Boric acid solution concentration spectrum self-calibration measurement method and system using Raman spectroscopy

Abstract

The embodiment of the present application provides a method for self-calibration measurement of boric acid solution concentration spectrum using Raman spectroscopy. The method includes the following steps: obtaining a Raman spectrum of a solution at a specific concentration containing a Raman characteristic peak of a calibration object as a standard spectrum, wherein the calibration object is arranged in the optical path of the Raman spectroscopy system, and the calibration object is not in the solution to be tested; obtaining the original Raman measurement spectrum of the solution to be tested; based on the standard spectrum, obtaining the Raman scattered light intensity within a preset range around the characteristic peak position of the calibration object; calibrating the original Raman measurement spectrum based on the Raman scattered light intensity to obtain a Raman calibration spectrum; and obtaining the concentration of the solution to be tested based on the Raman calibration spectrum. Based on the method provided in the present application, the accuracy of the spectrum calibration can be improved, thereby further improving the accuracy of solution concentration detection.

Description

Technical Field

[0001] The present application relates to the technical field of concentration measurement, and in particular to a method and system for self-calibration measurement of boric acid solution concentration spectrum using Raman spectroscopy. Background Art

[0002] Since the intensity of the characteristic peak in the Raman spectrum of a substance is closely related to the concentration of the substance, it is theoretically feasible to use Raman spectroscopy to quantitatively detect the concentration of a substance. The intensity of the theoretically calculated surface Raman scattering signal is a function of the substance concentration, the frequency of the incident light, and the intensity of the incident light. The relationship between them can be expressed by the following function:

[0003]

[0004] in is the incident laser intensity, is the number of scattered molecules, Generally speaking, when the intensity of the excitation light and the temperature are constant, there is a proportional linear relationship between the intensity of the Raman scattered light and the number of scattered molecules. Therefore, the industry often uses Raman spectroscopy to fit and calibrate the concentration of substances based on this linear relationship to detect the concentration of substances.

[0005] However, in practical applications, due to the extremely high sensitivity of Raman spectroscopy, the spectral signal intensity and peak position are affected by factors such as ambient temperature, circuit system, CCD type, interaction between chemical substances in solution, solution flow rate, laser power fluctuation, vibration, etc., resulting in the actual tested Raman spectrum being affected by these factors and presenting the problem of spectral intensity fluctuation. This spectral intensity fluctuation causes even solutions of the same concentration to present spectra with different intensity changes. This intensity change seriously affects the accuracy of quantitative detection based on spectral intensity. Therefore, it is generally believed that Raman spectroscopy is difficult to use as an accurate quantitative detection of substance concentration, and is more used for semi-quantitative detection. In order to improve the accuracy of quantitative detection of substance concentration in solution using Raman spectroscopy, it is necessary to process the original Raman spectrum obtained by the test. During the data processing process, the measured spectra at different times and different substance concentrations are calibrated to avoid the problem of spectral intensity offset caused by laser power changes, system errors, etc.

[0006] There are generally two ways of calibration. One is to use the Raman characteristic peaks of the inherent substances in the solution as a reference, such as the Raman characteristic peaks of the solvent. This method is also called the internal standard method. The other is to use the Raman characteristic peaks of external substances as a reference. This method is also called the external standard method. When the internal standard method is used to calibrate the Raman spectrum, the concentration of the substance at low concentrations does not have a significant effect on the solvent, and the calibration error is small. However, if the concentration of the substance is high, the concentration of the substance has a significant effect on the intensity of the characteristic peaks of the Raman spectrum of the solvent. At this time, the calibration error is large. When the external standard method is used to calibrate the spectrum, it is necessary not only to consider the impact of environmental changes on the spectrum during the measurement process, but also to consider the impact of the introduced external substances on the solution. Therefore, there has been no suitable Raman spectrum calibration solution in actual engineering applications. Summary of the invention

[0007] The purpose of the present application is to provide a technical solution to calibrate the Raman spectrum, thereby solving the problem of inaccurate quantitative detection of solution concentration by the Raman spectrum detection method in the related art.

[0008] Based on the above purpose, the embodiment of the present application provides a self-calibration measurement method of boric acid solution concentration spectrum using Raman spectroscopy. The self-calibration measurement method uses a Raman spectroscopy system to perform quantitative concentration detection on the solution to be tested. The method includes the following steps:

[0009] A Raman spectrum of a solution at a specific concentration containing a Raman characteristic peak of a calibration object is obtained as a standard spectrum, wherein the calibration object is arranged in the optical path of the Raman spectroscopy system, and the calibration object is not in the solution to be tested;

[0010] Obtaining the original Raman measurement spectrum of the solution to be tested;

[0011] Based on the standard spectrum, the Raman scattered light intensity within a preset range around the characteristic peak position of the calibration object is obtained;

[0012] The original Raman measurement spectrum is calibrated based on the Raman scattered light intensity to obtain a Raman calibration spectrum;

[0013] The concentration of the solution to be tested is obtained based on the Raman calibration spectrum.

[0014] Furthermore, the method also includes:

[0015] Set the pixel interval so that the characteristic peak of the calibration object is located within the pixel interval;

[0016] Obtaining a standard value, where the standard value is the Raman scattering light intensity within a pixel interval calculated at any solution concentration;

[0017] Obtaining a reference value, where the reference value is the Raman scattering light intensity within a pixel interval calculated at other solution concentrations;

[0018] The ratio between the standard value and the reference value is calculated to obtain calibration data, and the original Raman measurement spectrum at the corresponding solution concentration is calibrated based on the calibration data.

[0019] Furthermore, both the standard spectrum and the original Raman measurement spectrum are spectra without baseline correction.

[0020] The present application also provides a boric acid solution concentration spectrum self-calibration and measurement system using Raman spectroscopy, the system comprising:

[0021] Calibration object, Raman detection unit and signal processing unit;

[0022] The calibration object is arranged in the optical path of the Raman detection unit, and the calibration object is not in the solution to be tested;

[0023] The Raman detection unit adopts a Raman spectrum detection method to obtain a Raman spectrum of a solution at a specific concentration containing a Raman characteristic peak of a calibration substance as a standard spectrum. The Raman detection unit is also used to detect the solution to be tested to obtain an original Raman measurement spectrum.

[0024] The signal processing unit obtains the Raman scattered light intensity within a preset range around the characteristic peak position of the calibration object based on the standard spectrum, and calibrates the original Raman measurement spectrum based on the Raman scattered light intensity to obtain the Raman calibration spectrum. The signal processing unit also obtains the concentration of the solution to be tested based on the Raman calibration spectrum.

[0025] Furthermore, the calibration object is a device in the Raman detection unit that is capable of exciting Raman light;

[0026] Alternatively, the calibration object is a device capable of exciting Raman light inserted between the Raman detection unit and the solution to be tested.

[0027] Furthermore, a material for an observation window is selected as a calibration object, and the observation window is arranged on a pipe through which the solution to be tested flows, and the observation window is used for the Raman spectroscopy system to irradiate a light beam to the solution to be tested.

[0028] Furthermore, the material used for the observation window is one of quartz, sapphire, zinc sulfide, zinc selenide, and calcium fluoride.

[0029] Furthermore, the wave number difference between the Raman characteristic peak of the calibration object and the Raman characteristic peak of the solution to be tested is greater than or equal to 10 cm -1 , and, less than 1000 cm -1 .

[0030] Furthermore, both the standard spectrum and the original Raman measurement spectrum are spectra without baseline correction.

[0031] According to the above description, in the self-calibration measurement method of boric acid solution concentration spectrum using Raman spectroscopy provided in the embodiment of the present application, by selecting an object other than the solution to be tested as a calibration object, the influence of the introduction of the calibration object on the solution to be tested is avoided, and the calibration object is not affected by factors such as the concentration and flow rate of the solution to be tested. The method provided in the embodiment of the present application uses the Raman scattering light intensity at the characteristic peak position of the calibration object as a reference for calibration, which can avoid the problem of calibration error caused by signal fluctuations caused by noise in the signal intensity under a single pixel, thereby making the quantitative concentration detection of the solution to be tested using the Raman spectroscopy system more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A flow chart of a spectral self-calibration measurement method for solution concentration provided in an embodiment of the present application;

[0033] Figure 2 A schematic diagram of an uncalibrated raw Raman measurement spectrum provided by an embodiment of the present application;

[0034] Figure 3 for Figure 2 Schematic diagram of the calibrated spectrum;

[0035] Figure 4 A schematic diagram of a spectrum before calibration of a repeatability test spectrum provided in an embodiment of the present application;

[0036] Figure 5 for Figure 4 Schematic diagram of the spectrum after calibration;

[0037] Figure 6 A schematic diagram of the model error obtained after training with spectral samples without baseline subtraction and after baseline subtraction provided in an embodiment of the present application;

[0038] Figure 7 Schematic diagram of a solution concentration measurement system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The present application will be described in detail below in conjunction with the specific implementation modes shown in the accompanying drawings, but these implementation modes do not limit the present application. Structural, methodological, or functional changes made by ordinary technicians in the field based on these implementation modes are included in the protection scope of the present application.

[0040] like Figure 1As shown, the embodiment of the present application provides a spectral self-calibration measurement method for measuring the concentration of a solution using Raman spectroscopy (hereinafter referred to as the self-calibration measurement method). The self-calibration measurement method uses a Raman spectroscopy system to perform quantitative concentration detection on the solution to be measured. The solution to be measured can be a boric acid solution. Using the method provided by the present application, the concentration of the boric acid solution of the pressurized water reactor neutron-free radiation source can be quantitatively detected. The self-calibration measurement method includes the following steps:

[0041] Step S1, obtaining a Raman spectrum of a solution at a specific concentration containing a Raman characteristic peak of a calibration object as a standard spectrum, wherein the calibration object is arranged in the optical path of the Raman spectroscopy system, and the calibration object is not in the solution to be tested;

[0042] Step S2, obtaining the original Raman measurement spectrum of the solution to be tested;

[0043] Step S3, calibrating the original Raman measurement spectrum based on the standard spectrum to obtain a Raman calibration spectrum;

[0044] Step S4: obtaining the concentration of the solution to be tested based on the Raman calibration spectrum.

[0045] According to the above description, in the self-calibration measurement method provided in the embodiment of the present application, by selecting an object other than the solution to be tested as a calibration object, the influence of the introduction of the calibration object on the solution to be tested is avoided, and the calibration object is not affected by factors such as the concentration and flow rate of the solution to be tested. Therefore, the Raman characteristic peak of the calibration object is only affected by environmental factors, laser power fluctuations and system errors. The self-calibration measurement method provided in the embodiment of the present application uses the characteristic Raman spectrum of the calibration object as the standard spectrum and uses the standard spectrum to calibrate the original Raman measurement spectrum, which can eliminate the influence of environmental factors, laser power fluctuations and system errors, so that the quantitative concentration detection of the solution to be tested using the Raman spectroscopy system is more accurate.

[0046] As an optional implementation, the self-calibration measurement method provided in the embodiment of the present application also includes the selection of a calibration object. A device that can excite Raman light in the Raman spectroscopy system can be selected as the calibration object, or a device that can excite Raman light can be inserted between the Raman spectroscopy system and the solution to be measured, and the device can be used as the calibration object.

[0047] Specifically, in a Raman spectroscopy system, a light source emits a light beam, which passes through a number of optical devices and is focused onto a solution to be tested, and Raman scattered light is excited at the solution to be tested, and the Raman scattered light is finally received by a detector in the Raman spectroscopy system, thereby obtaining a Raman spectrum. From the light source to the solution to be tested, there may be some devices that can also excite Raman light. In the related art, these Raman lights excited by the devices are generally regarded as stray light, and will not be considered for application during the test process. Even in the design and construction of the Raman spectroscopy system, optical devices with Raman activity are avoided as much as possible to avoid interference with the Raman signal of the substance to be detected. However, in the present application, the original Raman-active optical device in the system when exciting the Raman spectrum of the solution is specially selected as a calibration object. The spectral signal of the calibration object is usually regarded as a stray light signal, but it will not be affected by factors such as solution concentration and flow rate, which can make the spectrum calibration more accurate.

[0048] In addition, the original optical device in the Raman spectroscopy system is used as a calibration object. The structural parameters and optical parameters of the calibration object are fixed, which is more convenient for spectral calibration. Moreover, this method does not require the introduction of additional optical devices, so there is no need to consider the installation of the device when introducing additional calibration objects. This solution is low in cost and easy to operate.

[0049] It is easy to understand that in addition to using the original optical devices in the Raman spectroscopy system as calibration objects, a substance with Raman activity can be inserted between the Raman spectroscopy system and the solution to be tested as a calibration object. In this way, the accurate calibration of the Raman spectrum can also be achieved.

[0050] As an optional implementation, in an embodiment of the present application, the calibration object is placed close to the solution to be tested and is located near the focus of the light beam emitted by the Raman spectroscopy system.

[0051] As an optional implementation method, in the embodiment of the present application, the material for the observation window is selected as the calibration object. It should be noted that the observation window is arranged on the pipeline through which the solution to be tested circulates, and the light beam emitted by the Raman spectroscopy system is focused by the optical device and then irradiated to the solution to be tested through the observation window. It is easy to understand that the focus of the light beam emitted by the Raman spectroscopy system is located at the solution to be tested. Therefore, in the overall optical path of the Raman spectroscopy system, the position of the observation window is closest to the focus of the light beam, the observation window can obtain the maximum excitation energy, and the Raman light excited by the observation window is more stable. Therefore, in the embodiment of the present application, the observation window is specially selected as the calibration object, which is conducive to the calibration of the spectrum.

[0052] As an optional implementation, the wave number difference between the Raman characteristic peak of the calibration object and the Raman characteristic peak of the solution to be tested is greater than or equal to 10 cm -1In this way, it can be ensured that there is a significant difference between the Raman characteristic peak of the optical device used as the calibration object and the Raman characteristic peak of the substance to be detected, thereby avoiding interference with the Raman signal of the substance to be detected.

[0053] As an optional implementation method, the wave number difference between the Raman characteristic peak of the calibration object and the Raman characteristic peak of the solution to be tested should be less than 1000 cm -1 In this way, it is possible to avoid a large difference between the Raman characteristic peaks of the calibration object and the Raman characteristic peaks of the substance to be detected.

[0054] According to the above description, the wave number difference between the Raman characteristic peak of the calibration object and the Raman characteristic peak of the test solution should be greater than or equal to 10 cm -1 , and, less than 1000 cm -1 In this way, it can be ensured that there is an appropriate deviation between the optical device used for calibration and the Raman characteristic peak of the substance to be detected, thereby avoiding error problems when other photophysics are introduced (such as fluorescence effect). Taking the fluorescence effect as an example, if the two Raman characteristic peaks are not much different, then the changes of the two Raman characteristic peaks are linear. If the difference is large, there is a nonlinear factor between the changes of the two Raman characteristic peaks. Therefore, through the above settings, the optical device selected for calibration should have an appropriate deviation from the Raman characteristic peak of the substance to be detected, which can avoid error problems when other photophysics are introduced.

[0055] As an optional implementation, in the self-calibration measurement method provided in the embodiment of the present application, step S3 further includes:

[0056] Based on the standard spectrum, the Raman scattered light intensity at the characteristic peak position of the calibration object is obtained;

[0057] The raw Raman measurement spectrum is calibrated based on the Raman scattered light intensity.

[0058] Specifically, the following steps are included:

[0059] Step S31, setting a pixel interval, wherein a characteristic peak of the calibration object is located within the pixel interval;

[0060] Step S32, obtaining a standard value, where the standard value is the Raman scattering light intensity within a pixel interval calculated at any solution concentration;

[0061] Step S33, obtaining a reference value, where the reference value is the Raman scattering light intensity within a pixel interval calculated at other solution concentrations;

[0062] Step S34: Calculate the ratio between the standard value and the reference value to obtain calibration data, and calibrate the original Raman measurement spectrum at the corresponding solution concentration based on the calibration data.

[0063] Specifically, Figure 2 As shown, it shows a schematic diagram of the uncalibrated original Raman measurement spectrum. In the embodiment of the present application, a laser with the same excitation power is selected to excite the Raman spectrum of solutions containing different substance concentrations, and the same integration time and number of integration times are selected during the excitation process. The lens or window material on the light path generated by the excitation of the solution Raman spectrum is used as a calibration object, and the spectral integral area of ​​the Raman characteristic peak of the calibration object in the preset pixel interval is calculated, and the characteristic peak integral value of the calibration object is used as the standard value. According to the standard value, the integral value of the preset pixel interval in the Raman spectrum under other solution concentrations is compared, and the signal intensity at other positions of the spectrum is calibrated using the ratio as the calibration data, and finally the calibrated Raman spectrum is obtained. The calibrated spectral curve is shown in Figure 3 As shown. Figure 3 , the present application can achieve high-sensitivity solution concentration detection of 35ppm.

[0064] It should be noted that the Raman scattered light intensity is expressed as the integrated area of ​​the spectrum within a pixel interval in the Raman spectrum. In the self-calibration measurement method provided in the embodiment of the present application, the Raman scattered light intensity at the characteristic peak position of the calibration object is used as a reference for calibration. This calibration method is different from the method of using the signal intensity of a single pixel point on the detector as a reference for calibration in the traditional calibration method. It can avoid the problem of calibration error caused by signal fluctuations caused by noise in the signal intensity under a single pixel, which is conducive to deducting the deviation caused by system performance fluctuations, making the calibration more accurate, and improving the spectral stability and repeatability of the calibration.

[0065] In order to further illustrate the self-calibration measurement method provided in the embodiment of the present application, the present application also performs multiple tests on the substances in the stable solution, that is, multiple tests are performed on the solution with the same concentration at different times. Figure 4 and Figure 5 It can be seen that the Raman spectrum calibrated by this method can show very good consistency at low solution concentration (below 50 ppm), which proves that the stability and repeatability of the Raman test spectrum calibrated by this method have been greatly improved.

[0066] In addition, in the self-calibration measurement method provided in the embodiment of the present application, the standard spectrum and the original Raman measurement spectrum can be smoothed in advance, but neither the standard spectrum nor the original Raman measurement spectrum is baseline corrected, nor is a differential calculation performed, and only the integral area of ​​the spectrum within the pixel interval is calibrated. In this way, the influence of data processing during spectrum calibration on the information contained in the original Raman spectrum can be avoided, and the detection accuracy of the subsequent concentration prediction model can be ensured.

[0067] Specifically, Figure 6As shown in the figure, it shows the model error diagram obtained after training with spectral samples without baseline subtraction and after baseline subtraction, where the horizontal axis represents the predicted sample concentration, and the vertical axis represents the mean value and error range of the sample concentration predicted by the training model. The center point on the line represents the predicted mean concentration, the upper and lower error bars represent the error range of the predicted concentration, and the spacing size represents the size of the error. Figure 6 It can be seen that under low concentration conditions (the concentration of the boric acid solution to be tested is lower than 700 mg / L), the predicted concentration error of the model obtained after training using the spectral samples after baseline subtraction is significantly greater than that without baseline subtraction. According to the above description, in the embodiment of the present application, during the process of spectral self-calibration, the spectral data of the spectral training samples and the test samples are not subjected to baseline subtraction processing, thereby reducing the predicted concentration error of the concentration prediction model under low concentration conditions and improving the detection accuracy of the concentration prediction model.

[0068] like Figure 7 As shown, as an optional implementation, the embodiment of the present application also provides a solution concentration measurement system 100, and the measurement system 100 applies the self-calibration measurement method provided in the embodiment of the present application. Specifically, the measurement system 100 includes: a calibration object 11, a Raman detection unit 12 and a signal processing unit 13;

[0069] The calibration object 11 is disposed in the optical path of the Raman detection unit 12, and the calibration object 11 is not in the solution to be tested;

[0070] The Raman detection unit 12 detects the calibration object 11 using a Raman spectrum detection method to obtain a standard spectrum. The Raman detection unit 12 is also used to detect the solution to be tested to obtain an original Raman measurement spectrum.

[0071] The signal processing unit 13 calibrates the original Raman measurement spectrum based on the standard spectrum to obtain a Raman calibration spectrum. The signal processing unit 13 also obtains the concentration of the solution to be measured based on the Raman calibration spectrum.

[0072] According to the above description, in the solution concentration measurement system 100 provided in the embodiment of the present application, an object other than the solution to be measured is used as the calibration object 11, thereby avoiding the influence of the introduction of the calibration object 11 on the solution to be measured, making the calibration more accurate.

[0073] As an optional implementation, the calibration object 11 is a device capable of stimulating Raman light that is originally in the Raman detection unit 12; or, the calibration object 11 is a device capable of stimulating Raman light that is inserted between the Raman detection unit 12 and the solution to be tested.

[0074] Specifically, in the embodiment of the present application, the Raman spectrum of the native substance on the Raman spectrum excitation light path is used as the calibration peak of the calibration object 11, especially the observation window of the solution pool on the light path, the lens material on the light path, etc. Through this setting, the stability of the external standard spectrum peak and the convenience of testing can be taken into account.

[0075] As an optional implementation, the wave number difference between the Raman characteristic peak of the calibration object 11 and the Raman characteristic peak of the solution to be tested is greater than or equal to 10 cm -1 , and, less than 1000 cm -1 .

[0076] It is easy to understand that the wave number of the characteristic peak of the calibration object 11 is related to the material of the calibration object 11. In the embodiment of the present application, taking the detection of boron solution as an example, the Raman characteristic peak of the calibration object 11 is at 300 cm -1 To 3000 cm -1 For example, sapphire can be used as the observation window material. In this way, high-precision solution concentration measurement below 100ppm and within an error of 15ppm can be achieved. It should be noted that in addition to sapphire as the observation window material, when facing boron solution detection, one of titanium oxide, gallium phosphide, quartz, zinc sulfide, zinc selenide, calcium fluoride, etc. can also be selected.

[0077] As an optional implementation, the signal processing unit 13 obtains the Raman scattered light intensity at the characteristic peak position of the calibration object 11 based on the standard spectrum, and calibrates the original Raman measurement spectrum based on the Raman scattered light intensity. Through this setting, the problem of calibration error caused by signal fluctuations caused by noise in the signal intensity under a single pixel can be avoided, which is conducive to deducting the deviation caused by system performance fluctuations, making the calibration more accurate.

[0078] In summary, according to the spectral self-calibration measurement method and system for measuring solution concentration using Raman spectroscopy provided in the embodiments of the present application, the original Raman measurement spectrum of the solution to be tested is calibrated, which can improve the repeatability and stability of the spectral test of the solution to be tested (especially at low solution concentrations, such as below 50 ppm), and can achieve high-precision solution concentration detection at low solution concentrations.

[0079] The above disclosure is only the preferred embodiment of the present application, but it is not intended to limit the scope of rights of the present application. A person of ordinary skill in the art can understand that without departing from the spirit and scope of the present application and the appended claims, changes, modifications, substitutions, combinations, and simplifications should all be equivalent replacement methods and still fall within the scope of the invention.

Claims

1. A method for self-calibration measurement of boric acid solution concentration spectrum using Raman spectroscopy, wherein the method uses a Raman spectroscopy system to perform quantitative concentration detection on a solution to be measured, characterized in that: The method comprises the following steps: Acquire a Raman spectrum of a solution at a specific concentration containing a Raman characteristic peak of a calibration object as a standard spectrum, wherein the calibration object is arranged in the optical path of the Raman spectroscopy system, and the calibration object is not in the solution to be tested; Obtaining an original Raman measurement spectrum of the solution to be tested; Based on the standard spectrum, obtaining the Raman scattered light intensity within a preset range around the characteristic peak position of the calibration object; Calibrate the original Raman measurement spectrum based on the Raman scattered light intensity to obtain a Raman calibration spectrum; Obtaining the concentration of the solution to be tested based on the Raman calibration spectrum; The Raman scattered light intensity within a preset range around the characteristic peak position of the calibration object is the spectral integral area of ​​the Raman characteristic peak of the calibration object within a preset pixel interval, and both the standard spectrum and the original Raman measurement spectrum are spectra without baseline correction processing; The wave number difference between the Raman characteristic peak of the calibration object and the Raman characteristic peak of the solution to be tested is greater than or equal to 10 cm -1 , and, less than 1000 cm -1 The Raman characteristic peak of the calibration substance is at 300 cm -1 To 3000 cm -1 The observation window is made of sapphire; the method is applied to quantitatively detect the concentration of boric acid solution of a pressurized water reactor neutronless radiation source, and the quantitative detection lower limit of the boric acid solution in the method is 35ppm.

2. The method according to claim 1, characterized in that The method further comprises: Setting a pixel interval, wherein the characteristic peak of the calibration object is located within the pixel interval; Obtaining a standard value, where the standard value is the Raman scattering light intensity in the pixel interval calculated at any solution concentration; Acquire a reference value, where the reference value is the Raman scattering light intensity in the pixel interval calculated at other solution concentrations; The ratio between the standard value and the reference value is calculated to obtain calibration data, and the original Raman measurement spectrum at the corresponding solution concentration is calibrated based on the calibration data.

3. A boric acid solution concentration spectrum self-calibration and measurement system using Raman spectroscopy, characterized in that: The system comprises: Calibration object, Raman detection unit and signal processing unit; The calibration object is arranged in the optical path of the Raman detection unit, and the calibration object is not in the solution to be tested; The Raman detection unit adopts a Raman spectrum detection method to obtain a Raman spectrum of a solution at a specific concentration containing a Raman characteristic peak of a calibration substance as a standard spectrum. The Raman detection unit is also used to detect the solution to be tested to obtain an original Raman measurement spectrum. The signal processing unit obtains the Raman scattered light intensity within a preset range around the characteristic peak position of the calibration object based on the standard spectrum, and calibrates the original Raman measurement spectrum based on the Raman scattered light intensity to obtain a Raman calibration spectrum, and the signal processing unit also obtains the concentration of the solution to be tested based on the Raman calibration spectrum; The Raman scattered light intensity within a preset range around the characteristic peak position of the calibration object is the spectral integral area of ​​the Raman characteristic peak of the calibration object within a preset pixel interval, and both the standard spectrum and the original Raman measurement spectrum are spectra without baseline correction processing; The wave number difference between the Raman characteristic peak of the calibration object and the Raman characteristic peak of the solution to be tested is greater than or equal to 10 cm -1 , and, less than 1000 cm -1 The Raman characteristic peak of the calibration substance is at 300 cm -1 To 3000 cm -1 In between is an observation window made of sapphire; the system is used to quantitatively detect the concentration of boric acid solution of a pressurized water reactor neutronless radiation source, and the detection lower limit of the boric acid solution in the system is 35ppm.

4. The system according to claim 3, characterized in that The calibration object is a device in the Raman detection unit that is capable of exciting Raman light; Alternatively, the calibration object is a device capable of exciting Raman light and inserted between the Raman detection unit and the solution to be tested.

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