Laser remote sensing calibration device

Abstract

The application provides a laser remote measurement calibration device, which comprises a device shell, an optical cavity, a light inlet, a reflector, a powder treatment module, an air inlet module, an air outlet module and an optical detection module. The laser remote measurement calibration device can effectively reduce the influence of the external environment and guarantee the accuracy of the laser remote measurement instrument through the design and accurate regulation of multiple modules. The calibration device can also be applied to the research and performance evaluation of other optical detection equipment. Through scientific and reasonable evaluation tests, the principle test performance is verified, a scientific evaluation method is provided, and the development of related professions and instrument equipment is promoted.

Description

Technical Field

[0001] This invention belongs to the field of laser telemetry calibration technology, specifically relating to a laser telemetry calibration device that provides dynamically adjustable aerosols. Background Technology

[0002] Laser telemetry technology primarily measures the distance, shape, and location of targets such as chemical and biological aerosol clouds by emitting laser beams and analyzing their reflection or scattering characteristics. It boasts high accuracy, good transmission stability, and the ability to perform precise measurements over long distances. Therefore, laser telemetry technology is widely used in various fields such as measurement science, meteorological monitoring, environmental surveillance, and military reconnaissance. Laser telemetry is mainly based on techniques such as Time-of-Flight (TOF), Frequency Modulation-Wave (FMCW), or laser scanning, all of which rely on precise optical systems and sensitive detection equipment. To ensure stable operation of the laser telemetry system under various environmental conditions, calibration is crucial. In laser telemetry, the laser beam characteristics, the alignment of the reflection system, and the detector response can all be affected by environmental conditions (such as temperature, humidity, and air pressure) and equipment aging, leading to deviations in measurement results. To overcome these problems and improve the measurement accuracy of laser telemetry technology, the laser telemetry system needs to be calibrated regularly. The main function of a laser telemetry calibration device is to precisely control the input angle and optical path of the laser, and create an aerosol environment (such as dust, metal powder, or pharmaceuticals) within the optical cavity. This allows for the determination of the absorption degree of lasers with different output powers by powder aerosols of a specific concentration at a specified optical path. This calibrates the output light intensity and detection effect of the laser telemetry system, enabling the calibration and adjustment of the light source, detection system, and optical components. It effectively eliminates measurement errors, ensures that the laser telemetry system can provide stable and accurate measurement data, and ensures that the equipment operates efficiently and accurately for a long time.

[0003] However, most current laser telemetry systems rely on static calibration methods, which are performed under fixed environmental conditions. In particular, the generated aerosols are singular and cannot provide a dynamically adjustable calibration environment to cope with complex usage requirements and constantly changing working conditions, so the calibration effect cannot be guaranteed. Summary of the Invention

[0004] (a) Technical problems to be solved This invention proposes a laser telemetry calibration device that can quickly and accurately provide aerosols with adjustable concentrations, thereby solving the technical problem that the static method used in existing laser telemetry system calibration cannot provide a dynamically adjustable working calibration environment.

[0005] (II) Technical Solution To address the aforementioned technical problems, this invention proposes a laser telemetry calibration device, which includes a device housing, an optical cavity, a light inlet, a reflector, a powder processing module, an air inlet module, an air outlet module, and an optical detection module; wherein... The optical cavity is located inside the device housing. The main body of the optical cavity is cylindrical, and the interior of the optical cavity forms a calibration environment free from external environmental influences. This environment is used to calibrate the laser telemetry instrument by comparing the powder weight with the air intake volume, ensuring measurement accuracy. Cylinders are respectively installed at the upper left and lower right of the main cylinder. The central axis of the upper left cylinder intersects the midpoint of the central axis of the main cylinder, and the central axis of the lower right cylinder overlaps with the central axis of the upper left cylinder. The light inlet is installed through the top of the upper left cylinder of the optical cavity. A reflector is hinged inside the light inlet to guide the light emitted by the laser telemetry instrument into the interior of the optical cavity at a specified angle. The powder processing module is installed at the top center of the outer side of the main cylinder of the optical cavity, and includes a powder dehumidification component, a powder dispersion component, and a powder conduit. The powder dispersion component adopts a dual fluidized bed structure, and the powder outlet is connected to the top center of the inner side of the main cylinder of the optical cavity through the powder conduit, for inputting a known weight of powder into the optical cavity. A powder inlet chamber is provided on the top of the powder dispersion component, and the periphery of the powder inlet chamber is connected to the powder dehumidification component through a mesh, for continuously dehumidifying and drying the powder inside the powder inlet chamber. An air intake module is installed on the top side of the main cylindrical body of the optical cavity to fill the cavity with gas. It includes a pressurization and dispersion component, an adsorption component, a flow monitoring component, and a first air pump. These components are sequentially connected to the interior of the main cylindrical body of the optical cavity via pipelines. The adsorption component dehumidifies and removes impurities from the gas introduced by the first air pump, while the flow monitoring component measures the intake volume of the first air pump. The pressurization and dispersion component pressurizes the gas and delivers it to the interior of the optical cavity. The flow monitoring component includes a housing, a fixed-point interval monitoring component, and a data transmission device. The housing is connected to a connecting pipe, and the fixed-point interval monitoring component is located inside the housing to monitor the gas content flowing through it. The fixed-point interval monitoring component is electrically connected to the data transmission device, which outputs the flow data monitored by the fixed-point interval monitoring component to a remote terminal. The air outlet module is installed at the bottom center of the outer side of the main cylinder of the optical cavity and is connected to the inside of the optical cavity. It is used to export the gas inside the optical cavity. It includes an air outlet and a second air pump. The air outlet and the second air pump are connected to the inside of the main cylinder of the optical cavity through pipelines. The air outlet is installed at the bottom center of the main cylinder of the optical cavity and is used to export the gas inside the optical cavity under the action of the second air pump and prevent impurities from entering the inside of the optical cavity. The optical detection module is installed at the center of the outer right side of the main cylinder of the optical cavity. It is used to detect the fluorescence generated by the excited powder aerosol inside the optical cavity. The absolute concentration of aerosol is calculated by the powder weight and the air intake volume, and compared with the concentration of aerosol detected by the calibrating laser telemetry instrument to calibrate the laser telemetry instrument.

[0006] Furthermore, a retaining ring for isolating vibration is provided between the inner wall of the device housing and the outer wall of the optical cavity.

[0007] Furthermore, the fixing ring includes a support layer and an elastic layer. The support layer has a ring structure, with the outer ring connected to the inner wall of the device housing and the inner ring connected to the outer wall of the optical cavity. An elastic layer is provided at the connection points with both the inner wall of the device housing and the outer wall of the optical cavity. The elastic layer includes a multi-layer elastic damping structure. From the support layer to the inner wall of the device housing and from the support layer to the outer wall of the optical cavity, the thickness and elastic coefficient of each layer of the elastic damping structure increase progressively according to the Fibonacci sequence, decreasing from the device housing to the fixing ring and increasing from the fixing ring to the optical cavity. The elastic damping structure includes multiple horizontally arranged springs and rubber pads for isolating the springs, with the springs and rubber pads arranged alternately.

[0008] Furthermore, the upper left cylinder is at a 10° angle to the central axis of the cylinder, and the lower right cylinder is at a 170° angle to the central axis of the cylinder.

[0009] Furthermore, the adsorption component employs a multi-layer activated carbon layer, with porous activated carbon particles filling the interior of the activated carbon layer. These particles are fixed inside the connecting pipe by a fixing mesh, the mesh size of which is smaller than the size of the activated carbon particles. The adsorption component is equipped with a flow guide to evenly distribute the airflow. The connecting pipe between the first air pump and the adsorption component is spiral-shaped.

[0010] Furthermore, the fixed-point interval monitoring component includes a gas monitoring channel, a gas blowing ball, scale lines, and a fixed-point photographing device. The gas monitoring channel is vertically connected to the connecting pipe, scale lines are provided on the side wall of the gas monitoring channel, a mesh is provided at the connection between the gas monitoring channel and the gas delivery component, the gas blowing ball is located inside the gas monitoring channel, and the mesh is used to catch the gas blowing ball to prevent it from entering the connecting component. A fixed-point photographing device is fixedly installed on the gas monitoring channel, and the fixed-point photographing device is used to take interval photographs of the position of the gas blowing ball at the same location.

[0011] Furthermore, an extinction device is installed at the bottom of the lower right cylinder to absorb the light emitted by the laser telemetry instrument, thereby avoiding light scattering interference with fluorescence detection.

[0012] Furthermore, the interior of the powder dehumidification component is filled with a honeycomb-shaped desiccant.

[0013] Furthermore, the pressurization and dispersion component includes an air inlet and an air outlet. The air inlet is located at the end near the first air pump, and the air outlet is located at the end near the optical cavity. The cross-sectional area of ​​the air inlet is larger than that of the air outlet. Two symmetrical funnel-shaped structures are provided inside the air outlet. The two funnel-shaped structures are connected as one unit through the end with the smaller cross-sectional area to form a fluid channel.

[0014] Furthermore, the air outlet of the air outlet module is designed with a double-layer mesh structure.

[0015] (III) Beneficial Effects This invention proposes a laser telemetry calibration device, comprising a device housing, an optical cavity, a light inlet, a reflector, a powder processing module, an air inlet module, an air outlet module, and an optical detection module. Through the design and precise control of multiple modules, this laser telemetry calibration device effectively reduces the influence of the external environment, ensuring the accuracy of the laser telemetry instrument. This calibration device can also be applied to the research and performance evaluation of other optical detection equipment. Through scientific and reasonable evaluation tests, it verifies the principle, tests performance, and provides scientific assessment methods, thus promoting the development of related disciplines and instruments. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the external structure of the laser telemetry calibration device of the present invention; Figure 2 This is a schematic diagram of the internal structure of the laser telemetry calibration device of the present invention; Figure 3 This is a schematic diagram of the powder dispersion component in this invention; Figure 4 This is a schematic diagram of the structure of a fixed-point interval monitoring component.

[0017] In the diagram: 1-Light inlet; 2-Reflector; 3-Powder dehumidification component; 4-Powder dispersion component; 5-Powder conduit; 6-Optical cavity; 7-Pressure-boosting dispersion component; 8-Adsorption component; 9-Flow monitoring component; 10-First air pump; 11-Optical detection module; 12-Extinction device; 13-Air outlet; 14-Second air pump; 15-Housing; 16-Fixing ring; 17-Gas monitoring channel; 18-Gas blowing ball; 19-Scale line; 20-Fixed-point imaging device; 21-Temperature and humidity sensor. Detailed Implementation

[0018] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0019] This invention proposes a laser telemetry calibration device, the structure of which is as follows: Figure 1 and 2As shown, the device mainly includes a housing 15, an optical cavity 6, a fixing ring 16, a light inlet 1, an extinction device 12, a reflector 2, a powder processing module, an air inlet module, an air outlet module, an optical detection module 11, and a temperature and humidity sensor 21.

[0020] The housing 15 is square in shape and primarily serves to protect and support the internal components of the calibration device. The optical cavity 6 is located inside the housing 15. A retaining ring 16 is positioned between the inner wall of the housing 15 and the outer wall of the optical cavity 6 to isolate vibrations and ensure the accuracy of the measurement data. The retaining ring 16 comprises a support layer and an elastic layer. The support layer is annular, with its outer ring connected to the inner wall of the housing 15 and its inner ring connected to the outer wall of the optical cavity 6. Elastic layers are provided at the connections between the support layer and both the inner and outer walls of the housing 15 and the optical cavity 6. Each elastic layer comprises multiple layers of elastic damping structures. From the support layer to the inner wall of the housing 15 and from the support layer to the outer wall of the optical cavity 6, the thickness and elastic coefficient of each layer increase progressively according to the Fibonacci sequence. This decrease from the housing 15 to the retaining ring 16, followed by a further increase from the retaining ring 16 to the optical cavity 6, simultaneously reduces energy rebound and isolates vibrations, preventing the internal structure of the optical cavity 6 from being affected and ensuring measurement accuracy. The elastic damping structure includes multiple horizontally arranged springs and rubber pads that isolate the springs. The springs and rubber pads are arranged alternately, and the elastic coefficient of each layer of the elastic damping structure can be adjusted by changing the thickness and length of the springs.

[0021] The main body of the optical cavity 6 is cylindrical. The interior of the optical cavity 6 forms a calibration environment free from external environmental influences, used to calibrate the laser telemetry instrument by comparing the powder weight with the air intake volume, ensuring measurement accuracy. Cylinders are welded to the upper left and lower right of the main cylinder. The central axis of the upper left cylinder intersects the midpoint of the central axis of the main cylinder, and the central axis of the lower right cylinder overlaps with the central axis of the upper left cylinder. The upper left cylinder forms a 10° angle with the central axis of the main cylinder, and the lower right cylinder forms a 170° angle. The light inlet 1 is installed through the top of the upper left cylinder of the optical cavity 6. The light inlet 1 has a square structure and a reflector 2 is hinged inside. The reflector 2 can rotate within a 180° range, used to guide the light emitted by the laser telemetry instrument into the interior of the optical cavity 6 at a specified angle. An extinction device 12 is installed at the bottom of the lower right cylinder, used to absorb the light emitted by the laser telemetry instrument, thereby preventing light scattering interference with fluorescence detection.

[0022] The powder processing module is installed at the top center of the outer side of the main cylinder of the optical cavity 6, and includes a powder dehumidification component 3, a powder dispersion component 4, and a powder conduit 5. The powder dispersion component 4 adopts a dual fluidized bed structure, and its powder outlet is connected to the inner top center of the main cylinder of the optical cavity 6 via the powder conduit 5, for inputting a known weight of powder into the optical cavity 6. A powder inlet chamber is located at the top of the powder dispersion component 4, and the periphery of the powder inlet chamber is connected to the powder dehumidification component 3 through a mesh. The powder dehumidification component 3 is filled with a honeycomb-shaped desiccant for continuous dehumidification and drying of the powder inside the powder inlet chamber, removing moisture from the powder, preventing powder agglomeration, and ensuring good flowability and stability of the powder during subsequent use. By calculating the amount of powder entering, the powder processing module controls the concentration of the powder aerosol, providing a standard for quantitatively calculating the light absorption of the telemetry laser at a specific optical path, thereby ensuring the accuracy of calibration. Simultaneously, by adjusting the powder mass through the powder processing module, the concentration of the powder aerosol within the optical cavity 6 can be dynamically adjusted, achieving linear dynamic calibration of the telemetry laser output power.

[0023] An air inlet module is installed on the top side of the main cylindrical body of the optical cavity 6 to fill the interior of the optical cavity 6 with gas. It includes a pressurization and dispersion component 7, an adsorption component 8, a flow monitoring component 9, and a first air pump 10. These components are sequentially connected to the interior of the main cylindrical body of the optical cavity 6 via pipelines. The adsorption component 8 further dehumidifies and removes impurities from the gas introduced by the first air pump 10, while the flow monitoring component 9 measures the intake volume of the first air pump 10 to ensure accurate calibration data. The pressurization and dispersion component 7 pressurizes the gas before delivering it into the optical cavity 6. The adsorption component 8 uses a multi-layer activated carbon layer, filled with porous activated carbon particles, which are fixed inside the connecting pipe by a mesh with a pore size smaller than the activated carbon particles. The adsorption component 8 is equipped with a flow guide to evenly distribute the airflow, ensuring sufficient contact between the gas and the activated carbon to maximize the adsorption effect. The connecting pipe between the first air pump 10 and the adsorption component 8 is spiral-shaped to effectively guide airflow through every corner of the adsorption component 8. The pressurized dispersion component 7 includes an air inlet and an air outlet. The air inlet is located at the end near the first air pump 10, and the air outlet is located at the end near the optical cavity 6. The cross-sectional area of ​​the air inlet is larger than that of the air outlet. Two symmetrical funnel-shaped structures are arranged inside the air outlet. The two funnel-shaped structures are connected as one piece through the end with the smaller cross-sectional area to form a fluid channel.

[0024] The flow monitoring component 9 includes a flow monitoring component housing, a fixed-point interval monitoring component, and a data transmission component. The flow monitoring component housing is connected to the connecting pipe. The fixed-point interval monitoring component is located inside the flow monitoring component housing and is used to accurately monitor the gas content flowing through the fixed-point interval monitoring component. The fixed-point interval monitoring component is electrically connected to the data transmission component, which is used to output the flow data monitored by the fixed-point interval monitoring component to a remote terminal.

[0025] The fixed-point interval monitoring component includes a gas monitoring channel 17, a gas-blowing ball 18, a scale line 19, and a fixed-point photographing device 20. The gas monitoring channel 17 is vertically connected to the connecting pipe. The scale line 19 is provided on the side wall of the gas monitoring channel 17. A mesh is provided at the connection between the gas monitoring channel 17 and the gas delivery component 17. The gas-blowing ball 18 is disposed inside the gas monitoring channel 17, and the mesh is used to catch the gas-blowing ball 18 to prevent it from entering the connecting component. The fixed-point photographing device 20 is fixedly installed on the gas monitoring channel 17. The fixed-point photographing device 20 is used to take interval photographs of the position of the gas-blowing ball 18 at the same location. The photographing interval of the fixed-point photographing device 20 is 2 minutes.

[0026] When the gas flows through the connecting pipe, it enters the transparent gas monitoring channel 17 vertically. The gas with extremely low density in the channel blows the small ball 18. The greater the airflow, the higher the small ball 18 rises. The inner wall of the channel is laser-etched with scale lines 19. The fixed-point imaging device 20 takes pictures of the position of the gas blowing the small ball 18 from the same angle every 2 minutes. The embedded algorithm identifies the scale value and substitutes it into the temperature compensation curve, so that the displacement of the small ball can be converted into real-time volumetric flow rate. Finally, the data is wirelessly sent to the remote terminal via the MQTT protocol, realizing contactless, low-power, ±2% FS accuracy fixed-point interval flow monitoring.

[0027] In use, the fixed-point photography device 20 accumulates the position scale of the gas blowing ball 18 at the same time intervals to accurately obtain the flow rate of gas flowing through the gas monitoring channel 17 during the calculation process, and transmits it to the remote terminal.

[0028] The specific steps for accumulating the scale values ​​on the image are as follows: Image preprocessing: First, the image needs to be preprocessed, including noise removal, contrast and brightness adjustment, etc., to ensure the accuracy of subsequent processing.

[0029] Image segmentation: Using image processing techniques, such as thresholding, edge detection, or region growing, to separate the scale lines from the background.

[0030] Detecting tick marks: The position and orientation of tick mark 19 are detected using image processing algorithms. Techniques such as Hough transform or edge detection can be used to detect straight lines and filter out those related to tick mark 19.

[0031] Extracting scale values: Analyze the detected scale line 19 to extract the numbers or markings on the scale line 19. Character recognition technology, such as optical character recognition, can be used to identify the numbers or text on the scale line 19.

[0032] Numerical accumulation: The extracted scale values ​​are accumulated. Based on the position and direction of scale line 19, the actual value corresponding to each scale value can be determined. These values ​​are then accumulated to obtain the total value on the image.

[0033] Correction and adjustment: Depending on the specific circumstances, correction and adjustment may be necessary. For example, considering factors such as the spacing of the scale lines, errors, and image distortion, it may be necessary to correct and adjust the accumulated values.

[0034] The temperature and humidity sensor 21 is installed inside the upper part of the optical cavity 6, below the air outlet of the pressurization and dispersion component 7, to detect the temperature and humidity inside the optical cavity 6 and to compensate for the ambient temperature and humidity inside the cavity.

[0035] The air outlet module is installed at the center of the bottom of the main cylinder of the optical cavity 6, and is in communication with the interior of the optical cavity 6. It is used to exhaust the gas inside the optical cavity 6. It includes an air outlet 13 and a second air pump 14. The air outlet 13 and the second air pump 14 are connected to the interior of the main cylinder of the optical cavity 6 in sequence through pipelines. The air outlet 13 is installed in the center of the bottom of the main cylinder of the optical cavity 6. The air outlet 13 is set with a double-layer mesh structure, which is used to exhaust the gas inside the optical cavity 6 under the action of the second air pump 14 and prevent impurities from entering the interior of the optical cavity 6.

[0036] The optical detection module 11 is installed at the center of the outer right side of the main cylinder of the optical cavity 6. It is used to detect the fluorescence generated by the excited powder aerosol inside the optical cavity 6, calculate the absolute concentration of aerosol by the powder weight and the air intake volume, and compare it with the concentration of aerosol detected by the calibrating laser telemetry instrument to calibrate the laser telemetry instrument.

[0037] The working principle of this invention is as follows: In use, the laser telemetry instrument is activated to emit a laser beam. The incident angle of the laser is adjusted by rotating the reflector 2 at the light inlet 1 to ensure that the laser beam accurately enters the optical cavity 6. Before use, the powder dehumidification component 3 is activated to remove moisture from the powder, preventing powder clumping and ensuring uniformity within the optical cavity 6. The treated powder is introduced into the optical cavity 6 through the powder conduit 5 to ensure uniform powder distribution and prevent inaccurate laser calibration results due to uneven powder distribution. The first air pump 10a and the second air pump 14 are activated to provide airflow into the optical cavity 6. The flow control system of the air pumps is adjusted as needed to ensure stable and uniform gas flow. The gas entering the optical cavity 6 is cleaned by the adsorption component 8 to ensure gas purity and prevent impurities from interfering with the laser signal. The laser beam enters the optical cavity 6 through the adjusted light inlet 1, interacting with the powder within the optical cavity 6 to complete the precise telemetry calibration process. At this time, the laser path and powder state within the optical cavity need to be carefully observed to ensure the accuracy of the calibration process. The gas flow rate and powder state within the optical cavity 6 are monitored by a fixed-point interval monitoring component to ensure ideal environmental conditions throughout the calibration process. A fixed-point imaging device 20 periodically records data and gas flow during the calibration process, ensuring accurate recording of the status and data at each step. The calibration effect is evaluated by analyzing the monitored data and photographic records. If deviations or inconsistencies are found, adjustments can be made by fine-tuning the laser intensity, powder distribution, or gas flow rate. After calibration, the gas pump, laser, and other equipment are shut down, and components such as the optical cavity 6 and powder conduit 5 are cleaned to ensure the equipment is clean and free of powder residue for the next use.

[0038] Example 1: Calibration of a laser telemetry instrument for measuring the particle size of metal powder Use cases: Precise particle size control is crucial for the powder metallurgy industry during metal powder production. Laser telemetry technology can be used to measure the particle size distribution of metal powders, while calibration devices are used to ensure the accuracy of the measurements.

[0039] Calibration data: Laser wavelength: 850nm Output power: 20mW (adjustable power range: 15mW~25mW) Detector accuracy: ±0.2μm (for error control when measuring particles in the range of 0.5μm to 100μm) Particle size measurement range: 0.1μm~500μm Calibration cycle: Calibration is performed monthly to ensure long-term stable measurement results.

[0040] Key technologies: Temperature and humidity compensation: The temperature and humidity sensor 21 automatically monitors the temperature (-10℃~40℃) and humidity (20%~80% RH) inside the optical cavity 6, and adjusts the measurement settings according to these parameters to ensure that the measurement error does not exceed ±0.5μm under different environmental conditions.

[0041] Example 2: Calibration of a laser telemetry instrument for measuring the particle size of ceramic powder Use cases: In the ceramics industry, the uniformity of powder particles is crucial for the sintering process. Laser telemetry technology is often used to measure the particle size and distribution of ceramic powders, thus requiring regular calibration to ensure accuracy.

[0042] Calibration data: Laser wavelength: 532nm Output power: 10mW (adjustable power range: 8mW~12mW) Particle size measurement range: 0.5μm~200μm Measurement accuracy: ±0.1μm (for particles smaller than 10μm, the error is ±0.05μm) Calibration cycle: Calibrate once a week to eliminate system drift that may be caused by ceramic powder.

[0043] Key technologies: Real-time temperature compensation: The built-in temperature and humidity sensor 21 can detect temperature changes in real time and adjust the laser power through an algorithm to avoid the influence of temperature fluctuations on the measurement results.

[0044] Example 3: Calibration of a laser telemetry instrument for measuring the particle size of pharmaceutical powders Use cases: In the pharmaceutical industry, the particle size of powder directly affects the dissolution rate and bioavailability of drugs; therefore, laser telemetry is required for precise particle size measurement of pharmaceutical powders. To ensure the accuracy of the measurement results, the equipment must be calibrated regularly.

[0045] Calibration data: Laser wavelength: 780nm Output power: 12mW (adjustable power range: 8mW~16mW) Particle size measurement range: 0.2μm~150μm Measurement accuracy: ±0.3μm (for particles smaller than 5μm, the error is controlled within ±0.2μm) Calibration cycle: Calibration is performed every two weeks to ensure accuracy during continuous production.

[0046] Key technologies: Humidity compensation: Pharmaceutical powders may easily absorb moisture in high humidity environments, affecting their particle size. The built-in temperature and humidity sensor 21 automatically adjusts calibration parameters to ensure that humidity fluctuations do not affect laser measurements.

[0047] Example 4: Calibration of a laser telemetry instrument for monitoring bioaerosol clouds Use cases: In the field of environmental monitoring, bioaerosols can cause various adverse reactions to human health, such as acute toxicity, infectious diseases, and allergies. Therefore, real-time monitoring of potentially leaking bioaerosol clouds is necessary. Laser remote sensing technology for bioaerosol clouds can achieve large-scale monitoring. Based on laser-induced fluorescence technology, it generates fluorescence by irradiating aerosol particles with a laser, and the fluorescence signal is analyzed to obtain an approximate concentration of bioaerosols. Therefore, calibration devices are required to ensure the accuracy of the monitoring data.

[0048] Calibration data: Laser wavelength: 355nm Pulse frequency: 2.5kHz Output power: 26.36mW Calibration cycle: Calibration is performed once a month, and a self-test is performed before each measurement.

[0049] Key technologies: Bioaerosol generation: Riboflavin is sprayed into optical cavity 6 via a powder processing module, and a dilution airflow is provided by the air intake module to dilute the riboflavin aerosol to the required concentration to simulate bacterial aerosols. Because different bacteria vary in size, bioaerosol monitoring typically only measures the number of biological particles. This laser telemetry calibration device creates an aerosol with the required concentration, which is then irradiated by the telemetry laser output from the bioaerosol cloud laser telemetry instrument. The excited fluorescence signal is quantitatively compared to calibrate the concentration value output by the instrument.

[0050] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A laser telemetry calibration device, characterized in that, The laser telemetry calibration device includes a device housing, an optical cavity, a light inlet, a reflector, a powder processing module, an air inlet module, an air outlet module, and an optical detection module; wherein... The optical cavity is located inside the device housing. The main body of the optical cavity is cylindrical, and the interior of the optical cavity forms a calibration environment free from external environmental influences. This environment is used to calibrate the laser telemetry instrument by comparing the powder weight with the air intake volume, ensuring measurement accuracy. Cylinders are respectively installed at the upper left and lower right of the main cylinder. The central axis of the upper left cylinder intersects the midpoint of the central axis of the main cylinder, and the central axis of the lower right cylinder overlaps with the central axis of the upper left cylinder. The light inlet is installed through the top of the upper left cylinder of the optical cavity. A reflector is hinged inside the light inlet to guide the light emitted by the laser telemetry instrument into the interior of the optical cavity at a specified angle. The powder processing module is installed at the top center of the outer side of the main cylinder of the optical cavity, and includes a powder dehumidification component, a powder dispersion component, and a powder conduit. The powder dispersion component adopts a dual fluidized bed structure, and the powder outlet is connected to the top center of the inner side of the main cylinder of the optical cavity through the powder conduit, for inputting a known weight of powder into the optical cavity. A powder inlet chamber is provided on the top of the powder dispersion component, and the periphery of the powder inlet chamber is connected to the powder dehumidification component through a mesh, for continuously dehumidifying and drying the powder inside the powder inlet chamber. An air intake module is installed on the top side of the main cylindrical body of the optical cavity to fill the cavity with gas. It includes a pressurization and dispersion component, an adsorption component, a flow monitoring component, and a first air pump. These components are sequentially connected to the interior of the main cylindrical body of the optical cavity via pipelines. The adsorption component dehumidifies and removes impurities from the gas introduced by the first air pump, while the flow monitoring component measures the intake volume of the first air pump. The pressurization and dispersion component pressurizes the gas and delivers it to the interior of the optical cavity. The flow monitoring component includes a housing, a fixed-point interval monitoring component, and a data transmission device. The housing is connected to a connecting pipe, and the fixed-point interval monitoring component is located inside the housing to monitor the gas content flowing through it. The fixed-point interval monitoring component is electrically connected to the data transmission device, which outputs the flow data monitored by the fixed-point interval monitoring component to a remote terminal. The air outlet module is installed at the bottom center of the outer side of the main cylinder of the optical cavity and is connected to the inside of the optical cavity. It is used to export the gas inside the optical cavity. It includes an air outlet and a second air pump. The air outlet and the second air pump are connected to the inside of the main cylinder of the optical cavity through pipelines. The air outlet is installed at the bottom center of the main cylinder of the optical cavity and is used to export the gas inside the optical cavity under the action of the second air pump and prevent impurities from entering the inside of the optical cavity. The optical detection module is installed at the center of the outer right side of the main cylinder of the optical cavity. It is used to detect the fluorescence generated by the excited powder aerosol inside the optical cavity. The absolute concentration of aerosol is calculated by the powder weight and the air intake volume, and compared with the concentration of aerosol detected by the calibrating laser telemetry instrument to calibrate the laser telemetry instrument.

2. The laser telemetry calibration device as described in claim 1, characterized in that, A retaining ring for isolating vibration is provided between the inner wall of the device housing and the outer wall of the optical cavity.

3. The laser telemetry calibration device as described in claim 2, characterized in that, The fixed ring includes a support layer and an elastic layer. The support layer has a ring structure, with the outer ring connected to the inner wall of the device housing and the inner ring connected to the outer wall of the optical cavity. An elastic layer is provided at the connection points with both the inner wall of the device housing and the outer wall of the optical cavity. The elastic layer includes a multi-layer elastic damping structure. From the support layer to the inner wall of the device housing and from the support layer to the outer wall of the optical cavity, the thickness and elastic coefficient of each layer of the elastic damping structure increase progressively according to the Fibonacci sequence, decreasing from the device housing to the fixed ring and increasing from the fixed ring to the optical cavity. The elastic damping structure includes multiple horizontally arranged springs and rubber pads for isolating the springs, with the springs and rubber pads arranged alternately.

4. The laser telemetry calibration device as described in claim 1, characterized in that, The upper left cylinder is at a 10° angle to the central axis of the cylinder, and the lower right cylinder is at a 170° angle to the central axis of the cylinder.

5. The laser telemetry calibration device as described in claim 1, characterized in that, The adsorption component uses a multi-layer activated carbon layer, with porous activated carbon particles inside. These particles are fixed inside the connecting pipe by a fixing mesh, the mesh size of which is smaller than that of the activated carbon particles. The adsorption component is equipped with a flow guide to evenly distribute the airflow. The connecting pipe between the first air pump and the adsorption component is spiral-shaped.

6. The laser telemetry calibration device as described in claim 1, characterized in that, The fixed-point interval monitoring component includes a gas monitoring channel, a gas blowing ball, scale lines, and a fixed-point photographing device. The gas monitoring channel is vertically connected to the connecting pipe, and scale lines are provided on the side wall of the gas monitoring channel. A mesh is provided at the connection between the gas monitoring channel and the gas delivery component. The gas blowing ball is located inside the gas monitoring channel, and the mesh is used to catch the gas blowing ball to prevent it from entering the connecting component. A fixed-point photographing device is fixedly installed on the gas monitoring channel, and this device is used to take interval photographs of the position of the gas blowing ball at the same location.

7. The laser telemetry calibration device as described in claim 1, characterized in that, The extinction device is installed at the bottom of the lower right cylinder to absorb the light emitted by the laser telemetry instrument, thereby avoiding light scattering interference with fluorescence detection.

8. The laser telemetry calibration device as described in claim 1, characterized in that, The interior of the powder dehumidification unit is filled with a honeycomb-shaped desiccant.

9. The laser telemetry calibration device as described in claim 1, characterized in that, The pressurization and dispersion component includes an air inlet and an air outlet. The air inlet is located at the end near the first air pump, and the air outlet is located at the end near the optical cavity. The cross-sectional area of ​​the air inlet is larger than that of the air outlet. Two symmetrical funnel-shaped structures are arranged inside the air outlet. The two funnel-shaped structures are connected as one piece through the end with the smaller cross-sectional area to form a fluid channel.

10. The laser telemetry calibration device as described in claim 1, characterized in that, The air outlet of the air outlet module is designed with a double-layer mesh structure.

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