Gas multi‑physical quantity measurement method and system capable of breaking through measurement range limit

Abstract

The present invention relates to a gas multi-physical quantity measurement method and system capable of breaking through a measurement range limit. A signal generator is used to generate a specially-shaped periodic driving voltage signal, and the wavelength of output light of a laser light source is controlled to undergo a periodic specially-shaped change; multiple artificial peaks are created outside absorption peaks to form an absorption peak group; the absorbance at each wavelength of the absorption peak group is simulated and calculated at different set temperatures, pressures and concentrations to form simulated data groups; then a measured data group of absorbance is obtained by means of actual measurement; the mean squared error between each simulated data group and the measured data group is calculated, and the temperature, pressure and concentration of the simulated data group corresponding to the smallest error are used as measured values. In the present invention, by means of only one absorption line, multiple pieces of absorption peak value data can be provided for measuring multiple physical quantities; compared with a dual-line measurement method in the prior art, the present invention greatly reduces measurement workload and system costs, and broadens the measurement range.

Description

A method and system for measuring multiple physical quantities of gas that breaks through the measurement range limit Technical Field

[0001] This invention relates to the field of laser absorption spectroscopy gas measurement technology, and in particular to a method and system for measuring multiple physical quantities of gas that breaks through the measurement range limit. Background Technology

[0002] Laser absorption spectroscopy is a method for qualitative or quantitative analysis of a component by measuring the absorption spectrum of transmitted light irradiated by light. It plays an important role in fields such as atmospheric environmental monitoring, biomedical applications, energy combustion diagnostics, food, and pharmaceuticals.

[0003] When designing laser gas sensors using absorption spectroscopy, the concentration of the analyte is typically inverted by the absorbance peak corresponding to the maximum absorption wavelength. Temperature measurement is achieved by comparing the integrated or peak absorbance of the analyte's absorption lines at two wavelengths; this ratio is independently correlated with temperature, a method known as the two-line method. Pressure measurement is accomplished by analyzing the pressure broadening and absorbance changes of the absorption curve of the analyte.

[0004] The dual-line method for temperature measurement requires absorbance measurement at two wavelengths, which places higher demands on the detection system setup and increases the workload.

[0005] Furthermore, all three methods for measuring the above physical quantities rely on the absorbance peak of the analyte being within the sensor's design range, meaning it doesn't reach absorption saturation. Therefore, the range is limited and tends to be small. In addition, the range and sensitivity of laser gas sensors are contradictory; to obtain higher detection sensitivity, the range is often reduced. This contradiction further restricts the measurement system's range. Summary of the Invention

[0006] In view of the shortcomings or deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a measurement method and system with a large range that can simultaneously measure the concentration, temperature and pressure of the analyte.

[0007] To solve the above-mentioned technical problems, the present invention has the following structure:

[0008] A method for measuring multiple physical quantities of gases that breaks through the measurement range limit is performed in the following steps: S1 Determine the wavelengths of multiple artificial absorption peaks based on the maximum absorption wavelength of the analyte; S2 Design a signal generator with a distorted periodic driving voltage signal function f(t) to control the output light of the laser source to periodically change at the wavelengths of the absorption peaks and artificial peaks; S3 Simulate and calculate the absorbance of each absorption peak under different temperature, pressure, and concentration values ​​to form a simulated absorbance group; S4 Set up a test system, use a data acquisition unit to collect the output light of the laser source and the transmitted light signal of the output light through the analyte, calculate the absorbance of the analyte, and find the absorption peak in the absorbance-time curve; S5 Screen out the effective absorption peaks from all absorption peaks, and the absorbance of the effective absorption peaks forms a measured absorbance group; S6 Compare each value of the simulated absorbance group in S3 with the measured absorbance group in S5, and the temperature, pressure, and concentration corresponding to the simulated absorbance value that is closest to the measured value are the measured temperature, pressure, and concentration values ​​of the analyte.

[0009] Specifically, in step S2, the signal generator generates a shaped periodic driving voltage signal f(t) and sends it to the laser controller. The laser controller generates a corresponding shaped periodic driving current signal, causing the output light wavelength of the laser source to change periodically. The output light wavelength is positively correlated with the shaped periodic driving voltage signal.

[0010] Specifically, step S4 includes:

[0011] The test system set up in S4.1 includes a signal generator, a laser controller, and a laser source. The laser source outputs light to illuminate the sample chamber, and the data acquisition unit collects the transmitted light signal passing through the sample chamber.

[0012] S4.2 The sample chamber has two states: no gas and full of the gas to be tested. The data acquisition unit collects the transmitted light signals under both conditions and plots two curves of light intensity change over time.

[0013] S4.3 Calculate the absorbance and plot the absorbance change curve over time;

[0014] The absorption peak is found in curve S4.4 in curve S4.3.

[0015] Further, in step S5, the absorption peak between the absorbance corresponding to the absorbance at absorption saturation and the minimum absorbance detectable by the system is the effective absorption peak. The number of effective absorption peaks in one cycle is greater than or equal to 3. If this condition is not met, S1 to S4 are repeated.

[0016] Specifically, in S6, the method of solving the mean square error between the simulated absorbance group and the measured absorbance group is used to determine the simulated absorbance group that is closest to the measured value.

[0017] Specifically, the formula for calculating absorbance using S3 simulation is: A(ν)=S(T)φ(ν)PCL.

[0018] This invention relates to a gas multi-physical quantity measurement system that breaks through the range limit, comprising a signal generator, a laser controller, a laser source, a sample chamber, a photodetector, and a data acquisition and processing system. The signal generator produces a shaped periodic driving voltage signal and sends it to the laser controller. The laser controller generates a corresponding shaped periodic driving current signal, causing the output wavelength of the laser source to change periodically. The wavelengths of the absorption peaks and artificial absorption peaks of the laser source output light are determined according to the maximum absorption wavelength of the analyte. The photodetector receives the light signal from the laser sweeping across the sample chamber and transmits it to the data acquisition and processing system. The data acquisition and processing system includes a data acquisition unit, a data processing unit, and a data output unit. The transmitted light signal passing through the sample chamber is converted into an electrical signal by a photodetector and transmitted to the data acquisition unit to measure the light intensity. The measurement data is then transmitted to the data processing unit. The data processing unit calculates the absorbance of the analyte over time based on the light intensity, identifies the effective absorption peaks in the curve, and groups the absorbance values ​​of the effective absorption peaks into a measured absorbance group. The data processing unit also simulates and calculates the absorbance of each absorption peak at different temperatures, pressures, and concentrations, forming a simulated absorbance group. It then calculates the simulated absorbance group that best approximates the measured data, thus obtaining the temperature, pressure, and concentration values ​​of the analyte. The data output unit displays the data and curves from the measurement process, as well as the final measured value.

[0019] The output wavelength of the laser source is positively correlated with the irregular periodic driving voltage signal generated by the signal generator.

[0020] Compared with the prior art, the advantages of the present invention are as follows:

[0021] The present invention provides a gas multi-physical quantity measurement method and system that breaks through the range limit. By using a periodic non-monotonic irregular scanning drive mode of a signal generator, the output wavelength of the laser light source can be controlled to undergo periodic non-monotonic irregular changes, creating multiple artificial absorption peaks on the original absorbance curve of the component to be measured. Therefore, only one absorption line is needed to provide multiple absorption peak value data for the measurement of multiple physical quantities, without the need for multiple absorption lines. Compared with the existing two-line method measurement, this greatly reduces the measurement workload and system cost.

[0022] Secondly, peaks with high absorbance values ​​such as A0 and A1 do not satisfy A min n max Under certain conditions, measurements can be continued using artificial absorption peaks with small absorbance values ​​to broaden the measurement range. Alternatively, the position of the artificial absorption peak can be changed by resetting the voltage generator's irregular periodic drive voltage signal f(t) to create an artificial peak with even smaller absorbance, further broadening the measurement range.​​

[0023] Therefore, the measurement method and measurement system of the present invention are simpler, have a wider range of applications, and can be used for the measurement of multiple physical quantities with a wider range and more components. Attached Figure Description

[0024] Figure 1: Flowchart of the measurement method of the present invention;

[0025] Figure 2: Comparison of the wavelength curve of the laser emitted by the light source in the measurement method of the present invention with the curve of the prior art;

[0026] Figure 3: Comparison of the transmitted light intensity curve measured in the measurement method of the present invention with the curve of the prior art;

[0027] Figure 4: Comparison of the transmitted light absorbance curve measured in the measurement method of the present invention with the curve of the prior art;

[0028] Figure 5: Schematic diagram of the measurement system of the present invention. Detailed Implementation

[0029] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention.

[0030] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only simplified descriptions for the convenience of describing this invention and do not mean that the indicated elements must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limitations on this invention.

[0031] This invention provides a method and system for measuring multiple physical quantities of gases that overcomes measurement range limitations. It utilizes a signal generator to produce a periodically shaped driving voltage signal, controlling the output wavelength of a laser source to change periodically and irregularly. This creates multiple artificial peaks beyond the absorption peaks, forming an absorption peak group. By setting different temperatures, pressures, and concentrations, the absorbance of each wavelength in the absorption peak group is simulated and calculated, forming a simulated data group. Then, a measured absorbance data group is obtained through actual measurement. The mean square error between the two is calculated, and the temperature, pressure, and concentration of the simulated data group with the smallest error are taken as the measured values. Therefore, this invention can provide multiple absorption peak values ​​for measuring multiple physical quantities using only one absorption line. Furthermore, when a peak with a large absorbance value does not meet the absorption saturation condition, measurement can continue using an artificial absorption peak with a smaller absorbance value, further widening the measurement range.

[0032] The gas multi-physical quantity measurement method of the present invention, which breaks through the range limit, is as shown in the flowchart in Figure 1, and is performed in the following steps:

[0033] S1 determines the wavelengths of multiple artificial absorption peaks based on the maximum absorption wavelength of the analyte.

[0034] At the maximum absorption wavelength, the substance absorbs light with the greatest intensity. Based on the standard spectrum of the component to be tested, the maximum absorption wavelength is determined. Then, n-1 artificial absorption peaks that meet the test requirements are set on both sides of the maximum absorption wavelength. In addition to the absorption peak at the maximum absorption wavelength, there are a total of n absorption peaks.

[0035] S2 designs a signal generator with a non-circular driving voltage signal function f(t) to control the output light of the laser source to change periodically at the absorption peak and artificial peak wavelengths.

[0036] Referring to Figure 2b, the periodic anisotropic change refers to the periodic fluctuation of the wavelength of the light output from the light source with time at the absorption peak wavelength selected by S1, rather than the monotonically increasing or decreasing wavelength as shown in the prior art in Figure 2a.

[0037] Specifically, a signal generator produces a shaped periodic driving voltage signal f(t), which is sent to the laser controller. The laser controller then generates a corresponding shaped periodic driving current signal to control the periodic variation of the output wavelength of the laser source. The output wavelength is positively correlated with the shaped periodic driving voltage signal.

[0038] S3 simulations calculate the absorbance of each absorption peak under different temperatures, pressures, and concentrations, forming a simulated absorbance group.

[0039] For example, the wavelengths of absorption peaks and artificial absorption peaks, from smallest to largest, are λ0, λ1, λ2…λ. n The corresponding wave numbers are υ0, υ1, υ2….υ n Given a set temperature T1, pressure P1, and concentration C1, calculate the simulated absorbance A(υ0), A(υ1), A(υ2)...A(υ) corresponding to the wavelengths using Beer-Lambert Law (1). n A set of simulated absorbance values ​​is obtained. By setting different temperature, pressure, and concentration values, multiple sets of absorbance values ​​are obtained, forming a simulated absorbance group. A(ν)=S(T)φ(ν)PCL (1)

[0040] In the formula, T is the temperature [K]; S(T) [cm] -2 [ / atm] represents the absorption line intensity related to temperature T; φ(ν) [cm] is the normalized absorption line type function highly related to temperature and pressure; υ is the wavenumber of the incident light [cm]. -1 P is the pressure [atm]; C is the gas concentration; L [cm] is the absorption optical path length. All the spectroscopic parameters mentioned above are obtained from the HITRAN database or through pre-calibrated measurements.

[0041] The S4 test system is set up, and the data acquisition unit collects the output light of the laser source and the transmitted light signal of the output light through the component to be tested. The absorbance of the component to be tested is calculated, and the absorption peak is found in the absorbance change curve over time.

[0042] The S4.1 testing system includes a signal generator, a laser controller, and a laser source. The laser source outputs light to illuminate the sample chamber, and the data acquisition unit collects the transmitted light signal passing through the sample chamber.

[0043] The signal generator produces an irregularly shaped periodic driving voltage signal f(t), which is sent to the laser controller. The laser controller generates a corresponding irregularly shaped periodic driving current signal, causing the output wavelength of the laser source to change periodically. The sample chamber is used to hold the gas component to be tested. The data acquisition unit collects the transmitted light signal and performs calculations.

[0044] The absorption optical path length of the sample chamber is the same as L in formula (1) of S3.

[0045] S4.2 The sample chamber has two states: no gas and full of the gas to be tested. The data acquisition unit collects the transmitted light signal under the two conditions and plots two curves of light intensity change over time.

[0046] The output wavelength of the laser source changes periodically and irregularly. A photodetector receives the transmitted light signal as the laser beam sweeps across the sample chamber, converts the light signal into a voltage signal, and transmits it to the data acquisition unit. When the laser beam does not sweep across the analyte, the data acquisition unit acquires the transmitted light signal and outputs the transmitted light intensity I0 (hereinafter referred to as the reference intensity) without information about the analyte. When the laser beam passes over the analyte, the data acquisition unit acquires the light signal and outputs the transmitted light intensity I0 containing information about the analyte. t Two light intensity curves were plotted as a function of time (Figure 3b). Compared with the curve in Figure 3a without artificial peaks, the light intensity curves show significantly more fluctuations.

[0047] S4.3 Calculate the absorbance and plot the absorbance change curve over time.

[0048] Using the two sets of light intensity values ​​measured by S4.2, the absorbance A as a function of time t is calculated according to formula (2), and the curve of absorbance A as a function of time t is plotted (Figure 4b).

[0049] The absorption peak is found in curve S4.4 in curve S4.3.

[0050] Compared to the unartificial curve in Figure 4a, curve 4b has significantly more peaks. The absorbance curve is periodic, and data from multiple periods within the curve are all valid. Taking one period as an example, each group of absorption peaks consists of n absorption peaks within that period, including a combination of one original absorption peak and n-1 artificial peaks, with the highest peak being the original absorption peak.

[0051] S5 selects the effective absorption peaks from all absorption peaks, and the absorbance of the effective absorption peaks forms the absorbance measurement group.

[0052] As a screening method, the absorption peak between the absorbance corresponding to the absorbance at absorption saturation and the minimum absorbance that the system can detect is the effective absorption peak. The number of effective absorption peaks in one cycle must be greater than or equal to 3. If this is not met, S1 to S4 are repeated.

[0053] In the absorbance curve obtained in S4, taking one period as an example, the absorbance of all n absorption peaks are A0, A1, A2…A n (Absorbance is sorted from largest to smallest). In the computer, A0, A1, A2…A…are evaluated sequentially from largest to smallest. n Does it satisfy A? min i max i ranges from 1 to n, where A max The absorbance at absorption saturation can be taken as 3.3, A. min This is the minimum absorbance that the system can detect. If it is satisfied, it is a valid absorption peak; if not, the next absorbance is checked, and so on, until all n peaks have been checked and k usable absorption peaks are obtained, where k must be greater than or equal to 3. If satisfied, the operation of selecting a valid absorption peak continues for the next cycle; if not satisfied, the process starts from redesigning the irregular periodic drive voltage signal function f(t) of the signal generator and repeats S1 to S4.

[0054] The effective absorption peak k≥3 (k≤n) for each cycle ensures that the values ​​of the three physical quantities of temperature, pressure and concentration can be demodulated.

[0055] After selecting the effective absorption peaks from all the measurement data, the absorbance data of all the effective absorption peaks are combined into a measurement absorbance group. Therefore, the measurement absorbance group is a set of absorbance data, which contains the absorbance values ​​of k effective absorption peaks from multiple periods.

[0056] S6 compares each set of values ​​from the simulated absorbance group in S3 with the measured absorbance group in S5. The temperature, pressure, and concentration corresponding to the simulated absorbance value that is closest to the measured value are the measured temperature, pressure, and concentration values ​​of the analyte.

[0057] ​​The method of calculating the mean square error between the simulated absorbance set and the measured absorbance set can be used to determine the set of simulated absorbance values ​​that are closest to the measured values. Specifically, according to formula (3), the mean square error between each absorbance value in the simulated absorbance set and the measured absorbance set is calculated in sequence. For example, if there are m sets of simulated absorbance values, m MSEs are obtained. The temperature, pressure, and concentration values ​​corresponding to the set of simulated absorbance values ​​with the smallest MSE are the measured temperature, pressure, and concentration values ​​of the analyte.

[0058] The above measurement method is illustrated with specific examples below.

[0059] The measured component in this example is CO, with a maximum absorption wavelength of 4854.6 nm. Two artificial absorption peaks larger than this wavelength can be created. The voltage function of the signal generator is designed so that the output light of the laser source has three periodically changing absorption peaks. According to formula (1), the absorbance A(υ0), A(υ1), and A(υ2) corresponding to the wavelengths (wavenumbers) of the three absorption peaks are simulated and calculated for 900,000 sets of different conditions (temperature T = 1000~2000K, pressure P = 0.5~5atm, gas concentration C = 0~20000ppm, optical path L = 20cm) to form a simulated absorbance set. The test system detects the light intensity change curves with and without the measured component (as shown in Figure 3b). The absorbance is calculated according to formula (2), and the absorbance curve is shown in Figure 4b. From Figure 4b, it can be seen that the absorbances A0, A1, and A2 of the three absorption peaks are 1.216, 0.806, and 0.522, respectively. The absorbance corresponding to CO absorption saturation is A. max Take 3.3, A min The minimum detectable absorbance of the system is 0.001. Each absorbance is evaluated individually; A0, A1, and A2 are all within the range of A... min With A max Between these peaks, all three are effective absorption peaks, so A0, A1, and A2 constitute the absorbance measurement group. According to formula (3), the mean square error (MSE) between the measured absorbance groups A0, A1, and A2 and the 900,000 simulated absorbance groups A(υ0), A(υ1), and A(υ2) is calculated iteratively, and the minimum MSE is 0. The final measured values ​​are obtained for the simulated absorbance group with the minimum MSE: temperature T = 1600 K, pressure P = 1 atm, and gas concentration C = 10000 ppm.

[0060] The present invention also provides a gas multi-physical quantity measurement system that breaks through the range limit, as shown in Figure 5, including a signal generator, a laser controller, a laser source, a sample chamber, a photodetector, and a data acquisition and processing system.

[0061] A signal generator produces a shaped periodic driving voltage signal f(t), which is sent to the laser controller. The laser controller then generates a corresponding shaped periodic driving current signal, causing the output wavelength of the laser source to change periodically. The wavelengths of the absorption peaks and artificial absorption peaks of the laser source output light are determined based on the maximum absorption wavelength of the analyte. A photodetector receives the light signal from the laser sweeping across the sample chamber and transmits it to the data acquisition and processing system.

[0062] The data acquisition and processing system includes a data acquisition unit, a data processing unit, and a data output unit. The sample chamber operates with both the sample containing the analyte and the sample not containing the analyte. The data acquisition unit collects the electrical signals transmitted by the photodetector under both conditions, measures the light intensity, and transmits this data to the data processing unit. The data processing unit plots two light intensity versus time curves (Figure 3b) and calculates the absorbance of the analyte as a function of time t (Figure 4b). It identifies effective absorption peaks in the curves and groups the absorbance values ​​of these effective peaks into a measured absorbance set. The data processing unit also simulates and calculates the absorbance at different temperature, pressure, and concentration values ​​for each absorption peak wavelength, forming a simulated absorbance set. It then calculates the simulated absorbance set that best approximates the measured data, and measures the temperature, pressure, and concentration of the analyte. The data output unit displays the data and curves from the measurement process, as well as the final measured values.

[0063] To facilitate the control of the signal generator, the output wavelength of the laser source is positively correlated with the irregular periodic driving voltage signal generated by the signal generator.

[0064] The present invention provides a gas multi-physical quantity measurement method and system that breaks through the range limit. It utilizes the periodic non-monotonic irregular scanning drive mode of the signal generator to make the output wavelength of the laser light source change periodically and non-monotonicly, creating multiple artificial absorption peaks on the original absorbance curve of the component to be measured. Therefore, only one absorption line is needed to provide multiple absorption peak value data for the measurement of multiple physical quantities, without the need for multiple absorption lines. Compared with the existing two-line method measurement, this greatly reduces the measurement workload.

[0065] Peaks with high absorbance values, such as A0 and A1, do not satisfy A. min n max Under certain conditions, measurements can be continued using artificial absorption peaks with low absorbance values ​​to broaden the measurement range. Alternatively, the position of the artificial absorption peak can be altered by resetting the voltage generator's irregularly periodic driving voltage signal f(t), creating artificial peaks with even lower absorbance and further widening the measurement range.

[0066] Therefore, the measurement method and measurement system of the present invention have a simpler measurement process, higher efficiency, and adjustable range, making them applicable to the measurement of multiple physical quantities with a wider range and more components. ​​

[0067] The above embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Although the invention has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of the invention do not depart from the spirit and scope of the invention and should be covered within the scope of the claims of the invention.

Claims

1. A method for measuring multiple physical quantities of gas that breaks through the range limit, characterized in that, Follow these steps in sequence: S1 determines the wavelengths of multiple artificial absorption peaks based on the maximum absorption wavelength of the analyte. S2 designs a signal generator with an irregularly shaped periodic driving voltage signal function f(t) to control the output light of the laser source to change periodically at the absorption peak and artificial peak wavelengths; S3 simulations calculate the absorbance of each absorption peak under different temperatures, pressures, and concentrations, forming a simulated absorbance group; The S4 test system is set up to collect the output light of the laser source and the transmitted light signal of the output light through the component to be tested using the data acquisition unit. The absorbance of the component to be tested is calculated, and the absorption peak is found in the absorbance change curve over time. S5 selects the effective absorption peaks from all absorption peaks. The absorbance of the effective absorption peaks forms the absorbance measurement group. The absorption peak between the absorbance corresponding to the absorption saturation and the minimum absorbance that the system can detect is the effective absorption peak. The number of effective absorption peaks in one cycle is greater than or equal to 3. If it is not satisfied, repeat S1 to S4. S6 compares each set of values ​​from the simulated absorbance group in S3 with the measured absorbance group in S5. The temperature, pressure, and concentration corresponding to the simulated absorbance value that is closest to the measured value are the measured temperature, pressure, and concentration values ​​of the analyte.

2. The method for measuring multiple physical quantities of gas that breaks through the range limit according to claim 1, characterized in that, In step S2, the signal generator generates an irregular periodic driving voltage signal f(t) and sends it to the laser controller. The laser controller generates a corresponding irregular periodic driving current signal, causing the output light wavelength of the laser source to change periodically. The output light wavelength is positively correlated with the irregular periodic driving voltage signal.

3. The method for measuring multiple physical quantities of gas beyond the range limit according to claim 1, characterized in that, step S4 includes: The test system set up in S4.1 includes a signal generator, a laser controller, and a laser source. The laser source outputs light to illuminate the sample chamber, and the data acquisition unit collects the transmitted light signal passing through the sample chamber. S4.2 The sample chamber has two states: no gas and full of the gas to be tested. The data acquisition unit collects the transmitted light signals under both conditions and plots two curves of light intensity change over time. S4.3 Calculate the absorbance and plot the absorbance change curve over time; The absorption peak is found in curve S4.4 in curve S4.

3.

4. The method for measuring multiple physical quantities of gas beyond the range limit according to claim 1 or 3, characterized in that, In S6, the method of solving the mean square error between the simulated absorbance group and the measured absorbance group is used to determine the simulated absorbance group that is closest to the measured value.

5. The method for measuring multiple physical quantities of gas beyond the range limit according to claim 1, characterized in that, The formula for calculating absorbance using S3 simulation is: A(v)=S(T)φ(v)PCL, where T is the temperature; S(T) is the absorption line intensity related to temperature T; φ(v) is the normalized absorption line type function that is highly related to temperature and pressure; υ is the wavenumber of the incident light; P is the pressure; C is the gas concentration; and L is the absorption optical path.

6. A gas multi-physical quantity measurement system that breaks through the range limit, implementing the measurement method as described in claim 1, characterized in that, The system includes a signal generator, a laser controller, a laser source, a sample chamber, a photodetector, and a data acquisition and processing system. The signal generator produces a periodic driving voltage signal, which is sent to the laser controller. The laser controller then generates a corresponding periodic driving current signal, causing the output wavelength of the laser source to change periodically. The wavelengths of the absorption peaks and artificial absorption peaks of the laser source output light are determined based on the maximum absorption wavelength of the analyte. The photodetector receives the light signal from the laser sweeping through the sample chamber and transmits it to the data acquisition and processing system. The data acquisition and processing system includes a data acquisition unit, a data processing unit, and a data output unit. The transmitted light signal from the sample chamber is converted into an electrical signal by the photodetector and transmitted to the data acquisition unit. The light intensity is measured, and the measurement data is transmitted to the data processing unit. The data processing unit calculates the absorbance of the analyte as a function of time based on the light intensity, finds the effective absorption peaks in the curve, and forms a measured absorbance group by combining the absorbance values ​​of the effective absorption peaks. The data processing unit also simulates and calculates the absorbance of each absorption peak at different temperatures, pressures, and concentrations, forming a simulated absorbance group, and calculates the simulated absorbance group that is closest to the measured data, thus obtaining the temperature, pressure, and concentration values ​​of the analyte. The data output unit displays the data and curves from the measurement process, as well as the final measurement value.

7. The gas multi-physical quantity measurement system that breaks through the range limit according to claim 6, characterized in that, The output wavelength of the laser source is positively correlated with the irregular periodic driving voltage signal generated by the signal generator.

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