CN111624194A - Blade element nondestructive measurement method based on laser-induced breakdown spectroscopy - Google Patents
Blade element nondestructive measurement method based on laser-induced breakdown spectroscopy Download PDFInfo
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Abstract
The invention provides a laser-induced breakdown spectroscopy-based blade element nondestructive measurement method, which establishes a calibration relation by utilizing natural distribution nonuniformity of element content in a blade, and comprises the following steps: obtaining leaves to be calibrated which are dried to constant weight, and preparing dry leaf samples; obtaining the spectral intensity value distribution of elements to be measured on the dry leaf specimen by a laser-induced breakdown spectroscopy technology, dividing the dry leaf specimen into N calibration areas according to the spectral intensity value, wherein each calibration area corresponds to one spectral intensity value; measuring the concentration of elements to be measured in each calibration area on the dry leaf specimen, and drawing a calibration curve with the abscissa as the concentration of the elements to be measured and the ordinate as the spectral intensity value according to the measurement result; obtaining the blade to be measured which is dried to constant weight, obtaining the spectral intensity value of the blade to be measured through a laser-induced breakdown spectroscopy technology, and obtaining the concentration of the element to be measured of the blade to be measured by contrasting a calibration curve. The method is suitable for simultaneously and nondestructively measuring various elements in the blade sample by laser-induced breakdown spectroscopy.
Description
Technical Field
The invention relates to the technical field of laser-induced breakdown spectroscopy analysis, in particular to a blade element nondestructive measurement method based on laser-induced breakdown spectroscopy.
Background
Laser-Induced Breakdown Spectroscopy (LIBS) is a technique for rapidly analyzing elements of a substance, a beam of short-pulse Laser light is focused by a lens and then ablates the surface of the substance to be detected to generate a micro plasma, and spectral signals radiated from the micro plasma and the intensity of the spectral signals are analyzed to determine the elements and the concentration of the elements. This analytical technique has a number of distinct advantages: the method has the advantages of no need of sample preparation, no damage, real-time and rapid detection, in-situ detection in site, simultaneous detection of multiple elements, various detection object forms and the like, and has wide application prospect. However, when the heavy metal of the leaf blade is actually measured, the technology is influenced by a sample matrix, a standard sample with similar matrix is usually difficult to find, and the calibration is difficult. And the heavy metal distribution of blade is inhomogeneous, in order to eliminate the influence, need to grind the back analysis with the sample, carry out the calibration based on the sample after grinding, consequently also need grind the sample in order to guarantee unanimously during the measurement, greatly reduced measuring speed. In order to eliminate or reduce the matrix effect, the currently adopted calibration methods mainly comprise an internal calibration method, a standard addition method and a free calibration method. The application of the methods promotes the development of the LIBS analysis technology, but the methods are only limited in the laboratory analysis and research stage, and some methods are complex in process and not beneficial to on-site on-line monitoring.
Disclosure of Invention
Based on the technical problems in the background art, the invention provides a blade element nondestructive measurement method based on laser-induced breakdown spectroscopy.
The invention provides a laser-induced breakdown spectroscopy-based blade element nondestructive measurement method, which comprises the following steps of:
s1, obtaining the leaves to be calibrated which are dried to constant weight, and preparing dry leaf samples;
s2, obtaining the spectral intensity value distribution of the elements to be measured on the dry leaf specimen through a laser-induced breakdown spectroscopy technology, and dividing the dry leaf specimen into N calibration areas according to the spectral intensity value, wherein each calibration area corresponds to one spectral intensity value;
s3, measuring the concentration of the element to be measured in each calibration area on the dry leaf specimen, and drawing a calibration curve with the abscissa as the concentration of the element to be measured and the ordinate as the spectral intensity value according to the measurement result;
s4, obtaining the blade to be measured dried to constant weight, obtaining the spectral intensity value of the blade to be measured through the laser-induced breakdown spectroscopy technology, and obtaining the concentration of the element to be measured of the blade to be measured by contrasting with the calibration curve.
Preferably, in step S3: and carrying out normalization processing on the spectral intensity value of each calibration area on the dry leaf specimen, and drawing a calibration curve according to the spectral intensity value after the normalization processing.
Preferably, in step S3, the model for normalizing the spectral intensity values is:
Preferably, step S4 specifically includes the following steps:
s41, selecting a calibration curve corresponding to the blade to be measured;
s42, selecting an alloy sample as a reference standard, and obtaining a spectral intensity value of the alloy sample in a dry leaf specimen measurement environment by a laser-induced breakdown spectroscopy technology;
s43, measuring the spectral intensity value of the blade to be measured and the spectral intensity value of the alloy sample in the same measuring environment through a laser-induced breakdown spectroscopy technology;
s44, carrying out normalization processing on the actually measured spectral intensity value of the blade to be measured, and correcting the spectral intensity value of the blade to be measured by combining the measurement results of the alloy sample in different environments to obtain a spectral intensity value correction value of the blade to be measured;
and S45, obtaining the content of the element to be measured of the blade to be measured according to the comparison result of the spectral intensity value correction value and the calibration curve.
Preferably, in step S44, the calculation model of the correction value of the spectral intensity value is:
Preferably, in step S41, the calibration curve obtained from the dry leaf specimen of the same type as the leaf to be measured is selected.
Preferably, in step S41, the method for selecting the calibration curve corresponding to the blade to be measured includes:
listing characteristic parameters influencing the slope of the breakdown spectrum line, and obtaining a neural network model taking the characteristic parameters as input and the slope of the breakdown spectrum line as output through sample training; and obtaining the spectral line slope of the blade to be measured through a neural network model, and selecting a calibration curve according to the spectral line slope.
Preferably, the neural network model is trained using a genetic-error back propagation neural network.
Preferably, the characteristic parameter comprises a base element content of the blade, the base element content comprising: C. one or more of H, O, N, P, S, Si, K, Mn.
According to the nondestructive measurement method for the blade elements based on the laser-induced breakdown spectroscopy, provided by the invention, the concentration of the elements to be measured is conveniently calibrated subsequently and directly according to the measured spectral intensity value of the blade to be measured by presetting the calibration curve, the blade to be measured does not need to be subjected to grinding, tabletting and other treatment, the field application of LIBS (laser induced breakdown spectroscopy) nondestructive measurement of the blade elements is realized, the nondestructive measurement method is suitable for simultaneously and nondestructively measuring various elements in a blade sample by using the laser-induced breakdown spectroscopy, overcomes the influence of different matrixes on quantitative analysis, and is suitable for field rapid.
Drawings
FIG. 1 is a flowchart of a nondestructive measurement method for blade elements based on laser-induced breakdown spectroscopy, which is provided in embodiment 1;
FIG. 2 is a flow chart of another nondestructive measurement method for blade elements based on laser-induced breakdown spectroscopy, which is provided in example 2.
Detailed Description
Example 1
Referring to fig. 1, the invention provides a blade element nondestructive measurement method based on laser-induced breakdown spectroscopy, which comprises the following steps.
And S1, obtaining the leaves to be calibrated which are dried to constant weight, and preparing dry leaf samples.
In specific implementation, the leaves are collected and then clamped in a grid specimen clamp to be dried to constant weight at 60 ℃, and a dry leaf specimen is prepared and stored in a sealing way, so that the leaf sample is kept flat while water is evaporated. Specifically, the grid specimen holder is made of polytetrafluoroethylene, can resist high temperature and does not influence the measurement of blade elements. The screen cloth of net specimen holder is more than 15 meshes, guarantees that the blade is indeformable after the stoving, and presss from both sides the blade back, and the centre has 0.5 cm's space, avoids pressing from both sides tightly to lead to the blade surface to have the net indentation.
S2, obtaining the distribution of the spectral intensity values of the elements to be measured on the dry leaf specimen through a laser-induced breakdown spectroscopy technology, and dividing the dry leaf specimen into N calibration areas according to the size of the spectral intensity values, wherein each calibration area corresponds to one spectral intensity value.
Specifically, when LIBS (laser induced breakdown spectroscopy) is used for scanning measurement, one pulse obtains one intensity value of an element to be measured, so that the spectral intensity value corresponding to each calibration region is the average value of a plurality of spectral intensity values obtained in the calibration region. And S3, measuring the concentration of the element to be measured in each calibration area on the dry leaf specimen, and drawing a calibration curve with the abscissa as the concentration of the element to be measured and the ordinate as the spectral intensity value according to the measurement result.
Specifically, in the step, the dry leaf specimen is cut according to the calibration area and then digested to obtain the concentration of the element to be detected. In this embodiment, N coordinate points are formed according to the spectral intensity values of the N calibration regions and the concentration of the element to be measured, and are used for drawing a calibration curve. Therefore, the larger the value of N is, the more the spectral intensity values are segmented, the more the marked areas are marked, and the more the finally obtained calibration curve is accurate. In the present embodiment, N is equal to or greater than 5.
S4, obtaining the blade to be measured dried to constant weight, obtaining the spectral intensity value of the blade to be measured through the laser-induced breakdown spectroscopy technology, and obtaining the concentration of the element to be measured of the blade to be measured by contrasting with the calibration curve.
Example 2
With respect to embodiment 1, in step S3 of the present embodiment: and carrying out normalization processing on the spectral intensity value of each calibration area on the dry leaf specimen, and drawing a calibration curve according to the spectral intensity value after the normalization processing.
Therefore, through the normalization processing of the spectral intensity value, the normalization correction of the spectral line is realized, and the influence of the change of system parameters and environmental conditions is favorably eliminated. In specific implementation, the fluctuation of laser energy, plasma temperature and the like can be used as external references, and the spectrum is subjected to normalization processing to improve the spectral measurement precision and the spectrum comparability
Specifically, the model for normalizing the spectral intensity values is as follows:
and S41, selecting a calibration curve corresponding to the blade to be measured.
During specific implementation, the calibration curve measured by the dry leaf specimen with the same type as the leaf to be measured is preferentially selected. Specifically, the same blade can be cut off along the central axis, and half of the blade is used as a dry blade sample for calculating a calibration curve and half of the blade is used as a blade to be measured. Therefore, the measurement of the same type of blades is facilitated according to the calibration curve, and the calibration curve can be verified through the measurement result of the blade to be measured.
The calibration curve can also be screened in the following manner.
Firstly, listing characteristic parameters influencing the slope of a breakdown spectrum line, and obtaining a neural network model taking the characteristic parameters as input and the slope of the breakdown spectrum line as output through sample training; and obtaining the spectral line slope of the blade to be measured through a neural network model, and selecting a calibration curve according to the spectral line slope.
The method for screening the calibration curve according to the characteristic parameters, provided by the embodiment, meets the calibration requirements of different blades to be tested, and is also beneficial to eliminating the influence of the same type of blades due to factors such as matrix effect.
Specifically, in this embodiment, the neural network model is trained by specifically using a genetic-error back propagation neural network. The characteristic parameters comprise the matrix element content of the blade, and the matrix element content comprises: C. one or more of H, O, N, P, S, Si, K, Mn.
And S42, selecting an alloy sample as a reference standard, and obtaining the spectral intensity value of the alloy sample in the dry leaf specimen measurement environment by using a laser-induced breakdown spectroscopy technology. Specifically, the alloy sample is selected from a type which is stable in properties and easy to store.
And S43, measuring the spectral intensity value of the blade to be measured and the spectral intensity value of the alloy sample in the same measuring environment through the laser-induced breakdown spectroscopy technology.
S44, carrying out normalization processing on the actually measured spectral intensity value of the blade to be measured, and correcting the spectral intensity value of the blade to be measured by combining the measurement results of the alloy sample in different environments to obtain a spectral intensity value correction value of the blade to be measured.
Specifically, the calculation model of the correction value of the spectral intensity value is as follows:
And S45, obtaining the content of the element to be measured of the blade to be measured according to the comparison result of the spectral intensity value correction value and the calibration curve.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention are equivalent to or changed within the technical scope of the present invention.
Claims (9)
1. A blade element nondestructive measurement method based on laser-induced breakdown spectroscopy is characterized by comprising the following steps:
s1, obtaining the leaves to be calibrated which are dried to constant weight, and preparing dry leaf samples;
s2, obtaining the spectral intensity value distribution of the elements to be measured on the dry leaf specimen through a laser-induced breakdown spectroscopy technology, and dividing the dry leaf specimen into N calibration areas according to the spectral intensity value, wherein each calibration area corresponds to one spectral intensity value;
s3, measuring the concentration of the element to be measured in each calibration area on the dry leaf specimen, and drawing a calibration curve with the abscissa as the concentration of the element to be measured and the ordinate as the spectral intensity value according to the measurement result;
s4, obtaining the blade to be measured dried to constant weight, obtaining the spectral intensity value of the blade to be measured through the laser-induced breakdown spectroscopy technology, and obtaining the concentration of the element to be measured of the blade to be measured by contrasting with the calibration curve.
2. The method for nondestructive measurement of blade element based on laser-induced breakdown spectroscopy as claimed in claim 1, wherein in step S3: and carrying out normalization processing on the spectral intensity value of each calibration area on the dry leaf specimen, and drawing a calibration curve according to the spectral intensity value after the normalization processing.
3. The method for nondestructive measurement of blade element based on laser-induced breakdown spectroscopy of claim 2 wherein in step S3, the model for normalization of the spectral intensity values is:
4. The laser-induced breakdown spectroscopy-based blade element nondestructive measurement method of claim 2, wherein the step S4 specifically comprises the steps of:
s41, selecting a calibration curve corresponding to the blade to be measured;
s42, selecting an alloy sample as a reference standard, and obtaining a spectral intensity value of the alloy sample in a dry leaf specimen measurement environment by a laser-induced breakdown spectroscopy technology;
s43, measuring the spectral intensity value of the blade to be measured and the spectral intensity value of the alloy sample in the same measuring environment through a laser-induced breakdown spectroscopy technology;
s44, carrying out normalization processing on the actually measured spectral intensity value of the blade to be measured, and correcting the spectral intensity value of the blade to be measured by combining the measurement results of the alloy sample in different environments to obtain a spectral intensity value correction value of the blade to be measured;
and S45, obtaining the content of the element to be measured of the blade to be measured according to the comparison result of the spectral intensity value correction value and the calibration curve.
5. The method for nondestructive measurement of blade element based on laser-induced breakdown spectroscopy of claim 4 wherein in step S44, the calculation model of the correction values of spectral intensity values is:
6. The method for nondestructive measurement of blade element based on laser-induced breakdown spectroscopy of claim 4 wherein in step S41, a calibration curve obtained by measuring a dry blade specimen of the same type as the blade to be measured is selected.
7. The method for nondestructive measurement of blade element based on laser-induced breakdown spectroscopy as claimed in claim 4, wherein in step S41, the method for selecting the calibration curve corresponding to the blade to be measured is as follows:
listing characteristic parameters influencing the slope of the breakdown spectrum line, and obtaining a neural network model taking the characteristic parameters as input and the slope of the breakdown spectrum line as output through sample training; and obtaining the spectral line slope of the blade to be measured through a neural network model, and selecting a calibration curve according to the spectral line slope.
8. The laser-induced breakdown spectroscopy-based blade element nondestructive measurement method of claim 7, wherein the neural network model is specifically trained using a genetic-error back propagation neural network.
9. The method of claim 7, wherein the characteristic parameter comprises a base element content of the blade, and the base element content comprises: C. one or more of H, O, N, P, S, Si, K, Mn.
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|---|---|---|---|---|
| CN112611745A (en) * | 2020-12-11 | 2021-04-06 | 华中科技大学 | Indirect nondestructive testing method and system for soluble solid matters of fruits |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102262076A (en) * | 2011-07-26 | 2011-11-30 | 清华大学 | Laser-induced breakdown spectroscopy element concentration determination method based on spectral line combination |
| US20170045459A1 (en) * | 2015-08-14 | 2017-02-16 | Bwt Property, Inc. | Laser Induced Breakdown Spectroscopy (LIBS) Apparatus for Analyzing Biological Samples |
| CN108333170A (en) * | 2018-03-27 | 2018-07-27 | 江南大学 | A method of based on lead element in laser induced breakdown spectroscopy quantitative analysis tealeaves |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102262076A (en) * | 2011-07-26 | 2011-11-30 | 清华大学 | Laser-induced breakdown spectroscopy element concentration determination method based on spectral line combination |
| US20170045459A1 (en) * | 2015-08-14 | 2017-02-16 | Bwt Property, Inc. | Laser Induced Breakdown Spectroscopy (LIBS) Apparatus for Analyzing Biological Samples |
| CN108333170A (en) * | 2018-03-27 | 2018-07-27 | 江南大学 | A method of based on lead element in laser induced breakdown spectroscopy quantitative analysis tealeaves |
Non-Patent Citations (1)
| Title |
|---|
| 孙海峰 等: "激光诱导击穿光谱与火焰光度法定量分析土壤钾元素含量", 《河南农业大学学报》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112611745A (en) * | 2020-12-11 | 2021-04-06 | 华中科技大学 | Indirect nondestructive testing method and system for soluble solid matters of fruits |
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