Portable LIBS system with carbon measurement function and method for detecting carbon element

Abstract

The application provides a portable LIBS system with a carbon element detection function and a carbon element detection method, the portable LIBS system with the carbon element detection function comprises a light source and a detector; a first light beam emitted by the light source is incident on a detection area of a sample after converging light of the light source passes through a light converging device; light at the detection area is reflected by a first light reflecting device, and reflected light passes through a light splitting component and is received by the detector; the light converging device and the first light reflecting device are arranged on a support; a first driving unit is used for driving the support to rotate, so that the converging light is incident on different detection areas of the sample when the support rotates. The application has the advantages of carbon element detection, portability, high resolution and the like.

Description

Technical Field

[0001] This invention relates to LIBS technology, and particularly to a portable LIBS system with carbon measurement function and a method for detecting carbon. Background Technology

[0002] Laser-induced breakdown spectroscopy (LIBS), also known as laser-induced plasma spectroscopy, is an atomic emission spectroscopy technique. This technique can analyze solid, liquid, and gaseous substances. In LIBS, a laser pulse is focused onto the surface of the sample (solid, liquid, gas, or soft material similar to biological tissue), at approximately 10e... 9 W / cm 2 Under the influence of high-power-density radiation, matter undergoes localized ablation, evaporation, and vaporization within a short time, forming transient plasma. LIBS technology utilizes two characteristics: the focused energy of the laser beam and the time-domain modulated short-pulse output. In nanosecond laser ablation, the ablated material and the initially formed plasma further interact with the laser pulse, resulting in a highly ionized vapor, which is the laser-induced plasma. The initial temperature of the plasma can reach tens of thousands of Kelvin, enabling it to effectively emit light radiation with a spectral range covering a broad spectrum from deep ultraviolet to infrared. These spectra contain the characteristic spectra of the particles (atoms, ions, and small molecules) contained in the plasma. Therefore, analysis of the plasma emission spectrum can reveal the elemental composition of the ablation vapor, thereby allowing for the analysis of the elemental composition of the initial sample.

[0003] Carbon is one of the most common elements in nature. In various processes such as mining, metal smelting, and material manufacturing, carbon is inevitably introduced into metallic materials and has a significant impact on the mechanical properties and manufacturing processes of metals. Therefore, it is of great significance to achieve accurate detection of carbon content in metals.

[0004] Currently, no one has made a portable LIBS analyzer, nor is there a portable LIBS analyzer capable of measuring carbon. Summary of the Invention

[0005] To address the shortcomings of the existing technical solutions, this invention provides a portable LIBS system with carbon measurement function that offers accurate detection results and a small size.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A portable LIBS system with carbon measurement capabilities, comprising a light source, a spectrometer, and a detector; the portable LIBS system further includes:

[0008] A light converging device, wherein the first light beam emitted by the light source is converged and incident on the detection area of ​​the sample after passing through the light converging device;

[0009] The first light reflecting device reflects the light at the detection area, and the reflected light is received by the detector after passing through the beam splitter.

[0010] The bracket, on which the light converging device and the first light reflecting device are mounted;

[0011] The first driving unit is used to drive the support to rotate, so that when the support is rotating, the focused light is incident on different detection areas of the sample.

[0012] Another objective of this invention is to provide a high-resolution method for detecting carbon, which is achieved through the following technical solution:

[0013] A method for detecting carbon, comprising the following steps:

[0014] (A1) The focused light from the laser after passing through the optical focusing device is focused on the detection area of ​​the sample;

[0015] (A2) The sample is ablated and vaporized by laser, forming transient plasma that emits light radiation;

[0016] (A3) The light radiation is reflected by the first light reflecting device, and the reflected light is received by the detector after passing through the beam splitting component. The electrical signal output by the detector is sent to the analysis unit.

[0017] (A4) Rotate the light converging device and the first light reflecting device to focus the converged light on different detection areas of the sample, and send the electrical signal output by the detector to the analysis unit;

[0018] (A5) The analysis unit uses LIBS technology to analyze the received electrical signal and obtain the carbon content in the sample;

[0019] During the above testing process, the sample remained stationary.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] 1. The test results are accurate;

[0022] The laser beam is focused onto the sample by the optical converging device, and as the sample is rotated, the laser beam is focused at different positions on the sample, making the detection results more representative and improving the accuracy of the detection results.

[0023] Furthermore, by utilizing the forward and reverse movement of the optical converging device, it is possible to first clean the sample surface (with the laser focusing point not on the sample) and then perform detection (with the laser focusing point on the sample). This ensures that during detection, the detection laser truly excites the sample, rather than the dirt on the sample surface, effectively improving the detection accuracy.

[0024] 2. Small size;

[0025] The light converging device and the first light reflecting device are mounted on the support. As the support rotates, the light converging device moves along its central axis as needed. The structure is compact and small in size, which improves portability.

[0026] The separate arrangement of the pump source and multiple optical components such as spectrometers and light converging devices also improves the portability of the system.

[0027] 3. It has a carbon measurement function;

[0028] It overcomes the limitations of traditional X-ray fluorescence technology in carbon element analysis, and can effectively perform mobile analysis for tasks such as determining carbon steel grades and element content, as well as distinguishing materials that use carbon as a differentiating element. Attached Figure Description

[0029] The disclosure of this invention will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are merely illustrative of the technical solutions of this invention and are not intended to limit the scope of protection of this invention. In the drawings:

[0030] Figure 1 A flowchart of a method for detecting carbon according to an embodiment of the present invention. Detailed Implementation

[0031] Figure 1 The following description illustrates optional embodiments of the invention to teach those skilled in the art how to implement and reproduce the invention. For the purpose of teaching the technical solutions of the invention, some conventional aspects have been simplified or omitted. Those skilled in the art should understand that variations or substitutions derived from these embodiments will be within the scope of the invention. Those skilled in the art should understand that the following features can be combined in various ways to form multiple variations of the invention. Therefore, the invention is not limited to the following optional embodiments, but only to the claims and their equivalents.

[0032] Example 1:

[0033] The portable LIBS system with carbon measurement function according to an embodiment of the present invention includes:

[0034] Light sources, such as lasers, have a pump source and a resonant cavity;

[0035] A light converging device, such as a convex lens, allows the first beam emitted by the light source to pass through the light converging device and then be focused onto the detection area of ​​the sample. If the light is focused onto the sample, the sample is ablated by the focused light to form plasma, which then excites light radiation.

[0036] The first light reflecting device, such as a concave mirror, is off-axis. The light at the detection area is reflected by the first light reflecting device, and the reflected light is received by the detector after passing through the beam splitter.

[0037] The bracket, on which the light converging device and the first light reflecting device are mounted;

[0038] A first driving unit, such as a motor, drives the support to rotate, so that when the support rotates, light is focused onto different detection areas of the sample, such as focusing on different detection areas of the sample.

[0039] To clean stains from the sample surface and improve detection accuracy, the portable LIBS system further includes:

[0040] The second driving unit drives the light converging device to move forward and backward along its central axis, so that when the focal point of the converged light is not on the sample (the light intensity is weak), it cleans the dirt on the sample surface, and when the focal point is on the sample (the light intensity is strong), it excites the sample.

[0041] To improve portability and implement a separate configuration, the portable LIBS system further includes:

[0042] An optical fiber, the first end of which is fixed to the bracket; the light reflected from the first light reflecting device at the detection area is coupled into the first end of the optical fiber, and the light emitted from the second end of the optical fiber is split into at least two beams.

[0043] To further improve detection resolution, the portable LIBS system also includes:

[0044] The spectrometers are equipped with at least two beams of light that are incident on each spectrometer. The spectrometers have different parameters for their dispersive components and detect different wavelengths. The detectors are located in each spectrometer.

[0045] In order to accurately receive light radiation, the first light reflector is fixed on the bracket, and the angle between the central axis of the first light reflector and the central axis of the light converging device remains unchanged.

[0046] To obtain stronger light pulses, the light source further includes:

[0047] A pump source, wherein the light emitted by the pump source is incident on the gain medium inside the resonant cavity;

[0048] The resonant cavity includes opposing cavity mirrors, and a gain medium and a Q-switching medium disposed between the cavity mirrors.

[0049] To further facilitate the separate arrangement of the various components, the portable LIBS system also includes:

[0050] An optical fiber, the first end of which is fixed on the support; the outgoing light of a pump source located outside the support is coupled into the second end of the optical fiber, and the light outgoing from the first end of the optical fiber enters the resonant cavity fixed on the support.

[0051] Figure 1 A flowchart illustrating a method for detecting carbon element according to an embodiment of the present invention is shown, such as... Figure 1 As shown, the method for detecting carbon includes the following steps:

[0052] (A1) The focused light from the laser after passing through the optical focusing device is focused on the detection area of ​​the sample;

[0053] (A2) The sample is ablated and vaporized by laser, forming transient plasma that emits light radiation;

[0054] (A3) The light radiation is reflected by the off-axis first light reflection device, and the reflected light is received by the detector after passing through the beam splitting component. The electrical signal output by the detector is sent to the analysis unit.

[0055] (A4) Rotate the light converging device and the first light reflecting device to focus the converged light on different detection areas of the sample, and send the electrical signal output by the detector to the analysis unit;

[0056] (A5) The analysis unit uses LIBS technology to analyze the received electrical signal and obtain the carbon content in the sample;

[0057] During the above testing process, the sample remained stationary.

[0058] In order to clean the stains on the sample surface and improve the detection accuracy, in step (A1), the light converging device is moved forward along the central axis of the light converging device, the focal point of the converged light is not on the sample, and the surface of the sample is cleaned.

[0059] The light converging device is moved in the opposite direction along its central axis, and the converged light is focused onto the sample.

[0060] Example 2:

[0061] An example of the application of the portable LIBS system with carbon measurement function and the carbon element detection method according to Embodiment 1 of the present invention in the determination of carbon steel grade.

[0062] In this application example, the light source is a laser, including a pump source and a resonant cavity. The resonant cavity is fixed on a support, and the pump source is located outside the support. Pump light is transmitted between the pump source and the resonant cavity via a first optical fiber: the light output from the pump source is coupled into the first optical fiber, and the light exiting from the second end of the optical fiber fixed on the support enters the resonant cavity; the optical converging device is a converging lens, and along the light transmission direction, the resonant cavity, collimating lens, and converging lens are arranged sequentially; the first optical reflecting device is a concave mirror, which is off-axis relative to the converging lens and fixed on the support; the second optical reflector... The component uses a concave reflector, which is fixed on the support. The angle between the central axis of the first light reflecting device and the central axis of the converging lens is fixed. The light radiation on the sample is reflected by the first light reflecting device and the second light reflecting device in sequence and then coupled into the first end of the second optical fiber. The first end of the second optical fiber is fixed on the support, and the light emitted from the second end of the optical fiber is split into at least two beams. The light source, resonant cavity, collimating lens, converging lens, first and second light reflecting devices, and support are all housed in the housing. The housing has a through hole, which is suitable for the light passing through the converging lens to pass through the through hole and be focused on the sample.

[0063] The first drive unit uses a motor to drive the housing to rotate around the axis, which is parallel to the main optical axis of the converging light, but not coincident. The second drive unit uses a VCM (voice coil motor) to drive the converging lens to move along its central axis in the positive and negative directions.

[0064] The second optical fiber transmits the light radiation, which is then split into three beams and sent to three spectrometers. Each spectrometer uses different grating parameters and has a different detection band. The detection bands of the three spectrometers are combined to 190nm-520nm.

[0065] The carbon element detection method of this invention includes the following steps:

[0066] (A1) The pump light emitted from the pump source is transmitted to the gain medium in the resonant cavity through the first optical fiber. The laser emitted from the resonant cavity passes through the collimating lens and the converging lens in sequence. The laser (first beam) is focused by the converging lens.

[0067] First, the converging lens is moved forward along the central axis of the converging lens. The converging light after the laser passes through the converging lens is focused on the sample, but the focal point is not on the sample, and the surface dirt of the sample is cleaned.

[0068] Next, the converging lens is moved in the opposite direction along the central axis of the converging lens, and the converging light after the laser passes through the converging lens is focused at the detection area of ​​the sample;

[0069] (A2) The sample is ablated and vaporized by laser, forming transient plasma that emits light radiation;

[0070] (A3) The light radiation is reflected by the first light reflecting device and the second light reflecting device in sequence. The reflected light is coupled into the second optical fiber and transmitted to the outside of the housing. It is then split into three beams and enters three spectrometers respectively. After being split by the grating, the beams are received by the detectors. The electrical signals output by the detectors are sent to the analysis unit.

[0071] (A4) Driven by the first driving unit, the housing is rotated. The rotating shaft is parallel to but not coincident with the main optical axis of the converging light. The converging light is focused on different detection areas of the sample, exciting different detection areas on the sample (before actually exciting the sample, the surface of the sample must be cleaned of dirt, etc. in step (A1)). The electrical signal output by the detector is sent to the analysis unit.

[0072] (A5) The analysis unit uses LIBS technology to analyze the received electrical signal and obtain the carbon content in the sample. The specific analysis method is existing in the field and will not be described in detail here.

[0073] During the above testing process, the sample remained stationary.

[0074] The above embodiments are merely illustrative examples of how the light source and the rotating shaft can be arranged. Of course, other technical means can also be used, such as both the pump source and the resonant cavity being arranged on the bracket or both being arranged outside the housing. The rotating shaft can also intersect with the main optical axis of the converging light, as long as it does not coincide with the main optical axis.

Claims

1. A portable LIBS system with carbon measurement function, the portable LIBS system with carbon measurement function comprising a light source, a spectrometer, and a detector; characterized in that: The portable LIBS system also includes: A light converging device, wherein the first light beam emitted by the light source is converged and incident on the detection area of ​​the sample after passing through the light converging device; The first light reflecting device reflects the light at the detection area, and the reflected light is received by the detector after passing through the beam splitting component; the first light reflecting device is off-axis relative to the light converging device, and the angle between the central axis of the first light reflecting device and the central axis of the light converging device remains unchanged. The bracket, on which the light converging device and the first light reflecting device are mounted; The housing contains the light converging device, the first light reflecting device, and the support; the housing has a through-hole that allows light passing through the light converging device to pass through. The first driving unit is used to drive the housing to rotate. The rotating shaft and the main optical axis of the converging light do not coincide. The converging light is focused on different detection areas of the sample.

2. The portable LIBS system with carbon measurement function according to claim 1, characterized in that: The portable LIBS system also includes: The second driving unit drives the light converging device to move forward and backward along its central axis.

3. The portable LIBS system with carbon measurement function according to claim 1, characterized in that: The portable LIBS system also includes: The second light reflecting device reflects the light at the detection area in sequence by the first light reflecting device and the second light reflecting device.

4. The portable LIBS system with carbon measurement function according to claim 1, characterized in that: The light source includes: A pump source, wherein the light emitted by the pump source is incident on the gain medium inside the resonant cavity; The resonant cavity includes opposing cavity mirrors, and a gain medium and a Q-switching medium disposed between the cavity mirrors.

5. The portable LIBS system with carbon measurement function according to claim 4, characterized in that: The portable LIBS system also includes: An optical fiber, the first end of which is fixed to the bracket; the emitted light from a pump source located outside the bracket is coupled into the second end of the optical fiber, and the light emitted from the first end is incident into the resonant cavity fixed to the bracket.

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