Portable electrochemical hydrogen meter, calibration method, measurement method and software system

Abstract

The invention discloses a portable electrochemical hydrogen meter, a calibration method, a measurement method and a software system. The portable electrochemical hydrogen meter comprises a standard hydrogen partial pressure generation module, an electrochemical sensing module, a flow path switching module and a control and operation module. The standard hydrogen partial pressure generation module is used for outputting at least two hydrogen partial pressures, the flow path switching module is connected with the flow cell, and the control and operation module is in communication connection with the standard hydrogen partial pressure generation module, the electrochemical sensing module and the flow path switching module. In the calibration state, the control and operation module establishes the corresponding relation between the dissolved hydrogen concentration and the electric signal according to the at least two hydrogen partial pressures and the corresponding current signals; and in the measuring state, the portable electrochemical hydrogen meter outputs the dissolved hydrogen concentration value of the measured liquid based on the corresponding relation and the real-time temperature signal. The device provided by the invention is portable, and can immediately give out legal and effective dissolved hydrogen concentration on a nuclear power site.

Description

Technical Field

[0001] This application relates to the field of dissolved hydrogen concentration measurement technology, and in particular to a portable electrochemical hydrogen meter, calibration method, measurement method and software system. Background Technology

[0002] During the operation of pressurized water reactor nuclear power units, the primary coolant simultaneously undertakes the dual tasks of heat removal and neutron moderation. Its aqueous chemical state directly affects the integrity of the fuel cladding, the stress corrosion resistance of structural materials, and the migration behavior of radioactive source terms. Dissolved hydrogen concentration, as a key redox control indicator, needs to be continuously or intermittently monitored and maintained within the range specified in the technical specifications to prevent stress corrosion cracking of stainless steel and nickel-based alloys caused by elevated dissolved oxygen, and to inhibit the activation and deposition of radioactive isotopes. Given the confined space, high radiation dose rate, and dispersed equipment layout within the nuclear island, the miniaturization, lightweighting, and rapid on-site deployment capabilities of hydrogen meters place stringent requirements on hydrogen meters that are higher than in conventional industrial scenarios.

[0003] While existing hydrogen analyzers possess the response advantages of electrochemical sensing principles, they generally rely on external devices and manual calibration during on-site calibration. This results in a heavy overall weight, long preparation time, and difficulty in maintaining the integrity of the measurement transmission chain in environments with strong radiation, high temperature, and high humidity. Furthermore, the complex external gas circuits and frequent manual valve operation further amplify the risks of on-site leaks and personnel exposure. Summary of the Invention

[0004] The main objective of this application is to propose a portable electrochemical hydrogen meter, calibration method, measurement method, and software system. The device is portable and can immediately provide the legally valid dissolved hydrogen concentration at the nuclear power plant site.

[0005] To achieve the above objectives, some embodiments of this application propose a portable electrochemical hydrogen meter, comprising: A standard hydrogen partial pressure generator module is used to output at least two hydrogen partial pressures; The electrochemical sensing module includes a flow cell, an electrochemical hydrogen sensor, and a temperature sensor. The hydrogen-sensitive electrode and the temperature-sensitive element are both connected to the flow cell. The flow path switching module connects to the flow cell and is used to connect the flow cell to the standard hydrogen partial pressure generating module or to the liquid being tested. The control and calculation module communicates with the standard hydrogen partial pressure generation module, the electrochemical sensing module, and the flow path switching module. The portable electrochemical hydrogen meter is configured to have a calibration state and a measurement state. In the calibration state, the control and calculation module establishes a correspondence between dissolved hydrogen concentration and electrical signal based on at least two hydrogen partial pressures and their corresponding current signals. In the measurement state, the portable electrochemical hydrogen meter outputs the dissolved hydrogen concentration value of the liquid being measured based on the correspondence and the real-time temperature signal.

[0006] In some embodiments, the standard hydrogen partial pressure generating module includes a replaceable hydrogen storage unit, a pressure reducing valve, and an electrically controlled regulating valve, all of which are connected to a flow cell.

[0007] In some embodiments, the hydrogen storage unit includes at least one of a high-pressure pure hydrogen cylinder, a metal hydride hydrogen storage device, or an in-situ water electrolysis hydrogen generator, and the hydrogen volume fraction of the hydrogen storage unit is ≥99%; and / or, The pressure range of the hydrogen storage unit is 0 to 15 MPa.a.

[0008] In some embodiments, the pressure reducing valve and the electrically controlled regulating valve are configured to be able to regulate in concert to maintain a pressure of 0.1 MPa.a to 1.0 MPa.a within the flow cell and to provide at least three discrete hydrogen partial pressure points.

[0009] In some embodiments, the control and calculation module has a built-in standard calibration curve, which is a linear fitting equation between hydrogen pressure and a reference value of dissolved hydrogen concentration.

[0010] In some embodiments, the linear fitting equation for the standard calibration curve is C = k·P + b, where C is the reference value of dissolved hydrogen concentration, P is the hydrogen pressure value, and k and b are constant terms.

[0011] In some embodiments, the goodness-of-fit R² is calculated using the following formula:

[0012] in, It is the residual sum of squares, which represents the sum of squared errors between the model's predicted values ​​and the actual values, reflecting the variation that the model did not capture; It is the residual sum of squares, which represents the sum of squares of the differences between the true value and its mean, reflecting the total variation of the dependent variable.

[0013] An embodiment of the second aspect of this application provides a calibration method for a portable electrochemical hydrogen meter according to any of the above claims. The calibration method includes the following steps: S101: Put the portable electrochemical hydrogen meter into calibration mode and connect the flow cell to the standard hydrogen partial pressure generating module; S103: The measurement range of dissolved hydrogen concentration is set through the control and calculation module, and the corresponding hydrogen pressure calibration range is automatically determined based on the measurement range; S105: The control and calculation module controls the standard hydrogen partial pressure generation module to sequentially establish 2 to 10 different target hydrogen pressure points P in the flow cell within the hydrogen pressure calibration range; S107: At each target hydrogen pressure point, the corresponding current signal i is obtained by measuring the electrochemical hydrogen sensor, and the current temperature T is measured by the temperature sensor. S109: For each target hydrogen pressure point P, the control and calculation module calculates the theoretical reference value C_ref of the dissolved hydrogen concentration based on Henry's law and the current temperature T, thereby generating a set of calibration data (C_ref, i), where C_ref is the theoretical concentration true value and i is the measured current; S111: Use the calibration data (C_ref, i) to perform linear fitting, generate a new calibration curve, and replace the original built-in calibration curve in the control and operation module with the new calibration curve; S113: After calibration, switch the portable electrochemical hydrogen meter to measurement mode and connect the flow cell to the liquid being measured.

[0014] In some embodiments, step S103 includes: When the set measurement range for dissolved hydrogen concentration is 0 to 5 ppm, the automatically selected hydrogen partial pressure calibration range is 0 to 5 bar.

[0015] In some embodiments, step S105 includes: The number of target hydrogen pressure points should be 3 to 5.

[0016] In some embodiments, step S109 includes: The temperature signal is used to correct the Henry's Law constant in real time, with a correction temperature range of 10°C to 50°C.

[0017] In some embodiments, in step S109, Henry's Law states: ; in, It is the mole fraction of volatile solute B (i.e., the dissolved gas) in the solution; It is the pressure of the gas on the liquid surface at equilibrium; It is a constant whose value depends on temperature, pressure, and the properties of the solute and solvent.

[0018] In some embodiments, step S111 includes: If the linear fit goodness R² ≥ 0.999, perform the replacement operation; otherwise, display a calibration failure message and prompt for a check.

[0019] An embodiment of the third aspect of this application provides a measurement method for a portable electrochemical hydrogen meter according to any of the above claims, the measurement method comprising: S201: Switch the flow cell to be connected to the liquid being measured; S203: Measure the current signal i and real-time temperature of the liquid being tested through the electrochemical sensing module; S205: The control and calculation module calls the new calibration curve generated by any of the above calibration methods, processes the current signal i, and compensates for it in combination with the real-time temperature, and finally calculates and outputs the corrected dissolved hydrogen concentration value.

[0020] An embodiment of the fourth aspect of this application provides a computer-readable storage medium storing a processor-executable program, which, when executed by a processor, is used to implement the calibration method described above.

[0021] An embodiment of the fifth aspect of this application provides a computer program product, including a computer program or computer instructions, characterized in that the computer program or computer instructions are stored in a computer-readable storage medium, a processor of a computer device reads the computer program or computer instructions from the computer-readable storage medium, and the processor executes the computer program or computer instructions, causing the computer device to perform any of the above-described calibration methods.

[0022] An embodiment of the sixth aspect of this application provides a software system for a portable electrochemical hydrogen meter according to any of the above claims. The software system is integrated within a control and calculation module, and includes: A pressure control unit is used to accurately output at least two hydrogen partial pressures during the calibration phase; The signal processing unit is used to synchronously acquire current and temperature signals; The calibration calculation unit is used to perform multi-point linear fitting and generate new correspondences between concentration and current; The measurement compensation unit is used to dynamically correct the correspondence based on real-time temperature during the measurement phase in order to eliminate system drift error.

[0023] According to the above embodiments, the beneficial effects of this application are: The portable electrochemical hydrogen meter of this application includes a standard hydrogen partial pressure generating module, an electrochemical sensing module, a flow path switching module, and a control and calculation module. The standard hydrogen partial pressure generating module outputs at least two hydrogen partial pressures. The electrochemical sensing module includes a flow cell, an electrochemical hydrogen sensor, and a temperature sensor; both the hydrogen-sensitive electrode and the temperature-sensitive element are connected to the flow cell. The flow path switching module is connected to the flow cell and is used to connect the flow cell to the standard hydrogen partial pressure generating module or to the liquid being measured. The control and calculation module is communicatively connected to the standard hydrogen partial pressure generating module, the electrochemical sensing module, and the flow path switching module. The portable electrochemical hydrogen meter is configured to have a calibration state and a measurement state. In the calibration state, the control and calculation module establishes a correspondence between dissolved hydrogen concentration and electrical signals based on at least two hydrogen partial pressures and their corresponding current signals. In the measurement state, the portable electrochemical hydrogen meter outputs the dissolved hydrogen concentration value of the liquid being measured based on the correspondence and the real-time temperature signal.

[0024] In summary, this application utilizes a four-in-one architecture integrating standard hydrogen partial pressure generation, electrochemical sensing, flow path switching, and control calculation. This architecture compresses the traditional discrete components requiring external gas sources, independent calibrators, and complex piping into a single portable host unit, achieving direct coupling between programmable hydrogen partial pressure output and in-situ electrochemical signal acquisition at the instrument level. In calibration mode, the flow path switching module connects the flow cell to the standard hydrogen partial pressure generation module. The control and calculation module simultaneously captures current and temperature information at at least two precisely controllable hydrogen partial pressure points, establishing a correspondence between dissolved hydrogen concentration and electrical signal based on Henry's Law. Once this correspondence is established, it can be reversed in subsequent measurements to perform real-time temperature compensation on the current generated by the measured liquid, directly outputting a traceable dissolved hydrogen concentration value. Therefore, the instrument can complete measurement value transfer on-site without carrying high-pressure gas cylinders or external gas distribution systems, eliminating sensor drift caused by transportation vibrations, temperature gradients, and radiation environments, and improving measurement reliability and metrological traceability under harsh operating conditions such as the primary loop of nuclear power plants. Meanwhile, the integrated design significantly reduces the weight and volume of the unit, meeting the stringent portability requirements for emergency inspections, confined spaces, and high-altitude operations, and providing a mobile, verifiable, and repeatable on-site metrology means for nuclear power chemical supervision.

[0025] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0026] To more clearly illustrate the technical solutions 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 the structures shown in these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of a portable electrochemical hydrogen meter in one embodiment of this application; Figure 2 This is a graph showing the calibration curve function of a portable hydrogen meter in one embodiment of this application; Figure 3 This is a logic diagram of the calibration and measurement secondary instrument in one embodiment of this application; Figure 4 This is a flowchart of a calibration method in one embodiment of this application; Figure 5 This is a flowchart of a measurement method in one embodiment of this application.

[0028] Explanation of icon numbers: 1. Miniature hydrogen cylinder; 2. Gas pipeline; 3. Pressure reducing valve; 4. Measuring pipeline; 5. Measuring pipeline regulating valve; 6. Calibration pipeline regulating valve; 7. Flow cell; 8. Measuring pipeline outlet; 9. Measuring main unit; 10. Secondary instrument.

[0029] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0031] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0032] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or," "and / or," or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0033] The following is for reference. Figures 1 to 5 This application describes a portable electrochemical hydrogen meter, calibration method, measurement method, and software system according to embodiments of the present application. (Refer to...) Figure 1 and Figure 2The first aspect of this application provides a portable electrochemical hydrogen meter, comprising a standard hydrogen partial pressure generating module, an electrochemical sensing module, a flow path switching module, and a control and calculation module. The standard hydrogen partial pressure generating module outputs at least two hydrogen partial pressures. The electrochemical sensing module includes a flow cell 7, an electrochemical hydrogen sensor, and a temperature sensor; both the hydrogen-sensitive electrode and the temperature-sensitive element are connected to the flow cell 7. The flow path switching module is connected to the flow cell 7 and is used to connect the flow cell 7 to the standard hydrogen partial pressure generating module or to the liquid being measured. The control and calculation module is communicatively connected to the standard hydrogen partial pressure generating module, the electrochemical sensing module, and the flow path switching module. The portable electrochemical hydrogen meter is configured to have a calibration state and a measurement state. In the calibration state, the control and calculation module establishes a correspondence between dissolved hydrogen concentration and electrical signals based on at least two hydrogen partial pressures and their corresponding current signals. In the measurement state, the portable electrochemical hydrogen meter outputs the dissolved hydrogen concentration value of the liquid being measured based on the correspondence and a real-time temperature signal.

[0034] In summary, this application utilizes a four-in-one architecture integrating standard hydrogen partial pressure generation, electrochemical sensing, flow path switching, and control calculation. This architecture compresses the traditional discrete components requiring external gas sources, independent calibrators, and complex piping into a single portable host, achieving direct coupling between programmable hydrogen partial pressure output and in-situ electrochemical signal acquisition at the instrument level. In calibration mode, the flow path switching module connects the flow cell 7 to the standard hydrogen partial pressure generation module. The control and calculation module simultaneously captures current and temperature information at at least two precisely controllable hydrogen partial pressure points, establishing a correspondence between dissolved hydrogen concentration and electrical signal based on Henry's Law. Once this correspondence is established, it can be reversed in subsequent measurements to perform real-time temperature compensation on the current generated by the measured liquid, directly outputting a traceable dissolved hydrogen concentration value. Therefore, the instrument can complete measurement value transfer on-site without carrying high-pressure gas cylinders or an external gas distribution system, eliminating sensor drift caused by transportation vibrations, temperature gradients, and radiation environments, and improving measurement reliability and metrological traceability under harsh operating conditions such as the primary loop of nuclear power plants. Meanwhile, the integrated design significantly reduces the weight and volume of the unit, meeting the stringent portability requirements for emergency inspections, confined spaces, and high-altitude operations, and providing a mobile, verifiable, and repeatable on-site metrology means for nuclear power chemical supervision.

[0035] Furthermore, when this application is in calibration mode, the flow path switching module, like a three-way valve, first connects the flow cell 7 to the standard hydrogen partial pressure generating module separately, forming a closed loop. At this time, the control and calculation module commands the standard hydrogen partial pressure generating module to sequentially output at least two known and precise controllable hydrogen partial pressures. The electrochemical hydrogen sensor generates a corresponding current in the flow cell 7, and the temperature sensor simultaneously records the liquid temperature. After packaging the three parameters of pressure, current, and temperature, the system converts them into a one-to-one mapping table of "true value of dissolved hydrogen - current" based on the physical relationship that gas partial pressure is proportional to dissolved concentration according to Henry's Law, and writes it into memory to complete the traceability of the quantitative values. Furthermore, the conversion process uses Henry's Law as the physical anchor point. The system first uses the Henry's constant k of pure hydrogen in water at the current temperature. H Set each hydrogen partial pressure P according to C _ref =P / k H Converted to "theoretical truth value of dissolved hydrogen C" _ref Then, the current i output by the sensor at the same moment and C _ref Pairing up to form several groups (C _ref i) Discrete points; then, the least squares method is used to perform linear fitting on these points to obtain the "C" curve formed by the slope k and the intercept b. _true =k·i+b” calibration equation (C _true (This refers to the actual concentration of dissolved hydrogen), and k, b, and the temperature correction factor are written into the non-volatile memory. Since P is controlled in a closed loop by a precision pressure reducing valve 3 traceable to national standards and a pressure sensor, k... H The data is derived from recognized data published by IUPAC (International Union of Pure and Applied Chemistry). Every step of the conversion chain is traceable back to the International System of Units (SI), thus achieving metrological traceability. The purpose is to ensure that even if the sensor drifts due to aging or environmental disturbances during subsequent measurement stages, the instrument can still use a fixed and traceable linear equation to back-calculate any new current i into a dissolved hydrogen concentration consistent with national standards. This allows for obtaining legally valid and internationally recognized reliable values ​​on-site. Furthermore, combined with the portable structure of this device, it enables timely on-site measurements.

[0036] When the application is in measurement mode, the flow path switching module connects the flow cell 7 to the sample being measured. When dissolved hydrogen in the sample diffuses to the sensor surface and generates a new current, the control and calculation module calls the pre-established correspondence from the calibration state and dynamically corrects the slope and intercept based on the real-time measured temperature, calculating the dissolved hydrogen concentration with the same dimensions as the standard hydrogen partial pressure, and directly displaying the result. Since the same flow cell 7, the same sensor, and the same temperature curve are used throughout the process, drift is automatically canceled out, thus ensuring that the on-site output value strictly corresponds to the national standard hydrogen partial pressure value, achieving high measurement efficiency and high accuracy.

[0037] In some embodiments, the standard hydrogen partial pressure generating module is a closed-loop pressure source integrated into the portable host, consisting of a replaceable hydrogen storage unit (high-pressure pure hydrogen cylinder, metal hydride or in-situ water electrolysis hydrogen generator), a pressure reducing valve 3, and an electric regulating valve connected in series. It can output at least three discrete hydrogen partial pressures in the range of 0–15 MPa.a (e.g. 0, 0.1 MPa.a, 5 MPa.a, 10 MPa.a, 15 MPa.a), providing a known and traceable calibration atmosphere for the flow cell 7, and completing multi-point value transfer without the need for an external gas source.

[0038] In some embodiments, the electrochemical sensing module includes a flow cell 7, an electrochemical hydrogen sensor, and a temperature sensor. The hydrogen-sensitive electrode and the temperature-sensitive element are directly coupled to the flow cell 7, enabling simultaneous acquisition of dissolved hydrogen current and real-time temperature signals at the same liquid path node. This provides original, homogeneous quantitative inputs for subsequent calibration curve establishment and temperature compensation. In some embodiments, the electrochemical sensing module is a combination of a three-electrode electrochemical hydrogen sensor embedded in the flow cell 7 and a fast-response temperature probe. The working electrode selectively oxidizes and reduces dissolved hydrogen and outputs current. The reference electrode provides a stable potential reference, the auxiliary electrode completes the current loop, and the temperature probe simultaneously acquires the liquid temperature for subsequent real-time correction of the Henry's constant and signal slope. This achieves simultaneous sensing of hydrogen concentration, electrical signal, and temperature within the same chamber, providing original, homogeneous, and simultaneous quantitative values ​​for subsequent calibration and measurement.

[0039] In some embodiments, the flow path switching module is connected to the flow cell 7. In calibration mode, the flow cell 7 can be connected to the standard hydrogen partial pressure generating module to introduce a known hydrogen partial pressure; or in measurement mode, it can be switched to connect to the liquid being measured to introduce a sample. This achieves program-controlled isolation between the calibration flow path and the measurement flow path, ensuring that the same sensing unit obtains standard and measured values ​​in a time-sharing manner without cross-contamination. In some embodiments, the flow path switching module is a combination of a three-way electric ball valve and a two-position four-way solenoid valve. For example, the three-way electric ball valve uses a rotary seal to selectively connect one inlet of the flow cell 7 to the standard hydrogen partial pressure generating module or the liquid being measured pipeline. The two-position four-way solenoid valve synchronously switches the discharge channel on the outlet side, allowing calibration exhaust gas and process sample liquid to be discharged independently. In some embodiments, the flow path switching module uses a microcontroller-driven multi-channel diaphragm valve array. The opening and closing of each valve is controlled by a program timing sequence to achieve a flow path structure without cross-contamination, thereby completing the time-sharing switching of the standard atmosphere and the sample being measured within the same flow cell 7.

[0040] In some embodiments, the control and calculation module is communicatively connected to the standard hydrogen partial pressure generation module, the electrochemical sensing module, and the flow path switching module. In calibration mode, it establishes a correspondence between dissolved hydrogen concentration and electrical signal based on at least two hydrogen partial pressures and their corresponding currents. In measurement mode, it invokes this relationship and calculates the dissolved hydrogen concentration of the measured liquid in conjunction with the real-time temperature signal, thus achieving automatic control and value calculation throughout the calibration and measurement process. In some embodiments, the control and calculation module can be an embedded measurement and control unit with a low-power microcontroller as its core. It acquires the current and temperature signals from the electrochemical sensor in real time through an isolated analog-to-digital converter, and after digital filtering, inputs them into a fixed Henry's Law algorithm. During the calibration phase, it performs linear fitting of the multi-point hydrogen partial pressures to generate a curve and writes it to a non-volatile memory. During the measurement phase, the same microcontroller invokes this curve and performs compensation calculations in conjunction with the real-time temperature, while simultaneously outputting isolated analog and digital communication interfaces, realizing full-process program control of calibration, measurement, diagnosis, alarm, and data recording.

[0041] Reference Figure 1 Taking one specific embodiment as an example, regarding the portable electrochemical hydrogen meter of this application, the standard hydrogen partial pressure generating module includes a miniature hydrogen cylinder 1, a pressure reducing valve 3, and a calibration pipeline regulating valve 6, which are connected in series to form a calibration gas path. The electrochemical sensing module includes an electrochemical hydrogen sensor and its temperature sensor installed in the flow cell 7. The flow path switching module includes a regulating valve for the measuring pipeline 4 and a regulating valve for the calibration pipeline 6, with a selective opening and closing structure for the two gas-liquid channels of measurement and calibration. The control and calculation module includes a measuring host 9 and a secondary instrument 10, along with their built-in power supply, power amplifier, calculation, storage, and programmable logic, used to uniformly collect signals from the above three types of modules and perform calibration calculations and measurement outputs.

[0042] Furthermore, the portable electrochemical hydrogen meter of this application performs multi-point calibration by adjusting different gas pressures through a miniature hydrogen cylinder 1, a pressure reducing valve 3, and an electric regulating valve. This solves the limitation of current calibration methods that only allow for a single point of calibration, enabling multi-point calibration and improving the instrument's automatic and multi-point calibration capabilities. Specifically, the miniature hydrogen cylinder 1 has a hydrogen concentration of 100% and a pressure of 0-15 MPa.a. By adjusting the pressure reducing valve 3 and the calibration pipeline regulating valve 6, different hydrogen pressures in the flow cell 7 are maintained, resulting in hydrogen pressures of 0.1 MPa.a, 0.2 MPa.a, 0.3 MPa.a, 0.4 MPa.a, 0.5 MPa.a, and 1.0 MPa.a.

[0043] Furthermore, the multi-point calibration of this application involves adjusting the gas pressure, with the gas pressure range between absolute pressure 0 bar and 3 bar (e.g., 0, 0.1 bar, 1 bar, 2 bar, 3 bar), and selecting 2-10 different gas pressure values ​​within this range for calibration. By using the dissolved hydrogen concentration corresponding to different gas pressure values, with the dissolved hydrogen concentration calibration range between 0-20 ppm (e.g., 0, 1 ppm, 5 ppm, 10 ppm, 15 ppm, 20 ppm), a more accurate calibration curve is established, improving measurement accuracy.

[0044] A typical calibration principle is shown below.

[0045] The working principle of the portable dissolved hydrogen meter is based on the following formula (Formula-1):

[0046] In the formula: This represents the total number of electrons in the electrochemical reaction. A s The surface area of ​​the sensor's working electrode; D is the oxygen permeability coefficient; F is Faraday's constant; σ represents the thickness of the sensor film; C DH The concentration of hydrogen molecules dissolved in the liquid; M is the permeability constant of hydrogen gas; This represents the hydrogen current generated by the reaction.

[0047] When the sensor structure is determined, parameter A s The values ​​of D and σ are determined to be constants. F and n are also constants. From the above formula, it can be seen that the current i generated by the electrochemical reaction is related to the concentration of hydrogen molecules C dissolved in the liquid. DH The relationship is linear. The current i is processed by the main unit and displayed as the dissolved hydrogen concentration.

[0048] According to Henry's Law (Formula-2), one of the fundamental laws of physical chemistry, at a constant temperature, the amount of gas dissolved in a liquid is directly proportional to the partial pressure of that gas above the liquid.

[0049]

[0050] in: It is the mole fraction of volatile solute B (i.e., the dissolved gas) in the solution; It is the pressure of the gas on the liquid surface at equilibrium; It is a constant whose value depends on temperature, pressure, and the properties of the solute and solvent.

[0051] Equations 1 and 2 show that there should be a linear relationship between the tested hydrogen pressure and the value measured by the portable dissolved hydrogen meter. Therefore, based on the test data of the portable dissolved hydrogen meter, a fitting was performed on the tested hydrogen pressure and dissolved hydrogen concentration values. The fitting effect was verified by R0. 2 The R² value is used to judge the fit. An R² close to 1 indicates a good fit, an R² greater than 0.9 is generally considered a very good fit, and an R² less than 0.7 indicates a poor fit. The formula for calculating the R² is:

[0052] in: It is the residual sum of squares, which represents the sum of squared errors between the model's predicted values ​​and the actual values, reflecting the variation that the model did not capture.

[0053] It is the residual sum of squares, which represents the sum of squares of the differences between the true value and its mean, reflecting the total variation of the dependent variable.

[0054] Fitting method: Linear fitting was used.

[0055] Fitting effect: R²=0.9999 (good fit).

[0056] Fitting equation: .

[0057] Data fitting curves are as follows Figure 2 As shown, the results of the dissolved hydrogen table are consistent with the theoretical derivation.

[0058]

[0059] Table 1 Typical calibration test results The calibration curve of this application Figure 2 It is pre-installed in the secondary instrument 10 at the factory. In practical applications, the values ​​obtained by dissolving hydrogen calibration measurement at 2-5 points are compared with the built-in calibration curve to achieve rapid calibration.

[0060] In some embodiments, the hydrogen temperature in the flow cell 7 of this application is measured in the range of 10-50°C, and the dissolved hydrogen concentration value is corrected at different temperatures.

[0061] In some embodiments, in order to improve calibration efficiency, this application may select an appropriate calibration hydrogen pressure according to the measurement range. For example, when measuring the dissolved hydrogen concentration range of 0-5 ppm (e.g., 0, 1 ppm, 2 ppm, 3 ppm, 4 ppm, 5 ppm), the hydrogen pressure range may be selected as 0-5 bar (e.g., 0, 1 bar, 2 bar, 3 bar, 4 bar, 5 bar), and 3-5 pressure values ​​may be selected within this hydrogen pressure range.

[0062] In some embodiments, the measurement system of this application is realized by an electric regulating valve of the regulating valve of the measuring pipeline 4, and the flow rate of the measured liquid and gas is between 100 ml / min and 1 L / min, for example, 100 ml / min, 500 ml / min, and 11 L / min.

[0063] In some embodiments, the flow cell 7 of this application is required for both calibration and measurement functions.

[0064] In some embodiments, the measurement host 9 and the secondary instrument 10 are core components of this application. The secondary instrument 10 not only integrates the signals of the measurement host 9, but also the measurement and control signals of the regulating valve, the pressure reducing valve 3, etc. need to be implemented in the secondary instrument 10.

[0065] The signal acquisition and control logic diagram of secondary instrument 10 is shown below. Figure 3 This includes detailed logic principles, encompassing power supply, power amplification, and computational functions. Specifically, this module serves as the control center of a portable electrochemical hydrogen meter. Its process begins with the power supply unit, providing a stable power source for the entire system. Subsequently, the raw current signal from the electrochemical hydrogen sensor first enters the preamplifier and filter unit for signal conditioning. The preamplifier initially amplifies the weak current signal, while the filter effectively suppresses environmental noise and high-frequency interference, ensuring signal purity. The conditioned analog signal is converted into a digital signal by the analog-to-digital converter unit for processing by the core microprocessor unit. In calibration mode, the microprocessor unit, on the one hand, precisely drives the pressure reducing valve 3 and the electric regulating valve in the standard hydrogen partial pressure generation module through the pressure control unit, establishing multiple target hydrogen pressure points within the flow cell 7. On the other hand, it simultaneously receives temperature signals from the temperature sensor and current signals from the hydrogen sensor, and converts the hydrogen partial pressure and temperature values ​​corresponding to each pressure point into theoretical reference values ​​for dissolved hydrogen concentration based on Henry's Law, generating a set of calibration data pairs (C...). _ref , i), such as Figure 2As shown in the diagram. Subsequently, the calibration calculation unit performs linear fitting based on this set of data to generate a new correspondence between concentration and current (i.e., a new calibration curve), replacing the original built-in curve. This process also determines the calibration validity by calculating the goodness of fit R² (R² ≥ 0.999 is considered valid). In measurement mode, the measurement compensation unit calls the updated calibration curve and dynamically compensates the acquired current in conjunction with the real-time temperature signal, ultimately outputting an accurate dissolved hydrogen concentration value. The entire logic chain achieves automatic switching between calibration and measurement modes through the control signal of the flow path switching module, realizing integrated closed-loop management of power supply, power amplifier, acquisition, control, calculation, and communication.

[0066] In some embodiments, the device of this application integrates calibration and measurement, is portable, and weighs less than 15 kg.

[0067] In some embodiments, this application has measurement error elimination capabilities, which are achieved by combining automatic calibration functions.

[0068] Reference Figure 1 In some embodiments, the standard hydrogen partial pressure generating module includes a replaceable hydrogen storage unit, a pressure reducing valve 3, and an electrically controlled regulating valve, all of which are connected to a flow cell 7. The standard hydrogen partial pressure generating module is configured as a series structure of the replaceable hydrogen storage unit, pressure reducing valve 3, and electrically controlled regulating valve, all three directly connected to the flow cell 7, allowing the generation, regulation, and delivery of hydrogen partial pressure to be completed within the same closed channel. The replaceable hydrogen storage unit design allows maintenance personnel to quickly replace the gas source on-site without requiring an external high-pressure gas source or interrupting the process loop, reducing reliance on centralized gas supply networks and large pressure reducing equipment. The coordinated regulation function of the pressure reducing valve 3 and the electrically controlled regulating valve enables stepwise precise output of hydrogen partial pressure during the calibration phase, ensuring that each pressure point is controlled in a closed loop and applied to the electrochemical sensor in real time, thereby eliminating additional uncertainties introduced by human intervention or external fluctuations. This structure integrates the gas source, pressure regulation, and sensor exposure into independent functional units, which not only improves the modularity and maintenance convenience of the whole machine, but also reduces the risk of dead volume and cross-contamination through the closed short-process design. This allows the portable hydrogen meter to be calibrated at any time in nuclear power plant sites, high-altitude platforms, or space-constrained areas, ensuring the traceability and long-term stability of the measurement results.

[0069] Reference Figure 1In some embodiments, the hydrogen storage unit includes at least one of a high-pressure pure hydrogen cylinder, a metal hydride hydrogen storage device, or an in-situ water electrolysis hydrogen generator, with a hydrogen volume fraction ≥99%. In some embodiments, the pressure range of the hydrogen storage unit is 0 to 15 MPa.a, for example, 0, 0.1 MPa.a, 1 MPa.a, 5 MPa.a, and 15 MPa.a. By limiting the hydrogen storage unit to at least one of a high-pressure pure hydrogen cylinder, a metal hydride hydrogen storage device, or an in-situ water electrolysis hydrogen generator, and specifying a hydrogen volume fraction of not less than 99%, while providing a wide range of pressure options from 0 to 15 MPa absolute pressure, the standard hydrogen partial pressure generating module can continuously output a high-purity, high-stability hydrogen source under different transportation conditions, different operating environments, and different safety level requirements. The high-pressure pure hydrogen cylinder solution is mature and reliable, suitable for conventional metering and transfer applications. The metal hydride hydrogen storage device reversibly absorbs and releases hydrogen in solid form, reducing the potential risks associated with high-pressure containers, and is particularly suitable for space-constrained or long-term maintenance-free scenarios. The in-situ water electrolysis hydrogen generator eliminates dependence on external gas sources, requiring only on-site deionized water to produce hydrogen as needed, meeting the immediate calibration needs of emergency or remote areas. All three components (hydrogen generator, water electrolysis equipment, and deionized water) share the same pressure reduction and regulation interface, ensuring both the continuity and consistency of hydrogen partial pressure output. Furthermore, the high purity requirement eliminates interference from impurity gases on the electrochemical sensor response, ensuring the traceability and reproducibility of the hydrogen partial pressure values ​​used for calibration. This lays a solid material foundation for achieving high-precision, high-reliability, and external-free on-site calibration of the entire unit under harsh operating conditions such as nuclear power plant primary loops.

[0070] Reference Figure 1In some embodiments, the pressure reducing valve 3 and the electrically controlled regulating valve are configured to work together to maintain a pressure of 0.1 MPa.a to 1.0 MPa.a within the flow cell 7, for example, 0.1 MPa.a, 0.5 MPa.a, and 1 MPa.a, providing at least three discrete hydrogen partial pressure points. Through the coordinated regulation mechanism of the pressure reducing valve 3 and the electrically controlled regulating valve, a continuous and controllable pressure range of 0.1 MPa.a to 1.0 MPa.a is constructed within the flow cell 7, and at least three independent hydrogen partial pressure points are output discretely within this range, thereby upgrading the standard hydrogen partial pressure generation module from a simple constant pressure supply to a programmable, staged pressure source. This configuration allows the same hydrogen storage unit to cover multiple pressure levels without replacement, reducing on-site operation steps and gas consumption. The setting of discrete pressure points ensures that the calibration curve has sufficient nodes in critical sections, effectively suppressing fitting deviations caused by excessively large partial pressure intervals. The coordinated regulation method continuously balances the high pressure before the valve and the low pressure after the valve through closed-loop feedback, eliminating zero-point drift caused by temperature drift and mechanical wear, ensuring traceable stability and reproducibility of the hydrogen partial pressure at each point. Simultaneously, the upper limit of the pressure range is constrained within the safe pressure tolerance range of the flow cell 7, fundamentally avoiding the risk of overpressure. Thus, while maintaining portability, the entire instrument achieves refined, stepped, and safe output of hydrogen partial pressure, providing a calibration atmosphere with a comprehensive range and complete traceability chain for electrochemical sensors, improving the rigor of on-site calibration and the legal validity of measurement results.

[0071] Reference Figure 1 and Figure 2 In some embodiments, the control and computation module has a built-in standard calibration curve, which is a linear fitting equation between hydrogen pressure and a dissolved hydrogen concentration reference value. By configuring a linear fitting equation with hydrogen pressure as the independent variable and the dissolved hydrogen concentration reference value as the dependent variable within the control and computation module as the standard calibration curve, the entire device can complete the measurement conversion on-site without relying on an external computing device. This built-in curve, based on Henry's Law, directly maps the traceable hydrogen partial pressure to the dissolved hydrogen concentration reference value, forming a closed and unique measurement transmission link. The linear equation is simple in form and has low computational load, enabling real-time solution on an embedded platform and shortening the measurement response time. Because the curve is stored in non-volatile memory, the parameters remain intact after power failure, avoiding the cumulative errors caused by repeated calibration. Furthermore, the curve coefficients correspond one-to-one with the sensors, preventing the potential risk of misusing historical coefficients after probe replacement. Its existence provides a benchmark for subsequent on-site calibration. When environmental disturbances cause sensor drift, the system only needs to compare real-time multi-point data with the built-in curve to quickly determine the direction of deviation, thereby guiding automatic or manual correction and ensuring that the measurement results are always in a controlled, traceable and reproducible metrological state, providing continuous and effective data support for nuclear electrochemical supervision.

[0072] In some embodiments, the linear fitting equation for the standard calibration curve is C = k·P + b, where C is the reference value of dissolved hydrogen concentration, P is the hydrogen pressure value, and k and b are constant terms. This fitting equation is a linear fitting equation between the standard calibration curve and the reference value of dissolved hydrogen concentration, establishing a concise, definite, and reversible mathematical mapping relationship between hydrogen pressure P and the reference value of dissolved hydrogen concentration C. Based on Henry's Law, this equation uses a first-order linear model to describe the relationship between pressure and concentration. It is simple in form, has unique parameters, and can be solved in real-time on an embedded platform with extremely low computing resources, reducing computational latency and power consumption. Once determined during the calibration phase, the constant terms k and b are permanently stored in non-volatile memory, preventing human modification of the path and ensuring the closed and traceable nature of the measurement value transfer. Since the equation contains only two undetermined coefficients, the number of experimental pressure points required for multi-point calibration in the field can be controlled to the minimum necessary range, shortening calibration time and reducing the frequency of high-pressure operations, thereby improving the safety of on-site operations. Simultaneously, the linear structure makes the error propagation path clear, facilitating subsequent uncertainty assessment and metrological standardization. The existence of this equation provides the whole machine with a reference concentration axis that is independent of temperature and flow rate. Any signal drift caused by sensor aging or environmental disturbances can be corrected by resolving k and b, ensuring that the measurement results are stable and legally valid in the long term.

[0073] In some embodiments, the goodness-of-fit R 2 The calculation formula is as follows:

[0074] Among them, SS res It is the residual sum of squares, representing the sum of squared errors between the model's predicted values ​​and the actual values, reflecting the variation that the model did not capture; SS tot It is the residual sum of squares, which represents the sum of squares of the differences between the true value and its mean, reflecting the total variation of the dependent variable.

[0075] Specifically, the formula directly reflects the model's interpretability by using the relative ratio of the residual sum of squares to the total sum of squares of variation. This allows the control and computation modules to automatically determine whether the current pressure and concentration mappings have reached a preset acceptable level during calibration. Once R² falls below the threshold, the system refuses to update and triggers a fault warning, preventing value deviations caused by underfitting from flowing into subsequent measurement stages. The formula's analytical form is concise and has no implicit parameters, facilitating real-time computation in embedded platforms. Furthermore, its mathematical meaning is clear and directly corresponds to the linear evaluation methods in national metrological technical specifications, ensuring that the evaluation results have legal traceability and laboratory interoperability. By calculating R², the entire system can output traceable model quality indicators at the end of each on-site calibration, providing objective electronic records for equipment maintenance, periodic verification, and uncertainty assessment. This fundamentally improves the reliability and metrological compliance level of dissolved hydrogen monitoring data at nuclear power plants.

[0076] To further elaborate on the above formula, for example, let n sets of calibration data yield the average hydrogen pressure. With average dissolved hydrogen concentration Total Sum of Squares SS tot =Σ(C i )² characterizes the original dispersion of concentration; after fitting with the formula C=kP+b mentioned above, the model predicts the value. i With truth value C i Sum of squared residuals SS res =Σ(C i i )² reflects fluctuations not explained by linear relationships, while the regression sum of squares (SS) reg =Σ( i )² represents the system information captured by the model, expressed by the identity SS tot =SS reg +SS res We know that R² = SS reg / SS tot =1 SS res / SS tot When R² approaches one, it indicates that the pressure variable almost completely explains the concentration variation within the framework of Henry's Law, the fitted straight line is consistent with the true value, and the calibration curve has traceable metrological validity. Conversely, it suggests that the pressure control or sensor response needs to be re-examined to ensure that subsequent measurement errors are within a controlled range.

[0077] Reference Figure 4 The second aspect of this application provides a calibration method for a portable electrochemical hydrogen meter according to any of the above claims. The calibration method includes the following steps: S101: Put the portable electrochemical hydrogen meter into calibration mode and connect the flow cell 7 to the standard hydrogen partial pressure generating module; S103: The measurement range of dissolved hydrogen concentration is set through the control and calculation module, and the corresponding hydrogen pressure calibration range is automatically determined based on the measurement range; S105: The control and calculation module controls the standard hydrogen partial pressure generation module to sequentially establish 2 to 10 different target hydrogen pressure points P in the flow cell 7 within the hydrogen pressure calibration range; S107: At each target hydrogen pressure point, the corresponding current signal i is obtained by measuring the electrochemical hydrogen sensor, and the current temperature T is measured by the temperature sensor. S109: For each target hydrogen pressure point P, the control and calculation module calculates the theoretical reference value C of the dissolved hydrogen concentration based on Henry's Law, using the target hydrogen pressure point P and the current temperature T. _ref This generates a set of calibration data (C _ref (i), where C _ref Where is the theoretical concentration, and i is the measured current; S111: Using calibration data (C _ref i) Perform linear fitting to generate a new calibration curve, and replace the original built-in calibration curve in the control and operation module with the new calibration curve. S113: After calibration, switch the portable electrochemical hydrogen meter to measurement mode and connect the flow cell 7 to the liquid being measured.

[0078] Specifically, step S101 connects the flow cell 7 to the standard hydrogen partial pressure generation module separately through flow path switching, forming a closed calibration gas path to block interference from the process sample liquid and establish a pure and controllable hydrogen atmosphere for all subsequent pressure points. Step S103 automatically maps the corresponding hydrogen pressure range according to the preset measurement range by the control and calculation module, ensuring that the calibration boundary covers the actual operating conditions, avoiding invalid high-pressure operations, and improving safety and efficiency. Step S105 establishes 2 to 10 target hydrogen partial pressure points within this range in a program-controlled manner, fully characterizing the sensor response characteristics through multi-point sampling to ensure that subsequent fitting is statistically significant. Step S107 synchronously records the current signal i and temperature T at each pressure point, binding the sensor output with environmental variables for acquisition, providing a synchronous benchmark for temperature compensation. Step S109 uses Henry's Law to convert P and T into the theoretical dissolved hydrogen concentration C in real time. _ref This ensures that each current value is directly linked to a traceable physical quantity, aligning the source of the measurement value with national standards. S111 uses (C _ref i) The sequence is linearly fitted to generate a new calibration curve and replace the old curve, completing sensor drift correction and ensuring that the measured value is consistent with the current state of the sensitive element. S113 switches the flow path again to introduce the liquid to be measured into the flow cell 7. The calibration atmosphere is completely replaced by the sample liquid, and the instrument enters the measurement mode based on the new curve. The whole process does not require disassembly or external computing devices, realizing on-site closed-loop value transfer and seamless transition from calibration state to measurement state, improving the timeliness, traceability and operational safety of dissolved hydrogen monitoring at nuclear power plants.

[0079] In some embodiments, step S103 includes: When the set measurement range for dissolved hydrogen concentration is 0 to 5 ppm, the automatically selected hydrogen partial pressure calibration range is 0 to 5 bar.

[0080] When the dissolved hydrogen concentration measurement range is set to 0 to 5 ppm, the hydrogen partial pressure calibration range is automatically compressed to 0 to 5 bar, ensuring a one-to-one correspondence between the range boundary and the pressure boundary. This correspondence stems from the linear nature of Henry's Law: at a fixed temperature, the dissolved hydrogen concentration is directly proportional to the hydrogen partial pressure above the liquid surface. Therefore, limiting the upper pressure limit to 5 bar fully covers the concentration range of 0–5 ppm, avoiding ineffective operations at higher pressures and reducing the fatigue rate and safety risks of high-pressure seals. The automatic selection mechanism is completed by the built-in logic judgment of the control and calculation module, eliminating the need for manual table lookups or secondary input, thus eliminating human error. Simultaneously, with the calibration range narrowed, the interval distribution of target pressure points is more compact, improving the fitting resolution with the same number of points or maintaining the same linearity with a reduced number of points, thereby shortening the single calibration time and reducing hydrogen consumption.

[0081] In some embodiments, step S105 includes: The number of target hydrogen pressure points should be 3 to 5.

[0082] Limiting the number of target hydrogen pressure points to 3 to 5 strikes an optimal balance between calibration coverage and on-site efficiency. Three points define a straight line, capturing the zero point and slope; appropriately increasing the number of sampling points allows for redundant linearity checks and identification of potential outliers without significantly extending operation time, ensuring the goodness of fit meets metrological requirements. Reducing the number of points to 2 directly decreases the number of high-pressure gas releases, shortens the total calibration time, reduces hydrogen consumption and seal wear, and simultaneously reduces the cumulative time on-site personnel are exposed to high-pressure conditions.

[0083] In some embodiments, step S109 includes: The temperature signal is used to correct the Henry's Law constant in real time, with a correction temperature range of 10°C to 50°C.

[0084] The Henry's Law constant is dynamically corrected using real-time temperature signals within the range of 10℃ to 50℃, transforming the fixed constant into a temperature function k. H (T) represents the theoretical concentration of dissolved hydrogen C corresponding to the same hydrogen partial pressure P at different ambient temperatures. _ref It consistently maintains consistency with true thermodynamic values. Clearly defined temperature range boundaries prevent extrapolation failure under extreme conditions, ensuring computational reliability. By embedding temperature variables into the core of Henry's Law calculations, the calibration curve is no longer affected by seasonal, regional, or heat dissipation variations. This ensures that the dissolved hydrogen concentration output in subsequent measurement stages maintains a traceable relationship with national standard values ​​at the same temperature and pressure, enhancing the legal validity and long-term comparability of hydrogen chemical monitoring data at nuclear power plant sites.

[0085] In some embodiments, in step S109, Henry's Law states: ; Where, x B It is the mole fraction of volatile solute B (i.e., the dissolved gas) in the solution; p B It is the pressure of the gas on the liquid surface at equilibrium; k x,B It is a constant whose value depends on temperature, pressure, and the properties of the solute and solvent.

[0086] Introducing the expression p of Henry's Law B =k x,B ·x B The equilibrium hydrogen partial pressure p above the liquid surface B mole fraction of dissolved hydrogen x B This direct correlation allows the control and calculation modules to immediately calculate the theoretical liquid phase concentration based on this formula after obtaining the target hydrogen pressure point P, thus completing the traceable conversion from gas phase quantity values ​​to liquid phase quantity values. In the formula, k... x,B Defined as a function of temperature, pressure, and solvent properties, this means that each calibration calculation must synchronously use real-time temperature and system pressure to correct the constant, ensuring that the Henry's coefficient always corresponds to the current thermodynamic state and avoiding system offsets caused by using a fixed constant. Mole fraction x B The introduction of this method places the dissolved hydrogen concentration within the framework of the International System of Units (SI), ensuring the subsequent generation of C... _ref Maintain homology with national standard material units of mass. By solidifying the original expression of Henry's Law in this step, the calibration process no longer relies on empirical approximations or simplified coefficients, and all calibration data (C...) are consistent with national standard units of mass. _ref i) All of them are based on publicly verifiable physical laws, which enables the entire calibration chain to be reproduced across laboratories and regions, providing a theoretical foundation for the measurement of dissolved hydrogen at nuclear power plants.

[0087] In some embodiments, step S111 includes: If the linear fit goodness R² ≥ 0.999, perform the replacement operation; otherwise, display a calibration failure message and prompt for a check.

[0088] A linear fit goodness of R² ≥ 0.999 is set as the judgment threshold, quantifying the reliability of the calibration curve into a single dimensionless index. After obtaining all calibration data, the control and calculation module immediately calculates the R² value: if it meets the threshold, it indicates that the deviation between the current sensor response and the Henry's Law linear model is below the allowable limit, and the new curve is immediately written to non-volatile memory, overwriting the old curve, ensuring that the coefficients called in subsequent measurement stages perfectly match the real-time state of the sensor; if it does not meet the threshold, the system immediately stops the replacement, issues a calibration failure prompt on the human-machine interface, and forces the operator to check pressure control, gas path sealing, or sensor performance to prevent unqualified curves from entering the measurement process. This judgment step internalizes the metrological criteria into automatic logic, making the calibration results no longer dependent on subjective experience. At the same time, this stringent threshold prevents slight drifts from being ignored, ensuring that every value transfer has the legally required linearity and reproducibility, providing a continuous, traceable, and highly reliable metrological basis for dissolved hydrogen monitoring at nuclear power plant sites.

[0089] Reference Figure 5 The third aspect of this application provides a measurement method for a portable electrochemical hydrogen meter according to any of the above claims, the measurement method comprising: S201: Switch the flow cell 7 to be connected to the liquid being measured; S203: Measure the current signal i and real-time temperature of the liquid being tested through the electrochemical sensing module; S205: The control and calculation module calls the new calibration curve generated by any of the above calibration methods, processes the current signal i, and compensates for it in combination with the real-time temperature, and finally calculates and outputs the corrected dissolved hydrogen concentration value.

[0090] Specifically, step S201 connects the flow cell 7 to the liquid being measured by switching the flow path, allowing the process fluid to enter the same electrochemical chamber under zero discharge and zero cross-contamination conditions, ensuring that the subsequent signal and calibration stages have the same geometric and mass transfer environment. S203 synchronously captures the current signal i generated by the liquid being measured and the real-time temperature, bundling the concentration information with its corresponding temperature disturbance for acquisition, providing a synchronous benchmark for temperature compensation and avoiding compensation errors caused by time lag. S205 The control and calculation module immediately calls the newly calibrated curve that has been rigorously judged and written, mapping the current i inversely to the initial concentration value, and then dynamically correcting the Henry's coefficient based on the real-time temperature to complete the online elimination of temperature drift, finally outputting the corrected dissolved hydrogen concentration value after traceability, compensation, and verification. This process encloses the measurement chain on the same hardware platform, eliminating the need for manual table lookups or secondary calculations, thus eliminating extrapolation risks and ensuring that each result matches the latest sensor status and thermodynamic conditions in real time, providing continuously legally valid dissolved hydrogen values ​​for demanding scenarios such as nuclear power plant primary loops.

[0091] An embodiment of the fourth aspect of this application proposes a computer-readable storage medium, characterized in that it stores a processor-executable program, which, when executed by the processor, is used to implement the calibration method described above. The computer-readable storage medium carries the entire instruction sequence of the calibration method in a non-volatile semiconductor or optical entity, enabling the portable electrochemical hydrogen meter to complete value transfer locally even when disconnected from a host computer and network environment. The storage medium is directly coupled to the microcontroller via a bus, and the program is loaded upon power-up, providing real-time control of flow path switching, pressure setting, signal acquisition, Henry's Law calculation, R² determination, and curve updating in steps S101 to S113. Once the instructions are solidified, they cannot be tampered with by on-site operators, preventing the traceability chain from being broken due to human modification of coefficients. The medium possesses industrial-grade temperature adaptability and resistance to ionizing radiation, ensuring long-term integrity in the high-temperature, high-irradiation environment of nuclear power plants. Simultaneously, its rewritable nature allows metrology institutions to write new algorithm versions during periodic verification, enabling rapid adaptation after regulatory updates. By encapsulating the calibration method into an executable image and embedding it into the instrument itself, the entire device becomes a measurement device with its own legal procedures. It can independently complete calibration cycles that meet the requirements of the International System of Units without the need for external computing resources, reducing the technical threshold and operation and maintenance costs on site, and providing continuous, traceable and reproducible metrological assurance for the monitoring of dissolved hydrogen in nuclear power plants.

[0092] An embodiment of the fifth aspect of this application proposes a computer program product, including a computer program or computer instructions, stored in a computer-readable storage medium. A processor of a computer device reads the computer program or computer instructions from the computer-readable storage medium and executes the computer program or computer instructions, causing the computer device to perform any of the aforementioned calibration methods. The computer program product embeds the calibration logic in the form of distributable instructions. Once read, the processor automatically completes pressure setting, signal acquisition, Henry's Law calculation, and R² determination, without any manual intervention. Its hardware platform independence allows the same set of quantitative value algorithms to be seamlessly deployed on production lines, in metrology institutions, or in field maintenance, ensuring that the calibration process for each instrument is tamper-proof and maintains traceability with national standards, providing continuous, reliable, and reproducible metrological assurance for nuclear power plant dissolved hydrogen monitoring.

[0093] An embodiment of the sixth aspect of this application proposes a software system for a portable electrochemical hydrogen meter according to any of the above claims. The software system is integrated within a control and calculation module and includes a pressure control unit, a signal processing unit, a calibration calculation unit, and a measurement compensation unit. The pressure control unit accurately outputs at least two hydrogen partial pressures during the calibration phase. The signal processing unit synchronously acquires current and temperature signals. The calibration calculation unit performs multi-point linear fitting and generates a new correspondence between concentration and current. The measurement compensation unit dynamically corrects the correspondence based on real-time temperature during the measurement phase to eliminate system drift errors. The software system, with the pressure control unit, signal processing unit, calibration calculation unit, and measurement compensation unit working together, forms a closed drift suppression chain. For example, during the calibration phase, the pressure control unit outputs at least two traceable hydrogen partial pressures to provide a reproducible excitation reference for the sensor; the signal processing unit simultaneously captures current and temperature to ensure a one-to-one correspondence between the original values ​​and time and thermal environment; the calibration calculation unit performs multi-point linear fitting accordingly to generate a new correspondence that perfectly matches the current state of the sensitive element, replacing the aging curve; the measurement compensation unit introduces temperature variables in real time during subsequent operation to dynamically correct the correspondence and offset thermal drift and long-term drift. The entire system embeds control and calculation modules, enabling closed-loop calibration, correction, and output within each measurement cycle without external hardware, continuously eliminating system errors introduced by radiation, aging, or environmental fluctuations, and ensuring that the dissolved hydrogen concentration results at the nuclear power plant site are always under control, traceable, and legally valid metrological conditions.

[0094] The portable electrochemical hydrogen meter, calibration method, measurement method, and software system of this application are described below with reference to a specific embodiment. Figures 1 to 5 This application provides a portable electrochemical hydrogen meter and its calibration, measurement, and software system. The entire device uses a miniature hydrogen cylinder 1 as the source, and a standard hydrogen partial pressure generating module consisting of a gas pipeline 2, a pressure reducing valve 3, and a calibration pipeline regulating valve 6 can establish at least two traceable hydrogen partial pressures within a flow cell 7, enabling multi-point calibration with transferable values. The miniature hydrogen cylinder 1 reduces high-pressure pure hydrogen to a controllable range through the pressure reducing valve 3, and then the electrically operated calibration pipeline regulating valve 6 outputs discrete pressure points in a step-by-step manner. The gas pipeline 2 adopts a metal armor structure to ensure no leakage or explosion risk under the high temperature, vibration, and radiation environment of a nuclear power plant. The flow cell 7 is a shared cavity for calibration and measurement, integrating an electrochemical hydrogen sensor and a temperature sensor. The hydrogen-sensitive electrode and the temperature-sensitive element are arranged at the same point to ensure synchronous acquisition of three-dimensional data of pressure, current, and temperature. When the flow path switching module drives the regulating valve of the measurement pipeline 4 to close and the regulating valve of the calibration pipeline 6 to open, the flow cell 7 and the standard hydrogen partial pressure generating module form a closed loop. After calibration, the flow cell 7 switches to the measurement pipeline 4. The process sample liquid enters the same cavity through the inlet of the measurement pipeline 4, realizing the dual use of one cell and avoiding dead volume and cross-contamination caused by different cavities.

[0095] The measuring host 9 and the secondary instrument 10 together constitute the core hardware carrier of the control and calculation module. The measuring host 9 performs micro-current amplification, filtering, and primary calculations, while the secondary instrument 10 integrates power supply, power amplifier, ADC, DAC, and non-volatile memory. It implements PID closed-loop control for the pressure reducing valve 3, calibration pipeline regulating valve 6, and measuring pipeline regulating valve 4, and has a built-in standard calibration curve C=k·P+b at the factory. During field operation, the secondary instrument 10 automatically limits the hydrogen pressure calibration range according to the set concentration range, collects the corresponding current through 3-5 target pressure points, and uses Henry's Law p B =k x,B ·x B Real-time calculation of the true theoretical concentration of dissolved hydrogen C _ref Generate calibration data (C _ref i) and perform linear fitting; when the goodness of fit R² ≥ 0.999, the new curve replaces the old curve; otherwise, a calibration failure is indicated, ensuring that each value transfer meets the legal metrological requirements. During the measurement phase, the secondary instrument 10 calls the latest calibration curve, dynamically corrects the Henry's constant in combination with the real-time temperature, and outputs the corrected dissolved hydrogen concentration value after temperature compensation of the current signal i, completing the closed loop of calibration, measurement, and compensation.

[0096] The software system is embedded within the secondary instrument 10 and consists of a pressure control unit, a signal processing unit, a calibration calculation unit, and a measurement compensation unit. The pressure control unit maintains a stepped pressure of 0.1–1.0 MPa within the flow cell 7 through the coordinated action of the pressure reducing valve 3 and the calibration pipeline regulating valve 6. The signal processing unit synchronously acquires current and temperature signals from the electrochemical sensing module. The calibration calculation unit performs multi-point linear fitting and generates a new correlation between concentration and current. The measurement compensation unit introduces temperature variables in real-time during subsequent operation to dynamically correct the correlation, continuously eliminating system errors introduced by radiation, aging, or thermal drift. All computational instructions are stored in a computer-readable storage medium as a computer program product, loaded and executed upon processor power-on. This allows for on-site measurement value transfer conforming to the International System of Units (SI) without the need for external computing resources, providing continuous, traceable, and legally valid metrological assurance for the monitoring of dissolved hydrogen in the primary loop of nuclear power plants.

[0097] In summary, this application achieves closed-loop calibration with a single unit weighing less than 15kg, enabling multi-point generation of standard hydrogen partial pressure, in-situ acquisition of electrochemical signals, and real-time temperature compensation. This eliminates the need for external high-pressure gas sources or constant-temperature devices, allowing for on-site traceability of measurement values. Through a program embedded in a computer-readable storage medium, it automatically performs Henry's Law calculations, linear fit goodness-of-fit determination, and calibration curve updates, ensuring that every measurement result maintains traceability with national standards in terms of origin, pressure, and temperature. The software system dynamically corrects for sensor drift, thermal drift, and radiation aging, continuously outputting legally verified dissolved hydrogen concentration values. This provides real-time, reliable, and reproducible on-site metrological means for nuclear electrochemical supervision, while simultaneously reducing maintenance costs and personnel radiation exposure time.

[0098] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural transformations made based on the content of the specification and drawings of this application under the concept of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A portable electrochemical hydrogen meter, characterized in that, include: A standard hydrogen partial pressure generator module is used to output at least two hydrogen partial pressures; An electrochemical sensing module includes a flow cell, an electrochemical hydrogen sensor, and a temperature sensor, wherein the hydrogen-sensitive electrode and the temperature-sensitive element are both connected to the flow cell; A flow path switching module is connected to the flow cell and is used to connect the flow cell to the standard hydrogen partial pressure generating module, or to connect the flow cell to the liquid being tested. The control and calculation module is communicatively connected to the standard hydrogen partial pressure generating module, the electrochemical sensing module, and the flow path switching module. The portable electrochemical hydrogen meter is configured to have a calibration state and a measurement state. In the calibration state, the control and calculation module establishes a correspondence between dissolved hydrogen concentration and electrical signal based on the at least two hydrogen partial pressures and their corresponding current signals. In the measurement state, the portable electrochemical hydrogen meter outputs the dissolved hydrogen concentration value of the liquid being measured based on the correspondence and the real-time temperature signal.

2. The portable electrochemical hydrogen meter according to claim 1, characterized in that, The standard hydrogen partial pressure generating module includes a replaceable hydrogen storage unit, a pressure reducing valve, and an electric regulating valve, all of which are connected to the flow cell.

3. The portable electrochemical hydrogen meter according to claim 2, characterized in that, The hydrogen storage unit includes at least one of a high-pressure pure hydrogen cylinder, a metal hydride hydrogen storage device, or an in-situ water electrolysis hydrogen generator, wherein the hydrogen volume fraction of the hydrogen storage unit is ≥99%; and / or, The pressure range of the hydrogen storage unit is 0 to 15 MPa.a.

4. The portable electrochemical hydrogen meter according to claim 2, characterized in that, The pressure reducing valve and the electric regulating valve are configured to be able to regulate in concert to maintain a pressure of 0.1 MPa.a to 1.0 MPa.a within the flow cell and to provide at least three discrete hydrogen partial pressure points.

5. The portable electrochemical hydrogen meter according to claim 1, characterized in that, The control and calculation module has a built-in standard calibration curve, which is a linear fitting equation between hydrogen pressure and dissolved hydrogen concentration reference values.

6. The portable electrochemical hydrogen meter according to claim 5, characterized in that, The linear fitting equation for the standard calibration curve is C = k·P + b, where C is the reference value of dissolved hydrogen concentration, P is the hydrogen pressure value, and k and b are constant terms.

7. The portable electrochemical hydrogen meter according to claim 5, characterized in that, The goodness of fit R 2 The calculation formula is as follows: in, It is the residual sum of squares, which represents the sum of squared errors between the model's predicted values ​​and the actual values, reflecting the variation that the model did not capture; It is the residual sum of squares, which represents the sum of squares of the differences between the true value and its mean, reflecting the total variation of the dependent variable.

8. A calibration method, characterized in that, For a portable electrochemical hydrogen meter according to any one of claims 1 to 7, the calibration method comprises the following steps: S101: Put the portable electrochemical hydrogen meter into calibration mode and connect the flow cell to the standard hydrogen partial pressure generating module; S103: The control and calculation module sets the measurement range of dissolved hydrogen concentration and automatically determines the corresponding hydrogen pressure calibration range based on the measurement range; S105: The control and calculation module controls the standard hydrogen partial pressure generating module to sequentially establish 2 to 10 different target hydrogen pressure points P in the flow cell within the hydrogen pressure calibration range; S107: At each target hydrogen pressure point, the corresponding current signal i is measured by the electrochemical hydrogen sensor, and the current temperature T is measured by the temperature sensor. S109: For each target hydrogen pressure point P, the control and calculation module calculates the theoretical reference value C of the dissolved hydrogen concentration based on Henry's Law, using the target hydrogen pressure point P and the current temperature T. _ref This generates a set of calibration data (C _ref (i), where C _ref Where is the theoretical concentration, and i is the measured current; S111: Using the calibration data (C) _ref i) Perform linear fitting to generate a new calibration curve, and replace the original built-in calibration curve in the control and operation module with the new calibration curve; S113: After calibration, switch the portable electrochemical hydrogen meter to measurement mode and connect the flow cell to the liquid being measured.

9. The calibration method according to claim 8, characterized in that, Step S103 includes: When the set measurement range for dissolved hydrogen concentration is 0 to 5 ppm, the automatically selected hydrogen partial pressure calibration range is 0 to 5 bar.

10. The calibration method according to claim 8, characterized in that, Step S105 includes: The number of target hydrogen pressure points is 3 to 5.

11. The calibration method according to claim 8, characterized in that, Step S109 includes: The temperature signal is used to correct the Henry's Law constant in real time, with the correction temperature range being 10°C to 50°C.

12. The calibration method according to claim 8, characterized in that, In step S109, Henry's Law is: ; in, It is the mole fraction of volatile solute B (i.e., the dissolved gas) in the solution; It is the pressure of the gas on the liquid surface at equilibrium; It is a constant whose value depends on temperature, pressure, and the properties of the solute and solvent.

13. The calibration method according to claim 8, characterized in that, Step S111 includes: The replacement operation is performed when the linear fit goodness R² ≥ 0.999; otherwise, a calibration failure is displayed and a check is prompted.

14. A measurement method, characterized in that, The portable electrochemical hydrogen meter according to any one of claims 1 to 7, wherein the measurement method comprises: S201: Switch the flow cell to be connected to the liquid being measured; S203: Measure the current signal i and real-time temperature of the liquid being tested through the electrochemical sensing module; S205: The control and calculation module calls the new calibration curve generated by any of the calibration methods described in claims 8 to 13, processes the current signal i, and compensates for it in conjunction with the real-time temperature, and finally calculates and outputs the corrected dissolved hydrogen concentration value.

15. A computer-readable storage medium, characterized in that, It stores a processor-executable program, which, when executed by a processor, is used to implement the calibration method as described in any one of claims 8 to 13.

16. A computer program product, comprising a computer program or computer instructions, characterized in that, The computer program or the computer instructions are stored in a computer-readable storage medium, and the processor of the computer device reads the computer program or the computer instructions from the computer-readable storage medium. The processor executes the computer program or the computer instructions, causing the computer device to perform the calibration method as described in any one of claims 8 to 13.

17. A software system, characterized in that, For a portable electrochemical hydrogen meter according to any one of claims 1 to 7, the software system is integrated within the control and calculation module, the software system comprising: A pressure control unit is used to accurately output at least two hydrogen partial pressures during the calibration phase; The signal processing unit is used to synchronously acquire current and temperature signals; The calibration calculation unit is used to perform multi-point linear fitting and generate new correspondences between concentration and current; A measurement compensation unit is used to dynamically correct the correspondence based on real-time temperature during the measurement phase in order to eliminate system drift error.

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