Gas measurement method, equipment, medium and system based on single-light-path direct absorption

Abstract

The invention provides a gas measurement method, device, medium and system based on single-light-path direct absorption. The gas measurement method comprises the following steps: collecting each light intensity voltage value containing gas absorption information; according to the head light intensity voltage value and the tail light intensity voltage value, the average interval of the adjacent light intensity voltage values is determined; according to the head light intensity voltage value and the average interval, determining each light intensity approximate voltage value which does not contain gas absorption information; determining an absorption peak value based on each light intensity voltage value and each light intensity approximate voltage value; and determining the gas concentration in combination with the absorption peak value. According to the invention, a direct absorption method can be realized under the condition of a single optical path, the data calculation amount is reduced, the system complexity is reduced, and the development cost is reduced.

Description

Technical Field

[0001] This application belongs to the technical field of gas measurement, and relates to a gas measurement method, in particular to a gas measurement method, device, medium and system based on single-path direct absorption. Background Technique

[0002] At present, TDLAS (Tunable Diode Laser Absorption Spectroscopy) has developed into the mainstream technology for gas detection. According to the different ways of obtaining absorption signals, TDLAS technology is mainly divided into direct absorption spectroscopy and wavelength modulation spectroscopy. Wavelength modulation spectroscopy has high precision and low detection limit, but the hardware and algorithms are relatively complex and the cost is relatively high. In some high-concentration gas detections, the cost requirements are often relatively strict, and the requirements for the detection limit are not so high. Therefore, it is often more appropriate to use the direct absorption method for such instruments.

[0003] TDLAS technology emits laser with a specific wavelength. The laser interacts with gas molecules, and part of the laser is absorbed. Gas molecules have different absorption characteristics for lasers with different wavelengths. Therefore, by measuring the change in the absorption signal, the type and concentration of the gas can be accurately analyzed. TDLAS technology utilizes the narrow linewidth of the tunable semiconductor laser and the characteristic that the wavelength changes with the injection current to measure a single or several absorption lines of molecules that are very close to each other.

[0004] TDLAS consists of the following parts:

[0005] (1) Laser: The core part of the TDLAS system is a tunable diode laser, which emits laser with a specific wavelength for interacting with target gas molecules.

[0006] (2) Modulator: The laser beam passes through the modulator, and usually changes the properties of the laser in the way of frequency modulation or amplitude modulation, which helps to extract the information of gas absorption from the background signal.

[0007] (3) Gas absorption cell: A container containing the gas to be measured, and the laser beam passes through this container to interact with the target gas molecules.

[0008] (4) Photoelectric detector: Converts the optical signal after passing through the gas sample into an electrical signal for subsequent processing.

[0009] (5) Signal processor: Receives the electrical signal from the photoelectric detector and amplifies and demodulates it to extract the information related to the concentration of the target gas.

[0010] (6) Data analyzer: Receives the processed signal, analyzes it according to the TDLAS principle, and obtains parameters such as gas concentration.

[0011] TDLAS technology has the advantages of being real-time, efficient, highly sensitive and highly selective, and is suitable for various gas detection scenarios. For example, it can monitor the oxygen concentration in real time during industrial processes to help adjust process parameters and optimize production processes. In addition, TDLAS technology is also widely used in methane gas detection. Through long-distance non-contact telemetry methods, it can ensure the personal safety of operators in high-risk scenarios.

[0012] However, the conventional direct absorption method requires a double optical path, and the system is still relatively complex. Summary of the Invention

[0013] This application provides a gas measurement method, device, medium and system based on single optical path direct absorption, which is used to solve the problems of large data calculation amount and complex system of the direct absorption method under double optical paths.

[0014] In a first aspect, this application provides a gas measurement method based on single optical path direct absorption. The method includes: collecting each light intensity voltage value containing gas absorption information; determining the average interval between adjacent light intensity voltage values through the head light intensity voltage value and the tail light intensity voltage value; determining each light intensity approximate voltage value that does not contain gas absorption information according to the head light intensity voltage value and the average interval; determining the absorption peak based on each light intensity voltage value and each light intensity approximate voltage value; and determining the gas concentration in combination with the absorption peak.

[0015] In an implementation manner of the first aspect, each of the light intensity voltage values includes: a first light intensity voltage value, a second light intensity voltage value,..., a one-hundredth light intensity voltage value; the first light intensity voltage value is used as the head light intensity voltage value, and the one-hundredth light intensity voltage value is used as the tail light intensity voltage value.

[0016] In an implementation manner of the first aspect, the step of determining the average interval between adjacent light intensity voltage values through the head light intensity voltage value and the tail light intensity voltage value includes: subtracting the tail light intensity voltage value from the head light intensity voltage value to obtain a subtraction result; dividing the subtraction result into 100 equal parts to obtain the average interval.

[0017] In an implementation manner of the first aspect, the calculation expression of each light intensity approximate voltage value is: the nth light intensity approximate voltage value = head light intensity voltage value + average interval * n, where n represents the serial number of the first light intensity approximate voltage value, the second light intensity approximate voltage value,..., the one-hundredth light intensity approximate voltage value, and n takes an integer from 0 to 100.

[0018] In one implementation of the first aspect, the step of determining the absorption peak based on each of the light intensity voltage values and each of the light intensity approximate voltage values includes: obtaining a first difference by subtracting the first light intensity voltage approximate value from the first light intensity voltage value, and so on, until obtaining a one-hundredth difference by subtracting the one-hundredth light intensity voltage approximate value from the one-hundredth light intensity voltage value; taking the peak value between the first difference and the one-hundredth difference as the absorption peak.

[0019] In one implementation of the first aspect, the step of determining the gas concentration in combination with the absorption peak includes: determining the gas concentration corresponding to the absorption peak according to the linear relationship between the absorption peak and the gas concentration.

[0020] In one implementation of the first aspect, the step of determining the gas concentration in combination with the absorption peak includes: the absorption peak is the first absorption peak, and the corresponding gas concentration is 10%; the absorption peak is the second absorption peak, and the corresponding gas concentration is 20%, and the second absorption peak is 2 times the first absorption peak; the absorption peak is the third absorption peak, and the corresponding gas concentration is 40%, and the third absorption peak is 4 times the first absorption peak.

[0021] In a second aspect, the present application provides an electronic device, which includes: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory so that the electronic device executes the method described above.

[0022] In a third aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed, the method described above is implemented.

[0023] In a fourth aspect, the present application provides a gas measurement system based on single-path direct absorption, and the system includes the electronic device described above, as well as a laser, a gas chamber, and a transmitted light intensity detection device; the laser generates laser light that passes through the gas in the gas chamber, the transmitted light intensity detection device detects the light intensity voltage value at the outlet end of the gas chamber, and the electronic device executes the method described above to determine the gas concentration according to the light intensity voltage value.

[0024] As described above, the gas measurement method, device, medium, and system based on single-path direct absorption according to the present application have the following beneficial effects:

[0025] The present application can implement the direct absorption method under single-path conditions, reduce the amount of data calculation, reduce the system complexity, and reduce the development cost. The present application uses an approximately fixed linear proportional relationship to transform the ln operation, realizing a simplified calculation method and reducing the amount of calculation. Description of the Drawings

[0026] Figure 1 Schematic diagram of the scenario of the gas measurement method shown as the prior art.

[0027] Figure 2 Schematic diagram of the scenario of the gas measurement method based on single - path direct absorption described in the embodiments of the present application.

[0028] Figure 3 Flowchart of the principle of the gas measurement method based on single - path direct absorption described in the embodiments of the present application.

[0029] Figure 4 Effect diagram of infrared light absorption of the gas measurement method based on single - path direct absorption described in the embodiments of the present application.

[0030] Figure 5 Comparison diagram of light intensity and voltage of the double - path of the direct absorption method in the prior art.

[0031] Figure 6 Light intensity data diagram of the gas measurement method based on single - path direct absorption described in the embodiments of the present application.

[0032] Figure 7 Concentration curve diagram of the gas measurement method based on single - path direct absorption described in the embodiments of the present application.

[0033] Figure 8 Specific flowchart of the gas measurement method based on single - path direct absorption described in the embodiments of the present application.

[0034] Figure 9 Schematic diagram of the structural connection of the electronic device described in the embodiments of the present application.

[0035] Figure 10 Schematic diagram of the structural principle of the gas measurement system based on single - path direct absorption described in the embodiments of the present application.

[0036] Description of component numbers

[0037] 1 Electronic device

[0038] 11 Processor

[0039] 12 Memory

[0040] 13 Communication interface

[0041] 14 System bus

[0042] Steps S31 - S35

[0043] Steps S81 - S86 Detailed implementation manners

[0044] The following describes the implementation manners of the present application through specific examples. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0045] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner. Therefore, only the components related to the present application are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and proportion of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0046] Please refer to Figure 1 , which shows a schematic diagram of the scenario of the gas measurement method in the prior art. As Figure 1 shown, as one of the implementation methods of the TDLAS technology, the direct absorption method divides the overall light intensity signal into two I / 2. Usually, it is necessary to measure the transmitted light intensity signal I0 without gas absorption information and the transmitted light intensity signal It containing gas absorption attenuation information. Then, according to the Lambert-Beer law, such as It = I0 * exp[-a(v) * c * L], where It is the transmitted light intensity after passing through the gas to be measured; I0 is the incident light intensity when entering the gas to be measured; a(v) is the absorption coefficient, which is related to the type of gas and the light frequency (wavelength) passing through the gas; c is the concentration of the gas to be measured. L is the absorption path length of the gas to be measured that the light passes through. Taking -a(v) and L as a constant coefficient j, the gas concentration information can be expressed as c = k * ln(It / I0), where k = 1 / j. When It (the transmitted light intensity signal containing gas absorption information) and I0 (the transmitted light intensity signal without gas absorption information) are normally measured, the gas concentration information can be obtained (where k can be obtained by inverse calculation based on the actual gas concentration).

[0047] Therefore, in the existing TDLAS gas detection technology, when using the direct absorption method, it is usually necessary to measure the transmitted light intensity signal I0 without gas absorption information and the transmitted light intensity signal It containing gas absorption attenuation information, and then calculate the gas concentration c according to the Lambert-Beer law: It = I0 * exp[-a(v) * c * L]. However, this requires a dual-path scheme, which increases the complexity and cost of the system hardware.

[0048] The following embodiments of the present application provide a gas measurement method, device, medium, and system based on single-path direct absorption, including applications in scenarios where a laser passes through a gas chamber for single-path measurement. The following will describe this hardware application scenario as an example.

[0049] Please refer to Figure 2 , which shows a schematic diagram of the scenario of the gas measurement method based on single-path direct absorption described in the embodiments of the present application. As Figure 2 shown, the laser in the present application emits a laser. After the laser passes through the gas chamber, a single-path It signal (a transmitted light intensity signal containing gas absorption information) is used, and the gas concentration can be obtained through self-differential operation.

[0050] Next, the technical solutions in the embodiments of the present application will be described in detail with reference to the accompanying drawings in the embodiments of the present application.

[0051] Please refer to Figure 3 , which shows a principle flowchart of the gas measurement method based on single-path direct absorption described in the embodiments of the present application. As Figure 3 shown, the present embodiment provides a gas measurement method based on single-path direct absorption, and the method specifically includes the following steps:

[0052] S31, collect each light intensity voltage value containing gas absorption information.

[0053] Please refer to Figure 4 , which shows an infrared light absorption effect diagram of the gas measurement method based on single-path direct absorption described in the embodiments of the present application. As Figure 4 shown, the principle of the direct absorption method is that a gas will absorb the energy of the infrared light passing through itself, and there are two characteristics. One is that the higher the gas concentration, the stronger the absorption effect on the infrared light energy; the second is that it has a strong absorption effect only on infrared light in a specific wavelength band. As Figure 4 shown, as the wavelength of the infrared light increases or decreases, the absorption effect will quickly become so small that it can be ignored.

[0054] S32, determine the average interval of adjacent light intensity voltage values through the head light intensity voltage value and the tail light intensity voltage value.

[0055] In one embodiment, each of the light intensity voltage values includes: a first light intensity voltage value, a second light intensity voltage value,..., a one-hundredth light intensity voltage value.

[0056] The first light intensity voltage value is used as the head light intensity voltage value, and the one-hundredth light intensity voltage value is used as the tail light intensity voltage value.

[0057] Specifically, in this application, the light intensity data It with gas absorption information is obtained, and then the minimum value at the head of It, i.e., the data V0 at the 0th point, and the maximum value at the tail, i.e., the data V100 at the 100th point, are extracted.

[0058] In one embodiment, step S32 specifically includes:

[0059] (1) Subtract the tail light intensity voltage value from the head light intensity voltage value to obtain a subtraction result.

[0060] (2) Divide the subtraction result into 100 equal parts to obtain the average interval.

[0061] Specifically, the average interval A between two points can be calculated by the formula (V100 - V0) / 100.

[0062] S33. Determine each light intensity approximate voltage value that does not contain gas absorption information according to the head light intensity voltage value and the average interval.

[0063] Specifically,, and then the data VT0 at the 0th point to the data VTn at the nth point can be calculated respectively according to the formula VTn = V0 + A * n.

[0064] Please refer to Figure 5 , which shows the light intensity voltage comparison diagram of the direct absorption method double optical path in the prior art. As Figure 5 shown, in combination with Figure 1 the existing scheme shown, by giving the laser a scanning current from low to high, a changing infrared light covering the gas absorption section is generated by the laser (changing the current of the laser can change the wavelength of the light emitted by the laser), and then by detecting the laser energy passing through the gas and not passing through the gas, the specific concentration of the gas can be calculated through the formula c = k * ln(It / I0) (in the formula, the gas concentration is linearly proportional to the natural logarithm of the ratio of the two light intensities, and the value of k can be calculated through a known gas concentration and the values of It and I0 measured for this concentration of gas). Figure 5 shows the 101-point light intensity data of the two paths of the direct absorption method double optical path. It should be noted that the number of 101 points is only one implementation manner in this application, and in actual application, it can be adjusted to thousands or even tens of thousands of points according to the size of the instrument processor resources.

[0065] In one embodiment, based on the transmitted light intensity signal containing gas absorption information, this application approximately calculates the transmitted light intensity signal I0 that does not contain gas absorption information, and the calculation expression of each light intensity approximate voltage value is:

[0066] The n-th approximate value of light intensity voltage = the head light intensity voltage value + the average interval * n, where n represents the serial numbers of the first approximate value of light intensity voltage, the second approximate value of light intensity voltage,..., the one-hundredth approximate value of light intensity voltage, and n takes integers from 0 to 100.

[0067] S34. Based on each of the light intensity voltage values and each of the approximate light intensity voltage values, determine the absorption peak.

[0068] In one embodiment, step S34 specifically includes:

[0069] (1) Subtract the first approximate value of light intensity voltage from the first light intensity voltage value to obtain a first difference, and so on, until subtracting the one-hundredth approximate value of light intensity voltage from the one-hundredth light intensity voltage value to obtain the one-hundredth difference.

[0070] Specifically, let d0 = V0 - VT0, d1 = V1 - VT1, d2 = V2 - VT2,..., d100 = V100 - VT100, and a set of data d0, d1, d2,..., d100 containing peak information can be obtained.

[0071] (2) Take the peak between the first difference and the one-hundredth difference as the absorption peak.

[0072] Specifically, then find the peak value of the 101 data of d0, d1, d2,..., d100, that is, P = MAX(d0, d1, d2,..., d100). Different peak values P correspond to different gas concentrations.

[0073] Please refer to Figure 6 , which shows the light intensity data graph of the gas measurement method based on single-path direct absorption described in the embodiments of the present application. As Figure 6 shown, different gas concentrations correspond to different peak height values, and the concentration c has a linear relationship with the peak value of '-1 * ln(It / I0)'. In the present application, the light intensity data It with gas absorption information is obtained, and then the minimum value at the head of It - the 0th point data V0 and the maximum value at the tail - the 100th point data V100 are extracted. The average interval A between the two points can be calculated by the formula (V100 - V0) / 100, and then the 0th point data VT0 to the nth point data VTn can be obtained respectively according to the formula VTn = V0 + A * n. VT0, VT1, VT2,..., VTn can be used to approximately replace I0 (because the influence of light attenuation caused by gas absorption at V0 and V100 is very small and can be basically ignored).

[0074] S35. Determine the gas concentration in combination with the absorption peak.

[0075] In one embodiment, step S35 specifically includes:

[0076] Determine the gas concentration corresponding to the absorption peak according to the linear relationship between the absorption peak and the gas concentration.

[0077] Further, please refer to Figure 7 , which shows the concentration curve graph of the gas measurement method based on single-path direct absorption described in the embodiments of the present application. As Figure 7 shown, the steps of determining the gas concentration in combination with the absorption peak include:

[0078] (1) The absorption peak is the first absorption peak of 0.004, and the corresponding gas concentration is 10%.

[0079] (2) The absorption peak is the second absorption peak of 0.008, and the corresponding gas concentration is 20%. The second absorption peak is 2 times the first absorption peak.

[0080] (3) The absorption peak is the third absorption peak of 0.016, and the corresponding gas concentration is 40%. The third absorption peak is 4 times the first absorption peak.

[0081] Therefore, the present application makes a transformation to the ln operation to simplify the calculation method and reduce the calculation amount. Specifically, the formula c = k * ln(It / I0) is transformed into c = f * (I0 - It). The basis for the transformation is that when It and I0 differ slightly, there is an approximately fixed linear proportional relationship between ln(It / I0) and (It - I0). During actual calculation, it can be calculated according to c = f * (I0 - It) to reduce the calculation amount, where f is the coefficient in the linear relationship of the transformation.

[0082] Please refer to Figure 8 , which shows the specific flowchart of the gas measurement method based on single-path direct absorption described in the embodiments of the present application. As Figure 8 shown, the specific process of the gas measurement method is as follows:

[0083] S81. Sequentially collect 101 points of light intensity voltage data V0, V1, V2, … V100 containing gas concentration information, where V0 is the measured starting voltage of the scan, i.e., the head light intensity voltage value, and V100 is the measured ending voltage of the scan, i.e., the tail light intensity voltage value. The place with the strongest gas absorption is approximately near V50.

[0084] S82. Obtain the average interval A between two points through the formula A = (V100 - V0) / 100.

[0085] S83. Then, through the formula VTn = V0 + A * n, the approximate light intensity voltage data without gas absorption at 101 points of VT0, VT1, VT2, … VT100 can be obtained respectively.

[0086] S84. Let \(d_0 = V_0 - VT_0\), \(d_1 = V_1 - VT_1\), \(d_2 = V_2 - VT_2\), …, \(d_{100} = V_{100} - VT_{100}\), then a set of data \(d_0\), \(d_1\), \(d_2\), …, \(d_{100}\) containing peak information can be obtained.

[0087] S85. Then, find the peak value of the 101 data \(d_0\), \(d_1\), \(d_2\), …, \(d_{100}\), that is, \(P=\text{MAX}(d_0,d_1,d_2,\cdots,d_{100})\).

[0088] S86. The gas concentration data can be obtained by \(c = K\times P + B\). Where, \(c\) is the concentration, \(P\) is the absorption peak value, \(K\) is the coefficient, \(B\) is the instrument offset. \(K\) and \(B\) can be obtained by solving equations with 2 known gas concentration \(c\) values and known \(P\) values. Different peak values \(P\) correspond to different gas concentrations.

[0089] The protection scope of the gas measurement method based on single - optical - path direct absorption described in the embodiments of the present application is not limited to the execution order of the steps listed in this embodiment. Any solution achieved by adding or reducing steps of the prior art and replacing steps according to the principle of the present application is included in the protection scope of the present application.

[0090] The present application provides an electronic device, which includes: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory so that the electronic device executes the gas measurement method based on single - optical - path direct absorption. The gas measurement method based on single - optical - path direct absorption includes: collecting each light intensity voltage value containing gas absorption information; determining the average interval between adjacent light intensity voltage values through the head light intensity voltage value and the tail light intensity voltage value; determining each light intensity approximate voltage value not containing gas absorption information according to the head light intensity voltage value and the average interval; determining the absorption peak value based on each light intensity voltage value and each light intensity approximate voltage value; and determining the gas concentration in combination with the absorption peak value.

[0091] Please refer to Figure 9 , which shows the structural connection diagram of the electronic device described in the embodiments of the present application. As Figure 9 shown, the electronic device 1 of the present application includes: a processor 11, a memory 12, a communication interface 13 or / and a system bus 14. The memory 12 and the communication interface 13 are connected to the processor 11 through the system bus 14 and complete mutual communication. The memory 12 is used to store a computer program, the communication interface 13 is used to communicate with other devices, and the processor 11 is used to run the computer program so that the electronic device 1 executes each step of the gas measurement method based on single - optical - path direct absorption.

[0092] The above-mentioned processor 11 can be a general-purpose processor, including a central processing unit (CPU for short), a network processor (NP for short), etc.; it can also be a digital signal processor (DSP for short), an application specific integrated circuit (ASIC for short), a field programmable gate array (FPGA for short), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0093] The above-mentioned memory 12 may include a random access memory (RAM for short), and may also include a non-volatile memory, such as at least one disk memory.

[0094] The above-mentioned system bus 14 can be a peripheral component interconnect (PCI for short) bus, an extended industry standard architecture (EISA for short) bus, etc. The system bus 14 can be divided into an address bus, a data bus, a control bus, etc. The communication interface is used to implement the communication between the database access device and other devices (such as clients, read-write libraries, and read-only libraries).

[0095] In practical applications, the electronic device can be a computer including all or part of components such as a memory, a storage controller, one or more processing units (CPUs), a peripheral interface, an RF circuit, an audio circuit, a speaker, a microphone, an input / output (I / O) subsystem, a display screen, other output or control devices, and external ports; the computer includes, but is not limited to, personal computers such as desktop computers, laptop computers, tablet computers, smart phones, smart TVs, and personal digital assistants (PDAs for short). In some other embodiments, the electronic device can also be a server, and the server can be arranged on one or more physical servers according to various factors such as function and load, or can be a cloud server composed of distributed or centralized server clusters, which is not limited in this embodiment.

[0096] The embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed, the gas measurement method based on single-path direct absorption described above is implemented. The gas measurement method based on single-path direct absorption includes: collecting each light intensity voltage value containing gas absorption information; determining the average interval between adjacent light intensity voltage values through the head light intensity voltage value and the tail light intensity voltage value; determining each light intensity approximate voltage value not containing gas absorption information according to the head light intensity voltage value and the average interval; determining the absorption peak value based on each light intensity voltage value and each light intensity approximate voltage value; and determining the gas concentration in combination with the absorption peak value.

[0097] Those of ordinary skill in the art can understand that all or part of the steps in the method of the above embodiment can be completed by instructing a processor through a program. The program can be stored in a computer-readable storage medium. The storage medium is a non-transitory medium, such as random access memory, read-only memory, flash memory, hard disk, solid-state drive, magnetic tape, floppy disk, optical disc, and any combination thereof. The above storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center integrating one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., digital video disc (DVD)), or a semiconductor medium (e.g., solid state disk (SSD)).

[0098] Please refer to Figure 10 , which shows the structural schematic diagram of the gas measurement system based on single-path direct absorption described in the embodiment of the present application. As Figure 10 shown, a gas measurement system based on single-path direct absorption is characterized in that the system includes the above-mentioned electronic device, a laser, a gas chamber, and a transmitted light intensity detection device.

[0099] The laser generated by the laser passes through the gas in the gas chamber. The transmitted light intensity detection device detects the light intensity voltage value at the outlet end of the gas chamber. The electronic device executes the above method to determine the gas concentration according to the light intensity voltage value.

[0100] The electronic device includes: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory so that the electronic device executes the gas measurement method based on single-path direct absorption.

[0101] The gas measurement method based on single optical path direct absorption includes: collecting each light intensity voltage value containing gas absorption information; determining the average interval of adjacent light intensity voltage values through the head light intensity voltage value and the tail light intensity voltage value; determining each light intensity approximate voltage value without gas absorption information according to the head light intensity voltage value and the average interval; determining the absorption peak value based on each light intensity voltage value and each light intensity approximate voltage value; and determining the gas concentration in combination with the absorption peak value.

[0102] As Figure 4 shown, the principle of the direct absorption method is that gas will absorb the energy of the infrared light passing through itself, and there are two characteristics. One is that the higher the gas concentration, the stronger the absorption of the infrared light energy; the second is that it has a strong absorption effect only on infrared light in a specific wavelength band. As Figure 4 shown, as the wavelength of the infrared light increases or decreases, the absorption effect will quickly become so small that it can be ignored.

[0103] As Figure 5 shown, in combination with Figure 1 the existing scheme shown, by giving the laser a scanning current from low to high, a changing infrared light covering the gas absorption section is generated by the laser (changing the current of the laser can change the wavelength of the light emitted by the laser), and then by detecting the laser energy passing through the gas and the laser energy not passing through the gas, the specific concentration of the gas can be calculated through the formula c = k * ln(It / I0) (in the formula, the gas concentration is linearly proportional to the natural logarithm of the ratio of the two light intensities, and the value of k can be calculated through a known gas concentration and the values of It and I0 measured for this concentration of gas). Figure 5 Shows the two-way 101-point light intensity data of the direct absorption method's double optical path. It should be noted that the number of 101 points is only one of the implementation modes in this application, and in actual application, it can be adjusted to thousands or even tens of thousands of points according to the size of the instrument processor resources.

[0104] In one embodiment, the present application approximately calculates the transmitted light intensity signal I0 without gas absorption information based on the transmitted light intensity signal containing gas absorption information.

[0105] As Figure 6As shown, different gas concentrations correspond to different peak height values, and the concentration c has a linear relationship with the peak value of '-1*ln(It / I0)'. In this application, the light intensity data It with gas absorption information is obtained, and then the minimum value at the head of It - the data V0 at the 0th point and the maximum value at the tail - the data V100 at the 100th point are extracted. The average interval A between the two points can be calculated by the formula (V100 - V0) / 100, and then the data VT0 at the 0th point to the data VTn at the nth point can be obtained respectively according to the formula VTn = V0 + A*n. VT0, VT1, VT2, … VTn can be used to approximately replace I0 (because the influence of light attenuation caused by gas absorption at V0 and V100 is very small and can be basically ignored).

[0106] As Figure 7 shown, the steps for determining the gas concentration in combination with the absorption peak include:

[0107] (1) The absorption peak is the first absorption peak of 0.004, corresponding to a gas concentration of 10%.

[0108] (2) The absorption peak is the second absorption peak of 0.008, corresponding to a gas concentration of 20%, and the second absorption peak is 2 times the first absorption peak.

[0109] (3) The absorption peak is the third absorption peak of 0.016, corresponding to a gas concentration of 40%, and the third absorption peak is 4 times the first absorption peak.

[0110] Therefore, this application makes a transformation of the ln operation to simplify the calculation method and reduce the calculation amount. Specifically, the formula c = k*ln(It / I0) is transformed into c = f*(I0 - It). The basis for the transformation is that when It and I0 differ little, ln(It / I0) and (It - I0) have an approximately fixed linear proportional relationship. In actual calculation, it can be calculated according to c = f*(I0 - It) to reduce the calculation amount, where f is the coefficient in the linear relationship of the transformation.

[0111] As Figure 8 shown, the specific process of the gas measurement method is as follows:

[0112] Collect 101 points of light intensity voltage data V0, V1, V2, …, V100 containing gas concentration information in sequence, where V0 is the measured starting voltage of the scan, i.e., the head light intensity voltage value, and V100 is the measured ending voltage of the scan, i.e., the tail light intensity voltage value. The strongest gas absorption is approximately near V50. Obtain the average interval A between the two points through the formula A = (V100 - V0) / 100. Then, through the formula VTn = V0 + A * n, the approximate light intensity voltage data without gas absorption at 101 points VT0, VT1, VT2, …, VT100 can be obtained respectively. Let d0 = V0 - VT0, d1 = V1 - VT1, d2 = V2 - VT2, …, d100 = V100 - VT100, and a set of data d0, d1, d2, …, d100 containing peak information can be obtained. Then, find the peak of the 101 data d0, d1, d2, …, d100, that is, P = MAX(d0, d1, d2, …, d100). The gas concentration data can be obtained through c = K * P + B. Among them, c is the concentration, P is the absorption peak, K is the coefficient, and B is the instrument offset. K and B can be obtained by solving equations with 2 known gas concentration c values and known P values. Different peak values P correspond to different gas concentrations.

[0113] The gas measurement system based on single - path direct absorption described in the embodiments of the present application can implement the gas measurement method based on single - path direct absorption described in the present application. However, the implementation device of the gas measurement method based on single - path direct absorption described in the present application includes, but is not limited to, the structure of the gas measurement system based on single - path direct absorption listed in this embodiment. Any structural deformation and replacement of the prior art made according to the principle of the present application are included in the protection scope of the present application.

[0114] In several embodiments provided by the present application, it should be understood that the disclosed system or method can be implemented in other ways. For example, the system embodiments described above are only illustrative. For example, the division of modules / units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules or units can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of devices or modules or units can be in electrical, mechanical or other forms.

[0115] The modules / units described as separate components may or may not be physically separated, and the components shown as modules / units may or may not be physical modules, that is, they may be located in one place or distributed over multiple network units. Some or all of the modules / units can be selected according to actual needs to achieve the objectives of the embodiments of the present application. For example, in each of the embodiments of the present application, the functional modules / units can be integrated into one processing module, or each module / unit can exist physically alone, or two or more modules / units can be integrated into one module / unit.

[0116] Those of ordinary skill in the art should further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0117] The descriptions of the processes or structures corresponding to the above-mentioned various drawings each have their own focuses. For parts not detailed in a certain process or structure, reference can be made to the relevant descriptions of other processes or structures.

[0118] The above embodiments are only illustrative of the principles and effects of the present application and are not used to limit the present application. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those of ordinary skill in the art within the spirit and technical ideas disclosed in the present application should still be covered by the claims of the present application.

Claims

1. A gas measurement method based on single light path direct absorption, characterized in that: The method comprises: Collect various light intensity voltage values ​​containing gas absorption information; Determine the average interval between adjacent light intensity voltage values ​​through the head light intensity voltage value and the tail light intensity voltage value; Determine the approximate voltage values ​​of each light intensity that does not contain gas absorption information according to the head light intensity voltage value and the average interval; Determining an absorption peak based on each of the light intensity voltage values ​​and each of the light intensity approximate voltage values; The gas concentration is determined in conjunction with the absorption peaks.

2. The method according to claim 1, characterized in that: Each of the light intensity voltage values ​​includes: a first light intensity voltage value, a second light intensity voltage value, ..., a 100th light intensity voltage value; The first light intensity voltage value is used as the head light intensity voltage value, and the first one hundred light intensity voltage values ​​are used as the tail light intensity voltage value.

3. The method according to claim 1, characterized in that The step of determining the average interval between adjacent light intensity voltage values ​​by using the head light intensity voltage value and the tail light intensity voltage value comprises: Subtract the tail light intensity voltage value from the head light intensity voltage value to obtain a subtraction result; The difference result is divided into 100 equal parts to obtain the average interval.

4. The method according to claim 3, characterized in that The calculation expression of the approximate voltage value of each light intensity is: The nth light intensity voltage approximate value = head light intensity voltage value + average interval * n, where n represents the sequence number of the first light intensity voltage approximate value, the second light intensity voltage approximate value, ..., the hundredth light intensity voltage approximate value, and n is an integer from 0 to 100.

5. The method according to claim 4, characterized in that The step of determining the absorption peak value based on each of the light intensity voltage values ​​and each of the light intensity approximate voltage values ​​comprises: A first difference is obtained by subtracting the first light intensity voltage value from the first light intensity voltage approximate value, and so on, until a first hundredth difference is obtained by subtracting the first one hundredth light intensity voltage value from the first one hundredth light intensity voltage approximate value; The peak value between the first difference value and the first one hundredth difference value is taken as the absorption peak value.

6. The method according to claim 1, characterized in that The step of determining the gas concentration in combination with the absorption peak comprises: According to the linear relationship between the absorption peak and the gas concentration, the gas concentration corresponding to the absorption peak is determined.

7. The method according to claim 6, characterized in that The step of determining the gas concentration in combination with the absorption peak comprises: The absorption peak is the first absorption peak, corresponding to a gas concentration of 10%; The absorption peak is the second absorption peak, and the corresponding gas concentration is 20%, and the second absorption peak is twice the first absorption peak; The absorption peak is the third absorption peak, and the corresponding gas concentration is 40%. The third absorption peak is 4 times the first absorption peak.

8. An electronic device, characterized in that: The electronic device comprises: a processor and a memory; The memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the electronic device executes the method according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed, the method according to any one of claims 1 to 7 is implemented.

10. A gas measurement system based on single optical path direct absorption, characterized in that: The system comprises the electronic device as claimed in claim 8, as well as a laser, an air chamber, and a transmission light intensity detection device; The laser generated by the laser passes through the gas in the gas chamber, the transmitted light intensity detection device detects the light intensity voltage value at the end passing through the gas chamber, and the electronic device executes the method described to determine the gas concentration according to the light intensity voltage value.

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