Method for measuring content of aging characteristic product of insulating paper
阅读说明：本技术 一种绝缘纸老化特征产物含量的测定方法 (Method for measuring content of aging characteristic product of insulating paper ) 是由 杨雪滢 李宗红 程雪婷 宋玉峰 于 2021-01-07 设计创作，主要内容包括：本发明涉及一种绝缘纸老化特征产物含量的测定方法,包括以下步骤：制备标准溶液；将不同含量的糠醛标准溶液分别注入多个第一顶空进样瓶,将第一顶空进样瓶放进顶空进样器,得到不同含量的糠醛标准溶液对应的标准色谱图,从标准色谱图中确定相应的糠醛的标准保留时间和标准峰面积；以标准含量为纵坐标,以标准峰面积为横坐标,根据标准含量和标准峰面积的值获得标准曲线,进而得到线性回归方程；吸取样品溶液注入第二顶空进样瓶,将第二顶空进样瓶放进顶空进样器,得到色谱图,并确定相应的糠醛的峰面积；将糠醛的峰面积带入线性回归方程,即可得到样品溶液中糠醛的含量。本发明为变压器绝缘纸老化的监督与维护提供了快速便捷的有效手段。(The invention relates to a method for measuring the content of an aging characteristic product of insulating paper, which comprises the following steps: preparing a standard solution; respectively injecting the furfural standard solutions with different contents into a plurality of first headspace sample injection bottles, putting the first headspace sample injection bottles into a headspace sample injector to obtain standard chromatograms corresponding to the furfural standard solutions with different contents, and determining the standard retention time and the standard peak area of corresponding furfural from the standard chromatograms; taking the standard content as a vertical coordinate and the standard peak area as a horizontal coordinate, and obtaining a standard curve according to the values of the standard content and the standard peak area so as to obtain a linear regression equation; absorbing the sample solution and injecting the sample solution into a second headspace sample injection bottle, placing the second headspace sample injection bottle into a headspace sample injector to obtain a chromatogram, and determining the peak area of corresponding furfural; and substituting the peak area of the furfural into a linear regression equation to obtain the content of the furfural in the sample solution. The invention provides a quick, convenient and effective means for supervision and maintenance of the aging of the transformer insulation paper.)
1. The method for measuring the content of the aging characteristic product of the insulating paper is characterized by comprising the following steps of:
preparing a standard solution, accurately weighing a furfural standard substance, and adding blank insulating oil to prepare furfural standard solutions with different contents;
preparing an insulating oil sample solution;
connecting a headspace sample injector with a gas chromatograph, and adjusting parameters of the headspace sample injector and the gas chromatograph to enable the headspace sample injector and the gas chromatograph to be suitable for furfural;
after the headspace sample injector and the gas chromatograph are stabilized, respectively injecting the furfural standard solutions with different contents into a plurality of first headspace sample injection bottles, putting the first headspace sample injection bottles into the headspace sample injector connected with the gas chromatograph, carrying out analysis and determination to obtain standard chromatograms corresponding to the furfural standard solutions with different contents, and determining the standard retention time and the standard peak area of the corresponding furfural from the standard chromatograms;
acquiring a standard mass spectrogram of the furfural corresponding to the standard retention time, and determining characteristic ions of the furfural;
taking the standard content as a vertical coordinate and the standard peak area as a horizontal coordinate, and obtaining a standard curve according to the specific numerical values of the standard content and the standard peak area so as to obtain a linear regression equation of the standard curve;
precisely absorbing the sample solution and injecting the sample solution into a second headspace sample injection bottle, placing the second headspace sample injection bottle into a headspace sample injector connected with a gas chromatograph, carrying out analysis and determination to obtain a chromatogram of furfural in the sample solution, and determining the peak area of corresponding furfural;
and substituting the peak area of the furfural into the linear regression equation to obtain the content of the furfural in the sample solution.
2. The method for determining the content of the insulation paper aging characteristic product according to claim 1, wherein the steps of preparing a standard solution, accurately weighing a furfural standard substance, adding blank insulation oil, and preparing the furfural standard solution with different contents comprise:
accurately weighing 0.5g of furfural standard substance, and dissolving the furfural standard substance in 500ml of white oil to form a furfural solution with the content of 1000 mg/L;
diluting the furfural solution with blank oil to prepare a standard furfural oil sample with the concentration of 10 mg/mL;
and then respectively sucking 1mL, 2mL, 3mL, 4mL and 5mL of the standard furfural oil sample, dissolving in 100mL of blank oil, and sequentially obtaining furfural series standard solutions with the contents of 0.1mg/L, 0.2mg/L, 0.3mg/L, 0.4mg/L and 0.5mg/L respectively.
3. The method for determining the content of the aging characteristic product of the insulating paper according to claim 1 or 2, wherein after the headspace sample injector and the gas chromatograph are stabilized, the furfural standard solutions with different contents are respectively injected into a plurality of first headspace sample injectors, the first headspace sample injectors are placed into the headspace sample injector connected with the gas chromatograph for analysis and determination, so as to obtain standard chromatograms corresponding to the furfural standard solutions with different contents, and the standard retention time and the standard peak area of the corresponding furfural are determined from the standard chromatograms, further comprising:
and after the headspace sample injector and the gas chromatograph are stabilized, respectively taking 5ml of furfural standard solutions with the contents of 0.1mg/L, 0.2mg/L, 0.3mg/L, 0.4mg/L and 0.5mg/L, respectively injecting the furfural standard solutions into five first headspace sample injection bottles, putting the five first headspace sample injection bottles into the headspace sample injector connected with the gas chromatograph, carrying out analysis and determination to obtain standard chromatograms corresponding to the furfural standard solutions with different contents, and determining the standard retention time and the standard peak area of the corresponding furfural from the standard chromatograms.
4. The method for determining the content of the aging characteristic products of the insulating paper according to claim 3, wherein the sample solution is precisely sucked and injected into a second headspace sample injection bottle, the second headspace sample injection bottle is placed into a headspace sample injector connected with a gas chromatograph, analysis and determination are performed, a chromatogram of furfural in the insulating oil is obtained, and a peak area of corresponding furfural is determined, and the method further comprises:
precisely absorbing 5ml of the sample solution, injecting the sample solution into a second headspace sample injection bottle, placing the second headspace sample injection bottle into a headspace sample injector connected with a gas chromatograph, carrying out analysis and determination to obtain a chromatogram of furfural in the sample solution, and determining the peak area of corresponding furfural.
5. The method for measuring the content of the aging characteristic product of the insulating paper according to claim 1, wherein the chromatographic conditions of the gas chromatograph are as follows:
gas chromatograph, 7890B, Agilent;
headspace sampler, 7697A, Agilent;
chromatography column, CP-WAX 57CB, 50m, 0.250mm, 0.2 μm;
the column temperature is 60 ℃ at the initial temperature, the temperature is kept for 10min, and then the temperature is increased to 220 ℃ at the speed of 30 ℃/min and kept for 15 min;
carrier gas, He,1.5 mL/min;
and a sample inlet is used for shunting and injecting samples, and the shunting ratio is 20:1 and 150 ℃.
Technical Field
The application relates to the technical field of content detection, in particular to a method for determining the content of an aging characteristic product of insulating paper.
Background
The main component of the transformer insulating paper, paperboard and the like is made of long tubular cellulose, and the cellulose is a macromolecule formed by connecting a plurality of glucosyl groups by 1, 4-beta glycosidic bonds. Due to the action of temperature, moisture and oxygen, the cellulose can be gradually degraded during the operation of the transformer, so that the degree of polymerization is reduced, and the tensile strength and the insulating property of the paperboard are reduced. The insulation in transformers is a composite insulation system consisting of insulating oil and insulating paper, wherein the insulating paper directly determines the service life of the transformer due to its irreplaceability and unrecoverable aging characteristics. During the operation of the transformer, the degradation of the insulating paper cellulose can generate a plurality of substances, wherein the most important aging characteristic product is furfural. Therefore, the current method for diagnosing the service life of the transformer is mainly based on the research of a solid insulation diagnosis method based on furfural analysis, furfural has less loss in the transformer due to high boiling point, and thus, the method for determining the aging degree of the insulation paper by measuring the furfural content in the insulation oil by using High Performance Liquid Chromatography (HPLC) is the most common method.
The standard method for detecting the furfural content in insulating oil at present is liquid chromatography. The method takes methanol as an extracting agent, the furfural in the oil needs to be enriched through operation steps of oscillation, centrifugation and the like, and the furfural dissolved in the methanol extraction liquid is analyzed by a high performance liquid chromatograph, so that the quantitative determination of the furfural in the oil is realized. The method needs to extract and enrich furfural during standard curve drawing and oil sample detection, and the sample pretreatment method is complicated. An oil sample may take approximately one hour from sample pre-treatment to completion of the test.
The main problems to be solved at present are to provide a detection method which does not need to manually carry out sample pretreatment, is quick and accurate in detection and high in sensitivity, and is simple and convenient in result data processing.
Disclosure of Invention
The application provides a method for measuring the content of an aging characteristic product of insulating paper, which aims to solve the problem that the prior art carries out content measurement through a high performance liquid chromatograph, and the sample pretreatment process is more complicated.
The technical scheme adopted by the application is as follows:
the invention provides a method for measuring the content of an aging characteristic product of insulating paper, which comprises the following steps:
preparing a standard solution, accurately weighing a furfural standard substance, and adding blank insulating oil to prepare furfural standard solutions with different contents;
preparing an insulating oil sample solution;
connecting a headspace sample injector with a gas chromatograph, and adjusting parameters of the headspace sample injector and the gas chromatograph to enable the headspace sample injector and the gas chromatograph to be suitable for furfural;
after the headspace sample injector and the gas chromatograph are stabilized, respectively injecting the furfural standard solutions with different contents into a plurality of first headspace sample injection bottles, putting the first headspace sample injection bottles into the headspace sample injector connected with the gas chromatograph, carrying out analysis and determination to obtain standard chromatograms corresponding to the furfural standard solutions with different contents, and determining the standard retention time and the standard peak area of the corresponding furfural from the standard chromatograms;
acquiring a standard mass spectrogram of the furfural corresponding to the standard retention time, and determining characteristic ions of the furfural;
taking the standard content as a vertical coordinate and the standard peak area as a horizontal coordinate, and obtaining a standard curve according to the specific numerical values of the standard content and the standard peak area so as to obtain a linear regression equation of the standard curve;
precisely absorbing the sample solution and injecting the sample solution into a second headspace sample injection bottle, putting the second headspace sample injection bottle into a headspace sample injector connected with a gas chromatograph, carrying out analysis and determination to obtain a chromatogram of furfural in the insulating oil, and determining the peak area of corresponding furfural;
and substituting the peak area of the furfural into the linear regression equation to obtain the content of the furfural in the sample solution.
Further, preparing a standard solution, accurately weighing a furfural standard substance, adding blank insulating oil, and preparing the furfural standard solution with different contents, wherein the method comprises the following steps:
accurately weighing 0.5g of furfural standard substance, and dissolving the furfural standard substance in 500ml of white oil to form a furfural solution with the content of 1000 mg/L;
diluting the furfural solution with blank oil to prepare a standard furfural oil sample with the concentration of 10 mg/mL;
and then respectively sucking 1mL, 2mL, 3mL, 4mL and 5mL of the standard furfural oil sample, dissolving in 100mL of blank oil, and sequentially obtaining furfural series standard solutions with the contents of 0.1mg/L, 0.2mg/L, 0.3mg/L, 0.4mg/L and 0.5mg/L respectively.
Further, after the headspace sample injector and the gas chromatograph are stabilized, the furfural standard solutions with different contents are respectively injected into the plurality of first headspace sample injectors, the first headspace sample injectors are placed into the headspace sample injectors connected with the gas chromatograph, analysis and determination are performed, standard chromatograms corresponding to the furfural standard solutions with different contents are obtained, and then the standard retention time and the standard peak area of the corresponding furfural are determined in the standard chromatograms, and the method further comprises the following steps:
and after the headspace sample injector and the gas chromatograph are stabilized, respectively taking 5ml of furfural standard solutions with the contents of 0.1mg/L, 0.2mg/L, 0.3mg/L, 0.4mg/L and 0.5mg/L, respectively injecting the furfural standard solutions into five first headspace sample injection bottles, putting the five first headspace sample injection bottles into the headspace sample injector connected with the gas chromatograph, carrying out analysis and determination to obtain standard chromatograms corresponding to the furfural standard solutions with different contents, and determining the standard retention time and the standard peak area of the corresponding furfural from the standard chromatograms.
Further, precisely absorbing the sample solution and injecting the sample solution into a second headspace sample injection bottle, placing the second headspace sample injection bottle into a headspace sample injector connected with a gas chromatograph, carrying out analysis and determination to obtain a chromatogram of furfural in the sample solution, and determining the peak area of corresponding furfural, further comprising:
precisely absorbing 5ml of the sample solution, injecting the sample solution into a second headspace sample injection bottle, placing the second headspace sample injection bottle into a headspace sample injector connected with a gas chromatograph, carrying out analysis and determination to obtain a chromatogram of furfural in the sample solution, and determining the peak area of corresponding furfural.
Further, the chromatographic conditions of the gas chromatograph are as follows:
gas chromatograph, 7890B, Agilent;
headspace sampler, 7697A, Agilent;
chromatography column, CP-WAX 57CB, 50m, 0.250mm, 0.2 μm;
the column temperature is 60 ℃ at the initial temperature, the temperature is kept for 10min, and then the temperature is increased to 220 ℃ at the speed of 30 ℃/min and kept for 15 min;
carrier gas, He,1.5 mL/min;
and a sample inlet is used for shunting and injecting samples, and the shunting ratio is 20:1 and 150 ℃.
The technical scheme of the application has the following beneficial effects:
the invention discloses a method for measuring the content of an aging characteristic product of insulating paper, which comprises the following steps: accurately weighing a furfural standard substance, adding blank insulating oil, and preparing furfural standard solutions with different contents; preparing an insulating oil sample solution; connecting the headspace sample injector with the gas chromatograph, and adjusting parameters of the headspace sample injector and the gas chromatograph to ensure that the headspace sample injector and the gas chromatograph are suitable for furfural; after the headspace sample injector and the gas chromatograph are stabilized, respectively injecting the furfural standard solutions with different contents into a plurality of first headspace sample injection bottles, putting the first headspace sample injection bottles into the headspace sample injector connected with the gas chromatograph, carrying out analysis and determination to obtain standard chromatograms corresponding to the furfural standard solutions with different contents, and determining the standard retention time and the standard peak area of the corresponding furfural from the standard chromatograms; acquiring a standard mass spectrogram of the furfural corresponding to the standard retention time, and determining characteristic ions of the furfural; taking the standard content as a vertical coordinate and the standard peak area as a horizontal coordinate, and obtaining a standard curve according to the specific numerical values of the standard content and the standard peak area so as to obtain a linear regression equation of the standard curve; precisely absorbing the sample solution and injecting the sample solution into a second headspace sample injection bottle, placing the second headspace sample injection bottle into a headspace sample injector connected with a gas chromatograph, carrying out analysis and determination to obtain a chromatogram of furfural in the sample solution, and determining the peak area of corresponding furfural; and substituting the peak area of the furfural into a linear regression equation to obtain the content of the furfural in the sample solution.
According to the invention, the sample pretreatment is not required to be carried out manually, the sample introduction of a standard solution and an insulating oil sample solution is directly carried out in a gas chromatograph through a headspace sample injector to obtain a standard curve and a chromatogram, and the furfural content in the sample solution is calculated according to the standard curve and the chromatogram; the method can accurately and conveniently detect the content of the furfural in the insulating oil, and realizes the qualitative and quantitative detection of the furfural in the insulating oil by applying the headspace sampling-gas chromatography technology.
The invention provides a quick, convenient and effective means for supervision and maintenance of the aging of the transformer insulation paper.
Drawings
In order to more clearly explain the technical solution of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious to those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a chromatogram of furfural in a standard solution of a method for measuring the content of aging characteristic products of insulating paper;
FIG. 2 is a chromatogram of furfural in insulating oil obtained by a method for measuring the content of aging characteristic products of insulating paper.
Detailed Description
Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following examples do not represent all embodiments consistent with the present application. But merely as exemplifications of systems and methods consistent with certain aspects of the application, as recited in the claims.
FIG. 1 is a chromatogram of furfural in a standard solution of a method for measuring the content of aging characteristic products of insulating paper;
FIG. 2 is a chromatogram of furfural in insulating oil obtained by a method for measuring the content of aging characteristic products of insulating paper.
The application provides a method for measuring the content of an aging characteristic product of insulating paper, which comprises the following steps:
s01: preparing a standard solution, accurately weighing a furfural standard substance, and adding blank insulating oil to prepare furfural standard solutions with different contents;
first, a standard furfural solution content value to be prepared is selected, and a series of standard furfural content values arranged in an arithmetic progression is generally selected. The more the amount of the prepared furfural standard solution is, the more accurate the result is. Then, the furfural standard substance is accurately weighed, blank insulating oil is added into the furfural standard substance, and standard oil with the required furfural standard content is prepared. The method comprises the following specific steps:
the method comprises the following steps: accurately weighing 0.5g of furfural standard substance, and dissolving the furfural standard substance in 500ml of white oil to form a furfural solution with the content of 1000 mg/L;
step two: diluting the furfural solution with blank oil to prepare a standard furfural oil sample with the concentration of 10 mg/mL;
step three: and then respectively sucking 1mL, 2mL, 3mL, 4mL and 5mL of the standard furfural oil sample, dissolving in 100mL of blank oil, and sequentially obtaining furfural series standard solutions with the contents of 0.1mg/L, 0.2mg/L, 0.3mg/L, 0.4mg/L and 0.5mg/L respectively.
S02: preparing an insulating oil sample solution;
s03: connecting a headspace sample injector with a gas chromatograph, and adjusting parameters of the headspace sample injector and the gas chromatograph to enable the headspace sample injector and the gas chromatograph to be suitable for furfural;
a headspace sample injector is a convenient and fast sample pretreatment method in gas chromatography, and is characterized in that a sample to be detected is placed in a closed container, volatile components are volatilized from a sample matrix through heating, balance is achieved in a gas-liquid (or gas-solid) phase, and top gas is directly extracted for chromatographic analysis, so that the components and the content of the volatile components in the sample are detected. The headspace sampling technology can avoid a tedious and tedious sample pretreatment process, avoid interference of an organic solvent on analysis, and reduce pollution to a chromatographic column and a sampling port.
S04: after the headspace sample injector and the gas chromatograph are stabilized, respectively injecting the furfural standard solutions with different contents into a plurality of first headspace sample injection bottles, putting the first headspace sample injection bottles into the headspace sample injector connected with the gas chromatograph, carrying out analysis and determination to obtain standard chromatograms corresponding to the furfural standard solutions with different contents, and determining the standard retention time and the standard peak area of the corresponding furfural from the standard chromatograms; the details are as follows:
and after the headspace sample injector and the gas chromatograph are stabilized, respectively taking 5ml of furfural standard solutions with the contents of 0.1mg/L, 0.2mg/L, 0.3mg/L, 0.4mg/L and 0.5mg/L, respectively injecting the furfural standard solutions into five first headspace sample injection bottles, putting the five first headspace sample injection bottles into the headspace sample injector connected with the gas chromatograph, carrying out analysis and determination to obtain standard chromatograms corresponding to the furfural standard solutions with different contents, and determining the standard retention time and the standard peak area of the corresponding furfural from the standard chromatograms.
S05: acquiring a standard mass spectrogram of the furfural corresponding to the standard retention time, and determining characteristic ions of the furfural;
s06: taking the standard content as a vertical coordinate and the standard peak area as a horizontal coordinate, and obtaining a standard curve according to the specific numerical values of the standard content and the standard peak area so as to obtain a linear regression equation of the standard curve;
s07: precisely absorbing the sample solution and injecting the sample solution into a second headspace sample injection bottle, placing the second headspace sample injection bottle into a headspace sample injector connected with a gas chromatograph, carrying out analysis and determination to obtain a chromatogram of furfural in the sample solution, and determining the peak area of corresponding furfural; the details are as follows:
precisely absorbing 5ml of the sample solution, injecting the sample solution into a second headspace sample injection bottle, placing the second headspace sample injection bottle into a headspace sample injector connected with a gas chromatograph, carrying out analysis and determination to obtain a chromatogram of furfural in the sample solution, and determining the peak area of corresponding furfural.
S08: and substituting the peak area of the furfural into the linear regression equation to obtain the content of the furfural in the sample solution.
Specifically, the specific value of the peak area of furfural in the sample solution obtained in step S07 is substituted into the linear regression equation obtained in step S05, and the obtained value is the content of furfural in the sample solution.
Specifically, in the present embodiment, the chromatographic conditions of the gas chromatograph are as follows:
gas chromatograph, 7890B, Agilent; headspace sampler, 7697A, Agilent;
chromatography column, CP-WAX 57CB, 50m, 0.250mm, 0.2 μm;
the column temperature is 60 ℃ at the initial temperature, the temperature is kept for 10min, and then the temperature is increased to 220 ℃ at the speed of 30 ℃/min and kept for 15 min;
carrier gas, He,1.5mL/min (EPC constant current mode); a sample inlet for split-flow sample injection, wherein the split-flow ratio is 20:1, 150 ℃;
a chromatography workstation; analytical balance, accurate to 0.00001 g.
The qualitative test in this example specifically was:
in this embodiment, after the headspace sample injector and the gas chromatograph are stabilized, the prepared furfural standard solution with any content (any one of 0.1mg/L, 0.2mg/L, 0.3mg/L, 0.4mg/L, and 0.5 mg/L) is injected into the headspace bottle for detection, as shown in fig. 1, the retention time of furfural in the standard solution is 12.11min, and the retention time of furfural in the insulating oil is 12.11 min.
The quantitative test in this example specifically was:
and (4) performing analysis and determination according to the standard solution prepared in the S03, performing regression analysis by taking the peak area A of the furfural as a vertical coordinate and the content C of the furfural as a horizontal coordinate, and processing data through a workstation to obtain a standard curve, wherein a linear regression equation and related coefficients are shown in a table 2. Meanwhile, 5 replicates of the standard solution having a content of 0.3mg/L were measured, and the Relative Standard Deviation (RSD) of the peak area A with respect to the retention time t was calculated, and the results are shown in Table 1.
TABLE 1 Linear relationship and Process precision for Furfural in insulating oils
The concentration of the furfural in the insulating oil and the chromatographic peak area of the furfural in the insulating oil have a very good linear relation, and r is 0.9992.
According to the regression equation A, 3.626 x 104C+1.332×103And calculating to obtain the content of the furfural in the insulating oil to be 13.32mg/L according to the specific numerical value of the peak area of the furfural in the sample solution obtained in the step S07.
The standard solution with a content of 0.3mg/L was subjected to 5 replicates, and the Relative Standard Deviation (RSD) of the peak area A to the retention time t was calculated, which is expressed as follows:
xiis the value of each of the measurements taken,is the average of the measured values, and n is the number of measurements.
Meanwhile, the relative standard deviation of the peak area obtained by furfural peak area obtained by 5-time parallel measurement of a standard solution having a content of 0.3mg/L was 2.12.
0.14 is the retention time standard deviation calculated for 5 retention times.
The method reliability verification through the standard adding recovery test in the embodiment specifically comprises the following steps:
the method accuracy is verified by a sample standard adding recovery experiment, a 110k main transformer oil sample is taken as a sample, and the measurement result of the furfural content in the oil and the measurement result of the standard adding recovery rate are both listed in table 2.
TABLE 2 sample recovery analysis by adding standard
Specifically, 3 standard samples (furfural standard solutions of 0.5, 5.5, and 9 mg/L) with different contents were added to the prepared insulating oil sample solution with a furfural content of 13.32mg/L, respectively, and the measurement was performed under the same operating conditions to calculate the recovery rate. The recovery rate here means and is calculated as: and (3) adding a certain amount of furfural standard solution into the same insulating oil sample solution for measurement while measuring the insulating oil sample solution, and deducting the measurement value of the insulating oil sample solution from the measurement result to obtain the recovery rate by calculation, so as to measure the accuracy of the measurement result, wherein the higher the recovery rate is, the more accurate the measurement result is. From the above table, it can be seen that: the standard recovery rate is 95-105%, and the method for determining the furfural content in the insulating oil is accurate and reliable.
The invention establishes a method for accurately and conveniently detecting the content of the furfural in the insulating oil without manually carrying out sample pretreatment, and realizes the qualitative and quantitative detection of the furfural in the insulating oil by using a headspace sample introduction-gas chromatography technology. The invention provides a quick, convenient and effective means for supervision and maintenance of the aging of the transformer insulation paper.
The embodiments provided in the present application are only a few examples of the general concept of the present application, and do not limit the scope of the present application. Any other embodiments extended according to the scheme of the present application without inventive efforts will be within the scope of protection of the present application for a person skilled in the art.