A method, apparatus and system for measuring trace moisture

Abstract

The application relates to the technical field of water content measurement, in particular to a trace moisture determination method, a determination instrument and a system, which comprises the following steps: obtaining an electrolytic current change curve of a sample to be measured; dividing the electrolytic current change curve into a baseline interval, a sample injection interval and a main reaction interval; obtaining a humidity interference factor in the moisture content determination process according to the discrete degree and the complexity of the period data of each data in the sample injection interval, the current abnormal characteristics in the sample injection interval, the determination interference factor in the moisture content determination process obtained in combination with the current abnormal characteristics of the baseline interval and the main reaction interval, and comparing the determination interference factor with a preset threshold value to determine whether the carrier gas flow needs to be adjusted; when the carrier gas flow needs to be adjusted, the carrier gas flow in the next moisture content determination is calculated. The application evaluates the measurement accuracy in the current moisture determination process, adjusts the carrier gas flow in the next moisture determination process, and improves the test accuracy in the next moisture determination.

Description

Technical Field

[0001] This application relates to the field of moisture content measurement technology, specifically to a method, instrument, and system for determining trace moisture. Background Technology

[0002] The trace moisture content of materials is one of the important indicators in the quality control process. The Karl Fischer method is based on the principle of chemical reaction between iodine and sulfur dioxide and water in an organic solvent containing pyridine (or other organic bases). It has the advantages of ultra-high sensitivity and accuracy. It can not only quickly and effectively determine the trace moisture content in materials, but also provide key technical support for the upgrading of quality control systems in various industries.

[0003] In the process of detecting trace moisture content in materials using the Karl Fischer method, the coulometric method is easily affected by external humidity. Moisture in the air may seep into the electrolytic cell, affecting the accuracy of the test results. At the same time, external oxygen will oxidize iodide ions in the titration cell, and external light will accelerate the oxidation reaction of iodide ions, causing the "endpoint-by-endpoint phenomenon" during electrolysis, that is, premature termination of the reaction, resulting in misjudgment of the endpoint of the test results and making the measured results too low. Therefore, there is an urgent need for a method to improve the accuracy of moisture determination. Summary of the Invention

[0004] To address the aforementioned technical problems, the purpose of this application is to provide a method, instrument, and system for determining trace moisture, the specific technical solution of which is as follows:

[0005] In a first aspect, embodiments of this application provide a method for determining trace moisture, the method comprising the following steps:

[0006] Obtain the electrolysis current variation curve during moisture determination of the sample;

[0007] The electrolytic current variation curve is divided into a baseline interval, an injection interval, and a main reaction interval based on the measurement start time, the start time of sample injection, the maximum value and the endpoint of the electrolytic current variation curve; the fitting curves of the injection interval and the main reaction interval are obtained; based on the dispersion and complexity of the periodic data of each data in the injection interval, the current rise rate in the injection interval, and the distance between the electrolytic current variation curve of the injection interval and its fitting curve, the humidity interference factor in the moisture content determination process is obtained.

[0008] The baseline rise fluctuation during the moisture content determination process is obtained by considering the difference between the first and last data within the baseline interval and the dispersion of all data within the baseline interval. The photo-oxidation interference factor during the moisture content determination process is obtained by combining the slope difference between all data and the previous data of the fitted curve of the main reaction interval and the duration of the main reaction interval.

[0009] Based on the humidity interference factor and photo-oxidation interference factor in the moisture content measurement process, the measurement interference factor in the moisture content measurement process is obtained and compared with the preset threshold to determine whether the carrier gas flow rate needs to be adjusted. When the carrier gas flow rate needs to be adjusted, the carrier gas flow rate for the next moisture content measurement is obtained based on the measurement interference factor in the current moisture content measurement process, the preset carrier gas flow rate, and the preset flow rate range.

[0010] Preferably, the specific process of dividing the electrolytic current variation curve into a baseline interval, an injection interval, and a main reaction interval is as follows: the data point corresponding to the maximum value of the electrolytic current in the electrolytic current variation curve is recorded as the injection peak value, and the data point corresponding to the start of the injection is recorded as the initial injection value; the data interval between the current data measured at the start time and the initial injection value in the electrolytic current variation curve is recorded as the baseline interval; the data interval between the initial injection value and the injection peak value in the electrolytic current variation curve is recorded as the injection interval; and the data interval between the injection peak value and the determination endpoint in the electrolytic current variation curve is recorded as the main reaction interval.

[0011] Preferably, the formula for calculating the humidity interference factor in the moisture content determination process is as follows: In the formula, Humidity is a factor that interferes with the moisture content determination process. It is the ratio of the difference between the last and first data points in the injection interval to the total number of data points in the injection interval. The approximate entropy of the injection period intensity sequence, The variance of the injection cycle intensity sequence, DTW distance between the electrolytic current variation curve of the injection interval and its fitted curve, norm() is the normalization function; the process of obtaining the injection cycle intensity sequence is as follows: obtain the cycle term intensity of each data point in the injection interval; and take the sequence of the cycle term intensities corresponding to all data points in the injection interval in the order of the data point time sequence as the injection cycle intensity sequence.

[0012] Preferably, the formula for calculating the baseline rise fluctuation during the moisture content determination process is: In the formula, This refers to the baseline rise fluctuation during the moisture content determination process. Let be the difference between the last and first data points within the baseline interval, and exp() be an exponential function with base e. is the coefficient of variation of the sequence consisting of all data points within the baseline interval.

[0013] Preferably, the formula for calculating the photo-oxidation interference factor during the moisture content determination process is as follows: In the formula, Photo-oxidation interference factors in the moisture content determination process; This refers to the baseline rise fluctuation during the moisture content determination process. The sum of the absolute differences between the slopes of all data points and the previous data point in the fitted curve of the main response interval. The duration of the main reaction interval is given by exp(), which is an exponential function with the natural constant e as the base.

[0014] Preferably, the formula for calculating the interference factor in the moisture content determination process is as follows: In the formula, These are interfering factors in the moisture content determination process. Humidity is a factor that interferes with the moisture content determination process. is the photo-oxidation interference factor in the moisture content determination process, and norm() is the normalization function.

[0015] Preferably, the specific process for determining whether the carrier gas flow rate needs to be adjusted is as follows: when the measurement interference factor of the sample to be tested in the current moisture content determination process is less than a preset threshold, then there is no need to adjust the carrier gas flow rate; otherwise, the carrier gas flow rate needs to be adjusted.

[0016] Preferably, the formula for calculating the carrier gas flow rate for the next moisture content determination is: In the formula, The carrier gas flow rate is used for the (i+1)th time to determine the moisture content of the sample. Let G be the preset carrier gas flow rate for the i-th moisture content determination of the sample, and let G be the preset flow rate range. This represents the interference factor in the i-th moisture content determination process. This is a preset threshold.

[0017] Secondly, embodiments of this application provide a trace moisture analyzer, which includes: a data acquisition module, a humidity influence analysis module, a light-oxygen interference analysis module, and an interference compensation module.

[0018] The data acquisition module is used to acquire the electrolysis current change curve during the moisture determination of the sample.

[0019] The humidity influence analysis module is used to obtain the humidity interference factor in the moisture content determination process based on the current characteristics of the electrolysis current change curve when affected by humidity.

[0020] The photo-oxidation interference analysis module is used to obtain the photo-oxidation interference factors in the moisture content determination process based on the current characteristics of the electrolysis current change curve under the influence of ambient light and external oxygen.

[0021] The interference compensation module is used to adjust the carrier gas flow rate for the next measurement process based on the humidity interference factor and photo-oxidation interference factor during the moisture content measurement process.

[0022] Thirdly, embodiments of this application also provide a trace moisture determination system, the system including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement the steps of any of the trace moisture determination methods described above.

[0023] As can be seen from the above embodiments, the trace moisture determination method, instrument, and system provided in this application have at least the following beneficial effects:

[0024] 1. This application provides a specific quantitative method for humidity interference factor and light-oxygen interference factor by analyzing the interference of external environmental humidity, light and oxygen intrusion on the Karl Fischer coulometric method for water content determination. The interference factor obtained by this method more accurately reflects the abnormal electrolytic current caused by multiple environmental interferences in the Karl Fischer coulometric method determination system, and can effectively evaluate the accuracy of the water content determination results of the sample to be tested by the Karl Fischer coulometric method.

[0025] 2. By measuring interference factors, the accuracy of sample moisture content determination is evaluated, and this is used as a basis to adjust the carrier gas flow rate of the determination system. This avoids misjudgment of the endpoint of the determination result caused by severe interference from the external environment, and effectively improves the accuracy of the test results in the next test of the moisture content of the sample. Attached Figure Description

[0026] To more clearly illustrate the technical solutions and advantages in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A flowchart illustrating the steps of a method for determining trace moisture according to one embodiment of this application;

[0028] Figure 2 This is a schematic diagram of a trace moisture analyzer provided in one embodiment of this application. Detailed Implementation

[0029] To further illustrate the technical means and effects adopted by this application to achieve the intended inventive purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a trace moisture determination method, measuring instrument, and system proposed according to this application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0030] Unless otherwise specified and limited, terms such as “comprising,” “including,” or any other variations thereof are intended to cover a non-exclusive inclusion, such that a circuit structure, article, or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the article or device that includes said element. Furthermore, the term “and / or” as used herein includes any and all combinations of one or more of the associated listed items. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0031] The following description, in conjunction with the accompanying drawings, details the specific scheme of the trace moisture determination method, instrument, and system provided in this application.

[0032] Please see Figure 1 The diagram illustrates a flowchart of a method for determining trace moisture according to an embodiment of this application. The method includes the following steps:

[0033] Step 1: Obtain the electrolysis current change curve during the moisture determination of the sample.

[0034] This application uses the Karl Fischer coulometric method to detect the internal moisture content of the material.

[0035] The Karl Fischer coulometric moisture analyzer used in this embodiment has an electrolysis current range of 0-400 mA and a resolution of 0.1. The balance has an accuracy of 0.1 mg, and the microsyringe has a capacity of 0.5-10 mg. Purity of dry nitrogen source 99.99%, the temperature in the measurement environment was maintained at 20-25 degrees Celsius. .

[0036] First, the electrolytic cell needs to be cleaned and assembled. Specifically, rinse the electrolytic cell and the sample inlet with anhydrous methanol to ensure that there is no residual water. Then, install the electrodes and inject new electrolyte to the liquid level line. The anolyte injection volume is 100-150 mL, avoiding exceeding 80% of the electrolytic cell volume; the catholyte injection volume is 5-10 mL. Under no-load electrolysis conditions, the background drift is automatically deducted.

[0037] This application involves testing solid samples by accurately weighing a preset weight of the solid sample using a balance and grinding it to the specified particle size. Then, it is placed in a Karl von Schüco furnace; the heating temperature is set to t. The value of t ranges from 100 to 150, and is set to 120 in this embodiment. After electrolysis is started, the electrolysis current change curve over time is obtained using the coulometer built into the Karl Fischer coulometric moisture analyzer. During electrolysis, nitrogen gas is used to purge the released moisture from the sample to be tested into the electrolysis cell. The preset carrier gas flow rate is set to P mL / min, and the value of P ranges from 30 to 100, with P set to 50 in this embodiment.

[0038] Step 2: Based on the start time of measurement, the start time of sample injection, the maximum value and the endpoint of the electrolytic current change curve, divide the electrolytic current change curve into a baseline interval, an injection interval, and a main reaction interval; obtain the fitting curves of the injection interval and the main reaction interval; based on the dispersion and complexity of the periodic data of each data in the injection interval, the current rise rate in the injection interval, and the distance between the electrolytic current change curve of the injection interval and its fitting curve, obtain the humidity interference factor in the moisture content determination process.

[0039] In the Karl Fischer coulometric method for determining sample moisture content, when no sample is introduced into the electrolytic cell, the electrolytic current remains within the background drift range. After the ground solid sample is heated by a cassette furnace to release moisture, nitrogen purging carries the released moisture into the electrolytic cell, causing the electrolytic current to rapidly rise to its peak value. The electrolytic current then maintains this level for a period before gradually decreasing until the endpoint determination stage, at which point the current drops to a certain level, triggering a termination signal on the Karl Fischer coulometric moisture analyzer. When ambient humidity is too high, moisture can enter the electrolytic cell through weak points in the seal, directly participating in the reaction to generate iodine, leading to abnormal electrolytic current. This is a typical interference mechanism of "non-sample moisture contributing to the electrolytic charge," which severely reduces the accuracy of measurements at low moisture concentrations.

[0040] Specifically, in the process of determining the moisture content of a sample using the Karl Fischer coulometric method, when the ambient humidity is high, the interference from non-sample moisture entering the electrolytic cell becomes more severe. During the sample introduction stage, the rate of increase in the electrolytic cell current is faster due to the influence of additional moisture. Over time, the unevenness of air humidity leads to unstable reaction rates, causing random fluctuations in power consumption. During the sample introduction stage, the electrolytic current exhibits stronger irregular oscillations. At the same time, the unevenness of air humidity also causes the electrolytic current curve to exhibit a strong nonlinear trend.

[0041] Based on the above analysis, the data point corresponding to the maximum value of the electrolytic current in the electrolytic current variation curve is recorded as the injection peak value, and the data point corresponding to the start of injection is recorded as the initial injection value. The data interval between the current data at the start of measurement and the initial injection value in the electrolytic current variation curve is recorded as the baseline interval; the data interval between the initial injection value and the injection peak value in the electrolytic current variation curve is recorded as the injection interval; and the data interval between the injection peak value and the determination endpoint in the electrolytic current variation curve is recorded as the main reaction interval.

[0042] Using all data points in the injection interval as input, the STL (Seasonal and Trend decomposition using Loess) algorithm is used to obtain the periodic term intensity of each data point in the injection interval. The sequence of periodic term intensities corresponding to all data points in the injection interval according to the time sequence of the data points is used as the injection periodic intensity sequence.

[0043] All data points within the injection interval and the main reaction interval of the electrolytic current variation curve are used as inputs, and a polynomial fitting algorithm is employed to obtain the fitted curves for the injection interval and the main reaction interval. The beneficial effects of using the polynomial fitting algorithm to obtain the fitted curves for each interval are: smoothing out abnormal changes in the electrolytic current within the original interval through polynomial fitting technology, maximizing the restoration of the electrolytic current variation trend within the interval under normal conditions, and quantitatively assessing the severity of the disruption of the linear trend of the electrolytic current caused by external environmental interference by analyzing the difference between the fitted curve and the original electrolytic current curve.

[0044] This application constructs a humidity interference factor to characterize the severity of the influence of external environmental humidity during the determination of moisture content in the sample to be tested.

[0045] In this embodiment, the humidity interference factor in the moisture content measurement process is denoted as... Its expression is: In the formula, Humidity is a factor that interferes with the moisture content determination process. It is the ratio of the difference between the last and first data points in the injection interval to the total number of data points in the injection interval. The approximate entropy of the injection period intensity sequence, The variance of the injection cycle intensity sequence, Let be the DTW distance between the electrolysis current variation curve in the injection interval and its fitted curve, and norm() be the normalization function, such that... The value range is within the range of [0,1]. In this embodiment, the tanh() function is used for normalization.

[0046] The more severe the interference of ambient humidity on the Karl Fischer coulometric determination of water content, the faster the rate of increase of the electrolytic current in the injection interval, the higher the irregularity of the electrolytic current, and the more significant the impact on the calculated indicators. and The larger the value, the more pronounced the nonlinear trend of the electrolysis current curve caused by interference from non-sample moisture, the greater the difference in the periodic intensity of the electrolysis current change, and the greater the difference between the electrolysis current change curve and the linear fitting curve. The calculated index... It gets bigger.

[0047] Thus, the humidity interference factor in the process of determining the moisture content of the sample using the Karl Fischer coulometric method can be obtained through the above method.

[0048] Step 3: Based on the differences between the first and last data within the baseline interval and the dispersion of all data within the baseline interval, obtain the baseline rise fluctuation during the moisture content measurement process. Combine the slope difference between all data and the previous data of the fitted curve of the main reaction interval, as well as the duration of the main reaction interval, to obtain the photo-oxidation interference factor during the moisture content measurement process.

[0049] Relying solely on humidity interference factors to assess the accuracy of water content determination using the Karl Fischer coulometric method still has certain drawbacks. Specifically, it does not consider the intrusion of external oxygen and the aggravation of iodide ion oxidation by light. In the Karl Fischer coulometric method for water content determination, the oxidation of iodide ions is a critical step. Increased external light and oxygen intrusion can lead to excessive oxidation of iodide ions, interfering with the balance of the electrolytic current. This may result in the "endpoint bias" phenomenon during electrolysis, causing misjudgment of the endpoint and affecting the accuracy of the measurement results.

[0050] Specifically, in the Karl Fischer coulometric method for determining water content, the more severe the interference from external light and oxygen intrusion, the more significant the abnormal rise or oscillation of the baseline current becomes due to the oxidation side reaction between oxygen and iodide ions in the electrolyte to generate free iodine, which directly contributes to the Faraday current. The unstable rate of the oxidation side reaction caused by light and oxygen intrusion leads to significant fluctuations in the electrolytic current decay within the main reaction zone of electrolysis. At the same time, oxygen intrusion further oxidizes iodide ions in the electrolytic cell into iodine, while light promotes the oxidation reaction between oxygen and iodide ions, resulting in a greater attenuation of the electrolytic current in the main reaction zone of electrolysis, thus reaching the endpoint prematurely.

[0051] In this embodiment, the baseline rise fluctuation during the moisture content measurement process is denoted as... Its specific expression is: In the formula, This refers to the baseline rise fluctuation during the moisture content determination process. Let be the difference between the last and first data points within the baseline interval, and exp() be an exponential function with base e. is the coefficient of variation of the sequence consisting of all data points within the baseline interval.

[0052] The greater the interference of ambient light and oxygen intrusion on the Karl Fischer coulometric determination of water content, the greater the initial rise of the electrolytic current in the baseline range, and the more severe the oscillation phenomenon of the electrolytic current in the baseline range. This results in a greater calculated baseline rise fluctuation. The larger.

[0053] Furthermore, the slope of each data point in the fitted curve of the main reaction interval is calculated. The method for obtaining the slope of each data point in the fitted curve is a well-known technique, and the specific process will not be described in detail.

[0054] As a preferred embodiment, the photo-oxidation interference factor during the moisture content determination process is obtained based on the baseline rise fluctuation during the moisture content determination process, the slope difference of the fitting curve of the main reaction interval between all data and the previous data, and the duration of the main reaction interval. This factor is used to characterize the degree of interference of the sample to be tested by ambient light and oxygen intrusion during the moisture content determination process.

[0055] In this embodiment, the photo-oxidation interference factor in the moisture content determination process is denoted as... Its specific expression is: In the formula, Photo-oxidation interference factors in the moisture content determination process; This refers to the baseline rise fluctuation during the moisture content determination process. The sum of the differences between the absolute values ​​of the slopes of all data points in the fitted curve of the main response interval and the previous data point (it should be noted that since there are no data points before the first data point, the first data point is not included in the calculation of the slope difference). The duration of the main reaction interval is given by exp(), which is an exponential function with the natural constant e as the base.

[0056] and The larger the value, the more severe the oscillation phenomenon in the baseline range, the faster the current decrease rate in the main reaction range, and the greater the degree of abnormality in the electrolysis current. In this case, the sample under test is more affected by ambient light and oxygen intrusion during the determination of water content.

[0057] Step 4: Obtain the measurement interference factor in the moisture content measurement process based on the humidity interference factor and the photo-oxidation interference factor, and compare it with the preset threshold to determine whether the carrier gas flow rate needs to be adjusted; when the carrier gas flow rate needs to be adjusted, obtain the carrier gas flow rate for the next moisture content measurement based on the measurement interference factor in the current moisture content measurement process, the preset carrier gas flow rate, and the preset flow rate range.

[0058] Furthermore, during the determination of water content in samples using the Karl Fischer coulometric method, the more severe the abnormal drift of the electrolytic current caused by ambient humidity, and the more severe the baseline abnormality and accelerated decay of the electrolytic current caused by ambient light and oxygen intrusion, the more the current water content determination system is affected by multiple environmental interference factors, leading to a significant increase in the risk of measurement result distortion.

[0059] Therefore, as a preferred embodiment, the measurement interference factor in the moisture content measurement process is obtained based on the humidity interference factor and the photo-oxidation interference factor in the moisture content measurement process, which is used to characterize the possibility of the measurement result accuracy distortion caused by external environmental interference during the moisture content measurement of the sample to be tested.

[0060] In this embodiment, the interference factor in the moisture content determination process is denoted as... Its specific expression is: In the formula, These are interfering factors in the moisture content determination process. Humidity is a factor that interferes with the moisture content determination process. The photo-oxidation interference factor in the moisture content determination process, norm() is the normalization function, which makes The value range is within the range of [0,1].

[0061] When the interference factor is larger, the electrolytic current drift anomaly is more significant during the Karl Fischer coulometric method for determining water content. The rise and fluctuation of the electrolytic current in the baseline range is more obvious, and the rate of decrease of the electrolytic current in the main electrolysis reaction zone is faster, which increases the risk of "endpoint borrowing".

[0062] Thus, the interference factors in the determination of moisture content of the sample to be tested can be obtained through the above methods.

[0063] Furthermore, when the interference factor of the sample under test in the current moisture content determination process is less than the preset threshold R, it indicates that in the current Karl Fischer coulometric determination system, the influence of external environmental humidity, light, and oxygen intrusion on the accuracy of the moisture content detection results is low, and there is no need to adjust the carrier gas flow rate. Conversely, it indicates that in the current Karl Fischer coulometric determination system, the interference of external environmental humidity, light, and oxygen intrusion on the accuracy of the moisture content detection results is high, the risk of misjudgment of the endpoint is high, and the measurement accuracy is poor. In this case, it is necessary to adjust the carrier gas flow rate to ensure that high-purity nitrogen purging can effectively isolate oxygen intrusion and avoid low accuracy in the next sample moisture content detection. In this embodiment, R is taken as 0.7, and the implementer can choose a value according to the actual situation.

[0064] The specific method for adjusting the carrier gas flow rate is as follows: Calculate the carrier gas flow rate for the next moisture content determination of the sample, using the following formula: In the formula, The carrier gas flow rate is used for the (i+1)th time to determine the moisture content of the sample. G represents the preset carrier gas flow rate for the i-th moisture content determination of the sample, and G is the preset flow rate range. In this embodiment, G is set to 50. This represents the interference factor in the i-th moisture content determination process. This is a preset threshold. In this embodiment, the unit of carrier gas flow rate is mL / min.

[0065] When testing the moisture content of the same type of sample again, the calculated carrier gas flow rate for the next moisture content determination will be used as the carrier gas flow rate of the measurement system, thereby improving the detection accuracy of the next moisture determination.

[0066] Please see Figure 2 , Figure 2 This is a schematic diagram of a trace moisture analyzer provided in an embodiment of this application. In this embodiment, the terminal includes units used to execute the steps in an embodiment corresponding to a trace moisture determination method. See also... Figure 2 The trace moisture analyzer includes: a data acquisition module, a humidity effect analysis module, a light-oxygen interference analysis module, and an interference compensation module.

[0067] The data acquisition module is used to acquire the electrolysis current change curve during the moisture determination of the sample.

[0068] The humidity influence analysis module is used to obtain the humidity interference factor in the moisture content determination process based on the current characteristics of the electrolysis current change curve when affected by humidity.

[0069] The photo-oxidation interference analysis module is used to obtain the photo-oxidation interference factors in the moisture content determination process based on the current characteristics of the electrolysis current change curve under the influence of ambient light and external oxygen.

[0070] The interference compensation module is used to adjust the carrier gas flow rate for the next measurement process based on the humidity interference factor and photo-oxidation interference factor during the moisture content measurement process.

[0071] Based on the same inventive concept as the above method, this application also provides a trace moisture determination system, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any of the trace moisture determination methods described above.

[0072] The various embodiments in this application are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0073] It should be noted that, unless otherwise specified and limited, terms such as “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a circuit structure, article, or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such article or device. Without further limitations, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the article or device that includes said element. Furthermore, the term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0074] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not invented in this application.

[0075] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A method for determining trace moisture, characterized in that, The method includes the following steps: Obtain the electrolysis current variation curve during moisture determination of the sample; The electrolytic current variation curve is divided into a baseline interval, an injection interval, and a main reaction interval based on the measurement start time, the start time of sample injection, the maximum value and the endpoint of the electrolytic current variation curve; the fitting curves of the injection interval and the main reaction interval are obtained; based on the dispersion and complexity of the periodic data of each data in the injection interval, the current rise rate in the injection interval, and the distance between the electrolytic current variation curve of the injection interval and its fitting curve, the humidity interference factor in the moisture content determination process is obtained. The baseline rise fluctuation during the moisture content determination process is obtained by considering the difference between the first and last data within the baseline interval and the dispersion of all data within the baseline interval. The photo-oxidation interference factor during the moisture content determination process is obtained by combining the slope difference between all data and the previous data of the fitted curve of the main reaction interval and the duration of the main reaction interval. Based on the humidity interference factor and photo-oxidation interference factor in the moisture content measurement process, the measurement interference factor in the moisture content measurement process is obtained and compared with the preset threshold to determine whether the carrier gas flow rate needs to be adjusted. When the carrier gas flow rate needs to be adjusted, the carrier gas flow rate for the next moisture content measurement is obtained based on the measurement interference factor in the current moisture content measurement process, the preset carrier gas flow rate, and the preset flow rate range.

2. The method for determining trace moisture as described in claim 1, characterized in that, The specific process of dividing the electrolysis current variation curve into a baseline interval, an injection interval, and a main reaction interval is as follows: the data point corresponding to the maximum value of the electrolysis current in the electrolysis current variation curve is recorded as the injection peak value, and the data point corresponding to the start of the injection is recorded as the initial injection value; the data interval between the current data measured at the start of the electrolysis current variation curve and the initial injection value is recorded as the baseline interval; the data interval between the initial injection value and the injection peak value in the electrolysis current variation curve is recorded as the injection interval; and the data interval between the injection peak value and the determination endpoint in the electrolysis current variation curve is recorded as the main reaction interval.

3. The method for determining trace moisture as described in claim 1, characterized in that, The formula for calculating the humidity interference factor in the moisture content determination process is as follows: In the formula, Humidity is a factor that interferes with the moisture content determination process. It is the ratio of the difference between the last and first data points in the injection interval to the total number of data points in the injection interval. The approximate entropy of the injection period intensity sequence, The variance of the injection cycle intensity sequence, DTW distance between the electrolytic current variation curve of the injection interval and its fitted curve, norm() is the normalization function; the process of obtaining the injection cycle intensity sequence is as follows: obtain the cycle term intensity of each data point in the injection interval; and take the sequence of the cycle term intensities corresponding to all data points in the injection interval in the order of the data point time sequence as the injection cycle intensity sequence.

4. The method for determining trace moisture as described in claim 1, characterized in that, The formula for calculating the baseline rise fluctuation during the moisture content determination process is as follows: In the formula, This refers to the baseline rise fluctuation during the moisture content determination process. Let be the difference between the last and first data points within the baseline interval, and exp() be an exponential function with base e. is the coefficient of variation of the sequence consisting of all data points within the baseline interval.

5. The method for determining trace moisture as described in claim 1, characterized in that, The formula for calculating the photo-oxidation interference factor during the moisture content determination process is as follows: In the formula, Photo-oxidation interference factors in the moisture content determination process; This refers to the baseline rise fluctuation during the moisture content determination process. The sum of the absolute differences between the slopes of all data points and the previous data point in the fitted curve of the main response interval. The duration of the main reaction interval is given by exp(), which is an exponential function with the natural constant e as the base.

6. The method for determining trace moisture as described in claim 1, characterized in that, The formula for calculating the interference factor in the moisture content determination process is as follows: In the formula, These are interfering factors in the moisture content determination process. Humidity is a factor that interferes with the moisture content determination process. is the photo-oxidation interference factor in the moisture content determination process, and norm() is the normalization function.

7. The method for determining trace moisture as described in claim 1, characterized in that, The specific process for determining whether the carrier gas flow rate needs to be adjusted is as follows: when the measurement interference factor of the sample to be tested in the current moisture content determination process is less than the preset threshold, then there is no need to adjust the carrier gas flow rate; otherwise, the carrier gas flow rate needs to be adjusted.

8. The method for determining trace moisture as described in claim 1, characterized in that, The formula for calculating the carrier gas flow rate for the next moisture content determination is as follows: In the formula, The carrier gas flow rate is used for the (i+1)th time to determine the moisture content of the sample. Let G be the preset carrier gas flow rate for the i-th moisture content determination of the sample, and let G be the preset flow rate range. This represents the interference factor in the i-th moisture content determination process. This is a preset threshold.

9. A trace moisture analyzer, characterized in that, The method for determining trace moisture as described in any one of claims 1-8, wherein the trace moisture analyzer comprises: The data acquisition module is used to acquire the electrolysis current change curve during the moisture determination of the sample. The humidity influence analysis module is used to obtain the humidity interference factor in the moisture content determination process based on the current characteristics of the electrolysis current change curve when affected by humidity. The photo-oxidation interference analysis module is used to obtain the photo-oxidation interference factors in the moisture content determination process based on the current characteristics of the electrolysis current change curve under the influence of ambient light and external oxygen. The interference compensation module is used to adjust the carrier gas flow rate for the next measurement process based on the humidity interference factor and photo-oxidation interference factor during the moisture content measurement process.

10. A trace moisture determination system, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements a method for determining trace moisture as described in any one of claims 1-8.

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