Apparatus and method for measuring ion exchange capacity of ion exchange membrane

Abstract

A method for measuring ion exchange capacity of an ion exchange membrane, according to one embodiment, comprises the steps of: adding an appropriate solution to a solution eluted from the ion exchange membrane, and generating first data that includes a change in the ion conductivity of the solution according to a reaction time; adding an appropriate solution to the solution eluted from the ion exchange membrane, and generating an image obtained by photographing a color change of the solution according to reaction time; generating second data representing the image as coordinates in a color space through image conversion; determining a final end point by combining the first data and the second data; and calculating the ion exchange capacity of the ion exchange membrane on the basis of the concentration of the solution at the final end point.

Description

Device and method for measuring the ion exchange capacity of an ion exchange membrane

[0001] The present invention relates to an apparatus and method for measuring the ion exchange capacity of an ion exchange membrane, and more specifically, to an apparatus and method for measuring the ion exchange capacity of an ion exchange membrane by combining changes in ion conductivity and color changes to measure objective ion exchange capacity.

[0002] Most existing methods for measuring ion exchange capacity rely solely on silver titration. Since silver titration is subjective and tends to depend on human intuition, it is difficult to universally apply measurement methods from different membrane manufacturers. In particular, when used in electrodialysis processes, stable supply is required through diversification of supply lines from membrane suppliers; however, silver titration presents a problem in that it cannot be applied objectively and universally to calculate performance indicators of ion exchange membranes.

[0003] One embodiment of the present invention aims to provide an apparatus and method for measuring the ion exchange capacity of an ion exchange membrane, wherein the color change of a solution is stored as an image, at least one image conversion technique is selectively applied to quantify the result through a reaction time / color change graph in a color space, a color change point is extracted from the graph, and a final endpoint is calculated by combining this with a group of endpoint candidates determined through the ion conductivity slope, and the ion exchange capacity is measured based thereon.

[0004] Among the embodiments, a method for measuring the ion exchange capacity of an ion exchange membrane comprises the steps of: adding a titration solution to a solution eluted from an ion exchange membrane and generating a first graph including a first trend line and a second trend line for the change in ion conductivity of the solution according to reaction time; calculating, respectively, a first boundary point where the slope of the first trend line changes and a second boundary point where the slope of the second trend line changes in the graph; extracting a plurality of candidate endpoints having different reaction times within an endpoint region between the first reaction time of the first boundary point and the second reaction time of the second boundary point; generating an image of the color change of the solution according to reaction time by adding a titration solution to a solution eluted from an ion exchange membrane; generating a second graph in which the color change according to reaction time is coordinated from the image and represented in a coordinate space; extracting at least one inflection point from the second graph; selecting an inflection point among the at least one inflection point that is included within the endpoint region based on the reaction time and determining it as a color change point; and among the plurality of candidate endpoints having the same reaction time as the color change point. It may include the step of selecting an endpoint to determine as the final endpoint and the step of calculating the ion exchange capacity of the ion exchange membrane based on the concentration of the titration solution at the final endpoint.

[0005] The step of extracting at least one inflection point in the second graph may include determining the point where the sign of the slope of the tangent line in the second graph changes as the at least one inflection point.

[0006] The step of generating a second graph in which the color change according to the reaction time from the above image is coordinated and represented in a coordinate space may include the step of generating the second graph from the above image using at least one color space among RGB, YCbCr, or HSV.

[0007] The step of generating the second graph from the image using at least one color space among RGB, YCbCr, or HSV may include the step of generating a first candidate graph, a second candidate graph, and a third candidate graph, respectively, using RGB, YCbCr, and HSV; the step of extracting at least one first inflection point for each of the first candidate graph, the second candidate graph, and the third candidate graph; and the step of determining as the second graph a specific graph having a second inflection point included within the endpoint region based on reaction time among the at least one first inflection point extracted for each of the first candidate graph, the second candidate graph, and the third candidate graph.

[0008] The step of determining the second graph as a specific graph having a second inflection point included within the endpoint region based on reaction time among at least one first inflection point extracted for each of the first candidate graph, the second candidate graph, and the third candidate graph may include, in the case where there are multiple specific graphs, determining the second graph as one specific graph among the multiple specific graphs in which the slope of the tangent line changes most steeply at the second inflection point.

[0009] The step of selecting an inflection point included within the endpoint region based on the reaction time among the at least one inflection point to determine the color conversion point may include the step of determining the second inflection point of the determined second graph as the color conversion point.

[0010] The step of determining a color conversion point by selecting an inflection point included within the endpoint region based on the reaction time among the at least one inflection point may include determining a specific inflection point that commonly appears at the same point within the endpoint region in a plurality of second graphs generated using at least one color space among RGB, YCbCr, or HSV as the color conversion point.

[0011] The step of generating the second graph from the image using at least one color space among RGB, YCbCr, or HSV may include the step of selectively using any one of RGB, YCbCr, or HSV depending on the shooting method or characteristics of the image.

[0012] The step of generating the second graph from the image using at least one color space among RGB, YCbCr, or HSV may include the step of generating the second graph by selectively using any one of RGB, YCbCr, or HSV based on the type of ion exchange membrane.

[0013] The step of calculating the ion exchange capacity of the ion exchange membrane based on the concentration of the titration solution at the above final endpoint includes the step of calculating the ion exchange capacity using the following mathematical formula.

[0014] [Mathematical Formula]

[0015] IEC = (C xfx A) / D

[0016] Here, IEC may be the ion exchange capacity of the ion exchange membrane, C may be the concentration of the titration solution at the final endpoint (mol / L), f may be a factor representing the total number of anions that can be exchanged for 1 mole of ions in the titration solution, A may be the volume of the titration solution (ml), and D may be the dry weight of the ion exchange membrane (g).

[0017] Among the embodiments, the ion exchange capacity measuring device of an ion exchange membrane is a device of an ion exchange capacity measuring device of an ion exchange membrane that measures objective ion exchange capacity by combining changes in ion conductivity and color changes of a solution by executing program code loaded in one or more memory devices through one or more processors, wherein the program code is executed to add a titration solution to a solution eluted from an ion exchange membrane and generate a first graph including a first trend line and a second trend line for changes in ion conductivity of the solution according to reaction time, and in the graph, respectively calculate a first boundary point where the slope of the first trend line changes and a second boundary point where the slope of the second trend line changes, and extract a plurality of candidate endpoints having different reaction times within an endpoint region between the first reaction time of the first boundary point and the second reaction time of the second boundary point, generate an image of the color change of the solution according to reaction time by adding a titration solution to a solution eluted from an ion exchange membrane and generating a second graph in which the color change according to reaction time is coordinated from the image and displayed in a coordinate space, and in the second graph at least one An inflection point is extracted, and among the at least one inflection point, an inflection point included within the endpoint region based on the reaction time is selected and determined as a color change point, and among the plurality of candidate endpoints, an endpoint having the same reaction time as the color change point is selected and determined as a final endpoint, and the ion exchange capacity of the ion exchange membrane can be calculated based on the concentration of the titration solution at the final endpoint.

[0018] Extracting at least one inflection point from the second graph above may include determining the point where the sign of the slope of the tangent line in the second graph changes as the at least one inflection point.

[0019] Generating a second graph that plots the color change according to the reaction time from the above image in a coordinate space may include generating the second graph from the image using at least one color space among RGB, YCbCr, or HSV.

[0020] Generating the second graph from the image using at least one color space among RGB, YCbCr, or HSV may include generating a first candidate graph, a second candidate graph, and a third candidate graph using RGB, YCbCr, and HSV, respectively, extracting at least one first inflection point for each of the first candidate graph, the second candidate graph, and the third candidate graph, and determining as the second graph a specific graph having a second inflection point included within the endpoint region based on reaction time among the at least one first inflection point extracted for each of the first candidate graph, the second candidate graph, and the third candidate graph.

[0021] Determining the second graph as a specific graph having a second inflection point included within the endpoint region based on reaction time among at least one first inflection point extracted for each of the first candidate graph, the second candidate graph, and the third candidate graph may include, in the case where there are multiple specific graphs, determining the second graph as one specific graph among the multiple specific graphs in which the slope of the tangent line changes most steeply at the second inflection point.

[0022] Determining an inflection point included within the endpoint region based on the reaction time among the at least one inflection point above as a color conversion point may include determining the second inflection point of the determined second graph as the color conversion point.

[0023] Determining a color conversion point by selecting an inflection point included within the endpoint region based on the reaction time among the at least one inflection point may include determining a specific inflection point that commonly appears at the same point within the endpoint region in a plurality of second graphs generated using at least one color space among RGB, YCbCr, or HSV as the color conversion point.

[0024] Generating the second graph from the image using at least one color space among RGB, YCbCr, or HSV may include selectively using any one of RGB, YCbCr, or HSV depending on the shooting method or image characteristics of the image.

[0025] Generating the second graph from the image using at least one color space among RGB, YCbCr, or HSV may include generating the second graph by selectively using any one of RGB, YCbCr, or HSV based on the type of ion exchange membrane.

[0026] Among the embodiments, a method for measuring the ion exchange capacity of an ion exchange membrane may include the steps of: adding a titration solution to a solution eluted from an ion exchange membrane and generating first data including a change in the ion conductivity of the solution over a reaction time; adding a titration solution to a solution eluted from an ion exchange membrane and generating an image capturing a change in the color of the solution over a reaction time; generating second data represented as coordinates in a color space through image conversion of the image; determining a final endpoint by combining the first data and the second data; and calculating the ion exchange capacity of the ion exchange membrane based on the concentration of the solution at the final endpoint.

[0027] The step of generating second data represented as coordinates in a color space through image conversion of the above image may include the step of generating a graph in the color space showing the color change according to the reaction time using at least one color model among RGB, YCbCr, or HSV.

[0028] The step of determining the final endpoint by combining the first data and the second data includes the step of calculating an endpoint region based on the change in ion conductivity included in the first data, and the step of extracting a plurality of inflection points from the graph, and determining at least one inflection point among the plurality of inflection points that is included within the endpoint region as the final endpoint, wherein the plurality of inflection points may correspond to points where the sign of the slope of the tangent changes.

[0029] The step of extracting a plurality of inflection points from the above graph and determining at least one inflection point among the plurality of inflection points that is included within the endpoint region as the final endpoint may include, in the case of a plurality of graphs, determining one inflection point among the inflection points extracted from the plurality of graphs where the slope of the tangent changes most steeply as the final endpoint.

[0030] The apparatus and method for measuring the ion exchange capacity of an ion exchange membrane according to one embodiment of the present invention can be applied objectively and universally because they store the color change of a solution as an image, quantify it through a reaction rate / color change graph in a color space using at least one image coordinate system, generate a color transition point, calculate a final endpoint by combining it with a group of endpoint candidates determined through the ion conductivity gradient, and measure the ion exchange capacity based on this.

[0031] FIG. 1 is a block diagram of an ion exchange capacity measuring device of an ion exchange membrane according to one embodiment of the present invention.

[0032] FIG. 2 is a flowchart showing the steps for calculating candidate endpoints of an endpoint region according to one embodiment of the present invention.

[0033] FIG. 3 is a flowchart showing the steps of extracting color conversion points from an image according to one embodiment of the present invention.

[0034] FIG. 4 is a flowchart showing the steps of calculating ion exchange capacity based on candidate endpoints and color change points according to one embodiment of the present invention.

[0035] FIG. 5 is a table showing the reaction time, the amount of titrant added, and the change in ion conductivity according to one embodiment of the present invention.

[0036] Figure 6 is a graph showing the change in ionic conductivity of a solution according to reaction time in one embodiment of the present invention.

[0037] FIG. 7 is a graph of color change extracted from an image showing the color change of a solution according to reaction time according to one embodiment of the present invention.

[0038] FIG. 8 is a diagram illustrating a step for detecting a final endpoint according to an embodiment of the present invention.

[0039] FIG. 9 is a flowchart of the step of generating a graph in a color space from an image capturing a color change according to one embodiment of the present invention.

[0040] FIG. 10 is a diagram illustrating the steps for determining a color space graph and a color transition point according to an embodiment of the present invention.

[0041] FIG. 11 is a drawing for explaining a computing device according to an embodiment of the present invention.

[0042] An apparatus and method for measuring the ion exchange capacity of an ion exchange membrane can store the color change of a solution as an image, selectively apply at least one image conversion technique to quantify the result through a reaction time / color change graph in a color space, extract a color change point from the graph, and calculate a final endpoint by combining this with a group of endpoint candidates determined through the ion conductivity slope, and measure the ion exchange capacity based on this.

[0043] Embodiments of the present invention are described below with reference to the attached drawings so that those skilled in the art can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification are denoted by similar reference numerals.

[0044] Throughout the specification and claims, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. Such terms are used solely for the purpose of distinguishing one component from another.

[0045] Terms such as "...part," "...unit," and "module" as used in the specification may refer to a unit capable of processing at least one function or operation described in this specification, and may be implemented as hardware or a circuit, software, or a combination of hardware or a circuit and software.

[0046] In addition, at least some components or functions of the apparatus and method for measuring the ion exchange capacity of an ion exchange membrane according to the embodiments described below may be implemented as a program or software, and the program or software may be stored on a computer-readable medium.

[0047] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0048] FIG. 1 is a block diagram of an ion exchange capacity measuring device of an ion exchange membrane according to one embodiment of the present invention.

[0049] An ion exchange capacity measuring device (100) of an ion exchange membrane according to one embodiment can execute program code or instructions loaded into one or more memory devices through one or more processors.

[0050] For example, the ion exchange capacity measuring device (100) of an ion exchange membrane may be implemented as a computing device (900) as described below in relation to FIG. 11. In this case, one or more processors may correspond to the processor (910) of the computing device (900), and one or more memory devices may correspond to the memory (930) of the computing device (900).

[0051] Program code or instructions are executed by one or more processors, and when any one of the candidate endpoints obtained based on the change in ion conductivity based on the titration time overlaps with the color change point obtained based on the color change of the solution, the ion exchange capacity of the ion exchange membrane can finally be measured using the concentration of the titration solution added at the corresponding reaction time.

[0052] In this specification, the term "module" is used to logically distinguish these functions performed by program code or instructions.

[0053] Referring to FIG. 1, the ion exchange capacity measuring device (100) of an ion exchange membrane may include an ion conductivity change calculation unit (110), a color change extraction unit (120), a final endpoint determination unit (130), and an ion exchange capacity calculation unit (140).

[0054] The ion conductivity change calculation unit (110) can derive a first trend line and a second trend line for the change in ion conductivity according to the reaction time of a solution in which a titrant (or titrant solution) is added to a solution containing anions eluted from an ion exchange membrane.

[0055] For example, the titrant may be silver nitrate (AgNO3). The titration solution may be a reaction solution in which the titrant is added at regular reaction times to a solution containing anions, which is the solution to be reacted.

[0056] Ionic conductivity can change each time a titrant is added to the titration solution. In other words, ionic conductivity can vary with reaction time.

[0057] Trend lines for the change in ion conductivity according to reaction time may be provided as multiple lines, including a first trend line and a second trend line. Various methods may be used to derive the trend lines, including the Method of Least Squares, Linear Regression, Polynomial Regression, Exponential Smoothing, and Moving Average.

[0058] The ion conductivity change calculation unit (110) can calculate a first boundary point where the slope of the first trend line changes and a second boundary point where the slope of the second trend line changes, respectively.

[0059] The ion conductivity change calculation unit (110) can select the one in which the reaction time of the first boundary point is calculated to be the smallest value among the multiple trend lines showing the change in ion conductivity with respect to reaction time as the first trend line, and select the one in which the reaction time of the second boundary point is calculated to be the largest value as the second trend line.

[0060] The ion conductivity change calculation unit (110) can determine the region between the first reaction time of the first boundary point and the second reaction time of the second boundary point as the endpoint region.

[0061] The ion conductivity change calculation unit (110) can extract multiple candidate endpoints having different reaction times within the endpoint region. Each of the multiple candidate endpoints can have different ion conductivity and a corresponding reaction time.

[0062] The color change extraction unit (120) can add a titration solution to the solution eluted from the ion exchange membrane and generate an image of the color change of the solution over time.

[0063] The color change extraction unit (120) can extract color information of the solution at regular reaction times from an image showing the color change of the solution according to the reaction time and display it as a graph.

[0064] The color change extraction unit (120) can extract color information including converted RGB information, YCbCr (Luma, Blue Chrominance, Red Chrominance) information and / or HSV (Hue, Saturation, Value) information for colors extracted from an image.

[0065] That is, the color change extraction unit (120) can generate a graph in a coordinate space by coordinating the color change according to the reaction time from the image.

[0066] The color change extraction unit (120) may use an image conversion technique including various color spaces or color models for coordinate conversion of color changes.

[0067] The color change extraction unit (120) can detect the reaction time that indicates the most rapid color change while tracking image transformation according to time series by selectively using one of various color models based on the image shooting method or image characteristics.

[0068] For example, the color change extraction unit (120) can generate a graph of the color change of the solution over reaction time in a coordinate space (or color space) using RGB information, YCbCr information and / or HSV information.

[0069] That is, the color change extraction unit (120) can generate a graph from an image using at least one color space or color model among RGB, YCbCr, or HSV.

[0070] In one embodiment, the color change extraction unit (120) can generate a first candidate graph, a second candidate graph, and a third candidate graph, respectively, using RGB, YCbCr, and HSV.

[0071] The color change extraction unit (120) extracts at least one first inflection point for each of the first candidate graph, the second candidate graph, and the third candidate graph, and

[0072] The color change extraction unit (120) can determine a specific graph as the final graph that has a second inflection point included within the endpoint region based on reaction time among at least one first inflection point extracted for each of the first candidate graph, the second candidate graph, and the third candidate graph.

[0073] The color change extraction unit (120) can determine, in the case of multiple specific graphs, one specific graph among the multiple specific graphs in which the slope of the tangent line changes most steeply at the second inflection point as the final graph.

[0074] The color change extraction unit (120) can determine a specific graph in which the slope of the tangent line is steepest through differentiation for each of the tangent lines. Alternatively, the color change extraction unit (120) can determine the graph having the inflection point with the largest slope value of the tangent line as the final graph.

[0075] The color change extraction unit (120) can generate a graph by selectively using one of RGB, YCbCr, or HSV based on the type of ion exchange membrane.

[0076] The color change extraction unit (120) can selectively use one of RGB, YCbCr, or HSV depending on the image shooting method or image characteristics.

[0077] The final endpoint determination unit (130) can extract at least one inflection point from the generated graph.

[0078] Here, an inflection point can be a point on the graph where the sign of the slope of the tangent line changes.

[0079] The final endpoint determination unit (130) can determine whether the sign of the slope of the tangent line changes at the inflection point by differentiating the graph and substituting the coordinates of the inflection point.

[0080] The final endpoint determination unit (130) can determine the color conversion point by selecting an inflection point included within the endpoint area based on reaction time from among at least one inflection point.

[0081] That is, the final endpoint determination unit (130) can determine the color change point by selecting an inflection point between the first boundary point and the second boundary point based on the reaction time among at least one inflection point.

[0082] The final endpoint determination unit (130) can select an endpoint having the same reaction time as the color change point from among a plurality of candidate endpoints and determine it as the final endpoint.

[0083] That is, the final endpoint determination unit (130) can determine a specific transition point as a color transition point that has the same reaction time as any one of the reaction times for each of the multiple candidate endpoints among at least one transition point.

[0084] Here, the color change point refers to the point where the color of the solution actually changes and can be expressed as a specific reaction time.

[0085] The ion exchange capacity calculation unit (140) can calculate the ion exchange capacity of the ion exchange membrane based on the titration solution at the color change point. The ion exchange capacity calculation unit (140) can detect the ion conductivity and the amount of titrant at the reaction time corresponding to the color change point.

[0086] The ion exchange capacity calculation unit (140) can calculate the ion exchange capacity of the ion exchange membrane based on the concentration of the titration solution at the final endpoint.

[0087] That is, the ion exchange capacity calculation unit (140) can measure the ion exchange capacity of the ion exchange membrane based on the amount of titrant administered at the reaction time corresponding to the color change point.

[0088] The ion exchange capacity calculation unit (140) can calculate the ion exchange capacity according to the following mathematical formula.

[0089] [Mathematical Formula]

[0090] IEC = (C xfxa) / D

[0091] Here, IEC is the ion exchange capacity of the ion exchange membrane, C is the concentration of the titrant at the final endpoint (mol / L), f is a factor representing the total number of anions that can be exchanged for 1 mole of the titrant, A is the volume of the titrant (ml), and D is the dry weight of the ion exchange membrane (g).

[0092] FIG. 2 is a flowchart showing the step of calculating candidate endpoints of an endpoint region according to an embodiment of the present invention. The step of calculating candidate endpoints of the endpoint region of FIG. 2 can be performed through an ion exchange capacity measuring device (100) of an ion exchange membrane.

[0093] The ion exchange capacity measuring device (100) of the ion exchange membrane can add a titration solution to a solution containing anions eluted from the ion exchange membrane and generate a graph of the change in ion conductivity of the solution over reaction time (step S210).

[0094] The ion exchange capacity measuring device (100) of the ion exchange membrane can derive a first trend line and a second trend line for the change in ion conductivity according to reaction time in a graph (step S220).

[0095] The ion exchange capacity measuring device (100) of the ion exchange membrane can calculate a first boundary point where the slope of the first trend line changes and a second boundary point where the slope of the second trend line changes, respectively (step S230).

[0096] The ion exchange capacity measuring device (100) of the ion exchange membrane can select the first trend line in which the reaction time at the first boundary point is calculated to be the smallest value among a plurality of trend lines showing the change in ion conductivity with respect to reaction time, and select the second trend line in which the reaction time at the second boundary point is calculated to be the largest value.

[0097] The ion exchange capacity measuring device (100) of the ion exchange membrane determines the region between the first reaction time corresponding to the first boundary point and the second reaction time corresponding to the second boundary point as the endpoint region, and can extract a plurality of candidate endpoints each having a different reaction time within the endpoint region (step S240).

[0098] FIG. 3 is a flowchart showing the step of extracting a color change point from an image according to an embodiment of the present invention. The step of extracting a color change point from the image of FIG. 3 can be performed through an ion exchange capacity measuring device (100) of an ion exchange membrane.

[0099] The ion exchange capacity measuring device (100) of the ion exchange membrane can add a titrant to a solution containing anions eluted from the ion exchange membrane and generate an image showing the color change of the solution over the reaction time (step S310).

[0100] For example, the ion exchange capacity measuring device (100) of the ion exchange membrane can generate a video image of the color change of the solution during the reaction time.

[0101] The ion exchange capacity measuring device (100) of the ion exchange membrane can generate a graph in a coordinate space by coordinating the color change according to the reaction time from an image (step S320).

[0102] The ion exchange capacity measuring device (100) of the ion exchange membrane can detect the reaction time that indicates the most rapid color change while tracking image transformation over time series by selectively using one of various color models based on the image shooting method or image characteristics. The ion exchange capacity measuring device (100) of the ion exchange membrane can use various color models, not limited to RGB, YCbCr, and HSV.

[0103] For example, the ion exchange capacity measuring device (100) of the ion exchange membrane can extract a certain portion of an image to extract a color and convert the extracted color into RGB, YCbCR, or HSV information.

[0104] The ion exchange capacity measuring device (100) of the ion exchange membrane can generate a graph showing RGB, YCbCr, or HSV information for reaction time. The ion exchange capacity measuring device (100) of the ion exchange membrane can extract at least one inflection point from the graph (step S330).

[0105] For example, the ion exchange capacity measuring device (100) of the ion exchange membrane can extract at least one inflection point where the color changes rapidly based on the generated graph.

[0106] The ion exchange capacity measuring device (100) of the ion exchange membrane can extract a tangent line to a graph for a certain reaction time and determine the point where the sign of the slope of the extracted tangent line changes as an inflection point.

[0107] The ion exchange capacity measuring device (100) of the ion exchange membrane can determine the color change point by selecting an inflection point between the first boundary point and the second boundary point based on reaction time among at least one inflection point (step S340).

[0108] That is, the ion exchange capacity measuring device (100) of the ion exchange membrane can determine a specific inflection point as a color change point that has a reaction time equal to any one of the reaction times for each of the multiple candidate endpoints among at least one inflection point.

[0109] FIG. 4 is a flowchart showing the steps for calculating the ion exchange capacity based on candidate endpoints and color change points according to one embodiment of the present invention. The steps for calculating the ion exchange capacity of FIG. 4 can be performed through an ion exchange capacity measuring device (100) of an ion exchange membrane.

[0110] The ion exchange capacity measuring device (100) of the ion exchange membrane can extract the reaction time for each of the multiple candidate endpoints within the endpoint region (step S410).

[0111] The ion exchange capacity measuring device (100) of the ion exchange membrane can extract the reaction time of the color change point (step S420).

[0112] The ion exchange capacity measuring device (100) of the ion exchange membrane can determine a specific candidate endpoint among a plurality of candidate endpoints as the final endpoint, where the reaction time is the same as the reaction time of the color change point (step S430).

[0113] The ion exchange capacity measuring device (100) of the ion exchange membrane can calculate the ion exchange capacity based on the concentration of the titration solution added to the solution at the final endpoint (step S440).

[0114] The ion exchange capacity measuring device (100) of the ion exchange membrane can detect the ion conductivity of the titration solution and the amount of added titrant at the reaction time corresponding to the final endpoint.

[0115] The ion exchange capacity measuring device (100) of the ion exchange membrane can measure the ion exchange capacity of the ion exchange membrane based on the amount or concentration of the titrant (AgNO3) at the reaction time corresponding to the final endpoint.

[0116] The ion exchange capacity measuring device (100) of the ion exchange membrane can calculate the ion exchange capacity according to the following mathematical formula.

[0117] [Mathematical Formula]

[0118] IEC = (C xfx A) / D

[0119] Here, IEC is the ion exchange capacity of the ion exchange membrane, C is the concentration of the titrant at the final endpoint (mol / L), f is a factor representing the total number of anions that can be exchanged for 1 mole of the titrant, A is the volume of the titrant (ml), and D is the dry weight of the ion exchange membrane (g).

[0120] FIG. 5 is a table showing the reaction time, the amount of titrant added, and the change in ion conductivity according to one embodiment of the present invention.

[0121] Referring to the table in Fig. 5, the solution may contain 0.1 M sodium hydroxide (NaOH) and 5% potassium chromate (K2CrO4) initially added. Sodium hydroxide may be included for ion elution, and potassium chromate may be included as an indicator.

[0122] Afterwards, 0.1 M silver nitrate (AgNO3) can be added to the solution as a titrant at intervals of 0.1 mol to 0.4 mol. For example, silver nitrate can be added to the solution at a rate of about 0.2 mol every 2 minutes from 16 minutes to 28 minutes of reaction time. Silver nitrate can be added to the solution at a rate of about 0.1 mol every 1 minute from 29 minutes to 43 minutes of reaction time.

[0123] Referring to the table in Figure 5, the ionic conductivity of the solution according to the amount of silver nitrate added at each reaction time can be seen. The ionic conductivity can gradually change at each reaction time, from an initial 19.01 to 18.52 at 43 minutes of reaction time.

[0124] For example, at a reaction time of 32 minutes, the amount of silver nitrate added is 4.2 ml and the ionic conductivity is 18.58. At a reaction time of 34 minutes, the amount of silver nitrate added is 4.4 ml and the ionic conductivity is 18.55.

[0125] Figure 6 is a graph showing the change in ionic conductivity of a solution according to reaction time in one embodiment of the present invention.

[0126] In FIG. 6, the graph shows a first trend line (TL1, trend line 1) and a second trend line (TL2, trend line 2) showing the change in ion conductivity according to reaction time. The first trend line (TL1) includes a first boundary point (BP1) of a first reaction time (RT1). The second trend line (TL2) includes a second boundary point (BP2) of a second reaction time (RT2).

[0127] The first boundary point (BP1) can define the boundary between the first region and the endpoint region. The second boundary point (BP2) can define the boundary between the second region and the endpoint region.

[0128] The first region is a region for the reaction time during which anions eluted from the ion exchange membrane react with silver nitrate. The second region is a region for the reaction time during which silver nitrate reacts with an indicator. The endpoint region is a region that includes the endpoint at which the reaction between the eluted anions and silver nitrate ends. The endpoint region is defined in the reaction time interval between the first reaction time (RT1) and the second reaction time (RT2) and may include multiple candidate endpoints (CEP).

[0129] For example, in the table of FIG. 6, the ionic conductivity of the first boundary point (BP1) is 18.64, the first reaction time (RT1) is 26 minutes, and the volume of the added titrant silver nitrate may be 3.6 ml. The ionic conductivity of the second boundary point (BP2) is 18.55, the second reaction time (RT2) is 35 minutes, and the volume of the added titrant silver nitrate may be 4.5 ml.

[0130] The endpoint region may correspond to a reaction time between 26 minutes and 35 minutes. Therefore, there may be 9 candidate endpoints (CEP), including the first boundary point (BP1) and the second boundary point (BP2). The candidate endpoint (CEP) shown in the graph of FIG. 6 is shown as one example among them.

[0131] FIG. 7 is a graph of color information extracted from an image showing the color change of a titration solution according to a reaction time according to an embodiment of the present invention.

[0132] The ion exchange capacity measuring device (100) of the ion exchange membrane can detect color information from an image of a solution whose color changes during the reaction time and generate a graph in a coordinate space from the detected color information.

[0133] The photograph in Fig. 7 shows the solution at reaction times T1, T2, T3, and T4, respectively, after adding the titrant. At each of T1, T2, T3, and T4, the color of the solution changes slightly, but it is difficult to distinguish with the naked eye. For example, T1 may correspond to 31 minutes, T2 to 32 minutes, T3 to 34 minutes, and T4 to 35 minutes.

[0134] The ion exchange capacity measuring device (100) of the ion exchange membrane can detect color information by extracting a specific region (AA) of the image of the solution at T1, T2, T3, and T4, respectively.

[0135] For example, color information may include RGB information, YCbCr information, and HSV information. Fig. 7 illustrates RGB information.

[0136] The ion exchange capacity measuring device (100) of the ion exchange membrane can coordinate the color change of the solution according to the reaction time using the detected RGB information and express it as a graph in a coordinate space or an RGB color space.

[0137] In the graph (GRP), the reaction time can be defined from T0 to Tn. In the graph (GRP), there are two points where the sign of the slope of the tangent changes: Tx and Tz. In the graph (GRP), the points where the sign of the slope of the tangent changes may correspond to inflection points.

[0138] Both Tx and Tz correspond to inflection points. For example, Tx could be an RGB coordinate value corresponding to a reaction time of 33 minutes between T2 and T3. Tz could be a reaction time prior to 26 minutes.

[0139] Either Tx or Tz can be determined as the color transition point (CTP). The color transition point (CTP), where the color of the solution changes, can then be determined as the endpoint where the reaction between the titrant and the anion in the solution is terminated.

[0140] FIG. 8 is a diagram illustrating a step for detecting a final endpoint according to an embodiment of the present invention. It will be explained with reference to FIG. 6 and FIG. 7.

[0141] In FIG. 8, the first region (AR1, area1) and the end point region (EAR, end point area) can be distinguished by the first boundary point (BP1). The first region (AR1) shows the ionic conductivity during the reaction time in which the anions in the solution eluted from the titrant react with the ion exchange membrane.

[0142] The second region (AR2, area2) and the endpoint region (EAR) can be distinguished by the second boundary point (BP2). The second region (AR2) represents the ionic conductivity during the reaction time in which the titrant and the indicator react.

[0143] The endpoint region (EAR) is a region containing multiple candidate endpoints where the reaction between the anion in the solution and the indicator is terminated. The endpoint region (EAR) is a region corresponding to the reaction time between the first boundary point (BP1) and the second boundary point (BP2). Each of the multiple candidate endpoints may correspond to a reaction time of 26 minutes to 35 minutes. That is, each of the multiple candidate endpoints may be determined to be one of the titrant addition amounts of 3.6 ml to 4.5 ml.

[0144] The first boundary point (BP1) and the second boundary point (BP2) were obtained from the trend lines of the change in ion conductivity over reaction time in Fig. 6.

[0145] In Figure 7, any one of the inflection points of Tx and Tz obtained from the graph of RGB coordinates according to reaction time (GRP) may correspond to the color transition point (CTP) where the color of the titration solution changes.

[0146] The ion exchange capacity measuring device (100) of the ion exchange membrane can determine one of a plurality of candidate endpoints of the endpoint region (EAR) as the final endpoint (EP).

[0147] The ion exchange capacity measuring device (100) of the ion exchange membrane can determine one inflection point that overlaps with multiple candidate endpoints among multiple inflection points (Tx, Tz) as the color change point (CTP). The ion exchange capacity measuring device (100) of the ion exchange membrane can determine the color change point (CTP) as the final endpoint (EP).

[0148] The reaction time of Tx is 33 minutes, and the reaction time coincides with one of the candidate endpoints between the first boundary point (BP1) and the second boundary point (BP2). Therefore, the ion exchange capacity measuring device (100) of the ion exchange membrane can determine Tx as the color change point (CTP) and determine it as the final endpoint (EP).

[0149] The ion exchange capacity measuring device (100) of the ion exchange membrane can measure the ion exchange capacity of the ion exchange membrane using 4.3 ml of titrant added at the final endpoint (EP, end point).

[0150] The ion exchange capacity measuring device (100) of the ion exchange membrane can measure the ion exchange capacity according to the following mathematical formula.

[0151] [Mathematical Formula]

[0152] IEC = (C xfxa) / D

[0153] Here, IEC is the ion exchange capacity of the ion exchange membrane (mmol / g), C is the concentration of the titrant (mol / L), f is a factor representing the total number of anions that can be exchanged for 1 mole of the titrant, A is the volume of the titrant (ml), and D is the dry weight of the ion exchange membrane (g).

[0154] For example, when C is 0.1 mol / L, f is 1, and D is 0.236 g, and the concentration of the titrant at the final endpoint is 4.3 ml, the ion exchange capacity of the ion exchange membrane can be 1.82 mmol / g.

[0155] The ion exchange capacity measuring device (100) of the ion exchange membrane can determine the calculation range of ion exchange capacity for candidate endpoints within the endpoint region between the first boundary point (BP1) and the second boundary point (BP2). At the first boundary point (BP1), the titrant volume is 3.6 ml and the ion exchange capacity is 1.52 mmol / g. At the second boundary point (BP2), the titrant volume is 4.5 ml and the ion exchange capacity is 1.91 mmol / g. That is, the final ion exchange capacity determined by the final endpoint can be determined within the range of 1.52 mmol / g to 1.91 mmol / g.

[0156] The ion exchange capacity measuring device (100) of the ion exchange membrane can determine the final endpoint (EP) when a color change point (CTP) is detected through the graph of FIG. 6 and the graphs (GRP) of FIG. 7 and FIG. 8, and based on this, calculate 1.82 mmol / g as the optimal ion exchange capacity within the range of 1.52 mmol / g to 1.91 mmol / g to increase the accuracy of the match.

[0157] FIG. 9 is a flowchart of the step of generating a graph in a color space from an image capturing a color change according to an embodiment of the present invention. The step of FIG. 9 is performed in a method for measuring the ion exchange capacity of an ion exchange membrane and can be performed through an ion exchange capacity measuring device (100, see FIG. 1) of an ion exchange membrane.

[0158] In FIG. 9, the ion exchange capacity measuring device (100) of the ion exchange membrane can generate a first candidate graph, a second candidate graph, and a third candidate graph from an image using the color spaces of RGB, YCbCr, and HSV, respectively (step S910).

[0159] The ion exchange capacity measuring device (100) of the ion exchange membrane can generate a graph of color change over reaction time from an image using at least one color space among RGB, YCbCr, or HSV.

[0160] Here, RGB, YCbCr, and HSV are the three major color spaces used in digital image processing and computer graphics. Each has a different method of representing color and can be used in a manner suitable for specific purposes.

[0161] RGB represents color information as the intensity of red, green, and blue. The value of each channel is typically represented as an integer in the range of 0 to 255.

[0162] In YCbCr, Y (Luma) represents brightness information. Cb (Blue Chrominance) represents color difference information (difference in blue components). Cr (Red Chrominance) represents color difference information (difference in red components).

[0163] In HSV, H (Hue) represents hue, expressed from 0 to 360°, and includes red (0°), green (120°), blue (240°), etc. S (Saturation) represents saturation, indicating the degree of purity of the color, and is expressed from 0 to 100%. V (Value) represents lightness, indicating the brightness of the color, and can be expressed from 0 to 100%.

[0164] The ion exchange capacity measuring device (100) of the ion exchange membrane can extract at least one first inflection point for each of the first candidate graph, the second candidate graph, and the third candidate graph (step S920).

[0165] The ion exchange capacity measuring device (100) of the ion exchange membrane can determine a specific graph as the final graph that has a second inflection point included within the endpoint region based on reaction time among at least one first inflection point extracted from each of the first candidate graph, the second candidate graph, and the third candidate graph (step S930).

[0166] In the case where there are multiple specific graphs, the ion exchange capacity measuring device (100) of the ion exchange membrane can determine one specific graph as the final graph among the multiple specific graphs, in which the slope of the tangent line changes most steeply at the second inflection point (step S940).

[0167] The ion exchange capacity measuring device (100) of the ion exchange membrane can determine the graph with the largest absolute value of the slope of the tangent line appearing at the second inflection point as the final graph, regardless of the sign of the slope of the tangent line.

[0168] The steepness of the slope is proportional to the magnitude of the slope, and the magnitude of the slope can be expressed as an absolute value.

[0169] The ion exchange capacity measuring device (100) of the ion exchange membrane can extract a second inflection point from the determined final graph and determine the second inflection point as the color change point.

[0170] FIG. 10 is a diagram illustrating the step of determining a graph and a color transition point in a color space according to an embodiment of the present invention.

[0171] In Figure 7, the color change according to the reaction time (T0 to Tn) is shown as a graph in the RGB coordinate space.

[0172] On the other hand, Figure 10 shows that color changes according to reaction time are coordinated using various image transformation techniques and represented as a graph in a coordinate space (color space).

[0173] Various image conversion techniques may include the previously mentioned RGB color space, YCbCr color space, and HSV color space.

[0174] The ion exchange capacity measuring device (100) of the ion exchange membrane can selectively use one of RGB, YCbCr, or HSV depending on the image shooting method or image characteristics.

[0175] In addition, the ion exchange capacity measuring device (100) of the ion exchange membrane can generate a reaction time / color change graph by selectively using one of RGB, YCbCr, or HSV based on the type of ion exchange membrane.

[0176] That is, the ion exchange capacity measuring device (100) of the ion exchange membrane can generate first to third candidate graphs using RGB, YCbCr, and HSV respectively, and determine a final graph from which a color change point is extracted among the first to third candidate graphs.

[0177] In FIG. 10, the reaction time / color change graph expressed in the RGB color space is the same as that described in FIG. 7. That is, based on the endpoint region (25 to 35 minutes) described in FIG. 6 and FIG. 8, the ion exchange capacity measuring device (100) of the ion exchange membrane determined the inflection point at a reaction time of 33 minutes in the RGB color space as the color change point (CTP1).

[0178] The ion exchange capacity measuring device (100) of the ion exchange membrane can select a graph in an RGB coordinate space containing an inflection point within the endpoint region as the final graph.

[0179] In the reaction time / color change graph coordinated in the YCbCr color space, inflection points appear at 26 minutes and 40 minutes, respectively.

[0180] Reaction times of 26 minutes and 40 minutes are not included in the endpoint region (25 minutes to 35 minutes) according to one embodiment. Therefore, it may be determined that the YCbCr color space is not suitable for expressing color changes from the image of the ion exchange membrane.

[0181] The ion exchange capacity measuring device (100) of the ion exchange membrane does not select a graph in the YCbCr coordinate space that does not include an inflection point within the endpoint region as the final graph.

[0182] In the case of the HSV color space, the inflection point in the reaction time / color change graph coordinated in the color space appears at 33 minutes, respectively.

[0183] The inflection point of a reaction time of 33 minutes is included in the endpoint region (26 minutes to 35 minutes) according to one embodiment, so it may be a color change point (CTP2).

[0184] The ion exchange capacity measuring device (100) of the ion exchange membrane can select a graph in the HSV coordinate space containing an inflection point within the endpoint region as the final graph.

[0185] If there are two or more graphs that can be selected as the final graph, the ion exchange capacity measuring device (100) of the ion exchange membrane can select the graph in which the slope of the tangent line changes more steeply at the inflection point within the endpoint region as the final graph.

[0186] The ion exchange capacity measuring device (100) of the ion exchange membrane determines that the accuracy for the corresponding color change point is higher when the slope of the tangent at the inflection point (color change point) within the endpoint region changes more steeply.

[0187] The steepness of the tangent slope is proportional to the magnitude of the slope. The magnitude of the tangent slope can be expressed as the absolute value of the slope. At a color transition point, the magnitude of the slope can represent the instantaneous rate of change at that point.

[0188] That is, the ion exchange capacity measuring device (100) of the ion exchange membrane selects the graph with a larger slope, derivative, and instantaneous rate of change at the color change point as the final graph.

[0189] In another embodiment, the ion exchange capacity measuring device (100) of the ion exchange membrane can calculate the rate of change of the slope by taking a second derivative with respect to the tangent to determine the magnitude or steepness of the change in the slope of the tangent.

[0190] That is, the ion exchange capacity measuring device (100) of the ion exchange membrane can determine the graph with the larger value as the final graph by substituting each color change point into a function calculated through the second derivative of the graph.

[0191] The ion exchange capacity measuring device (100) of the ion exchange membrane can finally use an image conversion technique that has a graph with a larger rate of change of the calculated slope, and determine the graph as the final graph.

[0192] In one embodiment of FIG. 10, the color conversion point (CTP2) extracted via HSV and the color conversion point (CTP1) extracted via RGB have the same reaction time.

[0193] In another embodiment, in the range of 26 minutes to 35 minutes, which is the endpoint area derived from the first trend line and the second trend line, there may be cases where the color conversion points extracted using image conversion techniques of different color spaces are different from each other.

[0194] That is, in another embodiment, if the color change point (CTP2) of HSV is 34 minutes and the color change point (CTP1) of RGB is 32 minutes, the ion exchange capacity measuring device (100) of the ion exchange membrane can finally select the color change point (CTP2) of the HSV graph where the change in the slope of the tangent is greater and determine the final endpoint of 34 minutes (both 32 minutes and 34 minutes are included in the terminal region between 26 minutes and 35 minutes).

[0195] In Fig. 10, the change in the slope of the tangent line at the color transition point (CTP2) determined at the final inflection point of the graph in the HSV color space is greater than the change in the slope of the tangent line at the color transition point (CTP1) of the graph in the RGB color space (the slope of the tangent line appears steeper at the point where the sign of the slope changes).

[0196] The magnitude of the slope at the color transition point can be expressed as the absolute value of the slope. It can be determined that the steeper the slope, the greater the magnitude of the slope. At the color transition point, the slope represents the derivative and the instantaneous rate of change. Therefore, the larger the derivative of the tangent line at the color transition point, the greater the magnitude of the derivative and the instantaneous rate of change.

[0197] For example, if the slope of the tangent line (LN2) at the color change point (CTP2) of the HSV graph is 6 or -6, and the slope of the tangent line (LN1) at the color change point (CTP1) of the RGB graph is 2 or -2, the ion exchange capacity measuring device (100) of the ion exchange membrane can determine the final endpoint through the HSV graph.

[0198] That is, the ion exchange capacity measuring device (100) of the ion exchange membrane can finally generate a graph using the HSV color space and determine the final endpoint based on the color transition point (CTP2) determined from the generated graph.

[0199] In another embodiment, the ion exchange capacity measuring device (100) of the ion exchange membrane can determine a specific inflection point that appears commonly at the same point within the endpoint region in a plurality of graphs generated using the respective color spaces of RGB, YCbCr, and HSV as a color transition point.

[0200] That is, the ion exchange capacity measuring device (100) of the ion exchange membrane may determine the inflection point that commonly appears at a reaction time of 33 minutes, which is the same endpoint region in a plurality of color spaces including RGB and HSV, as the color conversion point.

[0201] Referring to FIG. 11, the device and method for measuring the ion exchange capacity of an ion exchange membrane according to the embodiments can be implemented using a computing device (900).

[0202] The computing device (900) may include at least one of a processor (910), memory (930), user interface input device (940), user interface output device (950), and storage device (560) that communicate via a bus (920). The computing device (900) may also include a network interface (970) that is electrically connected to a network (90). The network interface (970) may transmit or receive signals to or from other entities via the network (90).

[0203] The processor (910) can be implemented in various types such as an MCU (Micro Controller Unit), AP (Application Processor), CPU (Central Processing Unit), GPU (Graphic Processing Unit), NPU (Neural Processing Unit), etc., and may be any semiconductor device that executes instructions stored in memory (930) or storage device (960). The processor (910) may be configured to implement the functions and methods described above in relation to FIGS. 1 to 10.

[0204] The memory (930) and storage device (960) may include various forms of volatile or non-volatile storage media. For example, the memory may include ROM (read-only memory) (931) and RAM (random access memory) (932). In this embodiment, the memory (930) may be located inside or outside the processor (910), and the memory (930) may be connected to the processor (910) through various known means.

[0205] In some embodiments, at least some configurations or functions of the device and method for measuring the ion exchange capacity of an ion exchange membrane according to the embodiments may be implemented as a program or software executed on a computing device (900), and the program or software may be stored on a computer-readable medium.

[0206] In some embodiments, at least some configurations or functions of the device and method for measuring the ion exchange capacity of an ion exchange membrane according to the embodiments may be implemented using hardware or circuits of a computing device (900), or may be implemented using separate hardware or circuits that can be electrically connected to the computing device (900).

[0207] Although embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art to which the present invention belongs, utilizing the basic concept of the present invention as defined in the following claims, also fall within the scope of the present invention.

[0208] The apparatus and method for measuring the ion exchange capacity of an ion exchange membrane according to one embodiment of the present invention can measure objective ion exchange capacity by combining changes in ion conductivity and color changes, thus having industrial applicability.

Claims

1. A step of adding a titration solution to a solution eluted from an ion exchange membrane and generating a first graph including a first trend line and a second trend line for the change in ion conductivity of the solution according to reaction time; In the above graph, a step of calculating a first boundary point where the slope of the first trend line changes and a second boundary point where the slope of the second trend line changes, respectively; A step of extracting a plurality of candidate endpoints having different reaction times, respectively, within an endpoint region between the first reaction time of the first boundary point and the second reaction time of the second boundary point; A step of adding a titration solution to the solution eluted from the ion exchange membrane and generating an image of the color change of the solution over reaction time; A step of generating a second graph that represents the color change according to the reaction time from the above image in a coordinate space; A step of extracting at least one inflection point from the second graph above; A step of selecting an inflection point included within the endpoint region based on the reaction time from among the at least one inflection point and determining it as a color conversion point; A step of selecting an endpoint having the same reaction time as the color change point from among the plurality of candidate endpoints and determining it as the final endpoint; and A method for measuring the ion exchange capacity of an ion exchange membrane, comprising the step of calculating the ion exchange capacity of the ion exchange membrane based on the concentration of the titration solution at the final endpoint.

2. In Paragraph 1, The step of extracting at least one inflection point from the second graph above is, A step comprising determining the point where the sign of the slope of the tangent line in the second graph changes as the at least one inflection point. Method for measuring the ion exchange capacity of an ion exchange membrane.

3. In Paragraph 2, The step of generating a second graph that plots the color change according to the reaction time from the above image in a coordinate space is: A step comprising selectively using one color space among a plurality of color spaces based on the shooting method of the image or the characteristics of the image, Method for measuring the ion exchange capacity of an ion exchange membrane.

4. In Paragraph 3, The step of selectively using one color space among a plurality of color spaces based on the shooting method of the image or the characteristics of the image is A method comprising the step of generating the second graph from the image using at least one color space among RGB, YCbCr, or HSV, Method for measuring the ion exchange capacity of an ion exchange membrane.

5. In Paragraph 4, The step of generating the second graph from the image using at least one color space among RGB, YCbCr, or HSV, is: A step of generating a first candidate graph, a second candidate graph, and a third candidate graph, respectively, using the RGB, YCbCr, and HSV; A step of extracting at least one first inflection point for each of the first candidate graph, the second candidate graph, and the third candidate graph; and A step comprising determining as the second graph a specific graph having a second inflection point included within the endpoint region based on reaction time among at least one first inflection point extracted for each of the first candidate graph, the second candidate graph, and the third candidate graph. Method for measuring the ion exchange capacity of an ion exchange membrane.

6. In Paragraph 5, The step of determining a specific graph as the second graph having a second inflection point included within the endpoint region based on reaction time among at least one first inflection point extracted for each of the first candidate graph, the second candidate graph, and the third candidate graph, is In the case where there are multiple specific graphs mentioned above, A method comprising the step of determining, among the plurality of specific graphs, one specific graph in which the slope of the tangent line changes most steeply at the second inflection point as the second graph. Method for measuring the ion exchange capacity of an ion exchange membrane.

7. In Paragraph 4, The step of generating the second graph from the image using at least one color space among RGB, YCbCr, or HSV, is: A step comprising generating the second graph by selectively using one of the RGB, the YCbCr, or the HSV based on the type of the ion exchange membrane. Method for measuring the ion exchange capacity of an ion exchange membrane.

8. In Paragraph 1, The step of calculating the ion exchange capacity of the ion exchange membrane based on the concentration of the titration solution at the above final endpoint is: The method includes the step of calculating the above ion exchange capacity using the mathematical formula below, and [Mathematical Formula] IEC = (C xfx A) / D Here, IEC is the ion exchange capacity of the ion exchange membrane, C is the concentration of the titration solution at the final endpoint (mol / L), f is a factor representing the total number of anions exchangeable per mole of ion in the titration solution, A is the volume of the titration solution (ml), and D is the dry weight of the ion exchange membrane (g). Method for measuring the ion exchange capacity of an ion exchange membrane.

9. An ion exchange capacity measuring device for an ion exchange membrane that measures objective ion exchange capacity by combining changes in ion conductivity and color changes of a solution by executing program code loaded into one or more memory devices through one or more processors, The above program code is executed, Adding a titration solution to a solution eluted from an ion exchange membrane and generating a first graph including a first trend line and a second trend line for the change in ion conductivity of the solution according to reaction time, In the above graph, a first boundary point where the slope of the first trend line changes and a second boundary point where the slope of the second trend line changes are each calculated, and A plurality of candidate endpoints having different reaction times are extracted within the endpoint region between the first reaction time of the first boundary point and the second reaction time of the second boundary point, and Adding a titration solution to the solution eluted from the ion exchange membrane and generating an image of the color change of the solution over reaction time, A second graph is generated by coordinating the color change according to the reaction time from the above image and representing it in a coordinate space, and Extract at least one inflection point from the second graph above, and Among the above at least one inflection point, an inflection point included within the endpoint region based on the reaction time is selected and determined as a color conversion point, and Among the above multiple candidate endpoints, an endpoint having the same reaction time as the color change point is selected and determined as the final endpoint, and An ion exchange capacity measuring device for an ion exchange membrane that calculates the ion exchange capacity of the ion exchange membrane based on the concentration of the titration solution at the above final endpoint.

10. In Paragraph 9, Extracting at least one inflection point from the second graph above is, Including determining the point where the sign of the slope of the tangent line changes in the second graph as the at least one inflection point. Device for measuring the ion exchange capacity of an ion exchange membrane.

11. In Paragraph 10, Generating a second graph that plots the color change according to the reaction time from the above image in a coordinate space is, Includes selectively using one color space among a plurality of color spaces based on the shooting method of the image or the characteristics of the image. Device for measuring the ion exchange capacity of an ion exchange membrane.

12. In Paragraph 11, Selectively using one color space among a plurality of color spaces based on the shooting method of the above image or the characteristics of the above image is, A method comprising generating the second graph from the image using at least one color space among RGB, YCbCr, or HSV. Device for measuring the ion exchange capacity of an ion exchange membrane.

13. In Paragraph 12, Generating the second graph from the image using at least one color space among RGB, YCbCr, or HSV, is, A first candidate graph, a second candidate graph, and a third candidate graph are generated, respectively, using the above RGB, YCbCr, and HSV, and For the first candidate graph, the second candidate graph, and the third candidate graph, at least one first inflection point is extracted for each, and The method comprises determining the second graph as a specific graph having a second inflection point included within the endpoint region based on reaction time among at least one first inflection point extracted for each of the first candidate graph, the second candidate graph, and the third candidate graph. Device for measuring the ion exchange capacity of an ion exchange membrane.

14. In Paragraph 13, Determining a specific graph as the second graph that has a second inflection point included within the endpoint region based on reaction time among the at least one first inflection point extracted for each of the first candidate graph, the second candidate graph, and the third candidate graph, is: In the case where there are multiple specific graphs mentioned above, A method comprising determining, among the plurality of specific graphs, one specific graph in which the slope of the tangent line changes most steeply at the second inflection point as the second graph. Device for measuring the ion exchange capacity of an ion exchange membrane.

15. In Paragraph 12, Selecting an inflection point included within the endpoint region based on the reaction time from among the above at least one inflection point and determining it as a color conversion point is, Determining a specific inflection point that commonly appears at the same point within the endpoint region in a plurality of second graphs generated using at least one of the color spaces of RGB, YCbCr, or HSV as the color transition point, Device for measuring the ion exchange capacity of an ion exchange membrane.

16. In Paragraph 9, Calculating the ion exchange capacity of the ion exchange membrane based on the concentration of the titration solution at the above final endpoint is, It includes calculating the above ion exchange capacity using the mathematical formula below, and [Mathematical Formula] IEC = (C xfx A) / D Here, IEC is the ion exchange capacity of the ion exchange membrane, C is the concentration of the titration solution at the final endpoint (mol / L), f is a factor representing the total number of anions exchangeable per mole of ion in the titration solution, A is the volume of the titration solution (ml), and D is the dry weight of the ion exchange membrane (g). Device for measuring the ion exchange capacity of an ion exchange membrane.

17. A step of adding a titration solution to a solution eluted from an ion exchange membrane and generating first data including a change in the ion conductivity of the solution over a reaction time; A step of adding a titration solution to the solution eluted from the ion exchange membrane and generating an image of the color change of the solution over reaction time; A step of generating second data represented as coordinates in a color space through image conversion of the above image; A step of determining a final endpoint by combining the first data and the second data; and A method for measuring the ion exchange capacity of an ion exchange membrane, comprising the step of calculating the ion exchange capacity of the ion exchange membrane based on the concentration of the solution at the above final endpoint.

18. In Paragraph 17, The step of generating second data represented as coordinates in a color space through image conversion of the above image is: A method comprising the step of generating a graph in the color space showing the color change according to the reaction time using at least one color model among RGB, YCbCr, or HSV. Method for measuring the ion exchange capacity of an ion exchange membrane.

19. In Paragraph 18, The step of determining the final endpoint by combining the first data and the second data is A step of calculating an endpoint region based on changes in ion conductivity included in the first data above; and The method includes the step of extracting a plurality of inflection points from the graph and determining at least one inflection point among the plurality of inflection points that is included within the endpoint region as the final endpoint. The aforementioned plurality of inflection points correspond to points where the sign of the slope of the tangent line changes. Method for measuring the ion exchange capacity of an ion exchange membrane.

20. In Paragraph 19, The step of extracting a plurality of inflection points from the above graph, and determining at least one inflection point among the plurality of inflection points that is included within the endpoint region as the final endpoint, If there are multiple graphs above, A step comprising determining one inflection point among the inflection points extracted from each of the plurality of graphs above, where the slope of the tangent line changes most steeply, as the final endpoint. Method for measuring the ion exchange capacity of an ion exchange membrane.

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