A method and system for monitoring salt mist concentration based on gas sampling

Abstract

The disclosure provides a salt mist concentration monitoring method and system based on the gas sampling method, and relates to the field of salt mist concentration monitoring. The method comprises the following steps: preparing a sample solution of salt mist gas based on the gas sampling method; collecting the potential and conductivity of the sample solution; correcting the potential of the sample solution in terms of temperature and drift, and obtaining the first chloride ion concentration of the sample solution based on the corresponding relationship between the potential and the concentration and the corrected potential of the sample solution; correcting the conductivity of the sample solution in terms of temperature and drift, and obtaining the second chloride ion concentration of the sample solution based on the corresponding relationship between the conductivity and the concentration and the corrected conductivity of the sample solution; and obtaining the chloride ion concentration of the salt mist gas based on the first chloride ion concentration and the second chloride ion concentration. In the salt mist concentration monitoring method and system based on the gas sampling method, the test precision is improved, and fast monitoring is realized.

Description

Technical Field

[0001] This disclosure relates to the field of salt spray concentration monitoring technology, and in particular to a salt spray concentration monitoring method and system based on gas sampling. Background Technology

[0002] Salt spray is a significant corrosive medium causing corrosion of materials, equipment, and facilities operating in marine environments. Therefore, monitoring salt spray concentration is crucial. By monitoring salt spray concentration, the corrosion risk level of the environment can be quantified, providing data support for material or equipment selection, corrosion protection measures, and evaluation of protection effectiveness, thereby reducing equipment failure or material loss due to corrosion. The accuracy of salt spray concentration monitoring is key to ensuring the targeted and economical nature of protective measures, and is also an important factor in ensuring product quality stability and standardization, especially in precision manufacturing and application fields. It is crucial for supporting infrastructure maintenance and improving the reliability of environmental assessments.

[0003] Currently, there are numerous methods for salt spray monitoring. In terms of online monitoring technology, these include high-precision methods based on ion chromatography, spectrophotometry, and atomic absorption spectroscopy, as well as rapid monitoring methods based on conductivity, chloride ion selective electrode method, and potentiometric titration. Improving monitoring accuracy while achieving rapid monitoring has become a popular research direction. Summary of the Invention

[0004] This disclosure aims to at least partially address one of the technical problems in the related art.

[0005] Therefore, the purpose of this disclosure is to provide a method and system for monitoring salt spray concentration based on gas sampling.

[0006] To achieve the above objectives, the first aspect of this disclosure provides a method for monitoring salt spray concentration based on a gas sampling method, comprising: preparing a sample solution of salt spray gas using a gas sampling method; acquiring the potential and conductivity of the sample solution; performing temperature correction and drift correction on the potential of the sample solution, and obtaining a first chloride ion concentration of the sample solution based on the correspondence between potential and concentration and the corrected potential of the sample solution; performing temperature correction and drift correction on the conductivity of the sample solution, and obtaining a second chloride ion concentration of the sample solution based on the correspondence between conductivity and concentration and the corrected conductivity of the sample solution; and obtaining the chloride ion concentration of the salt spray gas based on the first chloride ion concentration and the second chloride ion concentration.

[0007] Optionally, the temperature correction and drift correction of the potential of the sample solution includes: acquiring the temperature of the sample solution; and performing temperature correction on the potential of the sample solution based on a first formula and the temperature of the sample solution; wherein, the first formula is: E is the temperature-corrected potential value of the sample solution. m k represents the actual collected potential value of the sample solution. T T is the temperature coefficient, T is the actual sampling temperature of the sample solution, and T0 is the preset standard temperature.

[0008] Optionally, the temperature correction and drift correction of the potential of the sample solution includes: preparing a standard solution with a preset chloride ion concentration and acquiring the potential of the standard solution; and performing drift correction on the potential of the sample solution based on a second formula and the potential of the standard solution; wherein the second formula is: E is the potential value of the sample solution after drift correction. m E represents the actual collected potential value of the sample solution. st This refers to the actual collected potential value of the standard solution. This is the theoretical potential value of the standard solution.

[0009] Optionally, obtaining the first chloride ion concentration of the sample solution based on the correspondence between potential and concentration and the corrected potential of the sample solution includes: obtaining the first chloride ion concentration of the sample solution based on a third formula and the corrected potential of the sample solution; wherein, the third formula is: E is the corrected potential value of the sample solution, S0 is the slope of the curve corresponding to potential and concentration at the preset standard temperature, E0 is the intercept of the curve corresponding to potential and concentration at the preset standard temperature, C1 is the first chloride ion concentration of the sample solution, T is the actual sampling temperature of the sample solution, and T0 is the preset standard temperature.

[0010] Optionally, the temperature correction and drift correction of the conductivity of the sample solution includes: preparing a standard solution with a preset chloride ion concentration and collecting the conductivity of the standard solution; and performing drift correction on the conductivity of the sample solution based on the fourth formula and the conductivity of the standard solution; wherein the fourth formula is: K is the conductivity value of the sample solution after drift correction. m K represents the actual collected conductivity value of the sample solution. st This refers to the actual conductivity value collected for the standard solution. The theoretical conductivity value of the standard solution is given.

[0011] Optionally, obtaining the second chloride ion concentration of the sample solution based on the correspondence between conductivity and concentration, and the corrected conductivity of the sample solution, includes: obtaining a fifth formula based on the correspondence between temperature-corrected chloride ion conductivity and chloride ion concentration; obtaining a sixth formula based on the correspondence between temperature-corrected interfering ion conductivity and interfering ion concentration; and obtaining the second chloride ion concentration of the sample solution based on the fifth formula, the sixth formula, and the drift-corrected conductivity of the sample solution; wherein, the fifth formula is: The sixth formula is: ; K is the conductivity of the sample solution after drift correction. c C1 is the chloride ion conductivity in the sample solution, and C2 is the chloride ion concentration in the sample solution. The conductivity of a single interfering ion in the sample solution. The conductivity of all interfering ions in the sample solution is given. Including at least one , Where is the concentration of interfering ions in the sample solution, T is the actual sampling temperature of the sample solution, and j1, j2, j3, j4, j5, j6, j7, j8, j9 and j 10 These are the same or different coefficients, respectively.

[0012] Optionally, the step of performing temperature correction and drift correction on the conductivity of the sample solution, and obtaining the second chloride ion concentration of the sample solution based on the correspondence between conductivity and concentration and the corrected conductivity of the sample solution, further includes: obtaining a seventh formula based on the measured correspondence between total conductivity, chloride ion concentration, and interfering ion concentration at a reference temperature; obtaining an eighth formula based on the theoretical correspondence between total conductivity, chloride ion concentration, and interfering ion concentration; combining the seventh and eighth formulas to obtain a ninth formula based on the correspondence between total conductivity and interfering ion concentration; obtaining a tenth formula based on the correspondence between chloride ion concentration and interfering ion concentration based on the eighth and ninth formulas; and obtaining the sixth formula based on the tenth formula; wherein, the seventh formula is: The eighth formula is: The ninth formula is: The tenth formula is: K 25 j is the total conductivity at the reference temperature. 11 j 12 j 13 j 14 j 15 j 16 j 17 j18 j 19 j 20 j 21 j 22 and j 23 These are the same or different coefficients, respectively.

[0013] A second aspect of this disclosure provides a salt spray concentration monitoring system based on a gas sampling method, comprising: a gas sampling device and a processing module; wherein, an absorbent is introduced into the liquid inlet of the gas sampling device, and salt spray gas is introduced into the gas inlet of the gas sampling device; the gas sampling device is used to prepare a sample solution of salt spray gas based on the gas sampling method; the processing module is used to acquire the potential of the sample solution, and to perform temperature correction and drift correction on the potential of the sample solution, and to obtain a first chloride ion concentration of the sample solution based on the correspondence between potential and concentration and the corrected potential of the sample solution; furthermore, the module acquires the conductivity of the sample solution, and to perform temperature correction and drift correction on the conductivity of the sample solution, and to obtain a second chloride ion concentration of the sample solution based on the correspondence between conductivity and concentration and the corrected conductivity of the sample solution; and to obtain the chloride ion concentration of the salt spray gas based on the first chloride ion concentration and the second chloride ion concentration.

[0014] Optionally, the gas sampling device includes: a housing, a gas sampling bottle, a sample bottle, a gas sampling tube, a negative pressure mechanism, and a pumping mechanism; wherein, the gas sampling bottle and the sample bottle are respectively disposed within the housing, and the inlet end of the gas sampling bottle is supplied with an absorbent liquid, and the detection end of the processing module is disposed within the sample bottle; the outlet end of the gas sampling tube is disposed within the gas sampling bottle and located below the surface of the absorbent liquid, and the inlet end of the gas sampling tube extends out of the housing for supplying salt spray gas; the inlet end of the negative pressure mechanism is disposed within the gas sampling bottle and located above the surface of the absorbent liquid, and the outlet end of the negative pressure mechanism extends out of the housing. The signal input terminal of the negative pressure mechanism is connected to the signal output terminal of the processing module. The processing module controls the negative pressure mechanism to generate negative pressure in the gas sampling bottle so that the absorbent absorbs the salt spray gas introduced into the gas sampling pipe. The inlet terminal of the pumping mechanism is connected to the outlet terminal of the gas sampling bottle, and the outlet terminal of the pumping mechanism is connected to the inlet terminal of the sample bottle. The signal input terminal of the pumping mechanism is connected to the signal output terminal of the processing module. The processing module controls the pumping mechanism to deliver the absorbent that absorbs the salt spray gas to the sample bottle so that a sample solution is formed in the sample bottle.

[0015] Optionally, the gas sampling device further includes: a flow detection unit, wherein the flow detection unit is disposed between the negative pressure mechanism and the gas sampling cylinder, and the inlet end of the flow detection unit is disposed inside the gas sampling cylinder and above the liquid surface of the absorbent liquid; the outlet end of the flow detection unit is connected to the inlet end of the negative pressure mechanism; the flow detection unit is used to detect the inlet flow rate of the negative pressure mechanism; and the signal output end of the flow detection unit is connected to the signal input end of the processing module; and / or, a pressure detection unit, wherein the pressure detection unit is disposed between the negative pressure mechanism and the gas sampling cylinder, and the inlet end of the pressure detection unit is disposed inside the gas sampling cylinder and above the liquid surface of the absorbent liquid; the outlet end of the flow detection unit is connected to the inlet end of the negative pressure mechanism ... Above the surface of the absorbent liquid, the outlet of the pressure detection unit is connected to the inlet of the negative pressure mechanism. The pressure detection unit is used to detect the inlet pressure of the negative pressure mechanism. The signal output of the pressure detection unit is connected to the signal input of the processing module. And / or, a calibration bottle, which is disposed within the outer casing and contains a standard solution with a preset chloride ion concentration. The processing module is further used to acquire the potential and conductivity of the standard solution, and to perform drift correction on the potential of the sample solution based on the potential of the standard solution, and to perform drift correction on the conductivity of the sample solution based on the conductivity of the standard solution.

[0016] The technical solution provided in this disclosure may include the following beneficial effects: On one hand, the potential of the sample solution is acquired, and temperature and drift corrections are applied to the potential. Based on the correlation between potential and concentration, and the corrected potential of the sample solution, the first chloride ion concentration of the sample solution is obtained. Thus, rapid monitoring of chloride ion concentration in salt spray gas is achieved using potential detection. On the other hand, the conductivity of the sample solution is acquired, and temperature and drift corrections are applied to the conductivity. Based on the correlation between conductivity and concentration, and the corrected conductivity of the sample solution, the second chloride ion concentration of the sample solution is obtained. Thus, rapid monitoring of chloride ion concentration in salt spray gas is achieved using conductivity detection. The chloride ion concentration of the salt spray gas is obtained based on the first and second chloride ion concentrations. The mutual correction between the first and second chloride ion concentrations effectively improves the testing accuracy of chloride ion concentration in salt spray gas. Therefore, while improving testing accuracy, rapid monitoring is also achieved, meeting the monitoring requirements of salt spray concentration.

[0017] Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this disclosure will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, in which: Figure 1 This is a schematic flowchart of a salt spray concentration monitoring method based on gas sampling proposed in an embodiment of this disclosure; Figure 2 This is a schematic diagram of the structure of a salt spray concentration monitoring system based on gas sampling method proposed in an embodiment of this disclosure; As shown in the figure: 1. Gas sampling device, 11. Outer shell, 12. Gas sampling bottle, 13. Sample bottle, 14. Gas sampling pipe, 15. Negative pressure mechanism, 16. Calibration bottle, 17. Bubble blower, 18. Waste liquid tank. 2. Processing module; 21. Probe. Detailed Implementation

[0019] Embodiments of this disclosure are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are used only to explain this disclosure, and should not be construed as limiting this disclosure. Rather, embodiments of this disclosure include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0020] like Figure 1 As shown in the embodiments, this disclosure proposes a salt spray concentration monitoring method based on gas sampling, including: S1: Sample solution for preparing salt spray gas based on gas sampling method; S2: Collect the potential and conductivity of the sample solution; S3: Perform temperature correction and drift correction on the potential of the sample solution, and obtain the first chloride ion concentration of the sample solution based on the correspondence between potential and concentration and the corrected potential of the sample solution. S4: Perform temperature correction and drift correction on the conductivity of the sample solution, and obtain the second chloride ion concentration of the sample solution based on the correspondence between conductivity and concentration and the corrected conductivity of the sample solution; S5: Obtain the chloride ion concentration of the salt spray gas based on the first chloride ion concentration and the second chloride ion concentration.

[0021] Understandably, on the one hand, the potential of the sample solution is collected, and temperature and drift corrections are applied to the potential. Based on the correlation between potential and concentration, and the corrected potential of the sample solution, the first chloride ion concentration of the sample solution is obtained. Thus, rapid monitoring of chloride ion concentration in salt spray gas is achieved using potential detection. On the other hand, the conductivity of the sample solution is collected, and temperature and drift corrections are applied to the conductivity. Based on the correlation between conductivity and concentration, and the corrected conductivity of the sample solution, the second chloride ion concentration of the sample solution is obtained. Thus, rapid monitoring of chloride ion concentration in salt spray gas is achieved using conductivity detection. The chloride ion concentration of the salt spray gas is obtained based on the first and second chloride ion concentrations. The mutual correction between the first and second chloride ion concentrations can effectively improve the testing accuracy of chloride ion concentration in salt spray gas. Therefore, while improving testing accuracy, rapid monitoring can be achieved, meeting the monitoring needs of salt spray concentration.

[0022] It should be noted that the salt spray concentration monitoring method based on gas sampling in this embodiment adopts two rapid chloride ion concentration monitoring methods: a potential-based chloride ion concentration monitoring method and a conductivity-based chloride ion concentration monitoring method. Both methods are fast and economical in their monitoring process, and the accurate testing and mutual calibration of each method effectively improve the monitoring accuracy.

[0023] Specifically, in the salt spray concentration monitoring method based on gas sampling in this embodiment, the acquisition of the first chloride ion concentration and the second chloride ion concentration are independent of each other. The acquisition method of the first chloride ion concentration is highly targeted and can only identify chloride ions, but its accuracy and sensitivity are insufficient. The acquisition method of the second chloride ion concentration is highly sensitive, but other interfering factors need to be eliminated to achieve better accuracy. The first chloride ion concentration and the second chloride ion concentration are mutually verified.

[0024] In some embodiments, temperature correction and drift correction of the potential of the sample solution include: The temperature at which the sample solution was collected; Temperature correction is performed on the potential of the sample solution based on the first formula and the temperature of the sample solution; The first formula is: ; E is the potential value after temperature correction of the sample solution, in mV. m This represents the actual collected potential value of the sample solution, in mV and kJ / mV. T T represents the temperature coefficient, where T is the actual temperature of the sample solution collected in °C, and T0 is the preset standard temperature in °C.

[0025] For example, the constant temperature water bath was set to 25℃, 30℃, 35℃, 40℃, 55℃, 60℃, 65℃ and 70℃ respectively, and the relationship data between chloride ion concentration and potential E at different temperatures were recorded. Then, the corrected formula for potential and temperature (first formula) was obtained by fitting the data.

[0026] Wherein, the preset standard temperature T0 can be 30℃, and at the standard temperature of 30℃, the relationship between potential and temperature can be fitted as follows: .

[0027] It can be 0.52, meaning the first formula is: .

[0028] Understandably, based on the first formula, temperature correction of the sample solution potential is achieved, thereby significantly reducing the impact of temperature on chloride ion concentration monitoring and thus improving monitoring accuracy.

[0029] In some embodiments, temperature correction and drift correction of the potential of the sample solution include: Prepare a standard solution with a preset chloride ion concentration and collect the potential of the standard solution; The potential of the sample solution is corrected for drift based on the second formula and the potential of the standard solution; The second formula is: ; E is the potential value after drift correction of the sample solution. m E represents the actual collected potential value of the sample solution. st This represents the actual collected potential value of the standard solution. This is the theoretical potential value of the standard solution.

[0030] For example, a 2 mg / L standard solution has a measured potential of 240 mV at 30 °C, based on the formula... Theoretical calculation data is ,Right now, It is 240mV. It is 244.38mV. In the second formula, In other words, the actual collected potential value of the sample solution plus the drift value. Then, the potential value after drift correction of the sample solution was obtained.

[0031] Specifically, if the actual potential value of the standard solution is higher than the theoretical potential value, then ΔE = >0, the drift-corrected potential value of the sample solution is obtained by subtracting ΔE from the actual collected potential value of the sample solution. If the actual collected potential value of the standard solution is lower than the theoretical potential value of the standard solution, then ΔE = <0, the actual collected potential value of the sample solution plus The potential value after drift correction of the sample solution is obtained.

[0032] Understandably, based on the second formula, the drift correction of the sample solution potential is achieved, thereby improving the monitoring accuracy.

[0033] It should be noted that when performing temperature correction and drift correction on the potential of a sample solution at the same time, temperature correction can be performed first, followed by drift correction, or drift correction can be performed first, followed by temperature correction.

[0034] For example, when obtaining the temperature-corrected potential value E using the first formula, the temperature-corrected potential value E is used as E in the second formula. m Substitute the values ​​to perform further drift correction.

[0035] In some embodiments, obtaining the first chloride ion concentration of the sample solution based on the correspondence between potential and concentration and the potential corrected for the sample solution includes: The first chloride ion concentration of the sample solution is obtained based on the third formula and the corrected potential of the sample solution. The third formula is: ; E is the corrected potential value of the sample solution, in mV; S0 is the slope of the curve corresponding to potential and concentration at the preset standard temperature; E0 is the intercept of the curve corresponding to potential and concentration at the preset standard temperature, in mV; C1 is the concentration of the first chloride ion in the sample solution, in mg / L; T is the actual sampling temperature of the sample solution, in ℃; and T0 is the preset standard temperature, in ℃.

[0036] The conductivity is measured in µS / cm, and the ion concentration is measured in mg / L.

[0037] For example, first, establish the equation of the standard curve: The slope of the standard curve is a function of temperature, and its calculation formula is: Using the ratio method, with 30℃ as the standard solubility, the temperature-corrected slope was obtained. for: , where t is the absolute temperature.

[0038] Seeking , Therefore, the drift value calculated in the second formula is combined with The corrected equation: .

[0039] In some embodiments, temperature correction and drift correction of the conductivity of the sample solution include: A standard solution with a preset chloride ion concentration was prepared, and the conductivity of the standard solution was measured. The conductivity of the sample solution is corrected for drift based on the fourth formula and the conductivity of the standard solution. The fourth formula is: ; K is the conductivity value after drift correction of the sample solution. m K represents the actual conductivity value of the sample solution. st The actual conductivity value collected for the standard solution. This represents the theoretical conductivity value of the standard solution.

[0040] For example, a 2 mg / L chloride ion solution is used as the standard solution. for: .

[0041] In some embodiments, temperature correction and drift correction of the conductivity of the sample solution include: Based on formula Temperature correction is applied to the conductivity of the sample solution, where a is the slope of the fitted ion concentration versus conductivity standard curve, b is the fitting coefficient of the fitted ion concentration versus conductivity standard curve, T is the actual sampling temperature of the sample solution, T0 is the preset standard temperature, and x1, x2, x3 and x4 are the same or different coefficients, respectively.

[0042] Specifically, at a constant temperature, different chloride ion concentrations and conductivity data were tested, and a standard curve of ion concentration versus conductivity was obtained through data fitting. .

[0043] in, denoted as conductivity (µs / cm), C as ion concentration (mg / L), a as the slope of the standard curve, and b as the coefficient of the standard curve.

[0044] The conductivity changes of ion solutions with different concentrations were measured at different temperatures. The relationship between temperature, ion concentration, and conductivity was obtained by fitting the data using a multiple linear regression method. .

[0045] Where x1, x2, x3, and x4 are model coefficients obtained through regression analysis.

[0046] Substitute Conclusion: .

[0047] Since temperature changes do not affect concentration, therefore, = to further obtain Relationship with T: .

[0048] Will get Substituting the relationship between temperature and temperature (T) into the standard curve formula, we obtain the temperature-corrected ion concentration standard curve.

[0049] .

[0050] If the current test environment is a marine environment, an island environment, or another environment where the corrosive medium is negligible, the above formula is the formula for chloride ions and conductivity under temperature correction. When applying this formula, here... This is the value after drift correction.

[0051] In some embodiments, obtaining the second chloride ion concentration of the sample solution based on the correspondence between conductivity and concentration and the corrected conductivity of the sample solution includes: The fifth formula is derived based on the correspondence between chloride ion conductivity and chloride ion concentration after temperature correction. The sixth formula is derived based on the correspondence between the conductivity of interfering ions and the concentration of interfering ions after temperature correction. The second chloride ion concentration of the sample solution was obtained based on the fifth and sixth formulas and the drift-corrected sample solution conductivity. The fifth formula is: ; The sixth formula is: ; + ; K is the conductivity of the sample solution after drift correction. c C1 represents the chloride ion conductivity in the sample solution, in µS / cm, and C2 represents the chloride ion concentration in the sample solution, in mg / L. The conductivity of a single interfering ion in the sample solution is expressed in µS / cm. The conductivity of all interfering ions in the sample solution is expressed in µS / cm. Including at least one (When there are no interfering ions,) (can be 0) Where is the concentration of interfering ions in the sample solution, T is the actual sampling temperature of the sample solution, and j1, j2, j3, j4, j5, j6, j7, j8, j9 and j 10 These are either the same or different coefficients.

[0052] It should be noted that, since conductivity is significantly affected by interfering ions, efforts were made to eliminate interference from other ions as much as possible. Through research, the main soluble interfering ions in the atmosphere were found to be sulfate / sulfite ions, ammonium ions, nitrate ions, and sulfide ions. Further testing was conducted to assess the contribution of these interfering ions to conductivity. In this implementation case, sulfate ions were used as the interference source, and their contribution values ​​were corrected by elimination. The methods for eliminating and correcting the contribution values ​​of other ions were the same as for sulfate ions.

[0053] Correspondingly, .

[0054] The sixth formula is: ,and + .

[0055] Among them, K s C1 represents the sulfate ion conductivity in the sample solution, and C2 represents the sulfate ion concentration in the sample solution.

[0056] For example, j1 is 2.948; j2 is 0.1443; j3 is 5.2112; j4 is 1.4528; j5 is 0.0181; j6 is 2.7137; j7 is 0.08323; j8 is 0.7712; j9 is 0.7409; j 10 It is 0.0103.

[0057] In other words, , .

[0058] Furthermore, .

[0059] Further calculation of the sulfate ion concentration C3 in the sample solution is required.

[0060] In some embodiments, obtaining the second chloride ion concentration of the sample solution based on the correspondence between conductivity and concentration and the corrected conductivity of the sample solution further includes: At the reference temperature, the seventh formula is obtained based on the measured correspondence between total conductivity, chloride ion concentration and interfering ion concentration, and the eighth formula is obtained based on the theoretical correspondence between total conductivity, chloride ion concentration and interfering ion concentration. By combining the seventh and eighth formulas, we obtain the ninth formula based on the relationship between total conductivity and interfering ion concentration; Based on the eighth and ninth formulas, the tenth formula is obtained based on the correspondence between chloride ion concentration and interfering ion concentration, and the sixth formula is obtained based on the tenth formula. The seventh formula is: ; The eighth formula is: ; The ninth formula is: ; The tenth formula is:

[0061] K 25 j is the total conductivity at the reference temperature. 11 j 12 j 13 j 14 j 15 j 16 j 17 j 18 j 19 j 20 j 21 j 22 and j 23 These are either the same or different coefficients.

[0062] Accordingly, taking sulfate ions as an example, the seventh formula is: The eighth formula is: The tenth formula is: .

[0063] For example, j 11 It is 1.34269; j 12 3.15621; j 13 It is 2.75431; j 14 It is 0.02326; j 15 It is 3.561; j 16 It is 2.704; j 17 It is 1.2737; j 18 It is 0.08283; j 19 It is 3.6306; j 20 It is 0.05031; j 21 It is 0.02326; j 22 It is 3.561; j 23 It is 2.704.

[0064] In other words, , , , .

[0065] Based on formulas 5 and 6, as well as formulas 7, 8, 9, and 10, the derivation process is as follows: If other ions cannot be ignored, their contributions to conductivity are plotted using the above method to create a standard curve for each single ion. Subsequently, solutions with different proportions of the main ions are prepared, and conductivity data are tested at a constant temperature. The relationship between conductivity and different ion concentrations is obtained through fitting a multiple linear regression equation, as well as the relationship between total conductivity and each factor. .

[0066] .

[0067] By changing the temperature conditions, multiple sets of correlations between conductivity and concentration were obtained.

[0068] Based on the empirical formula relating ion migration rate and conductivity: .

[0069] In the formula, C represents the conversion difference between units S / m and μs / cm. i The concentration of the i-th ion is expressed in mol / m³. 3 , z i The absolute charge of the i-th ion, F is the Faraday constant, with a value of 96500 C / mol, u i Ion mobility, which is closely related to ion type, is measured in units of... At low concentrations, conductivity exhibits a linear relationship with concentration.

[0070] Na + K + Cl - NO3 - NO3 - and NH4 + =1, SO4 2- and S 2- 2, NO3 - 1 is the molar mass of the ion, and M is the molar mass of the ion, in g / mol.

[0071] The corrosive media of concern in the atmosphere are generally salt spray, sulfur dioxide and sulfates, hydrogen sulfide and sulfides, nitrogen dioxide and nitrates, and ammonia and ammonium salts. Other substances can generally be ignored unless there are special circumstances.

[0072] Electrical conductivity is determined by factors such as the migration rate of related ions.

[0073] The relationship between conductivity and contribution value is explained as follows: .

[0074] .

[0075] .

[0076] .

[0077] .

[0078] .

[0079] .

[0080] , The corresponding ion of interest can be calculated using charge conservation. In this case, sulfate is used as the interfering ion, and no other interfering factors are introduced. , , .

[0081] .

[0082] This embodiment takes the current environment containing two corrosive media, chloride ions and sulfate ions, as an example. Using known Cl... - Using a standard solution of a certain concentration as the base solution, a series of solutions containing sulfate ions were prepared, and their conductivity and potential data were recorded. Using the potential data as the benchmark for chloride ion data, the contribution coefficient of each ion to conductivity was obtained. Through data fitting, the chloride ion concentration was determined. - and SO4 2- The contribution fit.

[0083] Conductivity and potential data of different chloride ion solutions at different temperatures were measured and recorded. Using the potential data as a benchmark for chloride ion data, the contribution coefficient of each ion to conductivity was obtained. Through data fitting, the following relationship was established between chloride ion concentration, temperature, and conductivity data: .

[0084] Temperature changes do not affect concentration data, so we substitute T=25℃ and simplify to obtain: (Fifth Formula).

[0085] Under environmental conditions of 25℃, solutions containing different proportions of chloride and sulfate ions were mixed. Through data fitting, the relationship between total conductivity and the concentrations of chloride and sulfate ions was obtained as follows: .

[0086] Furthermore, it can be concluded that (Seventh Formula).

[0087] Based on empirical formulas relating conductivity to ion concentration and ion migration rate, the following equation is obtained: .

[0088] In the formula, K is in µS / cm and C is in mg / L. It is the conversion difference between the units S / m and us / cm.

[0089] According to the law of conservation of charge, , , Known , , Substitute and simplify as follows:

[0090] Furthermore, it can be concluded that (Eighth Formula).

[0091] Combining formulas 7 and 8, we obtain formula 9. .

[0092] The standard curve for sulfate ions at 25°C is as follows: .

[0093] The fitted relationship between sulfate ion concentration, temperature, and conductivity data is shown in the following temperature correction curve: .

[0094] Temperature changes do not affect concentration data, so we substitute T=25℃ and simplify to obtain: .

[0095] After conversion, (Sixth Formula).

[0096] Substituting the ninth formula into the eighth formula, we obtain the tenth formula. .

[0097] Substituting the tenth formula into the sixth formula, the calculation is as follows: .

[0098] Furthermore, .

[0099] Therefore, by collecting the conductivity and temperature of the sample solution, the accurate concentration of the second chloride ion can be obtained.

[0100] The method for removing and correcting the contribution values ​​of other ions is the same as that for removing and correcting sulfate ions.

[0101] like Figure 2As shown in the figure, this disclosure also proposes a salt spray concentration monitoring system based on gas sampling method, including: gas sampling device 1 and processing module 2.

[0102] The gas sampling device 1 is used to prepare a sample solution of salt spray gas based on the gas sampling method. The processing module 2 is used to collect the potential of the sample solution, perform temperature correction and drift correction on the potential of the sample solution, and obtain the first chloride ion concentration of the sample solution based on the correspondence between potential and concentration and the corrected potential of the sample solution. The processing module 2 is also used to collect the conductivity of the sample solution, perform temperature correction and drift correction on the conductivity of the sample solution, and obtain the second chloride ion concentration of the sample solution based on the correspondence between conductivity and concentration and the corrected conductivity of the sample solution. Finally, the processing module 2 obtains the chloride ion concentration of the salt spray gas based on the first chloride ion concentration and the second chloride ion concentration.

[0103] Understandably, on the one hand, the potential of the sample solution is collected, and temperature and drift corrections are applied to the potential. Based on the correlation between potential and concentration, and the corrected potential of the sample solution, the first chloride ion concentration of the sample solution is obtained. Thus, rapid monitoring of chloride ion concentration in salt spray gas is achieved using potential detection. On the other hand, the conductivity of the sample solution is collected, and temperature and drift corrections are applied to the conductivity. Based on the correlation between conductivity and concentration, and the corrected conductivity of the sample solution, the second chloride ion concentration of the sample solution is obtained. Thus, rapid monitoring of chloride ion concentration in salt spray gas is achieved using conductivity detection. The chloride ion concentration of the salt spray gas is obtained based on the first and second chloride ion concentrations. The mutual correction between the first and second chloride ion concentrations can effectively improve the testing accuracy of chloride ion concentration in salt spray gas. Therefore, while improving testing accuracy, rapid monitoring can be achieved, meeting the monitoring needs of salt spray concentration.

[0104] It should be noted that the gas sampling device 1 is used to prepare a sample solution of salt spray gas based on the gas sampling method. The specific type of the gas sampling device 1 can be set according to actual needs and there are no restrictions on it.

[0105] The processing module 2 is used to collect salt spray concentration and process and calculate the collected data to quickly obtain accurate chloride ion concentration in salt spray gas. The specific type of processing module 2 can be set according to actual needs and is not limited thereto. For example, processing module 2 can be a controller, processor, etc., and is also equipped with probe 21 for collecting data such as potential, conductivity, and temperature.

[0106] Specifically, processing module 2 includes a system motherboard, an execution control board, and a data acquisition system. The system motherboard is primarily responsible for sending commands for actions and information acquisition (monitoring data, status information, alarm information, etc.), calculating salt spray concentration, storing monitoring data, and outputting it externally. The execution control board is mainly responsible for receiving and responding to commands sent by the system motherboard and controlling each actuator (valve, pump, etc.) to complete corresponding actions according to the prescribed operating logic and requirements. This data acquisition system can simultaneously record parameters such as the potential value (mV), conductivity value (μS / cm), and temperature value (°C) of probe 21.

[0107] like Figure 2 As shown, in some embodiments, the gas sampling device 1 includes: a housing 11, a gas sampling bottle 12, a sample bottle 13, a gas sampling pipe 14, a negative pressure mechanism 15, and a pumping mechanism (not shown in the figure). The gas sampling bottle 12 and the sample bottle 13 are respectively disposed within the housing 11. The inlet end of the gas sampling bottle 12 is connected to an absorbent liquid. The detection end of the processing module 2 is disposed within the sample bottle 13. The outlet end of the gas sampling pipe 14 is disposed within the gas sampling bottle 12 and located below the surface of the absorbent liquid. The inlet end of the gas sampling pipe 14 extends out of the housing 11 and is used to introduce salt spray gas. The inlet end of the negative pressure mechanism 15 is disposed within the gas sampling bottle 12 and located above the surface of the absorbent liquid. The outlet end of the negative pressure mechanism 15 extends out of the housing 11. The signal input end of the negative pressure mechanism 15 and... The signal output terminal of the processing module 2 is connected to the negative pressure mechanism 15 to generate negative pressure in the gas sampling bottle 12 so that the absorbent liquid absorbs the salt spray gas introduced into the gas sampling pipe 14. The inlet terminal of the pumping mechanism is connected to the outlet terminal of the gas sampling bottle 12, and the outlet terminal of the pumping mechanism is connected to the inlet terminal of the sample bottle 13. The signal input terminal of the pumping mechanism is connected to the signal output terminal of the processing module 2. The processing module 2 is used to control the pumping mechanism to deliver the absorbent liquid that absorbs the salt spray gas to the sample bottle 13 so that a sample solution is formed in the sample bottle 13.

[0108] It is understandable that, since the outlet of the gas sampling pipe 14 is located inside the gas sampling bottle 12 and below the surface of the absorbent liquid, and the inlet of the gas sampling pipe 14 extends out of the outer shell 11, and the inlet of the negative pressure mechanism 15 is located inside the gas sampling bottle 12 and above the surface of the absorbent liquid, and the outlet of the negative pressure mechanism 15 extends out of the outer shell 11, after the negative pressure mechanism 15 is activated, it can use negative pressure to make the external salt spray gas pass through the gas sampling pipe 14 and the gas sampling bottle 12 in sequence and then be discharged again. At the same time, when the salt spray gas passes through the absorbent liquid, it can be absorbed by the absorbent liquid, thereby facilitating the formation of a sample solution.

[0109] Furthermore, since the inlet end of the pumping mechanism is connected to the outlet end of the gas sampling bottle 12, and the outlet end of the pumping mechanism is connected to the inlet end of the sample bottle 13, the absorbent liquid that absorbs the salt spray gas can be pumped to the sample bottle 13 by the pumping mechanism to form a sample solution, which facilitates the detection and processing by the processing module 2.

[0110] It should be noted that the outer shell 11 is used to integrate the gas sampling cylinder 12, sample bottle 13, etc. The specific type of the outer shell 11 can be set according to actual needs and there is no limitation. For example, the outer shell 11 can be a box structure, with the gas sampling cylinder 12 and sample bottle 13 arranged in the box, and the height of the sample bottle 13 is less than the height of the gas sampling cylinder 12.

[0111] The gas sampling cylinder 12 is used to contain the absorbent liquid and receive the salt spray gas delivered by the gas sampling pipe 14. The specific type of the gas sampling cylinder 12 can be set according to actual needs and there is no limitation. For example, the gas sampling cylinder 12 can be made of high temperature resistant material, and the top and bottom of the gas sampling cylinder 12 are respectively equipped with liquid level sensors to detect the liquid level of the absorbent liquid.

[0112] The gas sampling pipe 14 is used to guide and transport external salt spray gas into the gas sampling cylinder 12. The body type of the gas sampling pipe 14 can be set according to actual needs and is not limited thereto. For example, the air inlet of the gas sampling pipe 14 is located outside the outer shell 11 and can be in the shape of a conical funnel, covered with a filter screen with a mesh size slightly smaller than the inner diameter of the gas sampling pipe 14, so as to prevent excessive sand and gravel from being sucked in and clogging the pipe. At the same time, the air inlet of the gas sampling pipe 14 faces downward to reduce the settling or covering of surface dust and other foreign objects. Moreover, the air inlet of the gas sampling pipe 14 is equipped with a dryer filter with a hydrophobic PTFE membrane and a pore size of 0.2um. The gas outlet of the gas sampling pipe 14 is located inside the gas sampling cylinder 12 and can adopt a serpentine structure to increase the contact area with the absorbent liquid, or a perforated plate can be used for exhaust, which can also increase the contact area with the absorbent liquid.

[0113] Sample vial 13 is used to contain the sample solution to facilitate data acquisition by processing module 2. The specific type of sample vial 13 can be set according to actual needs and is not limited thereto. For example, sample vial 13 has a bottle structure and is equipped with a level sensor for detecting the liquid level of the sample solution. In addition, such as Figure 2 As shown, a bubbler 17 can be installed at the bottom of the sample vial 13 to achieve uniform mixing of the sample solution.

[0114] The negative pressure mechanism 15 is used to generate negative pressure within the gas sampling cylinder 12. The specific type of the negative pressure mechanism 15 can be set according to actual needs and is not limited thereto. For example, the negative pressure mechanism 15 may include a gas sampling pump, preferably a corrosion-resistant diaphragm pump, with a flow rate adjustable from 0.1L / min to 1L / min, a 24DC drive mode, PWM speed regulation, capable of continuous operation for more than 60 minutes, and a lifespan greater than 4000 hours in humid air environments, with a gas sampling flow rate fluctuation of less than ±3%. Additionally, the volumetric cumulative power at rated flow rate with a pressure drop < 5kPa is calculated in real time, with a resolution of 0.01L. Single / cumulative volume output is supported.

[0115] The pumping mechanism is used to pump the absorbent liquid that absorbs salt spray gas to the sample bottle 13. The specific type of pumping mechanism can be set according to actual needs and there are no restrictions on it.

[0116] A peristaltic pump and a flow meter can be used to deliver the external absorbent liquid into the gas sampling cylinder 12.

[0117] For gas extraction unit 1, a cleaning device can also be configured, specifically, such as Figure 2 As shown, the cleaning device includes a waste liquid tank 18 and a cleaning feedback module (not shown in the figure). The waste liquid tank 18 is located inside the outer casing 11, and the height of the waste liquid tank 18 is lower than that of the gas sampling bottle 12 and the sample bottle 13. The liquid inlet at the top of the waste liquid tank 18 is connected to the liquid outlet at the bottom of the gas sampling bottle 12 and the liquid outlet at the bottom of the sample bottle 13, respectively. After the sample solution is tested, the solution in the gas sampling bottle 12 and the sample bottle 13 is discharged into the waste liquid tank 18. In addition, the gas sampling bottle 12 and the sample bottle 13 are repeatedly rinsed with absorbent liquid, and the waste liquid generated during rinsing is also discharged into the waste liquid tank 18. The cleaning feedback module is located inside the gas sampling bottle 12 and / or the sample bottle 13. The cleaning feedback module uses optical characteristics, such as transmittance or scattering characteristics, to automatically adjust the number of cleaning cycles after each cleaning by comparing with the cleanliness data.

[0118] In addition, for sample bottle 13, the cleaning effect can be judged by comparing the data collected by processing module 2 with the cleanliness data.

[0119] The inlet at the top of the waste liquid tank 18 and the outlet at the bottom of the gas sampling bottle 12, as well as the inlet at the top of the waste liquid tank 18 and the outlet at the bottom of the sample bottle 13, can be controlled by switching valves. The waste liquid tank 18 can be made of corrosion-resistant and aging-resistant PE material and is equipped with a liquid level switch.

[0120] Level sensors for detecting the level of rinsing fluid can also be installed in the gas sampling bottle 12 and the sample bottle 13 respectively, and fixed with a buffer silicone pad. For example, the level sensor for detecting the level of rinsing fluid in the gas sampling bottle 12 is located at the top, that is, above the level sensor for detecting the level of absorption fluid.

[0121] In some embodiments, the gas sampling device 1 further includes a flow detection unit, which is disposed between the negative pressure mechanism 15 and the gas sampling cylinder 12. The inlet of the flow detection unit is disposed inside the gas sampling cylinder 12 and above the liquid surface of the absorbent. The outlet of the flow detection unit is connected to the inlet of the negative pressure mechanism 15. The flow detection unit is used to detect the inlet flow of the negative pressure mechanism 15. The signal output of the flow detection unit is connected to the signal input of the processing module 2.

[0122] It is understandable that, since the flow detection unit is located between the negative pressure mechanism 15 and the gas sampling bottle 12, and the signal output terminal of the flow detection unit is connected to the signal input terminal of the processing module 2, the processing module 2 can use the flow detection unit to obtain the air intake flow of the negative pressure mechanism 15, thereby achieving precise control of the air intake flow of the negative pressure mechanism 15 and ensuring the accurate preparation of the sample solution.

[0123] It should be noted that the flow detection unit is used to detect the intake flow of the negative pressure mechanism 15. The specific type of the flow detection unit can be set according to actual needs and there is no restriction. For example, the flow detection unit can be an electronic flow meter with a range of 0L / min-1.2L / min, and the pumping mechanism is controlled in real time according to the set flow.

[0124] In some embodiments, the gas sampling device 1 further includes a pressure detection unit, which is disposed between the negative pressure mechanism 15 and the gas sampling cylinder 12. The inlet of the pressure detection unit is disposed inside the gas sampling cylinder 12 and above the liquid surface of the absorbent. The outlet of the pressure detection unit is connected to the inlet of the negative pressure mechanism 15. The pressure detection unit is used to detect the inlet pressure of the negative pressure mechanism 15. The signal output of the pressure detection unit is connected to the signal input of the processing module 2.

[0125] It is understandable that, since the pressure detection unit is located between the negative pressure mechanism 15 and the gas sampling bottle 12, and the signal output terminal of the pressure detection unit is connected to the signal input terminal of the processing module 2, the processing module 2 can use the pressure detection unit to obtain the inlet pressure of the negative pressure mechanism 15, thereby achieving precise control of the inlet pressure of the negative pressure mechanism 15 and ensuring the accurate preparation of the sample solution.

[0126] It should be noted that the pressure detection unit is used to detect the intake pressure of the negative pressure mechanism 15. The specific type of pressure detection unit can be set according to actual needs and there is no limitation thereto. For example, the pressure detection unit can be a differential pressure sensor.

[0127] The processing module 2 controls the negative pressure mechanism 15 to dynamically adjust the gas sampling speed according to the intake pressure. When the gas sampling resistance increases, it automatically calculates the required gas sampling speed adjustment. When the resistance recovers, it returns to the set value, thereby ensuring the accuracy of the gas sampling volume.

[0128] like Figure 2 As shown, in some embodiments, the gas sampling device 1 further includes: a calibration bottle 16, which is disposed inside the housing 11 and contains a standard solution with a preset chloride ion concentration. The processing module 2 is also used to collect the potential and conductivity of the standard solution, and to perform drift correction on the potential of the sample solution based on the potential of the standard solution, and to perform drift correction on the conductivity of the sample solution based on the conductivity of the standard solution.

[0129] Understandably, by using the standard solution in calibration bottle 16, it is also possible to correct the drift of the sample solution potential and the drift of the conductivity, thereby ensuring that the processing module 2 accurately obtains the chloride ion concentration in the salt spray gas.

[0130] It should be noted that the calibration bottle 16 is used to contain standard solutions, such as the 2 mg / L chloride ion solution mentioned in this embodiment. The specific type of calibration bottle 16 can be set according to actual needs and is not limited thereto. For example, the calibration bottle 16 has a bottle structure and is located close to the sample bottle 13. The calibration bottle 16 is equipped with a level sensor for detecting the liquid level of the standard solution.

[0131] For standard solutions, the concentration of chloride ions within the standard curve that is >20% at the low end and <80% at the high end can be selected as the fixed-value chloride ion solution. The container, electrodes, and sensors should be sealed and stored to prevent evaporation and concentration. For example, if the standard curve range is 0.1 mg / L to 25 mg / L, then the fixed-value standard chloride ion solution should be selected between 0.12 mg / L and 20 mg / L.

[0132] It should be noted that in the description of this disclosure, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0133] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of preferred embodiments of this disclosure includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this disclosure pertain.

[0134] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0135] Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A method for monitoring salt spray concentration based on gas sampling, characterized in that, include: Sample solutions for salt spray gas were prepared using a gas sampling method. The potential and conductivity of the sample solution were collected; The potential of the sample solution is corrected for temperature and drift, and the first chloride ion concentration of the sample solution is obtained based on the correspondence between potential and concentration and the corrected potential of the sample solution. The conductivity of the sample solution is corrected for temperature and drift, and the second chloride ion concentration of the sample solution is obtained based on the correspondence between conductivity and concentration and the corrected conductivity of the sample solution. The chloride ion concentration of the salt spray gas is obtained based on the first chloride ion concentration and the second chloride ion concentration. The determination of the first chloride ion concentration of the sample solution based on the correspondence between potential and concentration and the corrected potential of the sample solution includes: The first chloride ion concentration of the sample solution is obtained based on the third formula and the corrected potential of the sample solution. The third formula is as follows: ; E is the corrected potential value of the sample solution, S0 is the fitting slope of the potential-concentration curve at the preset standard temperature, E0 is the intercept of the potential-concentration curve at the preset standard temperature, C1 is the first chloride ion concentration of the sample solution, T is the actual sampling temperature of the sample solution, and T0 is the preset standard temperature. The method of obtaining the second chloride ion concentration of the sample solution based on the correspondence between conductivity and concentration, and the corrected conductivity of the sample solution, includes: The fifth formula is derived based on the correspondence between chloride ion conductivity and chloride ion concentration after temperature correction. The sixth formula is obtained based on the correspondence between the conductivity of interfering ions and the concentration of interfering ions after temperature correction; The second chloride ion concentration of the sample solution is obtained based on the fifth and sixth formulas and the drift-corrected conductivity of the sample solution. The fifth formula is as follows: ; The sixth formula is: ; ； K is the conductivity of the sample solution after drift correction. c C1 is the chloride ion conductivity in the sample solution, and C2 is the chloride ion concentration in the sample solution. The conductivity of a single interfering ion in the sample solution. The conductivity of all interfering ions in the sample solution is given. Including at least one , Where is the concentration of interfering ions in the sample solution, T is the actual sampling temperature of the sample solution, and j1, j2, j3, j4, j5, j6, j7, j8, j9 and j 10 These are the same or different coefficients, respectively.

2. The salt spray concentration monitoring method based on gas sampling as described in claim 1, characterized in that, The temperature correction and drift correction of the potential of the sample solution includes: The temperature of the sample solution was collected; The potential of the sample solution is corrected for temperature based on the first formula and the temperature of the sample solution; The first formula is: ; E is the temperature-corrected potential value of the sample solution. m k represents the actual collected potential value of the sample solution. T T is the temperature coefficient, T is the actual sampling temperature of the sample solution, and T0 is the preset standard temperature.

3. The salt spray concentration monitoring method based on gas sampling method according to claim 1, characterized in that, The temperature correction and drift correction of the potential of the sample solution includes: A standard solution with a preset chloride ion concentration is prepared, and the potential of the standard solution is collected. The potential of the sample solution is corrected for drift based on the second formula and the potential of the standard solution; The second formula is: ; E is the drift-corrected potential value of the sample solution. m E represents the actual collected potential value of the sample solution. st This refers to the actual collected potential value of the standard solution. This is the theoretical potential value of the standard solution.

4. The salt spray concentration monitoring method based on gas sampling method according to claim 1, characterized in that, The temperature correction and drift correction of the conductivity of the sample solution includes: A standard solution with a preset chloride ion concentration is prepared, and the conductivity of the standard solution is measured. The conductivity of the sample solution is corrected for drift based on the fourth formula and the conductivity of the standard solution. The fourth formula is: ; K is the conductivity value of the sample solution after drift correction. m K represents the actual collected conductivity value of the sample solution. st The actual conductivity value collected for the standard solution. The theoretical conductivity value of the standard solution is given.

5. The salt spray concentration monitoring method based on gas sampling method according to claim 1, characterized in that, The method of obtaining the second chloride ion concentration of the sample solution based on the correspondence between conductivity and concentration and the corrected conductivity of the sample solution further includes: At the reference temperature, the seventh formula is obtained based on the measured correspondence between total conductivity, chloride ion concentration and interfering ion concentration, and the eighth formula is obtained based on the theoretical correspondence between total conductivity, chloride ion concentration and interfering ion concentration. By combining the seventh and eighth formulas, a ninth formula based on the relationship between total conductivity and interfering ion concentration is obtained; Based on the eighth and ninth formulas, a tenth formula is obtained based on the correspondence between chloride ion concentration and interfering ion concentration, and the sixth formula is obtained based on the tenth formula. The seventh formula is: ; The eighth formula is: ; The ninth formula is: ; The tenth formula is: K 25 j is the total conductivity at the reference temperature. 11 j 12 j 13 j 14 j 15 j 16 j 17 j 18 j 19 j 20 j 21 j 22 and j 23 These are the same or different coefficients, respectively.

6. A salt spray concentration monitoring system based on gas sampling method, characterized in that, The system is applicable to the salt spray concentration monitoring method based on gas sampling as described in any one of claims 1-5, and the system comprises: Gas extraction equipment and processing modules; The gas sampling device is equipped with an absorbent liquid at its liquid inlet and a salt spray gas at its gas inlet. The gas sampling device is used to prepare a sample solution of salt spray gas based on the gas sampling method. The processing module is used to acquire the potential of the sample solution, perform temperature correction and drift correction on the potential of the sample solution, and obtain the first chloride ion concentration of the sample solution based on the correspondence between potential and concentration and the corrected potential of the sample solution. Furthermore, the conductivity of the sample solution is collected, and temperature correction and drift correction are applied to the conductivity of the sample solution. Based on the correspondence between conductivity and concentration and the corrected conductivity of the sample solution, the second chloride ion concentration of the sample solution is obtained. Furthermore, the chloride ion concentration of the salt spray gas is obtained based on the first chloride ion concentration and the second chloride ion concentration.

7. The salt spray concentration monitoring system based on gas sampling method according to claim 6, characterized in that, The gas extraction device includes: The outer casing, gas sampling bottle, sample bottle, gas sampling tube, negative pressure mechanism, and pumping mechanism; The gas sampling bottle and the sample bottle are respectively disposed inside the outer shell, and the liquid inlet of the gas sampling bottle is fed with the absorption liquid, while the detection end of the processing module is disposed inside the sample bottle. The outlet end of the gas sampling pipe is located inside the gas sampling bottle and below the surface of the absorbent liquid, while the inlet end of the gas sampling pipe extends out of the outer shell and is used to introduce salt spray gas. The inlet end of the negative pressure mechanism is located inside the gas sampling bottle and above the surface of the absorbent liquid, and the outlet end of the negative pressure mechanism extends out of the outer shell. The signal input end of the negative pressure mechanism is connected to the signal output end of the processing module. The processing module is used to control the negative pressure mechanism to generate negative pressure inside the gas sampling bottle so that the absorbent liquid absorbs the salt spray gas introduced through the inlet end of the gas sampling pipe. The inlet end of the pumping mechanism is connected to the outlet end of the gas sampling bottle, and the outlet end of the pumping mechanism is connected to the inlet end of the sample bottle. The signal input end of the pumping mechanism is connected to the signal output end of the processing module. The processing module is used to control the pumping mechanism to deliver the absorbent liquid that absorbs salt spray gas to the sample bottle so that a sample solution is formed in the sample bottle.

8. The salt spray concentration monitoring system based on gas sampling method according to claim 7, characterized in that, The gas extraction device also includes: A flow detection unit is provided, which is disposed between the negative pressure mechanism and the gas sampling bottle. The inlet of the flow detection unit is disposed inside the gas sampling bottle and located above the liquid surface of the absorbent. The outlet of the flow detection unit is connected to the inlet of the negative pressure mechanism. The flow detection unit is used to detect the inlet flow of the negative pressure mechanism. The signal output of the flow detection unit is connected to the signal input of the processing module. And / or, A pressure detection unit is provided, which is disposed between the negative pressure mechanism and the gas sampling bottle. The inlet of the pressure detection unit is located inside the gas sampling bottle and above the liquid surface of the absorbent. The outlet of the pressure detection unit is connected to the inlet of the negative pressure mechanism. The pressure detection unit is used to detect the inlet pressure of the negative pressure mechanism. The signal output of the pressure detection unit is connected to the signal input of the processing module. And / or, A calibration bottle is disposed within the outer casing, and the calibration bottle contains a standard solution with a preset chloride ion concentration. The processing module is further configured to acquire the potential and conductivity of the standard solution, and to perform drift correction on the potential of the sample solution based on the potential of the standard solution, and to perform drift correction on the conductivity of the sample solution based on the conductivity of the standard solution.

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