Detection method and system based on laser induced breakdown spectroscopy

Abstract

The present application provides a detection method and system based on laser induced breakdown spectroscopy, which includes: striking the sample to be detected with initial laser energy to determine the actual plasma temperature of the sample to be detected; adjusting the initial laser energy to the target laser energy according to the actual plasma temperature and the target plasma temperature; striking the sample to be detected multiple times with the target laser energy to obtain multiple spectra of the sample to be detected. This method adjusts the laser energy so that the plasma temperature of the sample to be detected remains consistent, reduces the influence of the matrix effect and improves the accuracy of the detection results without increasing the equipment cost or performing complex sample processing.

Description

Technical Field

[0001] The present application relates to the field of detection technology, and in particular to a detection method and system based on laser induced breakdown spectroscopy. Background Art

[0002] Component detection technology refers to the technology of qualitative and quantitative detection of the various components of the sample to be detected. Using component detection technology, the composition of the sample can be understood so that the sample can be further analyzed. For example, component detection technology can include laser induced breakdown spectroscopy.

[0003] Laser induced breakdown spectroscopy uses pulsed laser to focus on the surface of the sample to be tested to form plasma. By collecting the light radiation of the plasma, the characteristic wavelength and intensity of different elements in the sample are obtained, thereby achieving qualitative and quantitative detection of the sample. However, during the sample detection process, the physical and chemical properties of the sample may affect the characteristics of the plasma, thereby affecting the sample detection results. This phenomenon can also be called the matrix effect.

[0004] The industry usually uses data compensation to reduce the impact of matrix effects on test results. For example, plasma image signals can be used to compensate spectral signals, or spectral standardization and molecular spectral line compensation methods can be used to correct and compensate for the impact of matrix effects. However, due to the high complexity and strong nonlinearity of matrix effects, data compensation methods are difficult to achieve ideal results and cannot obtain accurate test results. Summary of the invention

[0005] The present application provides a detection method based on laser induced breakdown spectroscopy, which does not require additional equipment and operating costs, can reduce the influence of matrix effects, and thus improve the accuracy of the detection results. The present application also provides a system corresponding to the above method.

[0006] In a first aspect, the present application provides a detection method based on laser induced breakdown spectroscopy. The method comprises:

[0007] Hitting the sample to be detected with initial laser energy to determine the actual plasma temperature of the sample to be detected;

[0008] According to the actual temperature of the plasma and the target temperature of the plasma, adjusting the initial laser energy to the target laser energy;

[0009] The sample to be detected is struck multiple times with the target laser energy to obtain multiple spectra of the sample to be detected.

[0010] In some possible implementations, adjusting the initial laser energy to a target laser energy according to the actual plasma temperature and the target plasma temperature includes:

[0011] Determining a temperature difference between the actual plasma temperature and the target plasma temperature according to the actual plasma temperature and the target plasma temperature;

[0012] If the temperature difference satisfies a preset condition, the target laser energy is the initial laser energy;

[0013] If the temperature difference does not satisfy the preset condition, the initial laser energy is adjusted to a target laser energy based on the temperature difference.

[0014] In some possible implementations, if the temperature difference does not satisfy the preset condition, adjusting the initial laser energy to a target laser energy based on the temperature difference includes:

[0015] Based on the temperature difference, adjusting the initial laser energy to a first laser energy;

[0016] striking the sample to be detected with the first laser energy to determine a first actual temperature of the plasma of the sample to be detected;

[0017] Determining a first temperature difference between the first actual plasma temperature and the plasma target temperature according to the first actual plasma temperature and the plasma target temperature;

[0018] If the first temperature difference satisfies the preset condition, the target laser energy is the first laser energy;

[0019] If the first temperature difference does not satisfy the preset condition, the first laser energy is adjusted to a target laser energy based on the first temperature difference.

[0020] In some possible implementations, the preset condition includes that the absolute value of the temperature difference is less than the allowable temperature deviation.

[0021] In some possible implementations, adjusting the initial laser energy to a target laser energy based on the temperature difference includes:

[0022] Based on the temperature difference and the adjustment coefficient, an adjustment value of the laser energy is determined, and the target laser energy is the sum of the initial laser energy and the adjustment value of the laser energy.

[0023] In some possible implementations, striking the sample to be detected with the initial laser energy to determine the actual plasma temperature of the sample to be detected includes:

[0024] Hitting the sample to be detected with initial laser energy, and collecting an initial spectrum of the sample to be detected;

[0025] The actual plasma temperature of the sample to be detected is determined according to the initial spectrum.

[0026] In some possible implementations, the method of determining the actual temperature of the plasma of the sample to be detected based on the initial spectrum includes: Boltzmann plane method, two-line ratio method and Saha-Boltzmann plane method.

[0027] In some possible implementations, the sample to be detected includes a first sample and a second sample, the target laser energy of the first sample is a first target laser energy, and the method further includes:

[0028] The first target laser energy is used as the initial laser energy of the second sample to detect the second sample.

[0029] In some possible implementations, the sample to be detected is calibrated based on multiple spectra of the sample to be detected.

[0030] In a second aspect, the present application provides a detection system based on laser induced breakdown spectroscopy. The system comprises: a pulsed laser, a processor and a spectrometer;

[0031] The pulse laser is used to strike the sample to be detected with initial laser energy;

[0032] The processor is used to determine the actual temperature of the plasma of the sample to be detected;

[0033] The processor is further used to adjust the initial laser energy to a target laser energy according to the actual plasma temperature and the target plasma temperature;

[0034] The pulse laser is also used to strike the sample to be detected multiple times with the target laser energy;

[0035] The spectrometer is used to obtain multiple spectra of the sample to be detected.

[0036] In some possible implementations, the processor is specifically configured to:

[0037] Determining a temperature difference between the actual plasma temperature and the target plasma temperature according to the actual plasma temperature and the target plasma temperature;

[0038] If the temperature difference satisfies a preset condition, the target laser energy is the initial laser energy;

[0039] If the temperature difference does not satisfy the preset condition, the initial laser energy is adjusted to a target laser energy based on the temperature difference.

[0040] In some possible implementations, the processor is specifically configured to: adjust the initial laser energy to a first laser energy based on the temperature difference;

[0041] The pulse laser is also used to strike the sample to be detected with the first laser energy;

[0042] The processor is specifically used to: determine a first actual temperature of the plasma of the sample to be detected; determine a first temperature difference between the first actual temperature of the plasma and the target temperature of the plasma according to the first actual temperature of the plasma and the target temperature of the plasma; if the first temperature difference meets the preset condition, the target laser energy is the first laser energy; if the first temperature difference does not meet the preset condition, adjust the first laser energy to the target laser energy based on the first temperature difference.

[0043] In some possible implementations, the preset condition includes that the absolute value of the temperature difference is less than the allowable temperature deviation.

[0044] In some possible implementations, the processor is specifically configured to:

[0045] Based on the temperature difference and the adjustment coefficient, an adjustment value of the laser energy is determined, and the target laser energy is the sum of the initial laser energy and the adjustment value of the laser energy.

[0046] In some possible implementations, the spectrometer is further used to collect an initial spectrum of the sample to be detected;

[0047] The processor is specifically configured to determine the actual plasma temperature of the sample to be detected according to the initial spectrum.

[0048] In some possible implementations, the method of determining the actual temperature of the plasma of the sample to be detected based on the initial spectrum includes: Boltzmann plane method, two-line ratio method and Saha-Boltzmann plane method.

[0049] In some possible implementations, the sample to be detected includes a first sample and a second sample, the target laser energy of the first sample is a first target laser energy, and the pulse laser is further used to: use the first target laser energy as the initial laser energy of the second sample.

[0050] In some possible implementations, the system further includes:

[0051] The calibration device is used to calibrate the sample to be detected based on multiple spectra of the sample to be detected.

[0052] Based on the implementations provided in the above aspects, this application can also be further combined to provide more implementations.

[0053] Based on the above description, it can be seen that the technical solution of this application has the following beneficial effects:

[0054] Specifically, the method first hits the sample to be detected with an initial laser energy to determine the actual plasma temperature of the sample to be detected, then adjusts the initial laser energy to the target laser energy according to the actual plasma temperature and the target plasma temperature, and then hits the sample to be detected multiple times with the target laser energy to obtain multiple spectra of the sample to be detected. This method adjusts the laser energy so that the plasma temperature of the sample to be detected remains consistent, reduces the influence of the matrix effect, and improves the accuracy of the detection results without increasing the equipment cost or performing complex sample processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The above and other features, advantages and aspects of the embodiments of the present application will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and the originals and elements are not necessarily drawn to scale.

[0056] Figure 1 A schematic diagram of a process of a detection method based on laser induced breakdown spectroscopy provided in an embodiment of the present application;

[0057] Figure 2 A graph showing the average actual temperature change of plasma provided in the embodiments of the present application;

[0058] Figure 3 A schematic diagram of the linear relationship between spectral line intensity and element concentration provided in the embodiments of the present application. DETAILED DESCRIPTION

[0059] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present application. It should be understood that the drawings and embodiments of the present application are only for exemplary purposes and are not intended to limit the scope of protection of the present application.

[0060] The term "including" and its variations used herein are open inclusions, i.e., "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the following description.

[0061] It should be noted that the concepts such as "first" and "second" mentioned in this application are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0062] It should be noted that the modifications of "one" and "plurality" mentioned in the present application are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0063] In order to facilitate understanding of the technical solution of the present application, the specific application scenarios in the present application are described below.

[0064] Laser-induced breakdown spectroscopy (LIBS), also known as laser-induced plasma spectroscopy, refers to focusing a pulsed laser on the surface of a sample to be detected through a focusing mirror, so that the focused laser burns the sample surface to form a laser-induced plasma. The light radiation of the plasma is then collected by a spectrometer to obtain the characteristic wavelength and intensity (i.e., characteristic spectral line intensity) of different elements in the sample, thereby achieving qualitative and quantitative detection and analysis of the elemental composition of the sample to be detected.

[0065] LIBS has the advantages of full element analysis, simple sample preparation, safety, speed, and convenience for in-situ online measurement. It has wide application in many fields such as metallurgy, energy, chemical industry, geology, and environment. However, in the process of using LIBS for sample detection, the existence of matrix effect will affect the detection accuracy.

[0066] The matrix effect refers to the fact that the physical and chemical properties of the sample affect the properties of the plasma itself (such as temperature, electron density, etc.), thereby affecting the characteristic spectral line intensity of the elements in the sample, causing the relationship between the characteristic spectral line intensity and the element concentration to deviate from the theoretical linear relationship, thereby reducing the detection accuracy of LIBS.

[0067] For example, when detecting the carbon content in coal, even if the carbon content of two types of coal is exactly the same, if the content of other elements (such as calcium, silicon, and aluminum) in the two types of coal is different, it will cause significant differences in the temperature and electron density of the plasma, resulting in different characteristic spectral line intensities of the carbon element produced by the two types of coal, affecting the accuracy of the coal carbon content detection.

[0068] In response to the above problems, the industry usually uses sample pretreatment and data compensation to reduce the impact of matrix effects. Sample pretreatment includes vaporizing the sample into fine particles, smearing the sample on the substrate, etc. Data compensation includes using plasma image signals to compensate spectral signals, using spectral standardization, molecular spectral line compensation, multivariate regression, etc.

[0069] However, the sample pretreatment method has a complicated sample preparation process and cannot perform sample detection quickly and in real time. Due to the high complexity and strong nonlinearity of matrix effects, the data compensation method is also difficult to achieve ideal results.

[0070] Based on this, an embodiment of the present application provides a detection method based on laser induced breakdown spectroscopy. Specifically, the method first hits the sample to be detected with an initial laser energy to determine the actual plasma temperature of the sample to be detected, and then adjusts the initial laser energy to the target laser energy according to the actual plasma temperature and the target plasma temperature, and then hits the sample to be detected multiple times with the target laser energy to obtain multiple spectra of the sample to be detected. The method adjusts the laser energy so that the plasma temperature of the sample to be detected remains consistent, and reduces the influence of the matrix effect without increasing the equipment cost and without complicated processing of the sample, thereby improving the accuracy of the detection results.

[0071] Next, the detection method based on laser induced breakdown spectroscopy provided in the embodiments of the present application is described in detail with reference to the accompanying drawings.

[0072] See also Figure 1 The schematic diagram of the process of the detection method based on laser induced breakdown spectroscopy shown in FIG. 1 is a flow chart of the detection method based on laser induced breakdown spectroscopy, and the method specifically comprises the following steps:

[0073] S101: Hitting the sample to be detected with initial laser energy to determine the actual plasma temperature of the sample to be detected.

[0074] The initial laser energy may be preset by the tester. For example, the tester may set the initial laser energy based on the type of sample to be tested and combined with test experience. In the embodiment of the present application, the size of the initial laser energy is not limited.

[0075] Specifically, the sample to be detected is struck with initial laser energy, an initial spectrum of the sample to be detected is collected, and the actual plasma temperature of the sample to be detected is determined based on the initial spectrum.

[0076] Among them, when the sample to be detected is struck with the initial laser energy, since the energy density is relatively high after laser focusing, the sample to be detected can be excited to form a plasma, so that the spectrum of the sample to be detected (which can also be called the initial spectrum) can be collected, and then based on this spectrum, the actual temperature of the plasma of the sample to be detected is calculated and determined.

[0077] Furthermore, the actual temperature of the plasma of the sample to be detected can be determined by means of the Boltzmann plane method, the two-line ratio method, the Saha-Boltzmann plane method, etc. In the embodiments of the present application, there is no limitation on the method for determining the actual temperature of the plasma.

[0078] S102: Adjust the initial laser energy to the target laser energy according to the actual temperature of the plasma and the target temperature of the plasma.

[0079] Among them, the target temperature of the plasma can be preset by the tester. For example, the tester can set the target temperature of the plasma according to the type of the sample to be detected and combined with the detection experience. In some possible implementation manners, the target temperature of the plasma can be 5000K to 15000K. In the embodiments of the present application, there is no limitation on the magnitude of the initial laser energy.

[0080] Specifically, according to the actual temperature of the plasma and the target temperature of the plasma, the temperature difference between the actual temperature of the plasma and the target temperature of the plasma is determined. If the temperature difference meets the preset condition, the target laser energy is the initial laser energy; if the temperature difference does not meet the preset condition, based on the temperature difference, the initial laser energy is adjusted to the target laser energy.

[0081] It can be understood that the temperature difference between the actual temperature of the plasma and the target temperature of the plasma represents the gap between the actual temperature of the plasma and the target temperature under the current initial laser energy. Therefore, when the temperature difference meets the preset condition, it indicates that the initial laser energy can meet the requirements, and at this time, the target laser energy can be the initial laser energy. When the temperature difference does not meet the preset condition, it indicates that the initial laser energy cannot meet the requirements, and at this time, the laser energy can be adjusted according to the magnitude of the temperature difference.

[0082] In some possible implementation manners, the preset condition may include that the absolute value of the temperature difference is less than the temperature allowable deviation. For example, if the target temperature of the plasma is T0, the actual temperature of the plasma is T1, and the temperature allowable deviation is e, then the preset condition can be expressed as |T0 - T1| < e. Among them, the temperature allowable deviation can be preset by the tester. For example, the tester can set the temperature allowable deviation according to the type of the sample to be detected and combined with the detection experience. In some possible implementation manners, the temperature allowable deviation can be less than 500K. In the embodiments of the present application, there is no limitation on the magnitude of the temperature allowable deviation.

[0083] In some possible implementations, the adjustment value of the laser energy may be determined based on the temperature difference and the adjustment coefficient, and the target laser energy is the sum of the initial laser energy and the adjustment value of the laser energy.

[0084] For example, if the initial laser energy is E0, the target laser energy is E1, and the adjustment coefficient is k, the target laser energy can be expressed as E1=E0+k(T0-T1). The adjustment coefficient can be pre-set by the tester. For example, the tester can set the adjustment coefficient based on the type of sample to be tested and the test experience. In some possible implementations, the adjustment coefficient can be 10 -5 Up to 10 5 In the embodiment of the present application, the size of the adjustment coefficient is not limited.

[0085] Further, if the temperature difference does not meet the preset condition, based on the temperature difference, the initial laser energy is adjusted to the first laser energy, the sample to be detected is struck with the first laser energy, the first actual temperature of the plasma of the sample to be detected is determined, and the first temperature difference between the first actual temperature of the plasma and the target temperature of the plasma is determined according to the first actual temperature of the plasma and the target temperature of the plasma. If the first temperature difference meets the preset condition, the target laser energy is the first laser energy; if the first temperature difference does not meet the preset condition, the first laser energy is adjusted to the target laser energy based on the first temperature difference.

[0086] It is understandable that if the temperature difference does not meet the preset condition, the initial laser energy needs to be adjusted. First, the initial laser energy is adjusted to the first laser energy, and then the sample to be detected is struck with the first laser energy to determine the temperature difference at this time (i.e., the first temperature difference). If the temperature difference at this time still does not meet the preset condition, the first laser energy can be adjusted again.

[0087] Furthermore, if the preset conditions are still not met after the first laser energy is adjusted again, the adjusted first laser energy can be further adjusted, and then the steps of striking the sample to be detected, determining the actual temperature of the plasma, and determining the temperature difference are repeated until the temperature difference meets the preset conditions.

[0088] S103: Hitting the sample to be detected multiple times with target laser energy to obtain multiple spectra of the sample to be detected.

[0089] It can be understood that after the sample to be detected is struck multiple times with the target laser energy, the actual temperatures of multiple plasmas are close to the target plasma temperature, thereby directly reducing the influence of the matrix effect.

[0090] Further, when the sample to be detected includes a first sample and a second sample, and the target laser energy of the first sample is the first target laser energy, the first target laser energy is used as the initial laser energy of the second sample to detect the second sample.

[0091] That is to say, when there are multiple samples to be tested, after determining the target laser energy of the first sample, the target laser energy of the first sample can be used as the initial laser energy of the second sample to reduce the number of times the laser energy of the second sample is adjusted, thereby improving the overall detection efficiency.

[0092] Furthermore, the sample to be detected can be calibrated based on multiple spectra of the sample to be detected. For example, a single variable calibration model, a multivariate calibration model or a calibration-free model can be established based on multiple spectra of the sample to be detected to carry out calibration and prediction.

[0093] Below, the implementation effect of the detection method based on laser induced breakdown spectroscopy provided in the embodiments of the present application will be described with reference to specific examples.

[0094] In the specific example, the samples to be tested are 11 brass alloy samples, and the specific information is shown in Table 1.

[0095] Table 1

[0096]

[0097]

[0098] In a specific example, the plasma target temperature is set to 10000K, the temperature tolerance is 500K, the initial laser energy is 60mJ, and the number of hits for each sample to be detected is 50.

[0099] For the first sample, after being struck with an initial laser energy of 60 mJ, its initial spectrum was collected. Based on the four copper characteristic spectral lines (453.07 nm, 515.32 nm, 570.03 nm, and 578.21 nm) in its initial spectrum, the actual plasma temperature was determined to be 8457 K using the Boltzmann plane method.

[0100] At this time, the temperature difference between the actual plasma temperature and the target plasma temperature is 1543 K, which is greater than the allowable temperature deviation and does not meet the preset conditions. Therefore, the initial laser energy is adjusted.

[0101] Specifically, the adjustment coefficient is set to 0.01, and the adjusted first laser energy is 75.43 mJ. The first sample is hit again with the first laser energy. At this time, the first actual temperature of the plasma is 9433 K, and the first temperature difference is 567 K, which still does not meet the preset conditions. Therefore, the first laser energy is adjusted again, and the adjusted first laser energy (also called second laser energy) is 81.1 mJ.

[0102] The first sample is hit again with the second laser energy, and the second actual temperature of the plasma is 9846 K and the second temperature difference is 154 K, which meets the preset conditions. Therefore, the target laser energy corresponding to the first sample is the second laser energy.

[0103] The first sample was hit 50 times with the target laser energy, and 50 spectra of the first sample were obtained.

[0104] Next, the second sample was tested, and the target laser energy corresponding to the first sample (ie, 81.1 mJ) was used as the initial laser energy of the second sample, and similarly, 50 spectra of the second sample were obtained.

[0105] All 11 brass alloy samples were tested according to the above steps to obtain spectra of the 11 brass alloy samples.

[0106] like Figure 2 The average actual temperature change diagram of the plasma is shown. It can be seen that when the sample is tested by the traditional method of fixing the laser energy to 80mJ, the actual temperatures of the 11 plasmas vary from 9629K to 11968K, with a variation of 2339K. When the sample is tested by the method provided in the embodiment of the present application, the actual temperatures of the 11 plasmas are nearly consistent, ranging from 9819K to 10359K, with a variation of only 540K, which is significantly lower than that of the traditional method.

[0107] Furthermore, the actual plasma temperatures of each sample tend to be consistent, which can improve the linear relationship between the spectral line intensity and element concentration of each sample spectrum, thereby improving the accuracy of the detection results.

[0108] See also Figure 2 From the schematic diagram of the linear relationship between the spectral line intensity and the element concentration shown, it can be seen that when the sample is tested in the manner provided in the embodiment of the present application, the fitting effect of the spectral line intensity and the element concentration is better.

[0109] This method first hits the sample to be tested with initial laser energy to determine the actual plasma temperature of the sample to be tested, then adjusts the initial laser energy to the target laser energy according to the actual plasma temperature and the target plasma temperature, and then hits the sample to be tested multiple times with the target laser energy to obtain multiple spectra of the sample to be tested. This method adjusts the laser energy to keep the plasma temperature of the sample to be tested consistent, reduces the influence of the matrix effect and improves the accuracy of the test results without increasing the equipment cost or performing complex sample processing.

[0110] Based on the above method provided in the embodiment of the present application, the embodiment of the present application also provides a detection system based on laser induced breakdown spectroscopy corresponding to the above method. The system includes: a pulsed laser, a processor and a spectrometer.

[0111] Wherein, the pulse laser is used to strike the sample to be detected with initial laser energy;

[0112] A processor for determining an actual temperature of the plasma of the sample to be tested;

[0113] The processor is further used to adjust the initial laser energy to the target laser energy according to the actual temperature of the plasma and the target temperature of the plasma;

[0114] Pulsed lasers are also used to hit the sample to be tested multiple times with targeted laser energy;

[0115] A spectrometer is used to obtain multiple spectra of the sample to be tested.

[0116] In some possible implementations, the processor is specifically configured to:

[0117] Determining a temperature difference between the actual plasma temperature and the target plasma temperature according to the actual plasma temperature and the target plasma temperature;

[0118] If the temperature difference meets the preset conditions, the target laser energy is the initial laser energy;

[0119] If the temperature difference does not satisfy the preset condition, the initial laser energy is adjusted to the target laser energy based on the temperature difference.

[0120] In some possible implementations, the processor is specifically configured to: adjust the initial laser energy to the first laser energy based on the temperature difference;

[0121] The pulse laser is also used to strike the sample to be detected with the first laser energy;

[0122] The processor is specifically used to: determine a first actual temperature of the plasma of the sample to be detected; determine a first temperature difference between the first actual temperature of the plasma and the target temperature of the plasma according to the first actual temperature of the plasma and the target temperature of the plasma; if the first temperature difference meets a preset condition, the target laser energy is the first laser energy; if the first temperature difference does not meet the preset condition, the first laser energy is adjusted to the target laser energy based on the first temperature difference.

[0123] In some possible implementations, the preset condition includes that the absolute value of the temperature difference is less than the allowable temperature deviation.

[0124] In some possible implementations, the processor is specifically configured to:

[0125] Based on the temperature difference and the adjustment coefficient, the adjustment value of the laser energy is determined, and the target laser energy is the sum of the initial laser energy and the adjustment value of the laser energy.

[0126] In some possible implementations, the spectrometer is also used to collect an initial spectrum of the sample to be detected;

[0127] The processor is specifically used to determine the actual plasma temperature of the sample to be detected according to the initial spectrum.

[0128] In some possible implementations, the methods for determining the actual temperature of the plasma of the sample to be detected based on the initial spectrum include: the Boltzmann plane method, the two-line ratio method and the Saha-Boltzmann plane method.

[0129] In some possible implementations, the sample to be detected includes a first sample and a second sample, the target laser energy of the first sample is a first target laser energy, and the pulse laser is further used to: use the first target laser energy as the initial laser energy of the second sample.

[0130] In some possible implementations, the system further includes:

[0131] The calibration device is used to calibrate the sample to be detected based on multiple spectra of the sample to be detected.

[0132] Although the subject matter has been described in language specific to structural features and / or methodological logical actions, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. On the contrary, the specific features and actions described above are merely example forms of implementing the claims.

[0133] Although several specific implementation details are included in the above discussion, these should not be interpreted as limiting the scope of the present application. Certain features described in the context of a separate embodiment can also be implemented in a single embodiment in combination. On the contrary, the various features described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable sub-combination.

[0134] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of disclosure involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other to form a technical solution.

Claims

1. A detection method based on laser induced breakdown spectroscopy, characterized in that: The method comprises: For each of the multiple samples to be tested, perform the following steps: Hitting the sample to be detected with the initial laser energy corresponding to the sample to be detected, and determining the actual temperature of the plasma corresponding to the sample to be detected; According to the actual plasma temperature and the target plasma temperature corresponding to the sample to be detected, the initial laser energy corresponding to the sample to be detected is adjusted to the target laser energy; wherein the target plasma temperature is determined based on the type of the sample to be detected, and after the sample to be detected is struck with the target laser energy, the absolute value of the temperature difference between the actual plasma temperature corresponding to the sample to be detected and the target plasma temperature is less than the allowable temperature deviation; The target laser energy is used to strike the sample to be detected multiple times to obtain multiple spectra corresponding to the sample to be detected, so as to reduce the influence of the matrix effect on the sample to be detected.

2. The method according to claim 1, characterized in that The step of adjusting the initial laser energy corresponding to the sample to be detected to the target laser energy according to the actual plasma temperature and the target plasma temperature corresponding to the sample to be detected comprises: Determine the temperature difference between the actual plasma temperature corresponding to the sample to be detected and the target plasma temperature according to the actual plasma temperature corresponding to the sample to be detected and the target plasma temperature; If the temperature difference meets the preset condition, the target laser energy is the initial laser energy corresponding to the sample to be detected; If the temperature difference does not satisfy the preset condition, the initial laser energy corresponding to the sample to be detected is adjusted to the target laser energy based on the temperature difference.

3. The method according to claim 2, characterized in that If the temperature difference does not meet the preset condition, based on the temperature difference, adjusting the initial laser energy corresponding to the sample to be detected to the target laser energy includes: Based on the temperature difference, adjusting the initial laser energy corresponding to the sample to be detected to the first laser energy; Hitting the sample to be detected with the first laser energy to determine a first actual temperature of the plasma of the sample to be detected; Determining a first temperature difference between the first actual plasma temperature and the plasma target temperature according to the first actual plasma temperature and the plasma target temperature; If the first temperature difference satisfies the preset condition, the target laser energy is the first laser energy; If the first temperature difference does not satisfy the preset condition, the first laser energy is adjusted to a target laser energy based on the first temperature difference.

4. The method according to claim 2, characterized in that: The step of adjusting the initial laser energy corresponding to the sample to be detected to the target laser energy based on the temperature difference comprises: Based on the temperature difference and the adjustment coefficient, the adjustment value of the laser energy is determined, and the target laser energy is the sum of the initial laser energy corresponding to the sample to be detected and the adjustment value of the laser energy.

5. The method according to claim 1, characterized in that The step of striking the sample to be detected with the initial laser energy corresponding to the sample to be detected and determining the actual temperature of the plasma corresponding to the sample to be detected comprises: Hitting the sample to be detected with an initial laser energy corresponding to the sample to be detected, and collecting an initial spectrum corresponding to the sample to be detected; According to the initial spectrum corresponding to the sample to be detected, the actual temperature of the plasma corresponding to the sample to be detected is determined.

6. The method according to claim 5, characterized in that The method of determining the actual temperature of the plasma corresponding to the sample to be detected according to the initial spectrum corresponding to the sample to be detected includes: Boltzmann plane method, two-line ratio method and Saha-Boltzmann plane method.

7. The method according to claim 1, characterized in that The plurality of samples to be detected include a first sample and a second sample, the target laser energy of the first sample is a first target laser energy, and the method further includes: The first target laser energy is used as the initial laser energy of the second sample to detect the second sample.

8. The method according to claim 1, characterized in that The method further comprises: The sample to be detected is calibrated based on multiple spectra corresponding to the sample to be detected.

9. A detection system based on laser induced breakdown spectroscopy, characterized in that: The system includes: a pulse laser, a processor and a spectrometer; For each of the multiple samples to be tested: The pulse laser is used to strike the sample to be detected with the initial laser energy corresponding to the sample to be detected; The processor is used to determine the actual temperature of the plasma corresponding to the sample to be detected; The processor is further used to adjust the initial laser energy corresponding to the sample to be detected to the target laser energy according to the actual plasma temperature and the plasma target temperature corresponding to the sample to be detected; wherein the plasma target temperature is determined based on the type of the sample to be detected, and after the sample to be detected is struck with the target laser energy, the absolute value of the temperature difference between the actual plasma temperature corresponding to the sample to be detected and the plasma target temperature is less than the allowable temperature deviation; The pulse laser is also used to strike the sample to be detected multiple times with the target laser energy; The spectrometer is used to obtain multiple spectra corresponding to the sample to be detected, so as to reduce the influence of the matrix effect on the sample to be detected.

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