Method for testing content of fluorine gas

Abstract

The invention discloses a fluorine gas content testing method. The fluorine gas content testing method comprises the following steps: irradiating a plurality of mixed gas samples containing fluorine gas by using an excitation light source to obtain Raman scattering light generated by the mixed gas samples containing fluorine gas, and inputting the Raman scattering light into a photoelectric conversion device to obtain Raman signal intensities of a plurality of standard fluorine gas; establishing a mapping relationship between the concentrations of the mixed gas samples containing the fluorine gas and the corresponding Raman signal intensities to form a data model; irradiating to-be-detected gas with an excitation light source to obtain Raman scattering light generated by fluorine gas in the to-be-detected gas, inputting the Raman scattering light into the photoelectric conversion device to obtain Raman signal intensity of the fluorine gas in the to-be-detected gas, and inputting the Raman signal intensity into the data model to obtain the concentration of the fluorine gas in the to-be-detected gas. According to the embodiment of the invention, the content of fluorine gas can be rapidly and accurately detected.

Description

Technical Field

[0001] The present application relates to the field of gas detection, and in particular to a method for testing fluorine gas content. Background Art

[0002] Fluorine, as a key chemical element, plays an indispensable role in the precision process of integrated circuit manufacturing and the cutting-edge field of nuclear material production. The precise control of its content is directly related to the performance and effectiveness of these high-tech applications. However, due to the strong oxidizing properties of fluorine, traditional detection methods such as tunable diode laser absorption spectroscopy and infrared spectroscopy are faced with the technical bottleneck of being unable to directly and quantitatively determine the fluorine content.

[0003] At present, the traditional conversion-gas chromatography analysis method widely used in the industry provides a feasible path for fluorine gas detection, but the process of this method is complicated and has limitations. It requires that the fluorine gas be converted into chlorine gas as an indirect measurement object first, and then the content is analyzed through fine separation of the chromatographic column and thermal conductivity detector to infer the concentration of fluorine gas. This process not only has many steps, but is also limited by the uncertainty of conversion efficiency and the sensitivity limitation of thermal conductivity detection technology, which may lead to deviations and errors in the measurement results.

[0004] In view of the above challenges, developing a new method that can achieve accurate, rapid and safe quantitative detection of fluorine gas content has great practical significance and urgent needs for improving product quality, production efficiency and safety in related industries. This is not only an innovation and transcendence of existing detection technology, but also an important driving force for promoting scientific and technological progress and industrial upgrading. Summary of the invention

[0005] The embodiment of the present application provides a method for testing the fluorine gas content, which can quickly and accurately detect the fluorine gas content.

[0006] In the first aspect, an embodiment of the present application provides a method for testing the fluorine gas content, comprising: irradiating a plurality of fluorine-containing gas mixture samples with an excitation light source to obtain Raman scattered light generated by the fluorine-containing gas mixture samples, inputting the Raman scattered light into a photoelectric conversion device to obtain the Raman signal intensity of the plurality of fluorine-containing gas mixture samples; establishing a mapping relationship between the concentrations of the plurality of fluorine-containing gas mixture samples and the corresponding Raman signal intensities to form a data model; irradiating the gas to be tested with an excitation light source to obtain Raman scattered light generated by the fluorine gas in the gas to be tested, inputting the Raman scattered light into a photoelectric conversion device to obtain the Raman signal intensity of the fluorine gas in the gas to be tested, and then inputting the data model to obtain the fluorine gas concentration in the gas to be tested.

[0007] In any embodiment of the present application, Raman scattered light is obtained by a collection device.

[0008] In any embodiment of the present application, the data model includes a standard curve or a stoichiometric ratio.

[0009] In any embodiment of the present application, the data model includes a standard curve, and the testing method includes: irradiating a plurality of fluorine-containing gas mixture samples with an excitation light source to obtain Raman scattered light generated by the fluorine-containing gas mixture samples, and inputting the Raman scattered light into a photoelectric conversion device to obtain Raman signal intensities of the plurality of fluorine-containing gas mixture samples; using the concentrations of the plurality of fluorine-containing gas mixture samples as the horizontal coordinate and the corresponding Raman signal intensities as the vertical coordinate to obtain a plurality of standard points, and fitting a curve composed of the plurality of standard points to obtain a standard curve; irradiating the gas to be tested with an excitation light source to obtain Raman scattered light generated by fluorine gas in the gas to be tested, inputting the Raman scattered light into a photoelectric conversion device to obtain the Raman signal intensity of fluorine gas in the gas to be tested, and then inputting it into the standard curve to obtain the fluorine gas concentration in the gas to be tested.

[0010] In any embodiment of the present application, the data model includes a stoichiometric ratio, and the testing method includes: irradiating a mixed gas sample of multiple fluorine-containing gases with an excitation light source to obtain Raman scattered light generated by the mixed gas, inputting the Raman scattered light into a photoelectric conversion device to obtain the Raman signal intensity of the multiple mixed gases, and the Raman signal intensity is recorded as Its volume concentration is recorded as C i , where i represents the volume concentration of each component of the mixed gas measured for the i-th time;

[0011] According to the Lambert-Beer law, the signal intensity of the Raman spectrum is directly proportional to the corresponding volume concentration. The algorithm model is established, and the relationship is as follows:

[0012]

[0013] In the formula, R n represents the Raman signal intensity of the nth pure gas, n represents the number of pure gases with known Raman signal intensity in the mixed gas sample; f represents the Raman signal intensity of the unknown interfering substance; e is the error value, which obeys the zero-mean-variance normal distribution. in It represents the volume concentration of the jth pure gas in the mixed gas measured for the i-th time;

[0014] After collecting the mixed gas spectrum according to the above method, quantitative analysis of fluorine gas is performed by the following method:

[0015] Method 1:

[0016] Step 1.1: Smooth the Raman spectrum and record the mixed gas spectrum after smoothing filtering as

[0017] Step 1.2: Smooth filtering of Raman spectroscopy data Perform normalization operation, denoted as

[0018]

[0019] Step 1.3: Select The wave number corresponding to the appropriate Raman shift in Establish a standard curve, where express A column of data in ;

[0020]

[0021] The standard curve can be established by solving the constants k and b, where l means that the first pure substance gas is pure fluorine gas;

[0022] Step 1.4: Collect the gas R to be tested unknown The Raman spectrum of the sample is processed according to Step 1.1 to Step 1.3, and the corresponding wave number is obtained. Calculate according to formula (3) to obtain the concentration of the gas to be measured; or,

[0023] Method 2:

[0024] Step 2.1: Smooth the mixed gas spectrum;

[0025] Step 2.2: Correct the smoothed spectrum again. The operations from Step 2.1 to Step 2.2 are denoted as F.

[0026] Step 2.3: Select the wavelength from the spectrum, denoted as S;

[0027] Step 2.4: After completing the wavelength selection, perform multivariate calibration to obtain the concentration C l and the prediction model of the spectrum, and the model is denoted as M;

[0028] C l =M(S(F(R mix ))) (5)

[0029] Step 2.5: Collect the gas R to be tested unknown The Raman spectrum of the gas is calculated according to formula (5) to obtain the concentration of the gas to be measured.

[0030] In any embodiment of the present application, a composite substrate is further provided between the excitation light source and the measuring gas, the composite substrate comprising a substrate and a coating coated on at least one surface of the substrate; the substrate comprises quartz having an oxide film on the surface, the coating comprises a fluorine-containing coating, the fluorine-containing coating comprises at least one of a fluorine-containing polyurethane coating and a fluorine-containing polyolefin coating; wherein the thickness of the oxide film is 10 to 1000 nm, and the thickness of the coating is 100 to 1000 nm.

[0031] In any embodiment of the present application, a composite substrate is further provided between the collection device and the measurement gas, the composite substrate comprising a substrate and a coating coated on at least one surface of the substrate; the substrate comprises quartz having an oxide film on the surface, the coating comprises a fluorine-containing coating, the fluorine-containing coating comprises at least one of a fluorine-containing polyurethane coating and a fluorine-containing polyolefin coating; wherein the thickness of the oxide film is 10 to 1000 nm, and the thickness of the coating is 100 to 1000 nm.

[0032] In any embodiment of the present application, the thickness of the oxide film is 500-1000 nm, and the thickness of the coating layer is 500-1000 nm.

[0033] In any embodiment of the present application, the fluorine-containing polyurethane coating includes a perfluorinated polyurethane coating.

[0034] In any embodiment of the present application, the fluorinated polyolefin coating includes a Teflon coating.

[0035] In any embodiment of the present application, the transmittance of the composite substrate at a wavelength of 500 to 1000 nm is 80% to 99%.

[0036] In any embodiment of the present application, the corrosion rate of the composite substrate under 20% fluorine gas is less than 0.01 mm / a.

[0037] The testing method for fluorine gas content in the embodiment of the present application can detect the concentration of standard gas through Raman spectroscopy to obtain a one-to-one correspondence between Raman signal intensity and gas concentration, and establish a data model using the mapping relationship. Then, by testing the Raman intensity of the unknown gas and substituting it into the data model, the concentration of the unknown gas can be accurately and quickly calculated. DETAILED DESCRIPTION

[0038] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the scheme of the present application will be further described below. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present application may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present application, rather than all of the embodiments.

[0040] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0041] If not otherwise specified, all embodiments and optional embodiments of the present application may be combined with each other to form new technical solutions, and such technical solutions should be deemed to be included in the disclosure of the present application.

[0042] Unless otherwise specified, all technical features and optional technical features of the present application may be combined with each other to form new technical solutions, and such technical solutions should be deemed to be included in the disclosure of the present application.

[0043] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0044] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0045] Unless otherwise specified, this application adopts conventional test methods or test methods recommended by the instrument.

[0046] Test method for fluorine gas content

[0047] The embodiment of the present application provides a method for testing fluorine gas content, comprising: irradiating a plurality of mixed gas samples containing fluorine gas with an excitation light source to obtain Raman scattered light generated by the mixed gas samples containing fluorine gas, inputting the Raman scattered light into a photoelectric conversion device to obtain Raman signal intensities of the mixed gas samples containing fluorine gas; establishing a mapping relationship between the concentrations of the mixed gas samples containing fluorine gas and the corresponding Raman signal intensities to form a data model; irradiating the gas to be tested with an excitation light source to obtain Raman scattered light generated by fluorine gas in the gas to be tested, inputting the Raman scattered light into a photoelectric conversion device to obtain the Raman signal intensity of fluorine gas in the gas to be tested, and then inputting the Raman scattered light into the data model to obtain the fluorine gas concentration in the gas to be tested.

[0048] The excitation light source can provide enough energy to excite the atoms or molecules in the gas, causing them to transition from the ground state to the excited state. When these atoms or molecules return to the ground state, they emit light of a specific wavelength, and the intensity and wavelength of these lights are related to the type and concentration of elements in the sample. By analyzing these spectral information, a qualitative analysis of the sample can be achieved. In an embodiment of the present application, the gas can be excited by transmitting the excitation light source through the Raman probe, so that the gas undergoes a Raman scattering effect, and thus a qualitative analysis of the sample can be achieved by analyzing the Raman scattering information.

[0049] Raman scattered light can be collected by a collection device, and then transmitted to a photoelectric conversion device through an optical fiber. The photoelectric conversion device performs spectroscopic processing on the collected Raman scattered light, and converts the optical signal into an electrical signal, and then passes through a subsequent A / D conversion circuit and a signal amplification circuit to obtain a high-quality digital signal that can be output to a subsequent system. The intensity of Raman scattered light can reflect information on molecular vibration and rotation, thereby forming a mapping relationship with the fluorine gas concentration and establishing a data model. In an embodiment of the present application, the structure of the collection device and the photoelectric conversion device is not specifically limited, and those skilled in the art can adjust it as needed. As an example, the collection device and the photoelectric conversion device can be set as an integrated device, such as a spectrometer. In practical applications, other portable spectrometers that can communicate with a microprocessor can also be selected.

[0050] The testing method for fluorine gas content in the embodiment of the present application can detect the concentration of standard gas through Raman spectroscopy to obtain a one-to-one correspondence between Raman signal intensity and gas concentration, and establish a data model using the mapping relationship. Then, by testing the Raman intensity of the unknown gas and substituting it into the data model, the concentration of the unknown gas can be accurately and quickly calculated.

[0051] In some embodiments, the data model includes a standard curve or a stoichiometric ratio.

[0052] The standard curve model is a type of linear regression model, which is a widely used statistical analysis method in statistics to describe the linear relationship between one or more independent variables (also called predictor variables or explanatory variables) and a dependent variable (also called response variable or target variable). This model predicts the value of the dependent variable by fitting a straight line (or more generally, a hyperplane), which is based on the linear relationship between the independent and dependent variables.

[0053] In the embodiments of the present application, the standard curve model and the stoichiometric ratio model may be used simultaneously to improve the detection accuracy of fluorine gas.

[0054] In some embodiments, the data model includes a standard curve, and the testing method includes: irradiating a plurality of fluorine-containing gas mixture samples with an excitation light source to obtain Raman scattered light generated by the fluorine-containing gas mixture samples, and inputting the Raman scattered light into a photoelectric conversion device to obtain Raman signal intensities of the plurality of fluorine-containing gas mixture samples; using the concentrations of the plurality of fluorine-containing gas mixture samples as the horizontal coordinate and the corresponding Raman signal intensities as the vertical coordinate to obtain a plurality of standard points, and fitting a curve composed of the plurality of standard points to obtain a standard curve; irradiating the gas to be tested with an excitation light source to obtain Raman scattered light generated by fluorine gas in the gas to be tested, inputting the Raman scattered light into a photoelectric conversion device to obtain the Raman signal intensity of fluorine gas in the gas to be tested, and then inputting it into the standard curve to obtain the fluorine gas concentration in the gas to be tested.

[0055] In the embodiment of the present application, in order to more accurately measure the fluorine concentration in the gas to be tested, when selecting multiple groups of mixed gas samples containing fluorine gas, the fluorine concentration in the standard gas should cover the expected fluorine concentration in the sample to be tested.

[0056] In the embodiment of the present application, in order to more accurately measure the fluorine gas concentration in the gas to be measured, the number of standard points can be multiple, for example, more than 5.

[0057] In some embodiments, the data model includes a stoichiometric ratio, and the test method includes: irradiating a plurality of mixed gas samples containing fluorine gas with an excitation light source to obtain Raman scattered light generated by the mixed gas, inputting the Raman scattered light into a photoelectric conversion device to obtain Raman signal intensities of the plurality of mixed gases, and recording the Raman signal intensities as Its volume concentration is recorded as C i , where i represents the volume concentration of each component of the mixed gas measured for the i-th time;

[0058] According to the Lambert-Beer law, the signal intensity of the Raman spectrum is directly proportional to the corresponding volume concentration. The algorithm model is established, and the relationship is as follows:

[0059]

[0060] In the formula, R n represents the Raman signal intensity of the nth pure gas, n represents the number of pure gases with known Raman signal intensity in the mixed gas sample; f represents the Raman signal intensity of the unknown interfering substance; e is the error value, which obeys the zero-mean-variance normal distribution. in It represents the volume concentration of the jth pure gas in the mixed gas measured for the i-th time;

[0061] After collecting the mixed gas spectrum according to the above method, quantitative analysis of fluorine gas is performed by the following method:

[0062] Method 1:

[0063] Step 1.1: To eliminate irrelevant signals such as noise introduced during the spectrum measurement process, the Raman spectrum is smoothed. Common smoothing operations include: mean filtering, SG filtering, etc. The mixed gas spectrum after smoothing filtering is recorded as

[0064] Step 1.2: To eliminate sample differences and reduce experimental errors, smooth the Raman spectral data. Perform normalization operation, denoted as

[0065]

[0066] Step 1.3: Select The wave number corresponding to the appropriate Raman shift in Establish a standard curve, where express A column of data in ;

[0067]

[0068] The standard curve can be established by solving the constants k and b, where l means that the first pure substance gas is pure fluorine gas;

[0069] Step 1.4: Collect the gas R to be tested unknown The Raman spectrum of the sample is processed according to Step 1.1 to Step 1.3, and the corresponding wave number is obtained. Calculate according to formula (3) to obtain the concentration of the gas to be measured; or,

[0070] Method 2:

[0071] Step 2.1: Spectral preprocessing: To eliminate irrelevant signals such as noise introduced during the spectrum measurement process, the mixed gas spectrum is smoothed. Common smoothing operations include: mean filtering, SG filtering, etc.

[0072] Step 2.2: Spectral correction. To eliminate spectral differences caused by uneven distribution, optical path change, etc., the smoothed spectrum is corrected. General corrections include: standard normal correction, multivariate scattering correction, etc. The operations from Step 2.1 to Step 2.2 are denoted as F;

[0073] Step 2.3: Wavelength selection. After completing the spectrum correction, the wavelength of the spectrum is selected. Commonly used methods include UVE, MC-UVE, CARS and other methods, denoted as S;

[0074] Step 2.4: Multivariate calibration. After completing the wavelength selection, multivariate calibration can be performed by multiple linear regression, principal component regression, partial least squares regression, support vector machine regression and other methods to obtain the concentration C l and the prediction model of the spectrum, and the model is denoted as M;

[0075] C l =M(S(F(R mix ))) (5)

[0076] Step 2.5: Collect the gas R to be tested unknown The Raman spectrum of the gas is calculated according to formula (5) to obtain the concentration of the gas to be measured.

[0077] In some embodiments, a composite substrate is further provided between the excitation light source and the measurement gas, the composite substrate comprising a substrate and a coating coated on at least one surface of the substrate; the substrate comprises quartz having an oxide film on the surface, the coating comprises a fluorine-containing coating, and the fluorine-containing coating comprises at least one of a fluorine-containing polyurethane coating and a fluorine-containing polyolefin coating; wherein the thickness of the oxide film is 10 to 1000 nm, and the thickness of the coating is 100 to 1000 nm.

[0078] In the embodiment of the present application, the measured gas includes a mixed gas sample of fluorine-containing gas and a gas to be measured.

[0079] In some embodiments, a composite substrate is further provided between the collection device and the measurement gas, the composite substrate comprising a substrate and a coating coated on at least one surface of the substrate; the substrate comprises quartz having an oxide film on the surface, the coating comprises a fluorine-containing coating, the fluorine-containing coating comprises at least one of a fluorine-containing polyurethane coating and a fluorine-containing polyolefin coating; wherein the thickness of the oxide film is 10 to 1000 nm, and the thickness of the coating is 100 to 1000 nm.

[0080] Optionally, the thickness of the oxide film is independently selected from 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm, 210nm, 220nm, 230nm, 240nm, 250nm , 260nm, 270nm, 280nm, 290nm, 300nm, 310nm, 320nm, 330nm, 340nm, 350nm, 360nm, 370nm, 380nm , 390nm, 400nm, 410nm, 420nm, 430nm, 440nm, 450nm, 460nm, 470nm, 480nm, 490nm, 500nm, 510nm , 520nm, 530nm, 540nm, 550nm, 560nm, 570nm, 580nm, 590nm, 600nm, 610nm, 620nm, 630nm, 640nm , 650nm, 660nm, 670nm, 680nm, 690nm, 700nm, 710nm, 720nm, 730nm, 740nm, 750nm, 760nm, 770nm , 780nm, 790nm, 800nm, 810nm, 820nm, 830nm, 840nm, 850nm, 860nm, 870nm, 880nm, 890nm, 900nm, 910nm, 920nm, 930nm, 940nm, 950nm, 960nm, 970nm, 980nm, 990nm, and 1000nm, or any range between any two of them.

[0081] Optionally, the thickness of the coating is independently selected from 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm, 210nm, 220nm, 230nm, 240nm, 250nm, 260nm, 270nm, 280nm, 290nm, 300nm, 310nm, 320nm, 330nm, 340nm, 350nm, 360nm, 370nm, 380nm, 390nm, 400nm, 410nm, 420nm, 430nm, 440nm, 450nm, 460nm, 470nm, 480nm, 490nm, 500nm, 510nm, 520nm, 530nm, 540nm, 550nm, 560nm, 570nm, 580nm, 590nm, 600nm, 610nm, 620nm, 630nm, 640nm , 650nm, 660nm, 670nm, 680nm, 690nm, 700nm, 710nm, 720nm, 730nm, 740nm, 750nm, 760nm, 770nm , 780nm, 790nm, 800nm, 810nm, 820nm, 830nm, 840nm, 850nm, 860nm, 870nm, 880nm, 890nm, 900nm, 910nm, 920nm, 930nm, 940nm, 950nm, 960nm, 970nm, 980nm, 990nm, and 1000nm, or any range between any two of them.

[0082] In the embodiment of the present application, when a composite substrate is provided between the excitation light source and the measurement gas, it includes: providing a test chamber and a spectrometer, the test chamber having a cavity for accommodating the measurement gas, the spectrometer having a Raman probe and a photoelectric conversion device for collecting Raman scattered light, and the test chamber can isolate the measurement gas from corroding the spectrometer. In addition, at least part of the outer wall of the test chamber is a composite substrate, so that the excitation light source passes through the outer wall to excite the gas to be measured.

[0083] In the embodiment of the present application, when a composite substrate is provided between the collection device and the measurement gas, it includes: providing a collection device and a photoelectric conversion device, the collection device is used to conduct an excitation light source to the measurement gas and collect Raman scattered light generated by the measurement gas, and the photoelectric conversion device converts the collected Raman scattered light into an electrical signal for output. A protective portion is provided around the collection device, and the protective portion is at least partially a composite substrate, which can isolate the collection device from contact with the measurement gas to avoid corrosion of the measurement gas to the collection device. At the same time, the Raman scattered light generated by the measurement gas can pass through the protective portion and be received by the collection device, and the collection device can input the Raman scattered light signal into the photoelectric conversion device through an optical fiber.

[0084] In an embodiment of the present application, a composite substrate is arranged between an excitation light source and a measuring gas or between a collection device and a measuring gas. The composite substrate is composed of a substrate and a coating. The substrate is quartz with an oxide film, which can improve the light transmittance while improving the stability of the quartz surface. The coating is a fluorine-containing coating, which can improve the corrosion resistance of the substrate. The setting of the coating and the oxide film thickness can make the composite substrate have excellent light transmittance and corrosion resistance at the same time.

[0085] In some embodiments, to improve the corrosion resistance of the composite substrate, the fluorine-containing polyurethane coating includes a perfluorinated polyurethane coating.

[0086] In some embodiments, to improve the corrosion resistance of the composite substrate, the fluorinated polyolefin coating includes a Teflon coating.

[0087] In some embodiments, the transmittance of the composite substrate at a wavelength of 500 to 1000 nm is 80% to 99%.

[0088] Optionally, the transmittance of the composite substrate at a wavelength of 500 to 1000 nm is independently selected from 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or any range between two of them.

[0089] In some embodiments, the corrosion rate of the composite substrate under 20% fluorine gas is less than 0.01 mm / a.

[0090] Optionally, the etching rate of the composite substrate under 20% fluorine gas is 0.001 mm / a to 0.01 mm / a.

[0091] Example

[0092] Example 1

[0093] Prepare standard gas: prepare standard gas with fluorine concentration of 0.1%, 1%, 5%, 10%, and 20%.

[0094] Measurement signal value: Use Raman spectrometer (model: Jianzhi RS2600) to measure each standard gas to obtain the corresponding Raman signal intensity.

[0095] Step 1.1: To eliminate irrelevant signals such as noise introduced during the spectrum measurement process, the Raman spectrum is smoothed. Common smoothing operations include: mean filtering, SG filtering, etc. The mixed gas spectrum after smoothing filtering is recorded as

[0096] Step 1.2: To eliminate sample differences and reduce experimental errors, smooth the Raman spectral data. Perform normalization operation, denoted as

[0097]

[0098] Step 1.3: Select The wave number corresponding to the appropriate Raman shift in Establish a standard curve, where express A column of data in .

[0099]

[0100] The standard curve can be established by solving the constants k and b, where l means that the lth pure substance gas is pure fluorine gas.

[0101] Quantitative analysis: The gas to be tested was detected by using a Raman spectrometer, and the Raman signal intensity was obtained and then inserted into the standard curve to obtain the concentration of fluorine gas in the gas to be tested, which was 1.03%.

[0102] Measurement error: The actual concentration of fluorine in the measured gas is 1.01%, and the detected concentration of fluorine in the measured gas is 1.03%, and the error is only 1.98%.

[0103] Example 2

[0104] Prepare standard gas: prepare standard gas with fluorine concentration of 0.1%, 1%, 5%, 10%, and 20%, which are recorded as C1, C2, C3, C4, and C5 respectively.

[0105] Measurement signal value: Use Raman spectrometer (model: Jianzhi RS2600) to measure each standard gas and obtain the corresponding Raman signal intensity, which is recorded as R1 mix , R2 mix 、R3 mix 、R4 mix 、R5 mix .

[0106] According to the Lambert-Beer law, the peak intensity of the Raman spectrum is directly proportional to the corresponding volume concentration. The algorithm model is established, and the relationship is as follows:

[0107]

[0108] In the formula, R n represents the Raman signal intensity of the nth pure gas, n represents the number of pure gases with known Raman signal intensity in the mixed gas sample; f represents the Raman signal intensity of the unknown interfering substance; e is the error value, which obeys the zero-mean-variance normal distribution. in It represents the volume concentration of pure gas in the jth mixed gas measured in the i-th time;

[0109] Spectral preprocessing: To eliminate irrelevant signals such as noise introduced during spectral measurement, the Raman spectrum is smoothed. Common smoothing operations include mean filtering, SG filtering, etc.

[0110] Spectral correction: To eliminate spectral differences caused by uneven distribution, optical path change, etc., the spectrum is corrected. General corrections include: standard normal correction, multivariate scattering correction, etc. Step 2.1~Step 2.2 operations are denoted as F;

[0111] Wavelength selection: After completing the spectrum correction, the spectrum is subjected to wavelength selection. Commonly used methods include UVE, MC-UVE, CARS and other methods, denoted as S;

[0112] Multivariate calibration: after wavelength selection, concentration C can be calculated by multivariate linear regression, principal component regression, partial least squares regression, support vector machine regression, etc. l and the prediction model of the spectrum, and the model is denoted as M;

[0113] C l =M(S(F(R mix ))) (5)

[0114] Measurement error: The actual concentration of fluorine in the measured gas is 5%, and the detected concentration of fluorine in the measured gas is 4.9%, and the error is only 2%.

[0115] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A method for testing fluorine gas content, characterized in that: include: Irradiating a plurality of mixed gas samples containing fluorine gas with an excitation light source to obtain Raman scattered light generated by the mixed gas samples containing fluorine gas, and inputting the Raman scattered light into a photoelectric conversion device to obtain Raman signal intensities of the mixed gas samples containing fluorine gas; Establishing a mapping relationship between the concentrations of multiple fluorine-containing gas mixture samples and the corresponding Raman signal intensities to form a data model; The gas to be tested is irradiated with an excitation light source to obtain Raman scattered light generated by fluorine gas in the gas to be tested, and the Raman scattered light is input into a photoelectric conversion device to obtain the Raman signal intensity of the fluorine gas in the gas to be tested, which is then input into the data model to obtain the fluorine gas concentration in the gas to be tested.

2. The testing method according to claim 1, characterized in that: The Raman scattered light is obtained by a collection device.

3. The testing method according to claim 1, characterized in that: The data model includes a standard curve or a stoichiometric ratio.

4. The testing method according to claim 3, characterized in that: The data model includes a standard curve, and the test method includes: Irradiating a plurality of mixed gas samples containing fluorine gas with an excitation light source to obtain Raman scattered light generated by the mixed gas samples containing fluorine gas, and inputting the Raman scattered light into a photoelectric conversion device to obtain Raman signal intensities of the mixed gas samples containing fluorine gas; using the concentrations of the mixed gas samples containing fluorine gas as the abscissa and the corresponding Raman signal intensities as the ordinate to obtain a plurality of standard points, and fitting a curve composed of the plurality of standard points to obtain a standard curve; The gas to be tested is irradiated with an excitation light source to obtain Raman scattered light generated by fluorine gas in the gas to be tested, and the Raman scattered light is input into a photoelectric conversion device to obtain the Raman signal intensity of the fluorine gas in the gas to be tested, which is then input into the standard curve to obtain the fluorine gas concentration in the gas to be tested.

5. The testing method according to claim 1, characterized in that: The data model includes a stoichiometric ratio, and the test method includes: A plurality of mixed gas samples containing fluorine gas are irradiated with an excitation light source to obtain Raman scattered light generated by the mixed gas. The Raman scattered light is input into a photoelectric conversion device to obtain the Raman signal intensity of the plurality of mixed gases. The Raman signal intensity is recorded as Its volume concentration is recorded as C i , where i represents the volume concentration of each component of the mixed gas measured for the i-th time; According to the Lambert-Beer law, the signal intensity of the Raman spectrum is directly proportional to the corresponding volume concentration. The algorithm model is established, and the relationship is as follows: In the formula, R n represents the Raman signal intensity of the nth pure gas, n represents the number of pure gases with known Raman signal intensity in the mixed gas sample; f represents the Raman signal intensity of the unknown interfering substance; e is the error value, which obeys the zero-mean-variance normal distribution. in It represents the volume concentration of the jth pure gas in the mixed gas measured for the i-th time; After collecting the mixed gas spectrum according to the above method, quantitative analysis of fluorine gas is performed by the following method: Method 1: Step 1.1: Smooth the Raman spectrum and record the mixed gas spectrum after smoothing filtering as Step 1.2: Smooth filtering of Raman spectroscopy data Perform normalization operation, denoted as Step 1.3: Select The wave number corresponding to the appropriate Raman shift in Establish a standard curve, where express A column of data in ; The standard curve can be established by solving the constants k and b, where l means that the first pure substance gas is pure fluorine gas; Step 1.4: Collect the gas R to be tested unknown The Raman spectrum of the sample is processed according to Step 1.1 to Step 1.3, and the corresponding wave number is obtained. Calculate according to formula (3) to obtain the concentration of the gas to be measured; or, Method 2: Step 2.1: Smooth the mixed gas spectrum; Step 2.2: Correct the smoothed spectrum again. The operations from Step 2.1 to Step 2.2 are denoted as F. Step 2.3: Select the wavelength from the spectrum, denoted as S; Step 2.4: After completing the wavelength selection, perform multivariate calibration to obtain the concentration C l and the prediction model of the spectrum, and the model is denoted as M; C l =M(S(F(R mix )))(5) Step 2.5: Collect the gas R to be tested unknown The Raman spectrum of the gas is calculated according to formula (5) to obtain the concentration of the gas to be measured.

6. The testing method according to claim 2, characterized in that: A composite substrate is also provided between the excitation light source and the measurement gas, wherein the composite substrate comprises a substrate and a coating applied on at least one surface of the substrate; The substrate comprises quartz having an oxide film on the surface, the coating comprises a fluorine-containing coating, and the fluorine-containing coating comprises at least one of a fluorine-containing polyurethane coating and a fluorine-containing polyolefin coating; Wherein, the thickness of the oxide film is 10 to 1000 nm, and the thickness of the coating is 100 to 1000 nm; and / or, A composite substrate is also provided between the collection device and the measured gas, wherein the composite substrate comprises a substrate and a coating applied on at least one surface of the substrate; The substrate comprises quartz having an oxide film on the surface, the coating comprises a fluorine-containing coating, and the fluorine-containing coating comprises at least one of a fluorine-containing polyurethane coating and a fluorine-containing polyolefin coating; Wherein, the thickness of the oxide film is 10 to 1000 nm, and the thickness of the coating is 100 to 1000 nm.

7. The testing method according to claim 6, characterized in that: The thickness of the oxide film is 500-1000 nm, and the thickness of the coating is 500-1000 nm.

8. The testing method according to claim 6, characterized in that: The fluorine-containing polyurethane coating comprises a perfluorinated polyurethane coating; and / or, The fluorine-containing polyolefin coating includes a Teflon coating.

9. The testing method according to claim 6, characterized in that: The transmittance of the composite substrate at a wavelength of 500 to 1000 nm is 80% to 99%.

10. The testing method according to claim 6, characterized in that: The corrosion rate of the composite substrate under 20% fluorine gas is less than 0.01 mm / a.

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