Chloride ion real-time monitoring device and monitoring method

Abstract

The invention discloses a chloride ion real-time monitoring device and a monitoring method. The chloride ion real-time monitoring device comprises a sensing probe, an optical fiber adapter, a Y-shaped optical fiber, main control equipment and terminal equipment which are connected in sequence, one end of the Y-shaped optical fiber is connected with the sensing probe, and the other two ends are respectively connected with a blue light emitting port and a fluorescence receiving port; the main control equipment comprises a filter, a photoelectric converter, an analog-to-digital converter, an MCU (Microprogrammed Control Unit) main control chip, a signal generator, an LED (Light Emitting Diode) driving circuit and a blue light LED which are connected in sequence; the blue light LED is connected with the blue light emitting port, the filter is connected with the fluorescence receiving port, and the MCU main control chip is connected with terminal equipment; when the chloride ion real-time monitoring device is used for measuring chloride ions, the obtained chloride ion value is obtained in real time, and the concentration of the chloride ions is monitored in real time; the chloride ion real-time monitoring device is low in structure cost, and the convenience and adaptability of chloride ion detection can be remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of chloride ion detection, and in particular relates to a chloride ion real-time monitoring device and a monitoring method. Background Art

[0002] Chloride ion (Cl - ) is an anion widely present in the environment. When its concentration is too high, it will have a negative impact on soil structure and building strength. In particular, the construction industry has an urgent need for real-time monitoring of chloride ion concentration, because in the concrete production process, the chloride ion content in the material needs to be strictly controlled to prevent its negative impact on the durability of the building.

[0003] Chloride ion monitoring technology has a long history in scientific research and practical applications. Traditional chloride ion concentration measurement methods include: chemical titration, ion selective electrode method, and colorimetry. Although the above methods can obtain relatively accurate measurement results under laboratory conditions, there are many limitations in practical applications. A fluorescent fiber optic sensor for detecting chloride ion concentration in concrete, which uses fiber optic sensing technology to convert the measured chloride ion parameter into a corresponding optical signal, has the advantages of high sensitivity, anti-electromagnetic interference, corrosion resistance, and small size; however, the technology still has the following problems: First, the laser light source is complex in design and not easy to carry, and requires both the measuring fiber optic probe and the balancing fiber optic probe to measure at the same time, which is not easy to integrate into miniaturized equipment, limiting the portability and field application of the sensor. In addition, the optical platform requires precise adjustment during use, which makes the entire experimental process complicated and requires a high level of technical skills for the operator, further limiting the popularity of this technology in ordinary laboratories and field operations. Thirdly, the data processing steps of spectral detection are cumbersome and usually require a lot of subsequent analysis to obtain the final result, which increases the time and cost of detection and limits the efficiency of fiber optic chloride ion sensors in practical applications.

[0004] Most importantly, the challenges of industrializing the above-mentioned technologies are relatively difficult, and economy is an important factor restricting the application of fiber-optic chloride ion sensors. The high cost of laser light sources, optical components, and precision adjustment equipment will make the overall price cost of the industrialized equipment of this detection method relatively high, which is not conducive to production and promotion. Therefore, the optical signal sensing principle can only obtain real-time optical signals, and it is impossible to directly obtain chloride ion measurement data. Instead, it requires analysis and calculation of optical signals, and has high requirements for operators, and the prospects for industrialization are not good. In other words, the prior art lacks a fast, intuitive, low-cost, and easy-to-promote device for real-time determination of chloride ion concentration. Based on the problems existing in the prior art, it is necessary to propose a more compact, easy-to-use, and efficient optical fiber chloride ion detection device and monitoring method. Summary of the invention

[0005] The present invention provides a chloride ion real-time monitoring device and a monitoring method, so as to solve the problem of lack of high-sensitivity and real-time chloride ion monitoring special equipment in environmental monitoring and industrial applications.

[0006] To solve the above problems, the technical solution provided by the present invention is as follows:

[0007] The embodiment of the present invention provides a chloride ion real-time monitoring device, comprising a sensing probe (1), an optical fiber adapter (4), a Y-type optical fiber (3), a main control device (2) and a terminal device (5) connected in sequence; wherein the sensing probe (1) is an optical fiber chloride ion sensitive probe; the Y-type optical fiber (3) is a one-to-two device, one end of which is connected to the sensing probe (1), and the other two ends of which are respectively connected to a blue light emitting port (31) and a fluorescence receiving port (32); the main control device (2) comprises a filter (21), a photoelectric converter (22), an analog-to-digital converter (23), an MCU main control chip (24), a signal generator (25), an LED drive circuit (26) and a blue light LED (27) connected in sequence; the filter (21) is connected to the fluorescence receiving port (32), the blue light LED (27) is connected to the blue light emitting port (31), and the MCU main control chip (24) is connected to the terminal device (5);

[0008] The photoelectric converter (22) comprises a photodiode (221) and an operational amplifier (222), the filter (21) is connected to the photodiode (221), the photodiode (221) is connected to the operational amplifier (222), and the operational amplifier (222) is connected to the analog-to-digital converter (23).

[0009] In an optional embodiment of the present invention, the MCU main control chip (24) exchanges and transmits data with the terminal device (5) via an RS485 serial port connection.

[0010] In an optional embodiment of the present invention, the terminal device (5) includes a display module (51) and a data analysis module (52).

[0011] An embodiment of the present invention provides a method for real-time monitoring of chloride ions, which is implemented by a real-time monitoring device for chloride ions as in the above embodiment, and comprises the following steps:

[0012] Step S1, preparation of the sensing probe (1): cutting an optical fiber segment, polishing it, coating the optical fiber, and finally coating it with a chloride ion sensitive film. The obtained sensing probe (1) is an optical fiber chloride ion sensitive probe;

[0013] Step S2, wiring debugging of the chloride ion real-time monitoring device: sequentially connecting the sensor probe (1), the main control device (2), the Y-type optical fiber (3), the optical fiber adapter (4) and the terminal device (5), debugging the signal, and ensuring that the fluorescence intensity data measured by the sensor probe (1) can be transmitted to the terminal device (5);

[0014] Step S3, drawing a standard curve: the debugged chloride ion real-time monitoring device monitors the fluorescence intensity under the chloride ion concentration to be measured through the chloride ion sensitive probe. The relationship between the chloride ion concentration and the fluorescence intensity and life span is described by the Stern-Volmer equation: Where: I0 is the fluorescence intensity under the environment of chloride ion concentration of 0; I is the fluorescence signal intensity after fluorescence quenching of the optical fiber chloride ion sensitive probe; τ0 is the initial lifetime of the fluorescence signal emitted by the optical fiber chloride ion sensitive probe; τ is the fluorescence signal lifetime after fluorescence quenching of the optical fiber chloride ion sensitive probe; K is the Stern-Volmer constant, and x(Cl) is the chloride ion concentration;

[0015] Step S3 also includes: step S31, collecting data: using an optical fiber chloride ion sensor to detect the fluorescence intensity in an environment with a known chloride ion concentration; under different chloride ion concentrations, the intensity of the fluorescence signal emitted by the probe will change accordingly, and the fluorescence signal is converted into an electrical signal through a photoelectric conversion module (22) and the sensor signal is analyzed by a data processing system of an MCU main control chip (24), and the measurement result is sent to a terminal device (5) through RS485 serial communication for real-time display; the above data are subjected to a de-extreme value averaging filtering method to obtain a series of optimal fluorescence intensities; step S32, curve fitting: the measured fluorescence intensity and chloride ion concentration are linearly fitted using the least squares method to obtain The standard curve of , B value is the intercept of the linear fit;

[0016] Step S4, real-time monitoring of chloride ions: insert the sensor probe (1) into the environment to be tested, measure the fluorescence intensity in the environment to be tested under unknown chloride ion concentration, substitute it into the standard curve equation of step S32, and obtain the chloride ion concentration in the solution to be tested by the fluorescence intensity;

[0017] Step S1 specifically includes the following: Step S11, cutting the optical fiber segment: cutting the optical fiber with a diameter of 1000 μm into an optical fiber segment of 10 cm; Step S12, polishing the optical fiber segment: using an optical fiber grinder to polish one end of the optical fiber segment to make it have a smooth plane with a mirror reflection effect; at the same time, using sandpaper of different meshes to polish the other end to form a smooth inclined surface with an inclination angle of 45°, which also has a mirror reflection characteristic; Step S13, optical fiber coating: coating the smooth end of the polished optical fiber segment, then peeling off the coating layer, then using ultrapure water and alcohol to clean the optical fiber end face, and allowing it to air dry naturally; Step S14, chloride ion sensitive film coating: using an optical fiber coating device to adopt a pull-up coating method to coat a chloride ion sensitive film on one end of the inclined surface of the optical fiber segment; after the coating is completed, the optical fiber segment is dried, and the obtained sensing probe (1) is a fiber optic chloride ion sensitive probe;

[0018] The chlorine-sensitive film is composed of a fluorescent indicator and a matrix material, and the fluorescent indicator is fixed on the matrix material by an embedding method; the fluorescent indicator is lucite, and the matrix material is composed of a polymer and a solvent: the polymer is cellulose acetate, which has the characteristics of good biocompatibility, stable performance, simple preparation, and good compatibility with the fluorescent indicator; the solvent is acetone.

[0019] In an optional embodiment of the present invention, the environment with known chloride ion concentration in step S31 is an environment of sodium chloride standard solution; specifically, the optical fiber chloride ion probe prepared in step S1 is inserted under the liquid surface of sodium chloride standard solutions of different concentrations, and the concentrations of the sodium chloride standard solutions are 0.000mol / L, 0.005mol / L, 0.010mol / L, 0.025mol / L, 0.050mol / L, 0.075mol / L, and 0.100mol / L, respectively.

[0020] In an optional embodiment of the present invention, the environment with known chloride ion concentration in step S31 is a sandy soil environment containing a sodium chloride standard solution; specifically, seven identical cubic containers are prepared, the center of the container is a sandy soil chamber, and solution chambers are symmetrically arranged on both sides, and a number of small holes are opened on the partition wall of the chambers, wherein the solution chamber on one side is used to pour in the sodium chloride solution, and the solution chamber on the other side is used to infiltrate the sodium chloride solution; clean sand is evenly buried in the sandy soil chamber, and the clean sand does not contain chloride ions; and the solution chambers on one side of the seven cubic containers are slowly poured into the solution chambers in turn. Pour sodium chloride solutions with concentrations of 0.000mol / L, 0.005mol / L, 0.010mol / L, 0.025mol / L, 0.050mol / L, 0.075mol / L, and 0.100mol / L, so that the seven cubic containers contain sodium chloride solutions of corresponding concentrations. Wait for the solution to seep into the sand from the bottom and completely submerge the sand, and the excess sodium chloride solution to seep out from the solution chamber on the other side. Insert the fiber optic chloride ion probe under the sand until it can fully detect the chloride ion concentration.

[0021] Compared with the prior art, the embodiments of the present invention provide a chloride ion real-time monitoring device and a monitoring method, which have the following beneficial effects:

[0022] (1) The present invention breaks through the application limitations of existing fiber optic chloride ion sensors in many aspects. First, thanks to the innovatively designed modulation and demodulation circuit structures, the functions of the measurement probe and the balance probe can be integrated into one probe, and the detection of the fluorescence signal can be directly performed in the photoelectric conversion module without relying on the traditional optical platform or spectrometer. This breakthrough greatly reduces the overall size of the fiber optic sensor, increases its integration and portability, solves the problem of the large size of the traditional laser light source, and greatly improves the field application capability of the sensor.

[0023] (2) The present invention no longer relies on an optical platform and a spectrometer, but directly performs signal processing through a photoelectric conversion module and an ADC analog-to-digital converter, which effectively avoids the need for precision adjustment of a traditional optical platform, simplifies the operation process, and greatly reduces the difficulty of use and the requirements for technicians.

[0024] (3) The cumbersome problem of spectral detection data processing has also been significantly improved. Through the data processing function integrated in the MCU main control chip, the calculation process of chloride ion concentration has become simpler and more direct, and the detection results can be obtained and displayed in real time, greatly improving the detection efficiency and data intuitiveness; this not only makes the detection process more efficient, but also facilitates real-time data collection and analysis in multi-scenario applications.

[0025] Through the above improvements, the present invention effectively solves the limitations of the fluorescent optical fiber sensor for detecting the chloride ion concentration in concrete in terms of volume, real-time performance, and integration in Chinese patent application number CN105510293A, and significantly improves the practicality and reliability of the system. The present invention can provide a more portable, stable, and intelligent solution for chloride ion detection, and is widely applicable to environmental monitoring, building health assessment, water quality monitoring and other fields, providing industry users with a more efficient and economical detection tool. By improving the integration of the monitoring device, reducing the dependence on external precision equipment, and simplifying the data processing process, the present invention not only reduces the overall cost, but also significantly improves the convenience and adaptability of detection, providing strong support for the promotion and application of optical fiber sensing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 A schematic structural diagram of a chloride ion real-time monitoring device provided in an embodiment of the present application.

[0028] Figure 2 A specific connection diagram of a chloride ion real-time monitoring device provided in an embodiment of the present application.

[0029] Figure 3 This is a schematic diagram of the detection of sodium chloride standard solution in the data collection link of Example 1 of the present application.

[0030] Figure 4 This is a standard curve diagram of fluorescence intensity-chloride ion concentration drawn in sodium chloride solution in Example 1 of the present application.

[0031] Figure 5 A block diagram of the data processing principle of chloride ion concentration is provided for an embodiment of the present application.

[0032] Figure 6 This is a schematic diagram of the structure of the cube container in Example 2 of the present application.

[0033] Figure 7 This is a schematic diagram of the process of injecting sodium chloride standard solution into the cube container in Example 2 of the present application.

[0034] Figure 8 This is a standard curve diagram of fluorescence intensity-chloride ion concentration drawn in sand containing sodium chloride standard solution in Example 2 of the present application.

[0035] Fig. 9 This is an actual effect diagram of the chloride ion concentration change curve measured in Example 2 of the present application.

[0036] The accompanying drawings are marked as follows: 1-sensing probe; 2-main control device; 21-filter; 22-photoelectric converter; 221-photodiode; 222-operational amplifier; 23-analog-to-digital converter; 24-MCU main control chip; 25-signal generator; 26-LED drive circuit; 27-blue light LED; 3-Y-type optical fiber; 31-blue light transmitting port; 32-fluorescence receiving port; 4-optical fiber adapter; 5-terminal device; 51-display module; 52-data analysis module. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for which protection is claimed, but merely represents the selected embodiments of the present application.

[0038] Example 1

[0039] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a chloride ion real-time monitoring device, including a sensing probe 1, an optical fiber adapter 4, a Y-type optical fiber 3, a main control device 2 and a terminal device 5 connected in sequence. Among them, the sensing probe 1 is an optical fiber chloride ion sensitive probe. The Y-type optical fiber 3 is a one-to-two device, one end of which is connected to the sensing probe 1, and the other two ends are respectively connected to a blue light emission port 31 and a fluorescence receiving port 32. The main control device 2 includes a filter 21, a photoelectric converter 22, an analog-to-digital converter 23, an MCU main control chip 24, a signal generator 25, an LED drive circuit 26 and a blue light LED 27 connected in sequence. The filter 21 is connected to the fluorescence receiving port 32, the blue light LED 27 is connected to the blue light emission port 31, and the MCU main control chip 24 is connected to the terminal device 5. The photoelectric converter 22 includes a photodiode 221 and an operational amplifier 222, the filter 21 is connected to the photodiode 221, the photodiode 221 is connected to the operational amplifier 222, and the operational amplifier 222 is connected to the analog-to-digital converter 23. The MCU main control chip 24 exchanges and transmits data with the terminal device 5 via the RS485 serial port connection. The terminal device 5 includes a display module 51 and a data analysis module 52.

[0040] The specific model and signal flow of the above-mentioned chloride ion real-time monitoring device are as follows: the sensing probe 1 is a fiber optic chloride ion sensitive probe, which can be directly contacted with the chloride ion environment to be measured, and then the chloride ion concentration in the environment to be measured is detected. The main control device 2 is the control terminal of the monitoring device, and the core component is the MCU main control chip 24. The signal generator 25 is a programmable logic device. In this embodiment, CPLD is used to generate a square wave with a frequency of 40Khz, and the required voltage is provided to the blue light LED 27 through the LED drive circuit 26. The MCU main control chip 24 controls the blue light signal generated by the blue light LED 27 through the signal generator 25 and the LED drive circuit 26, and then transmits it to the Y-type optical fiber 3 through the blue light emission port 31, and finally transmits it to the sensing probe 1, and excites the optical fiber chloride ion sensitive probe to emit a fluorescent signal.

[0041] The photoelectric converter 22 is used to collect the fluorescence signal emitted by the optical fiber chloride ion sensitive probe. Specifically: the fluorescence signal emitted by the optical fiber chloride ion sensitive probe is transmitted to the fluorescence receiving port 32 via the Y-type optical fiber 3, and then transmitted to the photodiode 221 after filtering by the filter 21, and then enters the operational amplifier 222, and the weak current signal generated by the photodiode 221 is converted into a voltage signal through the transimpedance amplifier and the programmable logic gain, and amplified, so as to facilitate the subsequent analog-to-digital converter 23 to collect data. The analog-to-digital converter 23 uses an ADC analog-to-digital converter, which is used to collect the amplified voltage signal, which is actually the fluorescence signal emitted by the optical fiber probe, that is, to collect the fluorescence intensity. The MCU main control chip 24 is used to process a large amount of fluorescence intensity data collected by the analog-to-digital converter 23, and linearly fit the above data, and then calculate the chloride ion concentration in the environment to be tested. Finally, the result is sent to the terminal device 5 via the RS485 serial port.

[0042] An embodiment of the present invention provides a method for real-time monitoring of chloride ions, which is implemented by using a real-time monitoring device for chloride ions in the above embodiment, and includes the following steps:

[0043] Step S1, preparation of the sensing probe 1: cutting an optical fiber segment, polishing it, coating the optical fiber, and finally coating it with a chloride ion sensitive film. The obtained sensing probe 1 is an optical fiber chloride ion sensitive probe;

[0044] Step S2, wiring debugging of the chloride ion real-time monitoring device: sequentially connect the sensor probe 1, the main control device 2, the Y-type optical fiber 3, the optical fiber adapter 4 and the terminal device 5, debug the signal, and ensure that the fluorescence intensity data measured by the sensor probe 1 can be transmitted to the terminal device 5;

[0045] Step S3, drawing a standard curve: the debugged chloride ion real-time monitoring device monitors the fluorescence intensity under the chloride ion concentration to be measured through the chloride ion sensitive probe. The relationship between the chloride ion concentration and the fluorescence intensity and life span is described by the Stern-Volmer equation: Where: I0 is the fluorescence intensity under the environment of chloride ion concentration of 0; I is the fluorescence signal intensity after fluorescence quenching of the optical fiber chloride ion sensitive probe; τ0 is the initial lifetime of the fluorescence signal emitted by the optical fiber chloride ion sensitive probe; τ is the fluorescence signal lifetime after fluorescence quenching of the optical fiber chloride ion sensitive probe; K is the Stern-Volmer constant, and x(Cl) is the chloride ion concentration;

[0046] Step S3 also includes: step S31, collecting data: using an optical fiber chloride ion sensor to detect the fluorescence intensity in an environment with a known chloride ion concentration; under different chloride ion concentrations, the intensity of the fluorescence signal emitted by the probe will change accordingly, and the fluorescence signal is converted into an electrical signal through the photoelectric conversion module 22 and the sensor signal is analyzed by the data processing system of the MCU main control chip 24, and the measurement result is sent to the terminal device 5 for real-time display through RS485 serial port communication; the above data are subjected to the method of de-extreme value averaging filtering to obtain a series of optimal fluorescence intensities; step S32, fitting curve: the measured fluorescence intensity and chloride ion concentration are linearly fitted using the least squares method to obtain In this embodiment, the fluorescence intensity and chloride ion concentration were linearly fitted using the least squares method, and the result was The standard curve is obtained by taking the obtained I0 value and the 6 I values ​​as Y. Taking the seven different chloride ion concentrations as X values, a linear fit is performed to obtain The equation of this formula is, therefore, K in this formula is The K in does not mean the same thing. The B value is the intercept of the linear fit.

[0047] Step S4, real-time monitoring of chloride ions: insert the sensor probe 1 into the test environment, measure the fluorescence intensity in the test environment under unknown chloride ion concentration, substitute it into the standard curve equation of step S32, and obtain the chloride ion concentration in the test solution through the fluorescence intensity.

[0048] Step S1 specifically includes the following: Step S11, cutting the optical fiber segment: cutting the optical fiber with a diameter of 1000 μm into an optical fiber segment of 10 cm; Step S12, polishing the optical fiber segment: using an optical fiber grinder to polish one end of the optical fiber segment to make it have a smooth plane with a mirror reflection effect; at the same time, using sandpaper of different mesh sizes to polish the other end to form a smooth inclined surface with a 45° inclination angle, which also has mirror reflection characteristics; Step S13, optical fiber coating: coating the smooth end of the polished optical fiber segment, then peeling off the coating layer, and then using ultrapure water and alcohol to clean the optical fiber end face, and allowing it to air dry naturally; Step S14, chloride ion sensitive film coating: using optical fiber coating equipment to adopt a pull-up coating method to coat a chloride ion sensitive film on one end of the inclined surface of the optical fiber segment; after the coating is completed, the optical fiber segment is dried, and the obtained sensor probe 1 is a fiber optic chloride ion sensitive probe.

[0049] The chlorine-sensitive film is composed of a fluorescent indicator and a matrix material, and the fluorescent indicator is fixed on the matrix material by an embedding method; the fluorescent indicator is lucite, and the matrix material is composed of a polymer and a solvent: the polymer is cellulose acetate, which has the characteristics of good biocompatibility, stable performance, simple preparation, and good compatibility with the fluorescent indicator; the solvent is acetone.

[0050] The environment with known chloride ion concentration in step S31 is the environment of sodium chloride standard solution; specifically: the optical fiber chloride ion probe prepared in step S1 is inserted into 3 cm below the liquid surface of sodium chloride standard solutions of different concentrations, and the concentrations of the sodium chloride standard solutions are 0.000 mol / L, 0.005 mol / L, 0.010 mol / L, 0.025 mol / L, 0.050 mol / L, 0.075 mol / L, and 0.100 mol / L, respectively.

[0051] In this embodiment, an optical fiber chloride ion sensor is used to detect the fluorescence intensity in an environment with a known chloride ion concentration. Standard sodium chloride solutions with concentrations of 0.000 mol / L, 0.005 mol / L, 0.010 mol / L, 0.025 mol / L, 0.050 mol / L, 0.075 mol / L, and 0.100 mol / L are configured for monitoring. The optical fiber chloride ion probe prepared in step S31 is inserted below the liquid surface of the sodium chloride standard solutions with different concentrations, preferably 3 cm below the liquid surface of the sodium chloride standard solutions. Figure 3As shown, it is ensured that it can fully detect the solution concentration. Under different chloride ion concentrations, the intensity of the fluorescent signal emitted by the probe will change accordingly, and the fluorescent signal is converted into an electrical signal by the photoelectric conversion module 22 and the sensor signal is analyzed by the data processing system of MCU24, and the measurement result is sent to the terminal 5 for real-time display through RS485 serial communication. The above data are filtered by the method of de-extreme value averaging, and a series of optimal fluorescence intensities can be obtained. The standard curve drawn in step S32 of this embodiment is shown in FIG. Figure 4 As shown, the above standard curve can be used for data fitting in the chloride ion sensor. The standard curve equation is: The process principle block diagram of step S4 of this embodiment is as follows: Figure 5 shown.

[0052] Example 2, measurement of unknown chloride ion concentration in sand and result optimization algorithm.

[0053] The difference between Example 2 and Example 1 is that the environment with known chloride ion concentration in step S31 is a sandy soil environment containing a sodium chloride standard solution; specifically: Figure 6 As shown, seven identical cubic containers (10cm×10cm×10cm) are prepared, with a sand chamber (10cm×8cm×10cm) in the center of the container, and solution chambers are symmetrically arranged on both sides, with a number of small holes on the chamber partition wall, one side of the solution chamber is used to pour in the sodium chloride solution, and the other side of the solution chamber is used to seep out the sodium chloride solution. Clean sand with a volume of 10cm×8cm×8cm is evenly buried in the sand chamber, and the clean sand does not contain chloride ions, that is, the clean sand is selected from sand with a soil quality similar to that of the soil, and is washed with deionized water for multiple times and dried to ensure that there are no chloride ions in the sand. Sodium chloride solutions with concentrations of 0.000 mol / L, 0.005 mol / L, 0.010 mol / L, 0.025 mol / L, 0.050 mol / L, 0.075 mol / L, and 0.100 mol / L were slowly poured into the solution chambers on one side of the seven cube containers. Figure 7 As shown, 7 cubic containers are filled with sodium chloride solutions of corresponding concentrations. When the solution seeps into the sand from the bottom and completely immerses the sand, the excess sodium chloride solution seeps out from the solution chamber on the other side. The optical fiber chloride ion probe is inserted into the sand to ensure that it can fully detect the chloride ion concentration, preferably 3 cm below the sand.

[0054] The fluorescence intensity of the chloride ion fiber optic probe in the sand at the above seven concentrations was measured respectively, and the above data were filtered by de-extreme value averaging to obtain a series of optimal fluorescence intensities.

[0055] The fitting curve in step S32 is: the measured fluorescence intensity and chloride ion concentration are linearly fitted using the least squares method to draw a curve and a chloride ion concentration standard curve, the standard curve is as follows Figure 8 The standard curve equation is:

[0056] Real-time monitoring of chloride ions in step S4: Prepare a structure such as Figure 6 A cube container (10cmx10cmx10cm) is provided, and the center of the container is a sand chamber (10cmx8cmx10cm). The sand chamber is evenly covered with sand of a volume (10cmx8cmx8cm). Sand similar to the soil quality is selected, and deionized water is used to wash it several times and dry it to ensure that there are no chloride ions in the sand. Solution chambers are symmetrically arranged on both sides, and small holes are opened on the partition wall of the chambers. One side of the solution chamber is used to pour in the sodium chloride solution, and the other side of the solution chamber is used to seep out the sodium chloride solution.

[0057] After completing the above preparation process, the real-time monitoring of the chloride ion solution can be performed: 0.000mol / L, 0.005mol / L, 0.010mol / L, 0.025mol / L, 0.050mol / L, 0.075mol / L, 0.100mol / L of sodium chloride standard solution are continuously and slowly injected into the solution chamber on one side according to the chloride ion concentration gradient, and the chamber on the other side is used to continuously discharge the sodium chloride solution that seeps out after pouring. The sensor probe 1 is inserted into the environment to be tested, and the fluorescence intensity in the environment to be tested under unknown chloride ion concentration is measured. The fluorescence intensity is substituted into the standard curve equation of step S32, and the chloride ion concentration in the solution to be tested can be obtained by the fluorescence intensity.

[0058] From the standard curve, we can know that: I0 is the fluorescence intensity when the chloride ion concentration is the initial value, that is, the pure water environment; I is the fluorescence intensity when the chloride ion concentration to be measured is x(cl); therefore, by obtaining I, the chloride ion concentration to be measured can be calculated. Draw a chloride ion concentration change curve as shown in Fig. 9 As shown in the figure, the ordinate is the amplitude, i.e., the fluorescence intensity, and the abscissa is the time; Fig. 9 As shown, it can be seen that by pouring sodium chloride solution according to the concentration gradient, the device can continuously monitor the changes in fluorescence intensity.

[0059] It can be seen that the chloride ion real-time monitoring device and monitoring method of the present invention can measure chloride ions in real time. When the probe is inserted, the chloride ion value is obtained immediately. What is obtained after the insertion is a light signal. The generated fluorescence signal is converted into an electrical signal through a photoelectric conversion module, and the chloride ion concentration can be obtained.

[0060] In summary, although the present invention has been disclosed as above in terms of preferred embodiments, the above preferred embodiments are not intended to limit the present invention. A person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined in the claims.

Claims

1. A chloride ion real-time monitoring device, characterized in that: The invention comprises a sensing probe (1), an optical fiber adapter (4), a Y-type optical fiber (3), a main control device (2) and a terminal device (5) which are connected in sequence; wherein the sensing probe (1) is an optical fiber chloride ion sensitive probe; the Y-type optical fiber (3) is a one-to-two device, one end of which is connected to the sensing probe (1), and the other two ends of which are respectively connected to a blue light emitting port (31) and a fluorescence receiving port (32); the main control device (2) comprises a filter (21), a photoelectric converter (22), an analog-to-digital converter (23), an MCU main control chip (24), a signal generator (25), an LED driving circuit (26) and a blue light LED (27) which are connected in sequence; the filter (21) is connected to the fluorescence receiving port (32), the blue light LED (27) is connected to the blue light emitting port (31), and the MCU main control chip (24) is connected to the terminal device (5); The photoelectric converter (22) comprises a photodiode (221) and an operational amplifier (222), the filter (21) is connected to the photodiode (221), the photodiode (221) is connected to the operational amplifier (222), and the operational amplifier (222) is connected to the analog-to-digital converter (23).

2. A chloride ion real-time monitoring device according to claim 1, characterized in that: The MCU main control chip (24) exchanges and transmits data with the terminal device (5) via an RS485 serial port connection.

3. A chloride ion real-time monitoring device according to claim 2, characterized in that: The terminal device (5) comprises a display module (51) and a data analysis module (52).

4. A method for real-time monitoring of chloride ions, implemented by a real-time monitoring device for chloride ions as claimed in claim 3, characterized in that: The following steps are involved: Step S1, preparation of the sensing probe (1): cutting an optical fiber segment, polishing it, coating the optical fiber, and finally coating it with a chloride ion sensitive film. The obtained sensing probe (1) is an optical fiber chloride ion sensitive probe; Step S2, wiring debugging of the chloride ion real-time monitoring device: sequentially connecting the sensor probe (1), the main control device (2), the Y-type optical fiber (3), the optical fiber adapter (4) and the terminal device (5), debugging the signal, and ensuring that the fluorescence intensity data measured by the sensor probe (1) can be transmitted to the terminal device (5); Step S3, drawing a standard curve: the debugged chloride ion real-time monitoring device monitors the fluorescence intensity under the chloride ion concentration to be measured through the chloride ion sensitive probe. The relationship between the chloride ion concentration and the fluorescence intensity and life span is described by the Stern-Volmer equation: Where: I0 is the fluorescence intensity under the condition of zero chloride concentration; I is the fluorescence signal intensity after fluorescence quenching of the optical fiber chloride ion sensitive probe; τ0 is the initial lifetime of the fluorescence signal emitted by the optical fiber chloride ion sensitive probe; τ is the lifetime of the fluorescence signal after fluorescence quenching of the optical fiber chloride ion sensitive probe; K is the Stern-Volmer constant, x ( Cl ) is the chloride ion concentration; Step S3 also includes: step S31, collecting data: using an optical fiber chloride ion sensor to detect the fluorescence intensity in an environment with a known chloride ion concentration; under different chloride ion concentrations, the intensity of the fluorescence signal emitted by the probe will change accordingly, and the fluorescence signal is converted into an electrical signal through a photoelectric conversion module (22) and the sensor signal is analyzed by a data processing system of an MCU main control chip (24), and the measurement result is sent to a terminal device (5) through RS485 serial communication for real-time display; the above data are subjected to a de-extreme value averaging filtering method to obtain a series of optimal fluorescence intensities; step S32, curve fitting: the measured fluorescence intensity and chloride ion concentration are linearly fitted using the least squares method to obtain The standard curve of , B value is the intercept of the linear fit; Step S4, real-time monitoring of chloride ions: insert the sensor probe (1) into the environment to be tested, measure the fluorescence intensity in the environment to be tested under unknown chloride ion concentration, substitute it into the standard curve equation of step S32, and obtain the chloride ion concentration in the solution to be tested by the fluorescence intensity; Step S1 specifically includes the following: Step S11, cutting the optical fiber segment: cutting the optical fiber with a diameter of 1000 μm into an optical fiber segment of 10 cm; Step S12, polishing the optical fiber segment: using an optical fiber grinder to polish one end of the optical fiber segment to make it have a smooth plane with a mirror reflection effect; at the same time, using sandpaper of different meshes to polish the other end to form a smooth inclined surface with an inclination angle of 45°, which also has a mirror reflection characteristic; Step S13, optical fiber coating: coating the smooth end of the polished optical fiber segment, then peeling off the coating layer, then using ultrapure water and alcohol to clean the optical fiber end face, and allowing it to air dry naturally; Step S14, chloride ion sensitive film coating: using an optical fiber coating device to adopt a pull-up coating method to coat a chloride ion sensitive film on one end of the inclined surface of the optical fiber segment; after the coating is completed, the optical fiber segment is dried, and the obtained sensing probe (1) is a fiber optic chloride ion sensitive probe; The chlorine-sensitive film is composed of a fluorescent indicator and a matrix material, and the fluorescent indicator is fixed on the matrix material by an embedding method; the fluorescent indicator is lucite, and the matrix material is composed of a polymer and a solvent: the polymer is cellulose acetate, which has the characteristics of good biocompatibility, stable performance, simple preparation, and good compatibility with the fluorescent indicator; the solvent is acetone.

5. A method for real-time monitoring of chloride ions according to claim 4, characterized in that: The environment with known chloride ion concentration in step S31 is an environment of sodium chloride standard solution; specifically, the optical fiber chloride ion probe prepared in step S1 is inserted under the liquid surface of sodium chloride standard solutions of different concentrations, and the concentrations of the sodium chloride standard solutions are 0.000mol / L, 0.005mol / L, 0.010mol / L, 0.025mol / L, 0.050mol / L, 0.075mol / L, and 0.100mol / L, respectively.

6. A method for real-time monitoring of chloride ions according to claim 4, characterized in that: The environment of known chloride ion concentration in step S31 is a sandy soil environment containing a standard sodium chloride solution; specifically, seven identical cubic containers are prepared, the center of the container is a sandy soil chamber, and solution chambers are symmetrically arranged on both sides, and a number of small holes are opened on the walls separating the chambers, one side of the solution chamber is used to pour in the sodium chloride solution, and the other side of the solution chamber is used to seep out the sodium chloride solution; clean sand is evenly buried in the sandy soil chamber, and the clean sand does not contain chloride ions; slowly pour the concentration of sodium chloride into the solution chambers on one side of the 7 cubic containers in turn. 0.000mol / L, 0.005mol / L, 0.010mol / L, 0.025mol / L, 0.050mol / L, 0.075mol / L and 0.100mol / L sodium chloride solutions are added to make the 7 cubic containers contain sodium chloride solutions of corresponding concentrations. When the solution seeps into the sand from the bottom and completely immerses the sand, the excess sodium chloride solution seeps out from the solution chamber on the other side. Insert the fiber optic chloride ion probe under the sand until the chloride ion concentration can be fully detected.

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