Laser-induced breakdown spectroscopy detection system and detection method

Abstract

The present invention relates to the field of spectrum detection technology, and specifically discloses a laser induced breakdown spectrum detection system and detection method. The laser induced breakdown spectrum detection system includes: a base, on which a mounting frame is fixed, a pulse laser is provided on the mounting frame, and a focusing lens is provided on the emitting end of the pulse laser; a protection unit, which includes a stand provided on the base, a mounting shell fixed on the stand, a lifting platform provided in the mounting shell and a cover tube provided on the lifting platform; a purge member for blowing air to protect the sample to be tested is provided in the cover tube. The purge ring is driven to rotate continuously in the circumferential direction by a rotating driving member, so that each air outlet moves around the sample at the center, ensuring that the argon gas flow is evenly wrapped around the sample, forming a stable argon gas protection atmosphere, reducing the detection error caused by uneven air flow, thereby effectively reducing background interference and improving detection accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of spectrum detection, and more particularly to a laser induced breakdown spectrum detection system and a detection method. Background Art

[0002] The laser-induced breakdown spectroscopy system focuses an ultrashort pulse laser on the sample surface to form a plasma. The spectrometer is used to analyze the plasma emission spectrum and identify the elemental composition of the sample. This allows for material identification, classification, qualitative and quantitative analysis.

[0003] When performing laser-induced breakdown spectroscopy testing on samples, the environmental atmosphere in which the samples are located has a certain impact on the detection accuracy. Certain elements will have different spectral characteristics under different gas environments. Therefore, before testing, a corresponding protective gas atmosphere must be set according to the characteristics of the sample. Currently, the protective gas atmosphere is mainly formed by a gas chamber structure. However, the gas chamber structure is relatively closed. In multi-sample testing, the gas chamber structure is prone to cross-contamination between samples. For example, residues from the previous group of samples may remain in the gas chamber structure and interfere with the test results of the next group of samples, thereby affecting the accuracy of the test results. Summary of the Invention

[0004] In order to overcome the above technical problems, the present invention proposes a laser induced breakdown spectroscopy detection system and detection method.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A laser induced breakdown spectroscopy detection system, comprising:

[0007] A base, on which a mounting frame is fixed, a pulse laser is provided on the mounting frame, and a focusing lens is installed at the emission end of the pulse laser;

[0008] A conveying member, which is provided on the base and is used to convey the sample to the focusing point of the focusing lens;

[0009] The protection unit is provided on the base and is located between the focusing lens and the conveying member, and includes a platform provided on the base, a mounting housing fixed to the platform, a lifting platform movably provided in the mounting housing, and a cover provided on the lifting platform, wherein the mounting housing is provided with a slide rail adapted to slide with the lifting platform;

[0010] A purge component for blowing air to protect the sample to be tested is provided in the cover tube; a light path collector for collecting spectra is provided on one side of the cover tube to transmit the light signal emitted by the plasma to the spectrometer for analysis.

[0011] As a further solution of the present invention: the conveying member includes a conveying frame fixed on the base, a conveying belt for carrying samples is rotatably mounted on the conveying frame, and a conveying motor for driving the conveying belt is mounted at one end of the conveying frame.

[0012] As a further solution of the present invention: a lifting guide rod is vertically fixed on the platform, a sliding sleeve on the lifting guide rod is provided with a support platform, the support platform is located below the conveyor belt, and a clamping member for driving the lifting platform and the support platform to move synchronously is provided on the mounting sleeve.

[0013] As a further solution of the present invention: the clamping part includes a clamping motor fixed on the mounting sleeve, the output end of the clamping motor is connected to a gear, a first rack rack is fixed on the lifting platform through a connecting column, a through groove for accommodating the connecting column is opened on the mounting sleeve, and a second rack rack is fixed on the support platform, and the first rack rack and the second rack rack are both engaged with the gear.

[0014] As a further solution of the present invention: the purge member includes an air supply cavity opened in the cover tube, a purge ring is rotatably installed in the air supply cavity, a plurality of air outlets are opened circumferentially on the purge ring, and a rotating drive member for driving the purge ring is provided on the inner wall of the cover tube.

[0015] As a further solution of the present invention: the rotary drive member includes a rotary motor fixed on the inner wall of the cover cylinder, the output end of the rotary motor is connected to a friction wheel, and the purge ring is provided with a friction ring adapted to the friction wheel.

[0016] As a further solution of the present invention: an elastically retractable annular sealing airbag is also provided in the cover tube, and the annular sealing airbag is located below the purge ring; during the argon purge process, the annular sealing airbag is inflated to cause the annular sealing airbag to expand radially and seal and wrap the upper end surface of the sample to be tested.

[0017] As a further solution of the present invention: a blowing groove is provided at the bottom of the cover tube, and a first air duct connected to the blowing groove and a second air duct connected to the annular sealing airbag are respectively provided in the cover tube, and a switching component adapted to the first air duct and the second air duct is provided in the cover tube; when the cover tube descends into position, the switching component only connects the air supply cavity with the second air duct; when the cover tube ascends and resets, the switching component only connects the second air duct with the first air duct.

[0018] As a further solution of the present invention: the switching part includes a flexible capsule arranged at the lower end of the cover tube, a slide is vertically slidably arranged in the cover tube, a push plate connected to the flexible capsule is fixed at the lower end of the slide, a third air duct is opened in the slide, and a first slot and a second slot are respectively opened at the upper and lower ends of the third air duct.

[0019] As a further solution of the present invention: a guide rod is vertically fixed on the push plate, the guide rod is slidably connected to the cover tube, and a spring is movable on the guide rod.

[0020] The present invention also discloses a detection method of a laser induced breakdown spectroscopy detection system, comprising the following steps:

[0021] S1, the conveyor transports the sample to be tested to the testing position;

[0022] S2, the cover tube moves downward to cover the sample to be tested;

[0023] S3, the purge unit purges argon gas into the cover tube to form a protective gas atmosphere that wraps the sample to be tested;

[0024] S4, the pulse laser generates laser pulses, which are focused on the sample surface through the focusing lens;

[0025] S5. The optical path collector transmits the optical signal emitted by the plasma to the spectrometer for detection and analysis.

[0026] Beneficial effects of the present invention:

[0027] The purge member provided in the present invention drives the purge ring to rotate continuously in the circumferential direction through the rotating drive member, so that each gas outlet moves in a circular motion around the sample at the center, ensuring that the argon gas flow is evenly wrapped around the sample, forming a stable argon protective atmosphere; the circumferential purge design ensures that the argon gas flow is evenly distributed, reducing the detection error caused by uneven gas flow, thereby effectively reducing the impact of oxygen and nitrogen in the environment on the plasma, reducing background interference, and improving the signal-to-noise ratio of the spectral signal. The protective gas atmosphere helps to improve the excitation efficiency of the plasma and the intensity of the spectral signal, thereby improving the detection accuracy and making the detection results more accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below with reference to the accompanying drawings.

[0029] Figure 1 A three-dimensional schematic diagram of a laser induced breakdown spectroscopy detection system of the present invention;

[0030] Figure 2 A three-dimensional schematic diagram of a laser induced breakdown spectroscopy detection system of the present invention from another perspective;

[0031] Figure 3 Schematic diagram of the structure of a pulsed laser and a focusing lens in a laser induced breakdown spectroscopy detection system of the present invention;

[0032] Figure 4 This is a schematic structural diagram of a protection unit in a laser induced breakdown spectroscopy detection system of the present invention;

[0033] Figure 5 It is a structural schematic diagram of a protection unit and a conveyor belt in a laser induced breakdown spectroscopy detection system of the present invention;

[0034] Figure 6 for Figure 5 Enlarged view of point A in the middle;

[0035] Figure 7 A cross-sectional view of an installation housing in a laser induced breakdown spectroscopy detection system according to the present invention;

[0036] Figure 8 A cross-sectional view of a cover tube in a laser induced breakdown spectroscopy detection system according to the present invention;

[0037] Figure 9 for Figure 8 Enlarged view of point B in the middle;

[0038] Figure 10 for Figure 8 Enlarged view of point C in the middle.

[0039] In the picture:

[0040] 100, base; 110, mounting frame; 120, pulse laser; 130, focusing lens; 140, conveyor; 141, conveyor rack; 142, conveyor belt; 143, conveyor motor; 150, sample; 160, light path collector; 200, protection unit; 210, stand; 211, lifting guide rod; 212, support platform; 220, mounting housing; 221, slide rail; 222, through groove; 230, lifting platform; 231, connecting column; 240, cover tube; 241, blowing slot; 242, first air channel; 243, second Air duct; 250, pressing member; 251, pressing motor; 252, gear; 253, first rack; 254, second rack; 260, purge member; 261, air supply chamber; 262, purge ring; 263, air outlet; 264, rotating motor; 265, friction wheel; 266, friction ring; 270, annular sealing airbag; 280, switching member; 281, flexible capsule; 282, push plate; 283, slide plate; 284, guide rod; 285, spring; 286, third air duct; 287, first notch; 288, second notch. DETAILED DESCRIPTION

[0041] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed solely to enable those skilled in the art to better understand and implement the subject matter described herein, and that the functions and arrangements of the elements discussed may be varied without departing from the scope of this specification. Various examples may omit, substitute, or add various processes or components as needed. In addition, features described with respect to some examples may also be combined in other examples.

[0042] See also Figure 1 、 Figure 2 and Figure 3 In a first aspect, the present invention discloses a laser-induced breakdown spectroscopy detection system, comprising a base 100, a conveying member 140, and a protection unit 200; a mounting frame 110 is fixed to the base 100, a pulse laser 120 is provided on the mounting frame 110, and a focusing lens 130 is installed at the transmitting end of the pulse laser 120; the conveying member 140 is provided on the base 100, and is used to convey a sample 150 to the focusing point of the focusing lens 130;

[0043] See also Figure 4 The protection unit 200 is arranged on the base 100 and is located between the focusing lens 130 and the conveying member 140. It includes a stand 210 arranged on the base 100, a mounting sleeve 220 fixed on the stand 210, a lifting platform 230 that can be lifted and lowered in the mounting sleeve 220, and a cover tube 240 arranged on the lifting platform 230. The mounting sleeve 220 is provided with a slide rail 221 that is slidably adapted to the lifting platform 230. The cover tube 240 is provided with a purge member 260 for blowing air to protect the sample 150 to be tested; a light path collector 160 for collecting spectra is provided on one side of the cover tube 240 to transmit the light signal emitted by the plasma to the spectrometer for analysis.

[0044] Specifically, the samples 150 are placed on the conveying member 140 in sequence, and the sample 150 is transported to the focusing point of the focusing lens 130 by the conveying member 140. The lifting platform 230 is moved down until the cover tube 240 is covered on the periphery of the corresponding sample 150. The sample 150 is purged with argon by the purge member 260, so that the environment around the sample 150 is filled with argon, thereby achieving a protective gas atmosphere; a high-energy laser pulse is generated by the pulse laser 120, and the laser pulse is focused on the surface of the sample 150 through the focusing lens 130, so that a small part of the material on the surface of the sample 150 instantly undergoes ablation, dissociation, atomization and ionization processes to form plasma. The excited atoms and ions will emit secondary light of a specific wavelength when returning to the ground state, and the secondary light can be collected and resolved by a spectrometer.

[0045] It is noteworthy that the present invention performs argon purging on the sample 150 through the purge member 260, so that the environment around the sample 150 is filled with argon, forming a protective gas atmosphere, thereby effectively reducing the impact of oxygen and nitrogen in the environment on the plasma, reducing background interference, and improving the signal-to-noise ratio of the spectral signal. The protective gas atmosphere helps to improve the excitation efficiency of the plasma and the intensity of the spectral signal, thereby improving the detection accuracy and making the detection results more accurate and reliable.

[0046] In addition, each sample 150 is protected by argon gas through an independent cover tube 240 and a purge piece 260 before testing, reducing the risk of residues from the previous sample being brought into the next sample testing area, effectively preventing cross-contamination, and ensuring the accuracy of the test results; after each sample test is completed, the test area can be cleaned by the purge piece 260, further reducing the impact of residues and improving the stability and reliability of the system.

[0047] Further, see Figure 2 The conveying member 140 includes a conveying frame 141 fixed on the base 100, a conveying belt 142 for carrying the sample 150 is rotatably mounted on the conveying frame 141, and a conveying motor 143 for driving the conveying belt 142 is mounted at one end of the conveying frame 141;

[0048] Specifically, the samples 150 are arranged in sequence on the conveyor belt 142, and the conveyor belt 142 is driven to move by the conveying motor 143, so that the samples 150 can be supplied to the detection area one by one, and the samples 150 that have been tested can be removed from the detection area.

[0049] In one embodiment, considering that the conveyor belt 142 has a certain degree of flexibility, when the cover tube 240 is pressed downward on the conveyor belt 142, the downward pressure will cause the conveyor belt 142 to bend downward, thereby affecting the flatness of the entire conveyor belt 142, and thus easily causing the sample 150 to slip, affecting the consistency of the detection position; for this reason, please refer to Figure 3 A lifting guide rod 211 is vertically fixed on the platform 210, and a support platform 212 is slidably sleeved on the lifting guide rod 211. The support platform 212 is located below the conveyor belt 142, and a pressing member 250 for driving the lifting platform 230 and the support platform 212 to move synchronously is provided on the mounting housing 220;

[0050] Specifically, in the initial state, the lifting platform 230 and the cover cylinder 240 are retracted upward into the mounting sleeve 220, and the support platform 212 is also located at the lower end of the lifting guide rod 211 and separated from the conveyor belt 142, so as not to affect the normal conveying of the sample 150 by the conveyor belt 142; when the conveyor belt 142 transports one group of samples 150 to the detection position, the lifting platform 230 and the support platform 212 are driven by the clamping member 250 to move toward each other, that is, the lifting platform 230 moves downward, and the support platform 212 moves upward at the same time, until the lower end of the cover cylinder 240 is just buckled on the upper surface of the conveyor belt 142, and the support platform 212 is just in contact with the lower surface of the conveyor belt 142, so as to realize the compression and fixation of the conveyor belt 142, and the conveyor belt 142 remains vertically in a horizontal state unchanged, and at the same time the sample 150 to be tested is covered in the cover cylinder 240 to isolate the sample 150 to be tested from the external environment, so as to facilitate the accuracy of subsequent laser induced breakdown spectroscopy detection.

[0051] It should be noted that when the cover cylinder 240 moves downward and presses on the conveyor belt 142, the support platform 212 moves upward and fits against the lower belt surface of the conveyor belt 142, which can effectively prevent the conveyor belt 142 from bending downward under the action of the downward pressure, thereby maintaining the flatness of the conveyor belt 142; the pressing member 250 drives the lifting platform 230 and the support platform 212 to move synchronously, ensuring that the cover cylinder 240 and the support platform 212 reach the predetermined position at the same time, thereby achieving uniform compression of the conveyor belt 142 and further preventing deformation of the conveyor belt 142;

[0052] The support platform 212 fits with the lower surface of the conveyor belt 142, ensuring that the conveyor belt 142 remains horizontal during the inspection process, preventing the sample 150 from slipping, helping to improve the consistency of the sample 150 in the inspection position, ensuring that the laser can be accurately focused on the sample surface during each inspection, improving the accuracy and repeatability of the inspection, and reducing the inspection position deviation caused by deformation of the conveyor belt 142 and sample slippage, thereby improving the reliability and consistency of the inspection results.

[0053] Further, see Figure 5 and Figure 6 The pressing member 250 includes a pressing motor 251 fixed to the mounting sleeve 220, the output end of the pressing motor 251 is connected to a gear 252, a first rack 253 is fixed to the lifting platform 230 via a connecting column 231, a through slot 222 for accommodating the connecting column 231 is formed on the mounting sleeve 220, and a second rack 254 is fixed to the support platform 212, and the first rack 253 and the second rack 254 are both engaged with the gear 252;

[0054] Specifically, after the conveyor belt 142 transports the sample to be tested 150 to the detection position, the gear 252 is driven to rotate by the clamping motor 251. Under the meshing transmission of the gear 252 and the first rack rack 253 and the second rack rack 254, the lifting platform 230 and the support platform 212 are driven to move toward each other synchronously until the cover tube 240 and the support platform 212 are in contact with the upper and lower belt surfaces of the conveyor belt 142 at the same time, thereby achieving the compression and fixation of the conveyor belt 142 and the wrapping of the sample to be tested 150.

[0055] For further information, see Figure 7 and Figure 8 The purge member 260 includes an air supply cavity 261 provided in the cover tube 240, a purge ring 262 is rotatably installed in the air supply cavity 261, and a plurality of air outlets 263 are provided on the circumference of the purge ring 262. A rotary driving member for driving the purge ring 262 is provided on the inner wall of the cover tube 240;

[0056] Specifically, during the detection process, the gas supply cavity 261 is connected to an external argon source so that argon fills the gas supply cavity 261, and the argon enters the purge ring 262 and is blown out from each gas outlet 263. The purge ring 262 is driven by a rotating driving member to rotate continuously in a circumferential direction, so that each gas outlet 263 can move in a circular motion around the sample 150 at the center, and the sample 150 is wrapped by the circumferentially ejected argon gas flow, so that the sample 150 is always wrapped in a stable argon protective atmosphere to reduce background interference and improve the signal-to-noise ratio of the spectral signal. The protective gas atmosphere helps to improve the excitation efficiency of the plasma and the intensity of the spectral signal, thereby improving the detection accuracy and making the detection results more accurate and reliable.

[0057] Accordingly, see Figure 8 The rotary drive member includes a rotary motor 264 fixed on the inner wall of the cover tube 240, the output end of the rotary motor 264 is connected to a friction wheel 265, and the purge ring 262 is provided with a friction ring 266 adapted to the friction wheel 265;

[0058] Specifically, the friction wheel 265 is driven to rotate by the rotating motor 264, and the friction force between the friction wheel 265 and the friction ring 266 is used to drive the friction ring 266 to rotate circumferentially, thereby driving the purge ring 262 to rotate circumferentially relative to the cover tube 240, so as to achieve circumferential argon purge protection for the sample 150 to be tested.

[0059] It is worth noting that the purge ring 262 is driven to rotate continuously in the circumferential direction by the rotating drive member, so that each gas outlet 263 moves in a circular motion around the sample 150 at the center, ensuring that the argon gas flow is evenly wrapped around the sample 150, forming a stable argon protective atmosphere; the circumferential purge design ensures that the argon gas flow is evenly distributed, reduces the detection error caused by uneven gas flow, and improves the stability and reliability of the system; in addition, the design of the friction wheel 265 and the friction ring 266 can smoothly drive the purge ring 262 to rotate, avoiding the destruction of the argon protective atmosphere due to vibration, and further improving the stability of the system.

[0060] In yet another embodiment, see Figure 8 The cover tube 240 is further provided with an elastically retractable annular sealing airbag 270, which is located below the purge ring 262. During the argon purge process, the annular sealing airbag 270 is inflated, so that the annular sealing airbag 270 expands radially and seals and wraps the upper end surface of the sample 150 to be tested.

[0061] Specifically, the annular sealing airbag 270 is made of a flexible material such as silicone. When argon purging is performed, the inside of the annular sealing airbag 270 is inflated, causing the annular sealing airbag 270 to expand radially, and the inner ring diameter of the lower end of the annular sealing airbag 270 is reduced until it contacts the upper end surface of the sample 150 and wraps and seals the sample 150. In this way, the argon gas sprayed by the purge ring 262 can completely wrap the sample 150. Since the mass of argon gas is greater than that of air, it settles in the lower space inside the cover tube 240, so that the sample 150 is always in a stable argon protection atmosphere. As the argon gas blown out by the purge ring 262 gradually increases, the air inside the cover tube 240 is gradually squeezed upward, thereby ensuring the stability of the gas protection environment inside the cover tube 240.

[0062] It is worth noting that the annular sealing airbag 270 is made of a flexible material such as silicone, and can expand radially after inflation, contact the upper end surface of the sample 150 and wrap and seal it, which can effectively prevent outside air from entering the interior of the cover tube 240, ensuring the stability and purity of the argon protection atmosphere; through the sealing effect of the annular sealing airbag 270, the loss of argon caused by leakage and the mixing of outside air are reduced, thereby improving the stability and reliability of the detection environment; since argon is heavier than air, the inflated annular sealing airbag 270 can effectively settle the argon in the lower space inside the cover tube 240, so that the sample 150 is always in a stable argon protection atmosphere; as the argon blown out by the purge ring 262 gradually increases, the air inside the cover tube 240 is gradually squeezed upward, further ensuring the stability of the gas protection environment inside the cover tube 240, reducing background interference, and improving the signal-to-noise ratio of the spectral signal;

[0063] The sealing effect of the annular sealing airbag 270 can effectively prevent the sample 150 from being contaminated by the outside world during the detection process, maintain the purity of the sample, and improve the accuracy of the detection result;

[0064] The annular sealing airbag 270 can be quickly inflated and deflated, ensuring the timely formation and release of the argon protective atmosphere during the detection process, thereby improving the overall efficiency of the system. The flexible material of the annular sealing airbag 270 can absorb some vibrations, reduce vibrations caused by airflow impact, and further improve the stability of the system.

[0065] Further, see Figure 8 and Figure 9 The bottom of the cover cylinder 240 is provided with an air blowing groove 241, and the cover cylinder 240 is provided with a first air channel 242 communicating with the air blowing groove 241 and a second air channel 243 communicating with the annular sealing airbag 270. The cover cylinder 240 is provided with a switching member 280 adapted to the first air channel 242 and the second air channel 243; when the cover cylinder 240 is lowered to its position, the switching member 280 only connects the air supply cavity 261 with the second air channel 243; when the cover cylinder 240 is reset when it is raised, the switching member 280 only connects the second air channel 243 with the first air channel 242;

[0066] Specifically, after the cover tube 240 descends and is pressed against the conveyor belt 142, the switching member 280 switches its state, so that the gas supply chamber 261 is connected to the second gas channel 243. Thus, during the argon purge process, the argon gas in the gas supply chamber 261 is used to inflate the annular sealing airbag 270, driving the annular sealing airbag 270 to expand and wrap and seal the sample 150.

[0067] After the detection is completed, the cover tube 240 moves upward and resets, and the switching member 280 switches the state again, so that the second air channel 243 is connected to the first air channel 242, so that the argon gas inside the annular sealing airbag 270 is ejected from the blowing groove 241 to achieve the blowing and cleaning of the inner wall of the cover tube 240, remove the debris, dust and other pollutants generated during the detection process, avoid interference with the next cycle of detection, and at the same time realize the reuse of argon gas.

[0068] Accordingly, see Figure 8 and Figure 10 The switching member 280 includes a flexible capsule 281 provided at the lower end of the cover tube 240. A slide plate 283 is vertically slidably provided in the cover tube 240. A push plate 282 connected to the flexible capsule 281 is fixed to the lower end of the slide plate 283. A third air passage 286 is defined in the slide plate 283. The third air passage 286 has a first notch 287 and a second notch 288 at its upper and lower ends, respectively.

[0069] Specifically, when the cover tube 240 descends into position, the flexible bag sheet 281 contacts the upper surface of the conveyor belt 142, thereby pushing the slide plate 283 upward through the push plate 282, so that the upper end of the slide plate 283 extends into the air supply cavity 261, the first notch 287 communicates with the air supply cavity 261, and the second notch 288 communicates with the second air channel 243, so as to achieve inflation of the annular sealing airbag 270;

[0070] When the cover tube 240 moves upward and resets, the flexible capsule 281 returns to its initial position, and the slide plate 283 slides down until the first notch 287 is connected to the second air channel 243, and the second notch 288 is connected to the first air channel 242, so as to discharge the argon gas in the annular sealing airbag 270 and blow it out from the blowing groove 241.

[0071] Furthermore, in order to achieve accurate switching of the state of the switching element 280, please refer to Figure 10 A guide rod 284 is vertically fixed on the push plate 282, and the guide rod 284 is slidably connected to the cover tube 240. A spring 285 is movably sleeved on the guide rod 284;

[0072] Specifically, when the cover tube 240 is separated from the conveyor belt 142, the push plate 282 pushes the flexible bag sheet 281 to the lower end under the elastic force of the spring 285. At this time, the second slot 288 is just connected to the first air channel 242 to ensure that the argon gas in the annular sealing airbag 270 is discharged smoothly, and at the same time achieve the effect of blowing and cleaning.

[0073] It is worth noting that, through the switching mechanism of the switching member 280, after the detection is completed, the argon gas inside the annular sealing airbag 270 can be ejected from the blowing groove 241 to be used for blowing and cleaning the inner wall of the cover tube 240. This not only realizes the reuse of the argon gas, but also reduces the waste of the argon gas and reduces the detection cost.

[0074] In addition, the design of the switching member 280 realizes automatic switching of the airway. When the cover tube 240 descends into place, the flexible capsule 281 contacts the conveyor belt 142, and pushes the slide plate 283 through the push plate 282, so that the first slot 287 is connected to the air supply chamber 261, and the second slot 288 is connected to the second airway 243, thereby realizing the inflation of the annular sealing airbag 270; when the cover tube 240 is reset upward, the flexible capsule 281 returns to its initial position, and the slide plate 283 slides down, so that the first slot 287 is connected to the second airway 243, and the second slot 288 is connected to the first airway 242, thereby realizing the discharge and blowing of the argon gas in the annular sealing airbag 270.

[0075] A second aspect of the present invention discloses a detection method of a laser induced breakdown spectroscopy detection system, comprising the following steps:

[0076] S1, the conveying member 140 conveys the sample 150 to be tested to the testing position;

[0077] S2, the cover tube 240 moves downward to cover the sample 150 to be tested;

[0078] S3, the purge member 260 purges the hood tube 240 with argon gas to form a protective gas atmosphere surrounding the sample 150 to be tested;

[0079] S4, the pulse laser 120 generates a laser pulse, and the laser pulse is focused on the surface of the sample 150 through the focusing lens 130;

[0080] S5. The light path collector 160 transmits the light signal emitted by the plasma to the spectrometer for detection and analysis.

[0081] The above describes the specific implementation of this embodiment, but this embodiment is not limited to the above specific implementation. The above specific implementation is merely illustrative and not restrictive. Ordinary technicians in this field can also make many forms based on the inspiration of this embodiment, all of which are protected by this embodiment.

Claims

1. A laser induced breakdown spectroscopy detection system, characterized in that: include: A base (100) is fixed with a mounting frame (110), a pulse laser (120) is provided on the mounting frame (110), and a focusing lens (130) is installed at the emission end of the pulse laser (120); A conveying member (140) is provided on the base (100) and is used to convey the sample (150) to the focusing point of the focusing lens (130); A protection unit (200) is provided on the base (100) and is located between the focusing lens (130) and the conveying member (140), comprising a stand (210) provided on the base (100), a mounting sleeve (220) fixed on the stand (210), a lifting platform (230) liftably provided in the mounting sleeve (220), and a cover cylinder (240) provided on the lifting platform (230), wherein a slide rail (221) is provided in the mounting sleeve (220) and is slidably adapted to the lifting platform (230); A purge member (260) for performing air blowing protection on the sample to be tested (150) is provided in the cover cylinder (240); a light path collector (160) for collecting a spectrum is provided on one side of the cover cylinder (240) to transmit the light signal emitted by the plasma to a spectrometer for analysis; The purge member (260) includes an air supply cavity (261) provided in the cover tube (240), a purge ring (262) rotatably installed in the air supply cavity (261), a plurality of air outlets (263) circumferentially provided on the purge ring (262), and a rotary drive member for driving the purge ring (262) provided on the inner wall of the cover tube (240); The rotary drive member includes a rotary motor (264) fixed on the inner wall of the cover cylinder (240); an output end of the rotary motor (264) is connected to a friction wheel (265); and a friction ring (266) adapted to the friction wheel (265) is provided on the purge ring (262); An elastically retractable annular sealing airbag (270) is further provided in the cover tube (240), and the annular sealing airbag (270) is located below the purge ring (262); during the argon purge process, the annular sealing airbag (270) is inflated, so that the annular sealing airbag (270) expands radially and seals and wraps the upper end surface of the sample to be tested (150).

2. The laser induced breakdown spectroscopy detection system according to claim 1, characterized in that: The conveying member (140) includes a conveying frame (141) fixed on the base (100), a conveying belt (142) for carrying the sample (150) is rotatably mounted on the conveying frame (141), and a conveying motor (143) for driving the conveying belt (142) is mounted at one end of the conveying frame (141).

3. The laser induced breakdown spectroscopy detection system according to claim 1, characterized in that: A lifting guide rod (211) is vertically fixed on the platform (210), a support platform (212) is provided on a sliding sleeve of the lifting guide rod (211), and the support platform (212) is located below the conveyor belt (142). A pressing member (250) is provided on the mounting housing (220) for driving the lifting platform (230) and the support platform (212) to move synchronously.

4. The laser induced breakdown spectroscopy detection system according to claim 3, characterized in that: The pressing member (250) includes a pressing motor (251) fixed on the mounting sleeve (220), the output end of the pressing motor (251) is connected to a gear (252), a first rack (253) is fixed to the lifting platform (230) via a connecting column (231), a through slot (222) for accommodating the connecting column (231) is provided on the mounting sleeve (220), a second rack (254) is fixed to the support platform (212), and the first rack (253) and the second rack (254) are both engaged with the gear (252).

5. The laser induced breakdown spectroscopy detection system according to claim 1, characterized in that: The bottom of the cover cylinder (240) is provided with an air blowing groove (241), and the cover cylinder (240) is provided with a first air channel (242) communicating with the air blowing groove (241) and a second air channel (243) communicating with the annular sealing airbag (270). The cover cylinder (240) is provided with a switching member (280) adapted to the first air channel (242) and the second air channel (243). When the cover cylinder (240) descends to its position, the switching member (280) only connects the air supply cavity (261) with the second air channel (243); when the cover cylinder (240) ascends and resets, the switching member (280) only connects the second air channel (243) with the first air channel (242).

6. The laser induced breakdown spectroscopy detection system according to claim 5, characterized in that: The switching member (280) includes a flexible capsule (281) arranged at the lower end of the cover tube (240), a slide plate (283) is vertically slidably arranged in the cover tube (240), a push plate (282) connected to the flexible capsule (281) is fixed at the lower end of the slide plate (283), a third air channel (286) is provided in the slide plate (283), and a first notch (287) and a second notch (288) are provided at the upper and lower ends of the third air channel (286), respectively; a guide rod (284) is vertically fixed on the push plate (282), the guide rod (284) is slidably connected to the cover tube (240), and a spring (285) is movably sleeved on the guide rod (284).

7. A detection method of a laser induced breakdown spectroscopy detection system according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, the conveying member (140) conveys the sample to be tested (150) to the testing position; S2, the cover tube (240) moves downward to cover the sample to be tested (150); S3, the purge member (260) purges the hood tube (240) with argon gas to form a protective gas atmosphere that envelops the sample to be tested (150); S4, the pulse laser (120) generates laser pulses, and the laser pulses are focused on the surface of the sample (150) through the focusing lens (130); S5. The light path collector (160) transmits the light signal emitted by the plasma to a spectrometer for detection and analysis.

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