas detection, and more specifically, to an infrared multi-channel gas detection method and a gas sensor. Background Technology

[0002] In recent years, the most common types of household gas are piped natural gas and bottled liquefied petroleum gas (LPG). The former's main component is... The latter's main component is Due to concerns about gas safety, people are increasingly concerned about and demanding reliable gas alarms. The core component of a gas alarm is a combustible gas sensor, used to detect the main characteristic gases of the gas. , monitor.

[0003] Currently, most combustible gas sensors on the market utilize electrochemical, catalytic combustion, and semiconductor principles, but these products have shortcomings in terms of sensitivity, measurement accuracy, maintenance, and lifespan. Infrared gas sensors, on the other hand, offer advantages such as high accuracy, good selectivity, high reliability, resistance to poisoning, and long lifespan, making them highly favored by users and widely used.

[0004] However, modern households frequently use cooking wine (containing ethanol) and vinegar (containing acetic acid) in their kitchens. When cookware is heated to high temperatures, ethanol and acetic acid readily evaporate into the air. Furthermore, the infrared absorption wavelengths of ethanol and acetic acid gases are similar to those of the main components of combustible gases. or There is overlap, which can cause interference and false alarms during monitoring. Existing technologies employ a combination of infrared principles and other technical principles to address this interference problem. For example, patent application CN111982850A discloses a sensor array detection device and method for infrared interference resistance to acetic acid, utilizing the characteristic that catalytic combustion sensors are unresponsive to acetic acid, and using infrared... The combined detection method of sensor and catalytic combustion sensor solves the problem of acetic acid interference on infrared detection. Due to the influence of sensors, this dual-sensor joint detection scheme can only operate in a single gas environment (such as only acetic acid or only...). To achieve resistance to acetic acid interference in a gaseous environment, while simultaneously present Interference-resistant detection is not possible in complex gas environments such as acetic acid; for example, patent application CN115901663A discloses an infrared gas detection system that also uses an infrared sensor, a catalytic combustion sensor, and an acetic acid gas detection device in combination to achieve interference resistance to acetic acid. Specifically, the acetic acid gas detection device acquires an acetic acid signal to characterize the concentration of acetic acid gas components in the gas; based on the different sensitivities of infrared and catalytic combustion sensors to acetic acid, the system acquires the concentration of acetic acid-containing gases... Two different gas detection signals are used to select and display the preferred detection signal based on the acetic acid detection signal, thus achieving resistance to acetic acid interference. While this method detects mixed gases, it fails to address interference-resistant detection of ethanol, and the use of three gas sensors based on different principles results in high measurement costs. Furthermore, the aforementioned existing technologies primarily target... Anti-interference detection, for There are very few reports on anti-interference testing.

[0005] In response, patent applications CN116893154A and CN116893153A disclose the use of infrared multi-channel sensors for detection, specifically by setting different wavelength filters on the multiple channels of the infrared detector to achieve detection. (or While it is resistant to interference from acetic acid and / or ethanol gases, its infrared light source can only radiate... The characteristics of wavelengths below and above, therefore, in targeting (or When selecting wavelengths for gases such as acetic acid and ethanol, it is difficult to find a suitable and interference-free absorption wavelength, which places high demands on the sensor's anti-interference algorithm. Furthermore, once the gas composition in the environment becomes complex, the sensor may still experience false alarms.

[0006] Furthermore, similar issues exist in other application areas. Anesthetic gas sensors are a core component of modern medical monitoring systems, primarily used in surgical anesthesia, intensive care, and emergency medicine. Their core function is to monitor in real-time anesthetic gases (such as isoflurane, sevoflurane, and desflurane) and life support gases (such as oxygen) in the patient's breathing circuit. , The concentration of anesthetic gas is controlled to ensure the safety and accuracy of the anesthesia process. Currently used anesthetic gas sensors employ infrared absorption technology to detect the concentration of anesthetic gas... as well as There are also absorption peaks that interfere with each other and cannot be distinguished. As a medical-grade sensor, the anesthetic gas sensor has even higher requirements for gas concentration detection accuracy. Summary of the Invention

[0007] To address the problem of severe interference between multiple target gases when using existing infrared absorption principles for measuring multi-component gases, as mentioned in the background, this invention first proposes an infrared multi-channel gas detection method. This method includes an infrared multi-channel gas sensor for detecting multiple components, comprising a multi-channel detector. The multi-channel detector includes a first measurement channel, a second measurement channel, a third measurement channel, and a reference channel. The first, second, and third measurement channels are used to detect the concentrations of a first target gas, a second target gas, and a third target gas, respectively. Each of the first, second, and third target gases is subject to interference from the other two target gases in its corresponding measurement channel. The gas detection method includes:

[0008] S1: Calculate the fitting function of the ratio of the absorption rate of the first, second, and third test gases at different known concentrations to each test gas in the corresponding measurement channel and reference channel;

[0009] S2: Calculate the fitting function between the ratio absorption rate of each of the test gases at different known concentrations in the corresponding measurement channel and reference channel and the interference absorption rate of each test gas in the other measurement channels;

[0010] S3: Introduce a mixture of gas of unknown concentration containing the first gas to be tested, the second gas to be tested, and the third gas to be tested into the infrared multi-channel gas sensor. By correcting the ratio of the absorption rate of each gas to be tested in its respective measurement channel and reference channel, the true ratio of the absorption rate of each gas to be tested in the corresponding measurement channel and reference channel is obtained after correction.

[0011] S4: Substitute the true ratio of the absorbance of each gas to be tested into the fitting functions in S1 to obtain the true concentration of each gas to be tested.

[0012] In S1 and S2, the goodness of fit of each fitting function Greater than 0.99.

[0013] Further, in step S1, the fitting functions for the ratio absorptivity of the first test gas, the second test gas, and the third test gas to the corresponding measurement channel and reference channel are respectively:

[0014] ,

[0015] ,

[0016] ,

[0017] in, The concentration of the first gas to be measured. The ratio of the absorbance of the first gas to be measured to that of the first measurement channel and the reference channel is given. , , , for The coefficients of the cubic function fit; The concentration of the second gas to be measured. The ratio of the absorbance of the second analyte gas in the second measurement channel to that in the reference channel is given. , , , for The coefficients of the cubic function fit; The concentration of the third gas to be measured. The ratio of the absorbance of the third analyte gas in the third measurement channel to that in the reference channel is given. , , , for The coefficients of the cubic function fit;

[0018] Further, in step S2, the fitting functions for the ratio of the absorbance of each gas to be tested in the corresponding measurement channel and the reference channel to the interference absorbance of each gas to be tested in the other measurement channels are as follows:

[0019] ,

[0020] ,

[0021] ,

[0022] ,

[0023] ,

[0024] ,

[0025] in, , The values ​​represent the interference absorption rates of the first gas to be measured in the second and third measurement channels, respectively. , , , for The coefficients of the cubic function fit. , , , for The coefficients of the cubic function fit; , The values ​​represent the interference absorption rates of the second gas to be measured in the first and third measurement channels, respectively. , , , for The coefficients of the cubic function fit. , , , for The coefficients of the cubic function fit; , The values ​​represent the interference absorption rates of the third gas to be measured in the first and second measurement channels, respectively. , , , for The coefficients of the cubic function fit. , , , for The coefficients of the cubic function fit.

[0026] Furthermore, the actual concentrations of the first, second, and third test gases are as follows:

[0027] ,

[0028] ,

[0029] ,

[0030] in, , , These are the total ratios of the absorption rates of the first, second, and third test gases in their respective measurement and reference channels.

[0031] Furthermore, the first gas to be tested is The second gas to be tested is acetic acid; the third gas to be tested is ethanol.

[0032] Furthermore, the preset infrared wavelength of the first measurement channel is... The preset infrared wavelength of the second measurement channel is... The preset infrared wavelength of the third measurement channel is... The preset infrared wavelength of the reference channel is... .

[0033] Furthermore, the first gas to be tested is an anesthetic gas; the second gas to be tested is... The third gas to be tested is .

[0034] Furthermore, the anesthetic gas is at least one of sevoflurane, desflurane, or isoflurane.

[0035] Furthermore, the preset infrared wavelength of the first measurement channel is... The preset infrared wavelength of the second measurement channel is... The preset infrared wavelength of the third measurement channel is... The preset infrared wavelength of the reference channel is... .

[0036] This invention also proposes a gas sensor based on the aforementioned infrared multi-channel gas detection method, comprising a gas chamber, an infrared light source, a multi-channel detector, and a circuit board. The gas chamber is used for gas flow; the infrared radiation source is a MEMS blackbody radiation source used to emit light into the gas chamber; the multi-channel detector includes three measurement channels and one reference channel; the circuit board is electrically connected to the infrared light source and the multi-channel detection unit, and the circuit board includes a signal processing unit for converting the optical signal detected by the multi-channel detector into an electrical signal, and processing the electrical signal to obtain the concentration of the gas to be measured.

[0037] Furthermore, the preset wavelength range of the light emitted by the MEMS blackbody radiation source is... More preferably, the preset wavelength range is .

[0038] The infrared multi-channel gas detection method and gas sensor provided by this invention have the following beneficial effects:

[0039] This invention is based on an infrared multi-channel gas sensor, which can radiate a wider wavelength range using a blackbody light source. The characteristics of the infrared wavelength of the multi-component gas to be tested are used to design the infrared wavelength, so as to minimize the cross-interference between the components. This makes the fitting degree of each channel fitting function in the anti-interference detection method S1 and S2 of the present invention higher. A value greater than 0.99 indicates that the influence of each gas to be measured on each measurement channel is essentially linear, allowing for high-precision gas interference correction in S3, thereby improving the detection accuracy of each component of the gas to be measured. Attached Figure Description

[0040] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0041] Figure 1 This invention provides Infrared absorption spectra of acetic acid and ethanol;

[0042] Figure 2 This is a flowchart of the infrared multi-channel gas detection method provided by the present invention;

[0043] Figure 3 This is a graph showing the fitting relationship between the concentrations of propane, ethanol, and acetic acid and the ratio of absorbance of the corresponding measurement channel and reference channel, provided by this invention.

[0044] Figure 4 This is a graph showing the fitting relationship between the ratio absorption rate of propane in the corresponding measurement channel and the reference channel and the interference absorption rate in the other two measurement channels, provided by the present invention.

[0045] Figure 5 This is a graph showing the fitting relationship between the ratio of acetic acid absorption rate in the corresponding measurement channel and the reference channel and the interference absorption rate to the other two measurement channels, provided by the present invention.

[0046] Figure 6 This is a graph showing the fitting relationship between the ratio of ethanol absorption rate in the corresponding measurement channel and the reference channel and the interference absorption rate to the other two measurement channels, provided by the present invention.

[0047] Figure 7 This is a structural diagram of the infrared multi-channel gas sensor provided by the present invention. Detailed Implementation

[0048] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0049] The most common types of household gas are piped natural gas and bottled liquefied petroleum gas (LPG). The former's main component is... The latter's main component is For gas safety reasons, reliable gas alarms are crucial, and the core component of a gas alarm is a combustible gas sensor, used to detect the main characteristic gases of the gas. or monitor.

[0050] In the monitoring of combustible gases in household kitchens, modern families frequently use condiments such as cooking wine (containing ethanol) and vinegar (containing acetic acid) when cooking. After the cookware is heated at high temperatures, ethanol and acetic acid are extremely easy to volatilize into the air. The infrared absorption wavelengths of ethanol and acetic acid gases are similar to those of the main components of combustible gases. or Overlapping signals can cause interference and false alarms during monitoring. Currently, most civilian propane sensors on the market utilize electrochemical, catalytic combustion, and semiconductor principles, and these products have shortcomings in sensitivity, measurement accuracy, maintenance, and lifespan. In contrast, infrared gas sensors offer advantages such as high accuracy, good selectivity, high reliability, resistance to poisoning, and long lifespan, making them highly popular among users. However, high interference resistance based on the infrared absorption principle... Sensors, however, are rarely reported.

[0051] To achieve the above effects, embodiments of the present invention provide an infrared multi-channel gas detection method, including an infrared multi-channel gas sensor for detecting multi-component gases. The infrared multi-channel gas sensor includes a multi-channel detector; the multi-channel detector includes a first measurement channel, a second measurement channel, a third measurement channel, and a reference channel; the first measurement channel, the second measurement channel, and the third measurement channel are respectively used for detection. The concentrations of acetic acid and ethanol, and Acetic acid and ethanol can interfere with each other. In this embodiment, a blackbody radiation source was selected to eliminate the interference between the three gases. This type of light source is superior to ordinary light sources ( It can emit a wider range of wavelengths (within) so that the wavelength absorption peaks of the three gases can be selected to minimize the interference between them.

[0052] In this embodiment, the preset wavelength range of the light emitted by the blackbody radiation source is: More preferably ,and The preset infrared wavelengths for the three gases, acetic acid and ethanol, are respectively , as well as The preset infrared wavelength of the reference channel is The principle for selecting the absorption wavelength of the reference channel is to avoid the absorption wavelengths of water vapor and other gases being measured as much as possible.

[0053] like Figure 1 As shown, acetic acid, ethanol and There is significant overlap, and because a blackbody radiation source is used, the absorption peaks for acetic acid and ethanol can be selected to... Within this range, the interference between the three gases is minimized, and on this basis, methods such as... Figure 2 The anti-interference method shown can obtain when The actual concentrations of each component when a leak occurs and acetic acid and ethanol gases are present in the environment; this anti-interference method specifically includes:

[0054] S1: Calculate the fitting function of the ratio of the absorption rate of the first, second, and third test gases at different known concentrations to each test gas in the corresponding measurement channel and reference channel;

[0055] S2: Calculate the fitting function between the ratio absorption rate of each of the test gases at different known concentrations in the corresponding measurement channel and reference channel and the interference absorption rate of each test gas in the other measurement channels;

[0056] S3: Introduce a mixture of gas of unknown concentration containing the first gas to be tested, the second gas to be tested, and the third gas to be tested into the infrared multi-channel gas sensor. By correcting the ratio of the absorption rate of each gas to be tested in its respective measurement channel and reference channel, the true ratio of the absorption rate of each gas to be tested in the corresponding measurement channel and reference channel is obtained after correction.

[0057] S4: Substitute the true ratio of the absorbance of each gas to be tested into the fitting functions in S1 to obtain the true concentration of each gas to be tested.

[0058] The first gas to be tested above is The second gas to be tested is The interfering gas is acetic acid, and the third gas to be tested is... Another interfering gas is ethanol.

[0059] In an exemplary embodiment, in step S1, the fitting functions for the ratio of the first test gas, the second test gas, and the third test gas to the absorption rates of the corresponding channels and the reference channel are respectively:

[0060] ,

[0061] ,

[0062] ,

[0063] in, The concentration of the first gas to be measured. The ratio of the absorbance of the first gas to be measured to that of the first measurement channel and the reference channel is given. , , , for The coefficients of the cubic function fit; The concentration of the second gas to be measured. The ratio of the absorbance of the second analyte gas in the second measurement channel to that in the reference channel is given. , , , for The coefficients of the cubic function fit; The concentration of the third gas to be measured. The ratio of the absorbance of the third analyte gas in the third measurement channel to that in the reference channel is given. , , , for The coefficients of the cubic function fit;

[0064] In step S2, the fitting functions for the ratio of the absorbance of each gas to be tested in the corresponding measurement channel and the reference channel to the interference absorbance of each gas to be tested in the other measurement channels are as follows:

[0065] ,

[0066] ,

[0067] ,

[0068] ,

[0069] ,

[0070] ,

[0071] in, , The values ​​represent the interference absorption rates of the first gas to be measured in the second and third measurement channels, respectively. , , , for The coefficients of the cubic function fit. , , , for The coefficients of the cubic function fit; , The values ​​represent the interference absorption rates of the second gas to be measured in the first and third measurement channels, respectively. , , , for The coefficients of the cubic function fit. , , , for The coefficients of the cubic function fit; , The values ​​represent the interference absorption rates of the third gas to be measured in the first and second measurement channels, respectively. , , , for The coefficients of the cubic function fit. , , , for The coefficients of the cubic function fit;

[0072] In step S3, the actual concentrations of the first gas to be tested, the second gas to be tested, and the third gas to be tested are respectively:

[0073] ,

[0074] ,

[0075] ,

[0076] in, , , These are the total ratios of the absorption rates of the first, second, and third test gases in their respective measurement and reference channels.

[0077] As an exemplary embodiment, the above-described gas detection method can not only achieve detection resistant to acetic acid and ethanol interference. The gas detection method accurately determines the true concentration of acetic acid and ethanol gases, and includes the following steps:

[0078] Different concentrations of propane gas were introduced. propane, propane, propane, propane, Propane is used to detect the first analyte gas (propane) in the channel, and the corresponding ratio of propane absorbance in the first measurement channel to the reference channel is obtained. They are respectively , , , , Therefore, the relation can be established as follows:

[0079] (like Figure 3 (As shown in Figure a).

[0080] In the same manner, propane gas of different concentrations was introduced. propane, propane, propane, propane, Propane is introduced into the second analyte gas (acetic acid) channel and the third analyte gas (ethanol) channel, where propane affects the absorption rate of the second analyte gas (acetic acid) channel. for: , , , , It can be established

[0081] (like Figure 4 (as shown in Figure a)

[0082] The effect of propane on the absorption rate of the second analyte gas (acetic acid) channel can be determined by the ratio of propane absorption rate in the first measurement channel to that in the reference channel.

[0083] Similarly, the absorption rate is affected by the third analyte gas (ethanol) channel. for , , , , It can be established

[0084] (like Figure 4 (as shown in Figure b)

[0085] The effect of propane on the absorption rate of the third analyte gas (ethanol) channel can be determined by the ratio of propane absorption rate in the first measurement channel to that in the reference channel.

[0086] Different concentrations of acetic acid gas were introduced. Acetic acid, Acetic acid, Acetic acid, Acetic acid, Acetic acid was used to detect the second analyte gas (acetic acid) in the second channel, and the ratio of the absorbance of acetic acid in the second measurement channel to that in the reference channel was obtained. : , , , , Therefore, a relation can be established:

[0087] (like Figure 3 (As shown in Figure b).

[0088] In the same manner, acetic acid gas of different concentrations was introduced. Acetic acid, Acetic acid, Acetic acid, Acetic acid, Acetic acid is introduced into the first analyte gas (propane) channel and the third analyte gas (ethanol) channel. The effect of acetic acid on the absorption rate of the first analyte gas (propane) channel is as follows: : , , , , It can be established

[0089] (like Figure 5 (as shown in Figure a)

[0090] The effect of acetic acid on the absorption rate of the first analyte gas (propane) channel can be determined by the ratio of the absorption rates of acetic acid in the second measurement channel and the reference channel.

[0091] Similarly, acetic acid affects the absorbance of the third analyte gas (ethanol) channel. They are respectively , , , , It can be established

[0092] (like Figure 5 (as shown in Figure b)

[0093] The effect of acetic acid on the absorption rate of the third analyte gas (ethanol) channel can be determined by the ratio of the absorption rates of acetic acid in the second measurement channel and the reference channel.

[0094] Different concentrations of ethanol gas were introduced. Ethanol, Ethanol, Ethanol, Ethanol, Ethanol is used to detect the third analyte gas (ethanol) in the third measurement channel, and the ratio of ethanol absorbance in the third measurement channel to that in the reference channel is obtained. They are respectively: , , , , Therefore, a relation can be established:

[0095] (like Figure 3 (As shown in Figure c).

[0096] In the same manner, ethanol gas of different concentrations was introduced. Ethanol, Ethanol, Ethanol, Ethanol, Ethanol is introduced into the first analyte gas (propane) channel and the second analyte gas channel (acetic acid), wherein ethanol affects the absorption rate of the first analyte gas (propane) channel. They are respectively: , , , , It can be established

[0097] (like Figure 6 (as shown in Figure a)

[0098] The effect of ethanol on the absorption rate of the first test gas (propane) channel can be determined by the ratio of ethanol absorption rate in the third measurement channel to that in the reference channel.

[0099] Similarly, ethanol affects the absorbance of the second analyte gas (acetic acid) channel. They are respectively , , , , It can be established

[0100] (like Figure 6 (as shown in Figure b)

[0101] The effect of ethanol on the absorption rate of the second analyte gas (acetic acid) channel can be determined by the ratio of ethanol absorption rate in the third measurement channel to that in the reference channel.

[0102] Because a wider wavelength range can be radiated through a blackbody light source ( The characteristics of ) The preset infrared wavelengths for the three gases, acetic acid and ethanol, are respectively , as well as The preset infrared wavelength of the reference channel is This minimizes cross-interference between components, thus improving the fit when performing function fitting in steps S2 and S3 on each analyte. Greater than In this way, the influence of each gas to be tested on each measurement channel is basically linear, which allows for subsequent high-precision gas interference correction, thereby improving the detection accuracy of each component of the gas to be tested.

[0103] In this embodiment, when there is a mixture of acetic acid, ethanol, and propane, the influence of the ratio of acetic acid absorption rate in the corresponding second gas channel and reference channel on the absorption rates of the first and third gas channels is first calculated, and then the ratio of absorption rate is subtracted. Next, the influence of ethanol absorption rate in the corresponding third gas channel and reference channel on the absorption rates of the first and second gas channels is calculated, and then the ratio of absorption rate is subtracted. Finally, the influence of propane absorption rate in the corresponding first gas channel and reference channel on the absorption rates of the second and third gas channels is calculated, and then the ratio of absorption rate is subtracted. The corrected ratios of absorption rates for the first, second, and third gas channels are then obtained and substituted into the appropriate values. , , The function can be used to calculate the actual concentrations of propane, acetic acid, and ethanol.

[0104] This embodiment is based on actual measurements. propane, Acetic acid, For example, with ethanol concentration, the ratio of absorption rate of the first gas channel to be measured is... The ratio of the absorption rate of the second gas channel to be tested is The ratio of the absorption rate of the third gas channel to be tested is ;

[0105] The ratio of the absorption rate of the second gas channel to be tested Substitute into The function obtains the absorption rate affecting the first gas channel. The ratio of the absorption rate of the first gas channel to be tested. Subtract factors that affect absorption The corrected absorbance of the first gas channel to be tested was obtained. ;

[0106] The ratio of the absorption rate of the second gas channel to be tested Substitute into The function obtains the absorption rate affecting the third gas channel. The ratio of the absorption rate of the third gas channel to be tested Subtract factors affecting absorption rate The corrected absorbance of the third gas channel was obtained. ;

[0107] The ratio of the absorption rate of the third gas channel to be tested Substitute into The function obtains the absorption rate affecting the first gas channel. Absorption rate of the first gas channel to be tested Subtract the factors affecting absorption rate The corrected absorbance of the first gas channel to be tested was obtained. ;

[0108] Absorption rate of the third gas channel to be tested Substitute into The absorption rate affecting the second gas channel is obtained from the function. Absorption rate of the second gas channel to be tested Subtract factors affecting absorption rate The corrected absorbance of the second gas channel was obtained. ;

[0109] Absorption rate of the first gas channel to be tested Substitute into The absorption rate affecting the second gas channel is obtained from the function. The absorption rate of the second gas channel to be tested Subtract factors affecting absorption rate The corrected absorbance of the second gas channel was obtained. ;

[0110] Absorption rate of the first gas channel to be tested Substitute into The function obtains the absorption rate affecting the third gas channel. The absorption rate of the third gas channel to be tested Subtract factors affecting absorption rate The corrected absorbance of the third gas channel was obtained. ;

[0111] The corrected absorbance of the first gas channel was then adjusted. Corrected absorption rate of the second gas channel to be tested Corrected absorption rate of the third gas channel to be tested Substitute into , , get concentration acetic acid concentration ethanol concentration The absolute values ​​of the errors are respectively , as well as All are within the error range.

[0112] By employing the above methods, this application embodiment designs the infrared wavelength of the multi-component gas to be tested using a blackbody light source, minimizing cross-interference between components, and further eliminating interference between components through anti-interference detection methods, thereby improving the detection accuracy of each component of the gas to be tested.

[0113] Similar issues exist in other application areas. Anesthetic gas sensors are a core component of modern medical monitoring systems, primarily used in surgical anesthesia, intensive care, and emergency medicine. Their core function is to monitor in real-time anesthetic gases (such as isoflurane, sevoflurane, and desflurane) and life support gases (such as oxygen) in the patient's breathing circuit. , The concentration of anesthetic gas is controlled to ensure the safety and accuracy of the anesthesia process. Currently used anesthetic gas sensors employ infrared absorption technology to detect the concentration of anesthetic gas... as well as There are also absorption peaks that interfere with each other and cannot be distinguished. As a medical-grade sensor, the anesthetic gas sensor has even higher requirements for gas concentration detection accuracy.

[0114] Based on this, in another embodiment of this application, the first measurement channel, the second measurement channel, and the third measurement channel of the infrared multi-channel sensor are respectively used to detect sevoflurane, as well as The concentrations of these three substances can interfere with each other. In this embodiment, sevoflurane, as well as The preset infrared wavelengths of the three gases are as follows: , as well as The reference channel is The specific methods for eliminating interference detection are similar to those in the above embodiments, and will not be described in detail here.

[0115] In addition, this application also proposes an infrared multi-channel gas sensor based on the above method, such as... Figure 7 As shown, the device includes a gas chamber, an infrared light source 12, a multi-channel detector 13, and a circuit board 11. The gas chamber is used for gas to flow through. The multi-channel detector 13 includes three measurement channels and one reference channel. The circuit board is electrically connected to the infrared light source and the multi-channel detector unit, and the circuit board includes a signal processing unit for converting the optical signal detected by the multi-channel detector into an electrical signal, and processing the electrical signal to obtain the concentration of the gas to be measured.

[0116] As an exemplary embodiment, the multi-channel detector is a thermopile / pyroelectric detector.

[0117] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. An infrared multi-channel gas detection method, characterized in that, This includes an infrared multi-channel gas sensor for detecting multi-component gases, comprising a multi-channel detector and an infrared radiation source; the infrared radiation source is a MEMS blackbody radiation source, and the preset wavelength range emitted by the MEMS blackbody radiation source is [missing information]. The multi-channel detector includes a first measurement channel, a second measurement channel, a third measurement channel, and a reference channel; the first measurement channel, the second measurement channel, and the third measurement channel are used to detect the concentrations of the first gas to be tested, the second gas to be tested, and the third gas to be tested, respectively; the first, second, and third gases to be tested are all subject to interference from the other two gases to be tested in their respective measurement channels; The gas detection method includes: S1: Calculate the fitting function of the ratio of the absorptivity of the first, second, and third test gases at different known concentrations to each test gas in the corresponding measurement channel and reference channel; S2: Calculate the fitting function of the ratio absorption rate of each of the test gases at different known concentrations in the corresponding measurement channel and reference channel and the interference absorption rate of each test gas in other measurement channels; S3: Introduce a mixture of gas of unknown concentration containing the first gas to be tested, the second gas to be tested, and the third gas to be tested into the infrared multi-channel gas sensor. By correcting the ratio of the absorption rate of each gas to be tested in its respective measurement channel and reference channel, the true ratio of the absorption rate of each gas to be tested in the corresponding measurement channel and reference channel is obtained after correction. Specifically, the process is as follows: First, the ratio of the absorption rate of the second gas to be tested in the corresponding second gas to be tested channel and the reference channel is calculated to determine its impact on the absorption rates of the first gas to be tested channel and the third gas to be tested channel, and then the ratio of the absorption rate is subtracted. Next, the ratio of the absorption rate of the third gas to be tested in the corresponding third gas to be tested channel and the reference channel is calculated to determine its impact on the absorption rates of the first gas to be tested channel and the second gas to be tested channel, and then the ratio of the absorption rate is subtracted. Finally, the ratio of the absorption rate of the first gas to be tested in the corresponding first gas to be tested channel and the reference channel is calculated to determine its impact on the absorption rates of the second gas to be tested channel and the third gas to be tested channel, and then the ratio of the absorption rate is subtracted. The final result is the corrected ratio of the absorption rates of the first, second, and third gas to be tested channels. S4: Substitute the true ratio of the absorbance of each gas to be tested into the fitting functions in S1 to obtain the true concentration of each gas to be tested. In S1 and S2, the goodness of fit of each fitting function Greater than 0.

99.

2. The infrared multi-channel gas detection method as described in claim 1, characterized in that, In step S1, the fitting functions for the ratio absorptivity of the first test gas, the second test gas, and the third test gas to the corresponding measurement channel and reference channel are as follows: ， ， ， in, The concentration of the first gas to be measured. The ratio of the absorbance of the first gas to be measured to that of the first measurement channel and the reference channel is given. , , , for The coefficients of the cubic function fit; The concentration of the second gas to be measured. The ratio of the absorbance of the second analyte gas in the second measurement channel to that in the reference channel is given. , , , for The coefficients of the cubic function fit; The concentration of the third gas to be measured. The ratio of the absorbance of the third analyte gas in the third measurement channel to that in the reference channel is given. , , , for The coefficients of the cubic function fit; In step S2, the fitting functions for the ratio of the absorbance of each gas to be tested in the corresponding measurement channel and the reference channel to the interference absorbance of each gas to be tested in the other measurement channels are as follows: ， ， ， ， ， ， in, , The values ​​represent the interference absorption rates of the first gas to be measured in the second and third measurement channels, respectively. , , , for The coefficients of the cubic function fit. , , , for The coefficients of the cubic function fit; , The values ​​represent the interference absorption rates of the second gas to be measured in the first and third measurement channels, respectively. , , , for The coefficients of the cubic function fit. , , , for The coefficients of the cubic function fit; , The values ​​represent the interference absorption rates of the third gas to be measured in the first and second measurement channels, respectively. , , , for The coefficients of the cubic function fit. , , , for The coefficients of the cubic function fit.

3. The infrared multi-channel gas detection method as described in claim 2, characterized in that, The actual concentrations of the first, second, and third test gases are as follows: ， ， ， in, , , These are the total ratios of the absorption rates of the first, second, and third test gases in their respective measurement and reference channels.

4. The infrared multi-channel gas detection method as described in claim 1, characterized in that, The first gas to be tested is The second gas to be tested is acetic acid; the third gas to be tested is ethanol.

5. The infrared multi-channel gas detection method as described in claim 4, characterized in that, The preset infrared wavelength of the first measurement channel is The preset infrared wavelength of the second measurement channel is... The preset infrared wavelength of the third measurement channel is... The preset infrared wavelength of the reference channel is... .

6. The infrared multi-channel gas detection method as described in claim 1, characterized in that, The first test gas is an anesthetic gas; the second test gas is... The third gas to be tested is .

7. The infrared multi-channel gas detection method as described in claim 6, characterized in that, The anesthetic gas is at least one of sevoflurane, desflurane, or isoflurane.

8. The infrared multi-channel gas detection method as described in claim 6, characterized in that, The preset infrared wavelength of the first measurement channel is The preset infrared wavelength of the second measurement channel is... The preset infrared wavelength of the third measurement channel is... The preset infrared wavelength of the reference channel is... .

9. An infrared multi-channel gas sensor, employing any one of the infrared multi-channel gas detection methods as described in claims 1-8, comprising a gas chamber, an infrared light source, a multi-channel detector, and a circuit board, characterized in that, The gas chamber is used for gas flow; the infrared radiation source is a MEMS blackbody radiation source used to emit light into the gas chamber; the multi-channel detector includes three measurement channels and one reference channel; the circuit board is electrically connected to the infrared light source and the multi-channel detection unit, and the circuit board includes a signal processing unit used to convert the light signal detected by the multi-channel detector into an electrical signal, and to process the electrical signal to obtain the concentration of the gas to be measured; the preset wavelength range of the light emitted by the MEMS blackbody radiation source is [missing information]. .

10. An infrared multi-channel gas sensor as described in claim 9, characterized in that, The preset wavelength range emitted by the MEMS blackbody radiation source is: .

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