Split type on-site laser-induced breakdown spectroscopy detection device

Abstract

The application discloses a split type on-site laser-induced breakdown spectroscopy detection device which is composed of a handheld laser detector and a control system, and is connected through a plastic-coated pipe between the handheld laser detector and the control system; the handheld laser detector is internally provided with a laser, an optical fiber, an optical fiber debugging rack and a fan, and the casing of the handheld laser detector is designed in an up-down symmetry mode; the laser excited by the laser is focused on the surface of a measured sample through a focusing mirror; the casing of the control system is divided into a front plate, a rear plate and a machine body; the machine body is internally provided with a spectrometer, a laser power supply, a direct current power supply and an FPGA control board; one end of a type B line of the FPGA control board is connected with a computer, and the other end is connected with the spectrometer. The device overcomes the problems of a large volume, a heavy equipment, a low analysis precision, a complicated operation process and dust pollution of a lens caused by a poor industrial site environment of a traditional LIBS detector.

Description

Technical Field

[0001] This invention relates to the field of laser-induced breakdown spectroscopy, and more particularly to a split-type on-site laser-induced breakdown spectroscopy detection device. Background Technology

[0002] Laser-induced breakdown spectroscopy (LIBS) is an atomic emission spectroscopy technique that uses a high-intensity pulsed laser to ablate a sample, generating a plasma light signal. The collected plasma light signal is then analyzed using a spectrometer to determine the types and amounts of elements present in the sample. LIBS technology offers great convenience for sample processing and, as a novel material identification and quantitative analysis technique, can be used in laboratories. However, due to the large size and weight of the equipment, as well as its suitability for harsh field environments, its application in industrial settings or online detection is challenging. Summary of the Invention

[0003] The purpose of this invention is to provide a split-type on-site laser-induced breakdown spectroscopy (LIBS) detection device. This device overcomes the problems of traditional LIBS detectors, such as large size, heavy equipment, low analytical accuracy, cumbersome and complicated operation procedures, and dust contamination of lenses due to harsh industrial environments. The device is compact, easy to carry, and improves analytical accuracy and efficiency.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] A split-type on-site laser-induced breakdown spectroscopy detection device, the device consists of two parts: a handheld laser detector and a control system, which are connected by a plastic-coated tube;

[0006] The handheld laser detector is equipped with a laser, an optical fiber, an optical fiber debugging frame and a fan. The housing of the handheld laser detector is designed with a symmetrical top and bottom and is placed in a positioning slot. The laser excited by the laser is focused on the surface of the sample being tested through a focusing lens.

[0007] The optical fiber is placed inside a plastic-coated tube and fixed on the optical fiber adjustment frame. The optical fiber adjustment frame is fixed to the device surface of the focusing lens with screws. The optical fiber adjustment frame includes a metal cylinder and an optical fiber fixing device. The height, angle and distance of the optical fiber from the excitation point of the sample under test are adjusted by three adjusting screws to facilitate the acquisition of the optimal spectral signal by the optical fiber.

[0008] The handheld laser detector is encapsulated with a fiber optic cover, which is fixed to the focusing lens. The height of the fiber optic cover is the optimal focusing position of the lens. The fiber optic cover is designed as a combination of rectangle and trapezoid. A small rectangle is opened on the upper surface of the trapezoid as the laser excitation point. The small rectangle has fiber optic grooves and fan vents inside, which can increase the air volume while avoiding interference from stray light.

[0009] The handle of the handheld laser detector consists of two parts: a laser interface and a grip. The laser interface includes a laser interface cable, and the grip contains an optical fiber, the laser interface cable, and a fan cable. The bottom of the handle is equipped with a plastic-coated tube connector, the thread of which matches the size of the plastic-coated tube, and the connector is connected to the control system through the plastic-coated tube.

[0010] The handheld laser detector is equipped with a fan on its side, which is fixed to the side of the focusing lens. The outer air inlet is enclosed by a slide rail and has an air inlet on its surface to prevent dust from entering the front excitation point and to avoid dust contamination of the lens during the excitation process.

[0011] The housing of the control system is divided into a front panel, a rear panel, and a body. The front panel is equipped with a three-phase power connector, an emergency stop button, a laser power switch, indicator lights, a control board switch, a plastic-coated pipe connector, and a control board communication interface. The front of the body is embedded in the front panel. The rear panel is equipped with ventilation holes.

[0012] The device housing includes a spectrometer, a laser power supply, a DC power supply, and an FPGA control board. The spectrometer is placed in a mounting bracket, the bottom of which is fixed to the bottom of the device. Four small supports are provided on each of the front and rear sides of the mounting bracket to fix the spectrometer in place. The laser power supply is fixed to the bottom of the device. The DC power supply is fixed to the side of the device. The FPGA control board is connected to a computer via one end of a Type-B cable and to the spectrometer via the other end. The handheld laser detector transmits the spectral signals acquired through optical fiber to the spectrometer to achieve spectral acquisition.

[0013] As can be seen from the technical solution provided by the present invention, the above-mentioned device overcomes the problems of traditional LIBS detectors, such as large size, heavy equipment, low analytical accuracy, cumbersome and complicated operation procedures, and dust contamination of lenses due to harsh industrial environments. The device is small in size, easy to carry, and improves analytical accuracy and efficiency. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of the split-type on-site laser-induced breakdown spectroscopy detection device provided in an embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the handheld laser detector described in an embodiment of the present invention;

[0017] Figure 3 This is a schematic diagram of the control system described in an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments, and do not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0019] like Figure 1 This is a schematic diagram of the structure of the split-type on-site laser-induced breakdown spectroscopy detection device provided in an embodiment of the present invention. The device consists of two parts: a handheld laser detector and a control system. The handheld laser detector and the control system are connected by a plastic-coated tube.

[0020] like Figure 2 The diagram shown is a structural schematic of the handheld laser detector according to an embodiment of the present invention. The handheld laser detector is equipped with a laser 10, an optical fiber 7, an optical fiber debugging frame, and a fan. The housing 6 of the handheld laser detector is designed with symmetrical upper and lower parts and is placed in a positioning slot. The laser emitted by the laser 10 is focused onto the surface of the sample under test by a focusing lens 8. In specific implementation, the focusing lens 8 focuses the parallel light emitted by the laser 10 into a single point. The focal point is the optimal focusing position, which can achieve the best excitation effect.

[0021] The optical fiber 7 is placed inside a plastic-coated tube and fixed on the optical fiber adjustment frame. The optical fiber adjustment frame is fixed to the device surface of the focusing lens 8 with screws. The optical fiber adjustment frame includes a metal cylinder and an optical fiber fixing device. The height, angle and distance of the optical fiber from the excitation point of the sample under test are adjusted by three adjusting screws to facilitate the acquisition of the best spectral signal by the optical fiber.

[0022] The handheld laser detector is encapsulated with an external fiber optic cover 9, which is fixed to the focusing lens 8. The height of the fiber optic cover 9 is the optimal position for lens focusing, which can avoid interference from stray light. The fiber optic cover 9 is designed as a combination of rectangle and trapezoid. A small rectangle is opened on the upper surface of the trapezoid as the laser excitation point. The small rectangle has fiber optic grooves and fan vents inside, which can increase the air volume while avoiding interference from stray light.

[0023] The handle 11 of the handheld laser detector consists of two parts: a laser interface and a grip. The laser interface includes a laser interface cable, and the grip includes an optical fiber, a laser interface cable, and a fan cable. The bottom of the handle 11 is equipped with a plastic-coated tube connector, the thread of which matches the size of the plastic-coated tube, and is connected to the control system through the plastic-coated tube.

[0024] The handheld laser detector is equipped with a fan 1 on its side. The fan 1 is fixed to the side of the focusing lens 8. The outer air inlet is enclosed by a slide rail and has an air inlet on its surface to prevent dust from entering the front excitation point and to avoid dust contamination of the lens during the excitation process.

[0025] like Figure 3 The diagram shown is a structural schematic of the control system according to an embodiment of the present invention. The housing of the control system is divided into a front panel, a rear panel, and a body. The front panel is provided with a three-phase power connector, an emergency stop button, a laser power switch, an indicator light, a control board switch, a plastic-coated pipe connector, and a control board communication interface. The front of the body is embedded in the front panel. The rear panel is provided with ventilation holes.

[0026] The device housing includes a spectrometer 2, a laser power supply 3, a DC power supply 4, and an FPGA control board 5. The spectrometer 2 is placed in a mounting bracket, the bottom of which is fixed to the bottom of the device housing. Four small supports are provided on each of the front and rear sides of the mounting bracket to fix the spectrometer 2 in place. The laser power supply 3 is fixed to the bottom of the device housing. The DC power supply 4 is fixed to the side of the device housing. The FPGA control board 5 is connected to a computer via a Type-B cable at one end and to the spectrometer 2 at the other end. The spectral signal collected by the handheld laser detector through an optical fiber 7 is transmitted to the spectrometer 2 to achieve spectral acquisition.

[0027] The aforementioned split design separates the laser from the control system, thereby improving the efficiency and accuracy of on-site LIBS detection.

[0028] In practice, the laser generates a lot of heat during operation inside the handheld laser detector. The laser is cooled by air through the heat dissipation devices on the surface of the casing and the back cover. At the same time, a semiconductor TEC is used for auxiliary cooling, which is simpler than a water cooling system. The energy range of the single pulse of the laser is 40-100mJ, and the repetition frequency is 1-10Hz.

[0029] The FPGA control board receives and transmits spectral signals via the RS422 communication protocol. It has three signal lines: a synchronization signal, an external Q trigger signal, and a clock signal, to achieve spectral acquisition. To reduce continuous background radiation during spectral acquisition and increase spectral stability, a timing delay is added to the FPGA control board, along with the synchronization signal and the external Q trigger signal, so that the spectrometer 2 acquires spectral signals simultaneously with the laser 10.

[0030] In addition, the spectrometer 2 is a multi-channel fiber optic spectrometer with a wavelength range of 185-840nm, wherein:

[0031] Using UE gratings in the 185nm-408nm wavelength range, with 2400 lines / mm, the average spectral resolution is 0.09-0.13nm;

[0032] Using a VC grating in the wavelength range of 405nm-840nm, with 1200 lines / mm, the average spectral resolution is 0.14-0.18nm;

[0033] Each channel of the spectrometer 2 is equipped with a CMOS detector with a 4096-pixel specification of 7x200um.

[0034] It is worth noting that the contents not described in detail in the embodiments of the present invention belong to the prior art known to those skilled in the art.

[0035] In summary, the device described in the embodiments of the present invention has the following advantages:

[0036] 1. By separating the laser and control system through a split design, the efficiency and accuracy of on-site LIBS detection are improved;

[0037] 2. The multi-channel spectrometer used has higher analytical accuracy and reduces analytical error. Its wavelength range is 185-840nm, and its high resolution meets the analytical accuracy requirements.

[0038] 3. When the laser starts working, controlling the fan switch can effectively prevent dust from entering the cavity and contaminating the lenses during testing;

[0039] 4. The FPGA microcontroller used has a faster operating speed and is more stable. It can be used to control the laser frequency, number of light outputs, delay time, and fan switching. It communicates with the computer through a Type-B cable, resulting in better performance.

[0040] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. The information disclosed in the background section is intended only to enhance the understanding of the overall background technology of the present invention and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art.

Claims

1. A split-type on-site laser-induced breakdown spectroscopy detection device, characterized in that, The device consists of two parts: a handheld laser detector and a control system, which are connected by a plastic-coated tube. The handheld laser detector is equipped with a laser, an optical fiber, an optical fiber debugging frame and a fan. The housing of the handheld laser detector is designed with a symmetrical top and bottom and is placed in a positioning slot. The laser excited by the laser is focused on the surface of the sample being tested through a focusing lens. The optical fiber is placed inside a plastic-coated tube and fixed on the optical fiber adjustment frame. The optical fiber adjustment frame is fixed to the device surface of the focusing lens with screws. The optical fiber adjustment frame includes a metal cylinder and an optical fiber fixing device. The height, angle and distance of the optical fiber from the excitation point of the sample under test are adjusted by three adjusting screws to facilitate the acquisition of the optimal spectral signal by the optical fiber. The handheld laser detector is encapsulated with a fiber optic cover, which is fixed to the focusing lens. The height of the fiber optic cover is the optimal focusing position of the lens. The fiber optic cover is designed as a combination of rectangle and trapezoid. A small rectangle is opened on the upper surface of the trapezoid as the laser excitation point. The small rectangle has fiber optic grooves and fan vents inside, which can increase the air volume while avoiding interference from stray light. The handle of the handheld laser detector consists of two parts: a laser interface and a grip. The laser interface includes a laser interface cable, and the grip contains an optical fiber, the laser interface cable, and a fan cable. The bottom of the handle is equipped with a plastic-coated tube connector, the thread of which matches the size of the plastic-coated tube, and the connector is connected to the control system through the plastic-coated tube. The handheld laser detector is equipped with a fan on its side, which is fixed to the side of the focusing lens. The outer air inlet is enclosed by a slide rail and has an air inlet on its surface to prevent dust from entering the front excitation point and to avoid dust contamination of the lens during the excitation process. The housing of the control system is divided into a front panel, a rear panel, and a body. The front panel is equipped with a three-phase power connector, an emergency stop button, a laser power switch, indicator lights, a control board switch, a plastic-coated pipe connector, and a control board communication interface. The front of the body is embedded in the front panel. The rear panel is equipped with ventilation holes. The device housing includes a spectrometer, a laser power supply, a DC power supply, and an FPGA control board. The spectrometer is placed in a mounting bracket, the bottom of which is fixed to the bottom of the device. Four small supports are provided on each of the front and rear sides of the mounting bracket to fix the spectrometer in place. The laser power supply is fixed to the bottom of the device. The DC power supply is fixed to the side of the device. The FPGA control board is connected to a computer via one end of a Type-B cable and to the spectrometer via the other end. The handheld laser detector transmits the spectral signals acquired through optical fiber to the spectrometer to achieve spectral acquisition.

2. The split-type on-site laser-induced breakdown spectroscopy detection device according to claim 1, characterized in that, Inside the handheld laser detector, the laser is cooled by air through a heat dissipation device on the surface of the housing and the back cover, while a semiconductor TEC is used for auxiliary cooling. The laser's single pulse energy range is 40-100mJ, and its repetition frequency is 1-10Hz.

3. The split-type on-site laser-induced breakdown spectroscopy detection device according to claim 1, characterized in that, The FPGA control board receives and transmits spectral signals via the RS422 communication protocol. It has three signal lines: a synchronization signal, an external Q trigger signal, and a clock signal, to achieve spectral acquisition. By adding timing delay, synchronization signal and external Q trigger signal through the FPGA control board, the spectrometer can acquire spectral signals and the laser can perform simultaneously.

4. The split-type on-site laser-induced breakdown spectroscopy detection device according to claim 1, characterized in that, The spectrometer is a multi-channel fiber optic spectrometer with a wavelength range of 185-840 nm, wherein: Using UE gratings in the 185nm-408nm wavelength range, with 2400 lines / mm, the average spectral resolution is 0.09-0.13nm; Using a VC grating in the wavelength range of 405nm-840nm, with 1200 lines / mm, the average spectral resolution is 0.14-0.18nm; Each channel of the spectrometer is equipped with a 7x200µm CMOS detector with a 4096-pixel specification.

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