Device and method for measuring chloride ions in concrete

Abstract

The present invention discloses a device and method for measuring chloride ions in concrete, relating to the technical field of chloride ion measurement. The device comprises a first optical system, a second optical system, a spectrometer, and a central control unit. The first optical system comprises a femtosecond laser, an ablation focusing lens assembly, and a sample; the second optical system comprises a heating light source, a dichroic mirror, a reflector, and a heating focusing lens assembly. The present invention utilizes a femtosecond laser as the ablation light source, improving sample ablation efficiency and addressing the issue of weak chloride ion spectral lines. Furthermore, the present invention employs a clustering algorithm during the sampling process, addressing issues such as large quantitative errors and poor repeatability caused by concrete heterogeneity.

Description

Technical Field

[0001] The present invention relates to the technical field of chloride ion measurement, and in particular to a device and method for measuring chloride ions in concrete. Background Art

[0002] Reinforced concrete is one of the most widely used materials in construction. However, the intrusion of chloride ions can cause corrosion in the steel bars, leading to a rapid deterioration in structural safety and material durability. Consequently, current standards have strict regulations on the chloride ion content in concrete, such as a 0.01% chloride ion limit in sand for prestressed concrete and a 0.06% limit for water-soluble chloride ions in colloids.

[0003] Therefore, chloride ion content needs to be measured during raw material production and construction to ensure building durability. Traditional methods for chloride ion detection are mainly potentiometric titration and X-ray fluorescence spectrometry (XRF). Potentiometric titration is based on the reaction between chloride ions and silver ions. The chloride ion solubility in the test solution can be calculated based on the concentration of the titrant and the volume of titrant consumed during the titration process. X-ray fluorescence spectrometry determines the chloride ion solubility in the sample by comparing the intensity of the sample's fluorescence radiation with the fluorescence radiation intensity of a standard sample of known solubility.

[0004] Deficiencies and reasons of traditional technology:

[0005] The problems of these two methods based on the detection principle are as follows:

[0006] ①It requires a complicated sample preparation process, and different samples require different processing methods, which is inconvenient to operate;

[0007] ② It takes a long time. A titration measurement may take several hours. Some types of concrete may even require more than 24 hours of processing time.

[0008] ③ It is impossible to measure in situ and can only be measured in the laboratory. The measurement results cannot be given in the construction scene;

[0009] ④ Only one type of particle can be detected each time. During the acceptance process, particles specified in other standards such as sulfate ions must be sampled and measured multiple times.

[0010] Laser-induced breakdown spectroscopy (LIBS) is a commonly used method for chloride ion detection. This method can achieve rapid, quantitative, and non-contact measurement of chloride ions. The advantages of this method are: no sample processing is required, the detection process is extremely fast, the detection conditions are friendly, on-site online measurement can be achieved, and all elements can be measured simultaneously.

[0011] However, the LIBS detection method has the following shortcomings and reasons:

[0012] The problem with the LIBS detection method is that its limit of quantification for chloride ions is low. This is due to two reasons: on the one hand, the intensity of the chloride ion spectral line is very weak, making it difficult to meet the detection limit requirements of current standards; on the other hand, concrete is highly heterogeneous, with many pores inside it, and the differences in the absorption efficiency of internal components for laser energy lead to poor repeatability of the test results.

[0013] Therefore, how to design a device and method for measuring chloride ions in concrete that can solve the problems of large quantitative errors and poor repeatability caused by weak chloride ion spectrum lines and heterogeneity of concrete has become a technical problem that needs to be solved urgently in this field. Summary of the Invention

[0014] The present invention aims to provide a device and method for measuring chloride ions in concrete. This device utilizes a femtosecond laser as the ablation light source, improving sample ablation efficiency and addressing the issue of weak chloride ion spectral lines. Furthermore, the device employs a clustering algorithm during the sampling process, addressing issues such as large quantitative errors and poor repeatability caused by concrete heterogeneity.

[0015] To achieve the above object, the present invention provides the following solutions:

[0016] In a first aspect, the present invention provides a device for measuring chloride ions in concrete, the device comprising: a first optical path system, a second optical path system, a spectrometer, and a central control unit.

[0017] The first optical path system includes:

[0018] Femtosecond laser, used to emit ablative femtosecond laser.

[0019] The ablation focusing lens group is used to focus the ablation femtosecond laser to obtain focused ablation femtosecond laser.

[0020] The sample is used to receive the focused ablation femtosecond laser to generate plasma.

[0021] The second optical path system includes:

[0022] A heating light source is used to emit heating laser.

[0023] The dichroic mirror is used to transmit the heating laser to obtain the transmitted heating laser.

[0024] The reflecting mirror is used to reflect the transmitted heating laser to obtain reflected heating laser.

[0025] The heating focusing lens group is used to focus the reflected heating laser to obtain focused heating laser, and irradiate the focused heating laser to the plasma to obtain plasma with enhanced spontaneous radiation intensity.

[0026] The heating and focusing lens group is also used to focus the spontaneous radiation of the plasma with enhanced spontaneous radiation intensity to obtain focused plasma spontaneous radiation.

[0027] The reflector is further used to reflect the focused plasma spontaneous radiation to obtain reflected plasma spontaneous radiation.

[0028] The dichroic mirror is further used to perform secondary reflection on the reflected plasma spontaneous radiation to obtain secondary reflected plasma spontaneous radiation.

[0029] The spectrometer is used to receive the plasma spontaneous radiation after the secondary reflection to obtain spectrum information.

[0030] The central control unit is used to perform cluster analysis on the spectral information to obtain the chloride ion content.

[0031] Optionally, the device further comprises:

[0032] The delay controller is connected to the femtosecond laser, the heating light source and the spectrometer respectively, and is used to provide system time and control the operation of the femtosecond laser, the heating light source and the spectrometer respectively.

[0033] Optionally, the first optical system and the second optical system are excited by using a dual light beam incident at an angle of 45°.

[0034] Optionally, the heating light source is a nanosecond laser with tunable wavelength.

[0035] In a second aspect, the present invention provides a method for measuring chloride ions in concrete based on the device for measuring chloride ions in concrete according to the first aspect, the method comprising:

[0036] An ablative femtosecond laser is irradiated on the sample to generate plasma.

[0037] A heating laser is irradiated on the plasma to obtain a plasma with enhanced spontaneous emission intensity.

[0038] Spectral information is obtained according to the spontaneous radiation of the plasma with enhanced spontaneous radiation intensity.

[0039] Cluster analysis is performed on the spectral information to obtain the chloride ion content.

[0040] Optionally, irradiating the sample with an ablative femtosecond laser to obtain plasma specifically includes:

[0041] The ablation femtosecond laser emitted by the femtosecond laser is focused by an ablation focusing lens group to obtain focused ablation femtosecond laser.

[0042] The focused ablation femtosecond laser is vertically irradiated onto the sample to generate plasma.

[0043] Optionally, irradiating the plasma with a heating laser to obtain a plasma with enhanced spontaneous radiation intensity specifically includes:

[0044] The heating laser emitted by the heating light source is transmitted through the dichroic mirror to obtain the transmitted heating laser.

[0045] The transmitted heating laser is reflected by a reflecting mirror to obtain reflected heating laser.

[0046] The reflected heating laser is focused by a heating focusing lens group to obtain a focused heating laser.

[0047] The heated laser is irradiated onto the plasma at an incident angle of 45° to obtain a plasma with enhanced spontaneous emission intensity.

[0048] Optionally, obtaining spectral information according to the spontaneous radiation of the plasma with enhanced spontaneous radiation intensity specifically includes:

[0049] The spontaneous radiation of the plasma with enhanced spontaneous radiation intensity is focused by a heating focusing lens group to obtain focused plasma spontaneous radiation.

[0050] The focused plasma spontaneous radiation is reflected by a reflecting mirror to obtain reflected plasma spontaneous radiation.

[0051] The reflected plasma spontaneous radiation is reflected twice by a dichroic mirror to obtain the twice-reflected plasma spontaneous radiation.

[0052] The plasma spontaneous radiation after the secondary reflection is collected and analyzed by a spectrometer to obtain spectral information.

[0053] Optionally, cluster analysis is performed on the spectral information to obtain the chloride ion content, specifically including:

[0054] Cluster analysis is performed on the spectral information to obtain the spectral intensity of chloride ions.

[0055] The chloride ion content is determined according to the relationship between the spectrum intensity of the chloride ions and the chloride ion content.

[0056] Optionally, the relationship between the spectral intensity of the chloride ion and the chloride ion content is:

[0057]

[0058] Where I is the spectral intensity of chloride ions, F is the system constant, C s is the chloride ion content, A is the corresponding energy level transition probability, g k is the energy level degeneracy, E k is the energy level, k B is the Boltzmann constant, T is the plasma temperature, and U(T) is the partition function of chloride ions at this temperature.

[0059] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0060] The present invention provides a device and method for measuring chloride ions in concrete. This device uses a femtosecond laser as an ablation light source to ablate the sample, quickly forming a plasma. This improves laser energy utilization, ablation efficiency, and the signal-to-noise ratio of chloride ion radiation. Simultaneously, a heating light source is used to irradiate the plasma, raising its temperature. The higher the plasma temperature, the stronger its radiation intensity. Furthermore, a clustering algorithm is employed during the sampling process to address issues such as large quantitative errors and poor repeatability caused by concrete heterogeneity. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0062] Figure 1 This is a schematic structural diagram of a device for measuring chloride ions in concrete provided in Example 1 of the present invention.

[0063] Figure 2 This is a schematic diagram of spectral signals at different times provided in Example 1 of the present invention.

[0064] Figure 3 Schematic diagram of the incident angle of the light path provided in Example 1 of the present invention.

[0065] Figure 4 This is a schematic diagram of the system structure provided in Example 1 of the present invention.

[0066] Figure 5 This is a flow chart of the measurement system provided in Example 1 of the present invention.

[0067] Figure 6 This is a schematic flow chart of a method for measuring chloride ions in concrete provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0068] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0069] The LIBS method is a spectral analysis method that detects the spontaneous radiation of plasma. The LIBS system first focuses the laser onto the sample surface through a converging optical path, causing it to absorb energy, forming a local energy absorption region with extremely high energy density. As the atoms absorb energy, they quickly evaporate to form vapor in a short period of time. The sample vapor continues to absorb heat or laser energy, eventually breaking down. This is when the electrons within the atoms absorb energy and escape, ionizing the atoms to form a plasma. When the plasma begins to cool, it radiates energy outward in the form of electromagnetic waves. Initially, this manifests as a high-intensity background spectrum, such as recombination radiation and bremsstrahlung. However, as the plasma temperature continues to decrease, electron energy level transitions begin to dominate, and the spectral signal appears as discrete ion lines, atomic lines, and molecular bands. By receiving and analyzing the signals with a spectrometer, the components and their contents within the sample can be determined. This is the measurement principle of LIBS.

[0070] The purpose of the present invention is to provide a device and method for measuring chloride ions in concrete, aiming to solve the problem of weak chloride ion spectrum lines and the problems of large quantitative errors and poor repeatability caused by the heterogeneity of concrete.

[0071] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0072] Example 1

[0073] like Figure 1 As shown, this embodiment provides a device for measuring chloride ions in concrete. The device has a cross common path optical structure and includes: a first optical path system, a second optical path system, a spectrometer, and a central control unit.

[0074] The first optical path system includes:

[0075] Femtosecond laser, used to emit ablative femtosecond laser.

[0076] The ablation focusing lens group is used to focus the ablation femtosecond laser to obtain focused ablation femtosecond laser.

[0077] The sample is used to receive the focused ablation femtosecond laser to generate plasma.

[0078] The second optical path system includes:

[0079] A heating light source is used to emit heating laser.

[0080] The dichroic mirror is used to transmit the heating laser to obtain the transmitted heating laser.

[0081] The reflecting mirror is used to reflect the transmitted heating laser to obtain reflected heating laser.

[0082] The heating focusing lens group is used to focus the reflected heating laser to obtain focused heating laser, and irradiate the focused heating laser to the plasma to obtain plasma with enhanced spontaneous radiation intensity.

[0083] The heating and focusing lens group is also used to focus the spontaneous radiation of the plasma with enhanced spontaneous radiation intensity to obtain focused plasma spontaneous radiation.

[0084] The reflector is further used to reflect the focused plasma spontaneous radiation to obtain reflected plasma spontaneous radiation.

[0085] The dichroic mirror is further used to perform secondary reflection on the reflected plasma spontaneous radiation to obtain secondary reflected plasma spontaneous radiation.

[0086] The spectrometer is used to receive the plasma spontaneous radiation after the secondary reflection to obtain spectrum information.

[0087] The central control unit is used to perform cluster analysis on the spectral information to obtain the chloride ion content.

[0088] It should be noted that the femtosecond laser forms plasma by emitting femtosecond laser pulses and focusing them on the sample surface; the heating light source enhances the intensity of the plasma's spontaneous radiation; the dichroic mirror can be used to ensure both the transmission of the heating light source beam and the reflection of the plasma's spontaneous radiation; the ablation focusing lens group and the heating focusing lens group focus the beam; Figure 1 The central control unit is not shown in the figure. Figure 4 .

[0089] The specific process is as follows:

[0090] The ablative femtosecond laser and the heating laser are incident at a wide angle. The ablative femtosecond laser passes through the ablative focusing lens assembly and is then perpendicularly irradiated onto the sample. The ablative focusing lens assembly ensures that the laser is well focused on the sample surface, vaporizing the sample in a short period of time. After a certain time interval, the heating laser irradiates the plasma at a specific wavelength to excite it, increasing the number of electrons in the upper energy level of the plasma and thus the intensity of the plasma's spontaneous radiation. The plasma's spontaneous radiation passes through the heating focusing lens assembly and is reflected by a reflector to the dichroic mirror. After being reflected by the dichroic mirror, it is received and analyzed by a spectrometer to determine the chloride ion content.

[0091] In this embodiment, the first optical system and the second optical system are excited by using a dual-beam incident at an angle of 45 degrees. The heating light source is a nanosecond laser with adjustable wavelength.

[0092] As an optional implementation provided by this embodiment, the device further includes:

[0093] The delay controller is connected to the femtosecond laser, the heating light source and the spectrometer respectively, and is used to provide system time and control the operation of the femtosecond laser, the heating light source and the spectrometer respectively.

[0094] The delay controller provides the system time. If the laser emission is taken as time 0, after the ablation laser breaks down the sample into plasma (about 150μs), it takes a certain period of time for the plasma to expand (about 1ns at this time). Then the heating laser is used to heat the plasma and increase the temperature, thereby increasing the spectral line intensity, achieving the purpose of improving sensitivity and reducing the detection limit. The plasma spectrum line takes a while to appear (about 10ns). At this time, the spectrometer starts to receive signals, which can improve the signal-to-noise ratio. Figure 2 shown.

[0095] The clustering algorithm is a data analysis algorithm that performs cluster analysis on the spectral information obtained during LIBS measurements. First, the spectral intensity of various known elements, such as calcium, aluminum, and sodium, is measured. After obtaining the spectral intensity distribution of these characteristic elements, components are set based on the corresponding spectral intensities of different elements, grouping sampling points with similar spectral intensities. Once the component parameters are set, the component information of the measured sampling point is determined to determine the specific structure of the sampling point in the concrete sample.

[0096] The relationship between the spectral intensity of chloride ions and the chloride ion content is:

[0097]

[0098] Where I is the spectral intensity of chloride ions, F is the system constant, C sis the chloride ion content, A is the corresponding energy level transition probability, g k is the energy level degeneracy, E k is the energy level, k B is the Boltzmann constant, T is the plasma temperature, and U(T) is the partition function of chloride ions at this temperature.

[0099] Similarly, other elements in a concrete sample will have similar spectral intensities, so the spectral information can be used to determine the corresponding elemental content. Different areas of concrete have different elemental contents, so the spectral information can be used to determine specific information about the sampling point. For example, areas with more pores have lower levels of each element, areas near aggregate (calcium carbonate) have higher carbon content, and areas near cement colloid (calcium silicate) have higher silicon and aluminum content.

[0100] For example, sampling points located near pores have a lower overall sample mass, resulting in lower spectral line intensities not only for chloride ions but also for elements like calcium, aluminum, and sodium. Meanwhile, sampling points near aggregates have a more pronounced calcium line, while the intensities of other elements like aluminum and sodium are relatively low. By assessing the properties of different sampling points, appropriate external standard models can be employed, improving the accuracy and repeatability of quantitative results.

[0101] This optical path structure has the following advantages:

[0102] (1) The light source uses a femtosecond laser as the ablation light source. The pulse width of the ablation femtosecond laser is shorter. At the femtosecond level, its interaction time with the sample is shorter than that of a general nanosecond laser. During the laser breakdown process, the plasma is formed approximately 150 picoseconds after the laser contacts the sample, while the ablation femtosecond laser ends its interaction with the sample before this time. There is no energy loss due to the shielding of the laser energy by the plasma, and it also avoids excessive bremsstrahlung due to the heating of the plasma. This method can improve the utilization efficiency of laser energy, improve the ablation efficiency, and improve the signal-to-noise ratio of chloride ion radiation.

[0103] (2) During the measurement process, the double beam is incident at a 45° angle for excitation. This refers to the angle between the heating laser and the ablation laser, that is, Figure 1 The angle between optical paths ① and ② in the image is 45°, which results in an appropriate area for the plasma to receive radiation and an appropriate energy density. This is because power density = laser energy / area. A larger area makes it easier for the spectrometer to receive the signal; however, increasing the area reduces the power density. Therefore, a balance between the two is necessary. The incident angle of the optical path is as follows: Figure 3 shown.

[0104] (3) Using a wavelength-tunable nanosecond laser as a heating light source, the plasma is irradiated to increase its temperature. The higher the plasma temperature, the stronger its radiation intensity. Different ions have different absorption peaks. By controlling the wavelength of the heating light source, the selective excitation of chloride ions is achieved. This method can increase the spectral line intensity of chloride ions and improve the signal-to-noise ratio.

[0105] (4) The signal collection optical path adopts a common path structure. The heating optical path and the plasma radiation optical path pass through the same components and paths to form a common path structure. The common path structure can eliminate chromatic aberration in the system and improve the signal collection angle of the spectrometer, solving the problem of too small numerical aperture when collecting optical fibers.

[0106] In specific applications, such as Figure 4 and Figure 5 As shown, before testing the chloride ion content of the sample to be tested, the sample group with known chloride ion content is calibrated and measured to establish a composite calibration model of different components. Calibration curves are established according to different concrete components, sampling points, etc., and the calibration results are recorded in the central control unit. The central control unit then divides the components according to the calibration results.

[0107] Since samples of different components absorb lasers of different intensities differently, the optimal laser intensity corresponding to the sample to be tested must be determined first to increase the radiation intensity of the plasma.

[0108] The sample translation stage controls the relative position of the sample within the measurement system through a transmission mechanism. Simultaneously, the intracavity illumination system illuminates the sample, and the imaging system locates the sampling point. The central control unit uses a clustering algorithm to estimate the composition of that sampling point. Based on the component information, the central control unit transmits the corresponding laser parameter information to the femtosecond laser and heating light source, respectively. The laser modulation system uses these parameters to adjust the femtosecond laser and heating light source to their respective optimal states. Simultaneously, the central control unit transmits the spectrometer acquisition information to the spectrometer's control system.

[0109] First, a femtosecond laser emits a femtosecond pulse, known as the ablation pulse. The moment the ablation pulse is emitted is the initial time of the system clock. The ablation pulse travels along optical path 1 through focusing system 1 and is focused onto the sample surface, causing the sample surface to absorb energy. The duration of the femtosecond laser pulse varies depending on the sampling point, but is generally around 10 fs system time. After the pulse ends, plasma is formed at approximately 100 ps system time.

[0110] The heating light source then emits a heating pulse after a delay, according to parameters assigned by the central control unit. The timing of the heating pulse varies depending on the sampling point, typically around 10 nanoseconds in system time. The heating pulse travels along optical path 2-1, passes through the spectrometer, and is focused by focusing system 2 along optical path 2 onto the plasma, heating it. During its evolution, the plasma continuously emits radiation. After absorbing the energy of the heating laser, its temperature rises, and its radiation increases. The plasma radiation is then reflected by the spectrometer along optical path 2 into optical path 2-2, arriving at the spectrometer's acquisition window.

[0111] Finally, according to the settings of the central control unit, the spectrometer opens the detector shutter after a delay and keeps it open for a period of time, continuously collecting radiation signals and recording them in the acquisition system. After the shutter closes, the collected spectral signals are accumulated and output. The spectral signal results are fed back to the central control unit, which retrieves the corresponding information from the external calibration database based on the component information of the sampling point, combines this information with the spectral signal results, and ultimately outputs the mass ratio of chlorine in the sample at that sampling point.

[0112] During the measurement, the air pressure in the sample chamber and the optical path can be adjusted, and helium is simultaneously input from inlet 1, inlet 2, and inlet 3 and output from the outlet pipe.

[0113] Example 2

[0114] like Figure 6 As shown, this embodiment provides a method for measuring chloride ions in concrete based on the chloride ion measuring device in concrete described in Example 1, the method comprising:

[0115] S1: Irradiate the sample with an ablative femtosecond laser to generate plasma.

[0116] S2: Irradiating the plasma with a heating laser to obtain a plasma with enhanced spontaneous emission intensity.

[0117] S3: Acquire spectrum information according to the spontaneous radiation of the plasma with enhanced spontaneous radiation intensity.

[0118] S4: performing cluster analysis on the spectral information to obtain chloride ion content.

[0119] As an optional implementation provided by this embodiment, in step S1, it specifically includes:

[0120] S11: focusing the ablation femtosecond laser emitted by the femtosecond laser through an ablation focusing lens group to obtain focused ablation femtosecond laser.

[0121] S12: irradiating the focused ablation femtosecond laser vertically onto the sample to obtain plasma.

[0122] As an optional implementation provided by this embodiment, in step S2, it specifically includes:

[0123] S21: transmitting the heating laser light emitted by the heating light source through the dichroic mirror to obtain the transmitted heating laser light.

[0124] S22: Reflecting the transmitted heating laser through a reflecting mirror to obtain reflected heating laser.

[0125] S23: focusing the reflected heating laser through a heating focusing lens group to obtain a focused heating laser.

[0126] S24: irradiating the heated laser light onto the plasma at an incident angle of 45° to obtain a plasma with enhanced spontaneous emission intensity.

[0127] As an optional implementation provided by this embodiment, in step S3, it specifically includes:

[0128] S31: focusing the spontaneous radiation of the plasma with enhanced spontaneous radiation intensity through a heating focusing lens group to obtain focused plasma spontaneous radiation.

[0129] S32: Reflecting the focused plasma spontaneous radiation through a reflector to obtain reflected plasma spontaneous radiation.

[0130] S33: The reflected plasma spontaneous radiation is subjected to secondary reflection by a dichroic mirror to obtain secondary reflected plasma spontaneous radiation.

[0131] S34: collecting and analyzing the plasma spontaneous radiation after the secondary reflection through a spectrometer to obtain spectral information.

[0132] As an optional implementation provided by this embodiment, in step S4, it specifically includes:

[0133] S41: performing cluster analysis on the spectral information to obtain the spectral intensity of chloride ions.

[0134] S42: Determine the chloride ion content according to a relationship between the spectral intensity of the chloride ions and the chloride ion content.

[0135] The relationship between the spectral intensity of the chloride ion and the chloride ion content is:

[0136]

[0137] Where I is the spectral intensity of chloride ions, F is the system constant, C s is the chloride ion content, A is the corresponding energy level transition probability, g k is the energy level degeneracy, E k is the energy level, k B is the Boltzmann constant, T is the plasma temperature, and U(T) is the partition function of chloride ions at this temperature.

[0138] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0139] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A device for measuring chloride ions in concrete, characterized in that: The device comprises: A first optical path system, a second optical path system, a spectrometer and a central control unit; The first optical path system includes: A femtosecond laser for emitting ablative femtosecond laser; an ablation focusing lens assembly, used for focusing the ablation femtosecond laser to obtain focused ablation femtosecond laser; A sample is used to receive the focused ablation femtosecond laser to generate plasma; The second optical path system includes: A heating light source, configured to emit a heating laser; the heating light source is a nanosecond laser with adjustable wavelength; a dichroic mirror, configured to transmit the heating laser light to obtain the transmitted heating laser light; a reflector, used to reflect the transmitted heating laser to obtain reflected heating laser; a heating focusing lens assembly, configured to focus the reflected heating laser light to obtain focused heating laser light, and irradiate the focused heating laser light onto the plasma to obtain a plasma with enhanced spontaneous radiation intensity; The heating and focusing lens group is further used to focus the spontaneous radiation of the plasma with enhanced spontaneous radiation intensity to obtain focused plasma spontaneous radiation; The reflector is further used to reflect the focused plasma spontaneous radiation to obtain reflected plasma spontaneous radiation; The dichroic mirror is further configured to perform secondary reflection on the reflected plasma spontaneous radiation to obtain secondary reflected plasma spontaneous radiation; The spectrometer is used to receive the plasma spontaneous radiation after the secondary reflection to obtain spectral information; The central control unit is configured to perform cluster analysis on the spectral information to obtain the chloride ion content, specifically comprising: performing cluster analysis on the spectral information to obtain the spectral intensity of the chloride ion; and determining the chloride ion content according to a relationship between the spectral intensity of the chloride ion and the chloride ion content; the relationship between the spectral intensity of the chloride ion and the chloride ion content is: Where I is the spectral intensity of chloride ions, F is the system constant, C s is the chloride ion content, A is the corresponding energy level transition probability, g k is the energy level degeneracy, E k is the energy level, k B is the Boltzmann constant, T is the plasma temperature, and U(T) is the partition function of chloride ions at this temperature; The first optical system and the second optical system are excited by using a dual-beam incident at a 45° angle to balance the area and power density; Before testing the chloride ion content of the sample to be tested, a calibration measurement is performed on the sample group with known chloride ion content to establish a composite calibration model for different components. Calibration curves are established according to different concrete components, sampling points, etc., and the calibration results are recorded in the central control unit. The central control unit then divides the components according to the calibration results.

2. A chloride ion measuring device in concrete according to claim 1, characterized in that: The device further comprises: The delay controller is connected to the femtosecond laser, the heating light source and the spectrometer respectively, and is used to provide system time and control the operation of the femtosecond laser, the heating light source and the spectrometer respectively.

3. A method for measuring chloride ions in concrete based on the chloride ion measuring device in concrete according to any one of claims 1 to 2, characterized in that: The method comprises: Irradiating the sample with an ablative femtosecond laser to generate plasma; irradiating the plasma with a heating laser to obtain a plasma with enhanced spontaneous emission intensity; acquiring spectral information according to the spontaneous radiation of the plasma with enhanced spontaneous radiation intensity; Cluster analysis is performed on the spectral information to obtain the chloride ion content, specifically including: Performing cluster analysis on the spectral information to obtain the spectral intensity of chloride ions; Determining the chloride ion content according to a relationship between the chloride ion spectral intensity and the chloride ion content; The relationship between the spectral intensity of the chloride ion and the chloride ion content is: Where I is the spectral intensity of chloride ions, F is the system constant, C s is the chloride ion content, A is the corresponding energy level transition probability, g k is the energy level degeneracy, E k is the energy level, k B is the Boltzmann constant, T is the plasma temperature, and U(T) is the partition function of chloride ions at this temperature.

4. The method for measuring chloride ions in concrete according to claim 3, wherein: The step of irradiating the sample with an ablative femtosecond laser to obtain plasma specifically includes: Focusing the ablation femtosecond laser emitted by the femtosecond laser through an ablation focusing lens group to obtain focused ablation femtosecond laser; The focused ablation femtosecond laser is vertically irradiated onto the sample to generate plasma.

5. The method for measuring chloride ions in concrete according to claim 3, wherein: The step of irradiating the plasma with a heating laser to obtain a plasma with enhanced spontaneous radiation intensity specifically includes: The heating laser emitted by the heating light source is transmitted through the dichroic mirror to obtain the transmitted heating laser; Reflecting the transmitted heating laser through a reflector to obtain reflected heating laser; Focusing the reflected heating laser through a heating focusing lens group to obtain focused heating laser; The heated laser is irradiated onto the plasma at an incident angle of 45° to obtain a plasma with enhanced spontaneous emission intensity.

6. The method for measuring chloride ions in concrete according to claim 3, wherein: Acquiring spectrum information according to the spontaneous radiation of the plasma with enhanced spontaneous radiation intensity, specifically comprising: focusing the spontaneous radiation of the plasma with enhanced spontaneous radiation intensity through a heated focusing lens group to obtain focused plasma spontaneous radiation; Reflecting the focused plasma spontaneous radiation through a reflector to obtain reflected plasma spontaneous radiation; Reflecting the reflected plasma spontaneous radiation for a second time through a dichroic mirror to obtain secondary reflected plasma spontaneous radiation; The plasma spontaneous radiation after the secondary reflection is collected and analyzed by a spectrometer to obtain spectral information.

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