Ultraviolet photolysis ozone detector with self-calibration function

Abstract

The present invention relates to the technical field of environmental monitoring, and discloses an ultraviolet photolysis ozone detector with a self-calibration function, the ultraviolet photolysis ozone detector comprises a cabinet, an isolation layer and an isolation plate are arranged in the cabinet, and the internal space is divided into an electric control area and a gas path area which are mutually sealed. Core electronic elements such as a main circuit board and the like are arranged in the electric control area, and all components such as an ultraviolet absorption cell and the like which are in contact with gas are arranged in the gas path area. A fan and a heat conducting plate are arranged in the electric control area, heat is conducted to the outside through internal air circulation, and effective heat dissipation in a sealed state is achieved. The detector is also integrated with a set of self-calibration system which comprises an ozone washing device and an ozone generator, and a main control unit controls an electromagnetic valve group to automatically switch gas paths and execute zero point and span calibration. Circuit corrosion is prevented through physical isolation design, high precision of long-term measurement is guaranteed through an automatic calibration function, reliability is improved through sealing heat dissipation, the service life of equipment is remarkably prolonged, and maintenance cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of environmental monitoring technology, specifically to an ultraviolet photolysis ozone detector with self-calibration function. Background Technology

[0002] Ozone is a key indicator for assessing air quality, and its accurate concentration measurement is of great significance in environmental science research, air quality forecasting, and industrial process control. Among existing detection technologies, the ultraviolet absorption method based on Lambert-Beer's law is widely used due to its high sensitivity and strong specificity for ozone molecules.

[0003] However, existing ozone detectors based on this principle generally suffer from several technical shortcomings during long-term operation. First, the measurement accuracy of the instrument drifts over time. This is mainly due to the performance degradation of core optical components; for example, the intensity of the ultraviolet light source gradually decreases, and the sensitivity of the photodetector also changes. To correct for such deviations, existing equipment typically needs to be periodically returned to the laboratory or manually calibrated on-site by specialized technicians using standard equipment. This process not only interrupts continuous monitoring but also significantly increases the maintenance costs and operational complexity of the equipment.

[0004] Furthermore, existing instruments often fail to adequately consider the impact of ozone's strong corrosiveness on the stability of the equipment in their structural design. In many designs, the gas path components and core electronic control units, such as the main circuit board, are placed in the same unisolated enclosure. Once a small amount of ozone leaks due to aging connections or poor sealing in the gas path system, these highly oxidizing gases will diffuse throughout the internal space, gradually corroding the solder joints, pins, and precision components on the circuit board, ultimately leading to abnormal signals, system malfunctions, and even permanent damage to the equipment, thus shortening the instrument's effective lifespan.

[0005] Meanwhile, the heat generated by the internal electronic components of the instrument during operation presents a technical dilemma. A common practice to dissipate heat from components such as the main circuit board is to use a fan to draw ambient air into the chassis for convection cooling. However, this method brings in dust, moisture, and other contaminants from the air, which can adhere to the circuit board and cause circuit malfunctions. If a completely sealed solution is used to protect the circuitry, the heat generated by the electronic components cannot be effectively dissipated, leading to excessively high internal temperatures, affecting the stability of system operation, and accelerating component aging. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides an ultraviolet photolysis ozone detector with self-calibration function, which solves the problems in existing technologies, such as ozone leakage and corrosion of electronic components due to ineffective isolation between the gas path and the circuit, heat dissipation difficulties of the core circuit in a closed and clean environment, and the need for frequent manual intervention for calibration due to measurement drift.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an ultraviolet photolysis ozone detector with self-calibration function, comprising a chassis and an isolation layer. Multiple heat dissipation holes are provided on both sides of the chassis. A display screen is electrically connected to one side of the chassis. A handle is fixedly connected to the top of the chassis. The bottom of the isolation layer is fixedly connected inside the chassis. A main circuit board is fixedly connected inside the isolation layer. The main circuit board contains an ozone detection system. A heat dissipation component is fixedly connected inside the isolation layer. An isolation plate is fixedly connected inside the isolation layer. An air guide pipe is fixedly connected inside the isolation layer. An air intake component is provided at one end of the air guide pipe. Solenoid valve one and solenoid valve two are fixedly connected to the other two ends of the air guide pipe, respectively. A flow pipe one is fixedly connected to the bottom end of solenoid valve one, and a flow pipe two is fixedly connected to the bottom end of solenoid valve two. A calibration component is provided at one end of flow pipe two, and a merging block is fixedly connected to one end of flow pipe one. A detection component is provided on one side of the merging block, and an exhaust component is provided on one side of the inner wall of the isolation layer.

[0008] Preferably, the heat dissipation component includes a fan and a heat-conducting plate. The outer wall of the fan is fixedly connected inside the isolation layer, the outer wall of the heat-conducting plate passes through one side of the isolation layer, and the fan side is located on one side of the main circuit board.

[0009] Preferably, the air intake assembly includes an air intake pipe and a filter. One end of the air intake pipe is fixedly connected to one end of the air guide pipe, the inner wall of the filter is fixedly connected to the inside of the air intake pipe, and the outer wall of the air intake pipe passes through the inside of the filter.

[0010] Preferably, the calibration assembly includes an ozone remover and an ozone generator. One end of the ozone remover is fixedly connected to one end of the flow pipe 2. The output end of the ozone remover is fixedly connected to multiple transport pipes 1. One of the transport pipes 1 is fixedly connected to a solenoid valve 3 inside. One end of another transport pipe 1 is fixedly connected to one side of the confluence block. The bottom of the ozone generator is fixedly connected to the inside of the isolation layer. The output end of the ozone generator is fixedly connected to a transport pipe 2. One end of the transport pipe 2 is fixedly connected to the top of the confluence block.

[0011] Preferably, the detection component includes a mass flow controller and an ultraviolet absorption cell. The input end of the mass flow controller is fixedly connected to one side of the confluence block, the output end of the mass flow controller is fixedly connected to the input end of the ultraviolet absorption cell, the bottom of the ultraviolet absorption cell is fixedly connected inside the isolation layer, and the output end of the ultraviolet absorption cell is fixedly connected to an outflow pipe.

[0012] Preferably, the exhaust assembly includes an intake pump and an exhaust pipe, with the input end of the intake pump fixedly connected to one end of the outlet pipe, and one end of the exhaust pipe fixedly connected to the output end of the intake pump, the exhaust pipe passing through the interior of the isolation layer.

[0013] Preferably, the first solenoid valve and the second solenoid valve are arranged in a symmetrical array on the inner wall of the isolation layer, with one side of the first solenoid valve fixedly connected to the inner wall of the isolation layer and the other side of the second solenoid valve fixedly connected to the inner wall of the isolation layer.

[0014] Preferably, the ozone generator and the mass flow controller are arranged in a parallel array on one side of the isolation plate, and the ozone remover and the mass flow controller are also arranged in a parallel array on one side of the isolation plate.

[0015] Preferably, the ozone detection system includes: The main control unit, which is set on the main circuit board, is used to control the detector to switch between measurement mode, zero-point calibration mode and span calibration mode, and is responsible for processing data and executing algorithms. The measuring gas path is controlled by the main control unit. In the measurement mode, the sample gas from the inlet assembly is sequentially guided through the flow pipe, the merging block, and the detection assembly consisting of a mass flow controller and an ultraviolet absorption cell by opening the solenoid valve. The self-calibrating gas path, controlled by the main control unit, guides the sample gas to the calibration component by opening solenoid valve two in calibration mode. The calibration component selectively performs one of the following two operations according to the instructions of the main control unit: Zero-point gas is generated by an ozone purifier and then transported to the confluence block. The zero-point gas generated by the ozone scrubber is further guided to the ozone generator to generate the span standard gas, and then delivered to the confluence block. The main control unit is further configured to: receive and process signals from the detection component, calculate ozone concentration according to Beer-Lambert's law, and after performing self-calibration, use the updated zero-point baseline and calibration coefficient to perform subsequent concentration calculations, and finally display the results on the display screen.

[0016] Preferably, the main control unit is further configured to perform the following operations in the calibration mode: Perform zero-point calibration: control the opening of the second solenoid valve to connect the self-calibration gas path, guide the sample gas through the ozone remover to generate zero-point gas, and automatically update and store the zero-point baseline based on the measurement signal of the zero-point gas by the detection component; Perform span calibration: After completing the zero-point calibration, the solenoid valve is further controlled to open, and the generated zero-point gas is guided to the ozone generator to generate a span standard gas of a preset concentration. The measured value of the span standard gas by the detection component is compared with the preset concentration value stored internally, and the response calibration coefficient is automatically calculated and updated. Application of calibration results: After calibration is completed, the control gas path returns to measurement mode, and in subsequent concentration calculations, the updated zero-point baseline and the response calibration coefficient are automatically invoked.

[0017] This invention provides an ultraviolet photolysis ozone detector with self-calibration function. It has the following beneficial effects: 1. This invention clearly divides the internal space into a sealed electrical control area and a gas passage area by setting an isolation layer and isolation plate inside the chassis. This structure physically isolates the corrosive ozone gas that may leak from the gas passage area from contacting the main circuit board and other precision electronic components in the electrical control area, fundamentally avoiding damage or failure of the circuit due to chemical corrosion, thereby ensuring the long-term stable operation of the entire machine.

[0018] 2. This invention utilizes an internal fan to create forced air circulation within the sealed electronic control area, efficiently transferring the heat generated by the main circuit board to a heat-conducting plate that penetrates the insulation layer. The heat is then conducted to the outside of the isolation area and dissipated. This design solves the heat dissipation problem of core electronic components without compromising the physical seal of the electronic control area or exchanging air with the outside, ensuring that the main circuit board operates stably within a suitable temperature range.

[0019] 3. This invention incorporates a self-calibration component consisting of an ozone remover, an ozone generator, and related solenoid valves. The main control unit executes an automatic calibration program, enabling periodic automatic correction of the instrument's zero point and range. This design effectively compensates for measurement drift caused by UV light decay, detector aging, or environmental changes, ensuring the instrument can output highly accurate and reliable concentration data over a long period without frequent manual intervention. Attached Figure Description

[0020] Figure 1 This is a perspective view of the present invention; Figure 2 This is a schematic diagram of the internal structure of the chassis of the present invention; Figure 3 This is a schematic diagram of the internal structure of the isolation layer of the present invention; Figure 4This is a schematic diagram of the ultraviolet absorption cell structure of the present invention; Figure 5 for Figure 4 A magnified view of the structure at point A in the middle; Figure 6 for Figure 4 A magnified schematic diagram of the structure at point B in the middle; Figure 7 This is a functional block diagram of the ozone detection system of the present invention; Figure 8 This is a flowchart illustrating the self-calibration method of the present invention.

[0021] The components are as follows: 1. Chassis; 2. Heat dissipation holes; 3. Display screen; 4. Handle; 5. Insulation layer; 6. Main circuit board; 7. Fan; 8. Heat conduction plate; 9. Isolation plate; 10. Air inlet pipe; 11. Filter; 12. Air guide pipe; 13. Solenoid valve one; 14. Solenoid valve two; 15. Flow pipe one; 16. Flow pipe two; 17. Ozone remover; 18. Transport pipe one; 19. Solenoid valve three; 20. Ozone generator; 21. Transport pipe two; 22. Confluence block; 23. Mass flow controller; 24. Ultraviolet absorption cell; 25. Outlet pipe; 26. Intake pump; 27. Exhaust pipe. Detailed Implementation

[0022] The technical solutions in 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please see the appendix Figure 1 -Appendix Figure 6 This invention provides an ultraviolet photolysis ozone detector with self-calibration function, including a chassis 1 and an isolation layer 5. The chassis 1 has multiple heat dissipation holes 2 on both sides. A display screen 3 is electrically connected to one side of the chassis 1. A handle 4 is fixedly connected to the top of the chassis 1. The bottom of the isolation layer 5 is fixedly connected to the inside of the chassis 1. A main circuit board 6 is fixedly connected inside the isolation layer 5. The main circuit board 6 has an ozone detection system built into it. A heat dissipation component is fixedly connected inside the isolation layer 5. An isolation plate 9 is fixedly connected inside the isolation layer 5. An air guide pipe 12 is fixedly connected inside the isolation layer 5. An air intake component is provided at one end of the air guide pipe 12. Solenoid valve 13 and solenoid valve 2 are fixedly connected at the other two ends of the air guide pipe 12, respectively. A flow pipe 15 is fixedly connected to the bottom end of solenoid valve 13. A flow pipe 26 is fixedly connected to the bottom end of solenoid valve 24. A calibration component is provided at one end of flow pipe 26. A confluence block 22 is fixedly connected to one end of flow pipe 15. A detection component is provided on one side of the confluence block 22. An exhaust component is provided on one side of the inner wall of the isolation layer 5. The air intake assembly includes an air intake pipe 10 and a filter 11. One end of the air intake pipe 10 is fixedly connected to one end of the air guide pipe 12. The inner wall of the filter 11 is fixedly connected to the inside of the air intake pipe 10, and the outer wall of the air intake pipe 10 passes through the inside of the filter 11. The exhaust assembly includes an air intake pump 26 and an exhaust pipe 27. The input end of the air intake pump 26 is fixedly connected to one end of the outlet pipe 25, and one end of the exhaust pipe 27 is fixedly connected to the output end of the air intake pump 26. The exhaust pipe 27 passes through the interior of the isolation layer 5. The solenoid valve 13 and the solenoid valve 24 are arranged symmetrically in an array on the inner wall of the isolation layer 5. One side of the solenoid valve 13 is fixedly connected to the inner wall of the isolation layer 5, and one side of the solenoid valve 24 is fixedly connected to the inner wall of the isolation layer 5. The detection assembly includes a mass flow controller 23 and an ultraviolet absorption cell 24. The input end of the mass flow controller 23 is fixedly connected to one side of the confluence block 22, and the output end of the mass flow controller 23 is fixedly connected to the input end of the ultraviolet absorption cell 24. The bottom of the ultraviolet absorption cell 24 is fixedly connected inside the isolation layer 5, and the output end of the ultraviolet absorption cell 24 is fixedly connected to an outflow pipe 25.

[0024] Specifically, an isolation plate 9 is fixedly connected inside the isolation layer 5. This isolation plate 9 divides the internal space defined by the isolation layer 5 into two independent and sealed areas: an electrical control area and a gas path area. The electrical control area houses electronic components requiring high environmental cleanliness, specifically including the main circuit board 6 and related power and control circuits. The gas path area integrates all components that come into direct contact with the gas to be tested, including solenoid valve 13, solenoid valve 14, solenoid valve 19, calibration components, detection components, and related connecting pipes. This structure ensures that even if a small amount of ozone gas leaks from the gas path area due to long-term use or aging of connections, the corrosive gas is strictly confined within the gas path area and cannot penetrate the electrical control area. This effectively prevents ozone and its decomposition products from causing oxidation and corrosion to the precision circuits, solder joints, and components on the main circuit board 6, thereby avoiding damage such as signal drift or equipment failure caused by such corrosion, and ensuring the long-term operational stability and service life of the instrument.

[0025] Please see the appendix Figure 3The heat dissipation component includes a fan 7 and a heat-conducting plate 8. The outer wall of the fan 7 is fixedly connected to the inside of the isolation layer 5, the outer wall of the heat-conducting plate 8 passes through one side of the isolation layer 5, and one side of the fan 7 is located on one side of the main circuit board 6.

[0026] Specifically, during prolonged operation of the instrument, the heat generated by the power consumption of the main circuit board 6 and its electronic components accumulates, causing the ambient temperature inside the electrical control area to rise. At this time, the fan 7, under the control of the main control unit, starts in a timely manner. Its function is to establish a forced internal air circulation field within the sealed electrical control area formed by the isolation layer 5 and the isolation plate 9. This circulating airflow is guided to flow over the surface of the heat-generating elements on the main circuit board 6, absorbing and transferring the heat generated by the elements to the air inside the area through convection heat transfer. Subsequently, the circulating air carrying heat is guided and flows over the surface of the heat-conducting plate 8 exposed inside the electrical control area. Here, the heat in the air is again transferred to the heat-conducting plate 8 through convection heat transfer. The heat-conducting plate 8 is made of a material with high thermal conductivity, such as aluminum or copper, and its structural feature is that it penetrates the wall of the isolation layer 5, with part of its surface inside and another part of its surface outside. Heat is efficiently transported from the inner surface of the heat-conducting plate 8 to its exposed surface outside the chassis 1 via solid-state heat conduction, and is finally dissipated into the surrounding atmosphere through natural convection and thermal radiation. In this way, without direct exchange with the outside air, thus ensuring the physical sealing of the electrical control area and the cleanliness of the internal environment, the heat inside the area is continuously discharged, ensuring that the main circuit board 6 can operate reliably within a safe temperature range.

[0027] Please see the appendix Figure 4 -Appendix Figure 6 The calibration assembly includes an ozone remover 17 and an ozone generator 20. One end of the ozone remover 17 is fixedly connected to one end of a flow pipe 16. The output end of the ozone remover 17 is fixedly connected to multiple transport pipes 18. One of the transport pipes 18 is fixedly connected to a solenoid valve 19. One end of another transport pipe 18 is fixedly connected to one side of the confluence block 22. The bottom of the ozone generator 20 is fixedly connected to the inside of the isolation layer 5. The output end of the ozone generator 20 is fixedly connected to a transport pipe 21. One end of the transport pipe 21 is fixedly connected to the top of the confluence block 22. The ozone generator 20 and the mass flow controller 23 are arranged in a parallel array on one side of the isolation plate 9. The ozone remover 17 and the mass flow controller 23 are arranged in a parallel array on one side of the isolation plate 9.

[0028] Specifically, to ensure the accuracy of long-term measurements and compensate for drift caused by component aging or environmental changes, this device can automatically execute a three-step self-calibration procedure by the main control unit according to a preset periodic plan or after receiving an external remote command.

[0029] In the first step, the zero-point calibration, the main control unit first closes solenoid valve 13 and simultaneously opens solenoid valve 14, switching the airflow path from the main measurement path to the calibration path. External sample gas is guided through flow tube 16 into ozone remover 17, where the ozone in the sample gas is completely decomposed, generating ozone-free zero-point gas. This zero-point gas is then sent into the ultraviolet absorption cell 24. The light intensity signal acquired by the system at this time represents the instrument's response to the zero-concentration gas. This signal is defined as the new zero-point baseline by the main control unit and stored, thereby completing the automatic compensation for zero-point drift of the optical or electronic system.

[0030] In the second step, the span calibration step, the main control unit, while keeping solenoid valve 2 14 open, further controls solenoid valve 3 19 to open. This directs some of the zero-point gas flowing out of ozone scrubber 17 into ozone generator 20. Inside ozone generator 20, this zero-point gas is irradiated with ultraviolet light, generating ozone gas with a preset standard concentration. This standard ozone gas is then sent to ultraviolet absorption cell 24 for measurement. Using the new zero-point baseline obtained in the previous step, the system calculates the measured concentration of the standard gas according to Lambert-Beer's law and compares it with the preset standard concentration value stored in the system. If there is a deviation, the system will automatically calculate and update a calibration coefficient to correct for instrument response deviations caused by factors such as ultraviolet light intensity attenuation or detector sensitivity changes.

[0031] In the third step, the return to measurement mode, after the calibration procedure is completed, the main control unit controls solenoid valves 14 and 19 to switch to the closed state, while simultaneously opening solenoid valve 13, restoring the gas path to the standard measurement path. In all subsequent measurement tasks, the system will automatically call the latest updated zero-point baseline and calibration coefficients to calculate the concentration, thereby ensuring that the final output ozone concentration value has high accuracy and traceability.

[0032] Please see the appendix Figure 7 and attached Figure 8 The ozone detection system includes: The main control unit, which is set on the main circuit board 6, is used to control the detector to switch between measurement mode, zero-point calibration mode and span calibration mode, and is responsible for processing data and executing algorithms. The measuring gas path is controlled by the main control unit. In the measurement mode, the sample gas from the gas inlet assembly is sequentially guided through the flow pipe 15, the confluence block 22 and the detection assembly consisting of the mass flow controller 23 and the ultraviolet absorption cell 24 by opening the solenoid valve 13. The self-calibrating gas path, controlled by the main control unit, guides the sample gas to the calibration component by opening solenoid valve 14 in calibration mode. The calibration component selectively performs one of the following two operations according to the instructions of the main control unit: Zero-point gas is generated by ozone remover 17 and delivered to confluence block 22; The zero-point gas generated by the ozone scrubber 17 is further guided to the ozone generator 20 to generate the span standard gas, and then delivered to the confluence block 22. The main control unit is further configured to: receive and process signals from the detection component, calculate ozone concentration according to Beer-Lambert's law, and after performing self-calibration, use the updated zero-point baseline and calibration coefficient to perform subsequent concentration calculations, and finally display the results on the display screen 3. The main control unit is further configured to perform the following operations in the calibration mode: Perform zero-point calibration: control the opening of the solenoid valve 14 to connect the self-calibration gas path, guide the sample gas through the ozone remover 17 to generate zero-point gas, and automatically update and store the zero-point baseline according to the measurement signal of the zero-point gas by the detection component. Perform span calibration: After the zero-point calibration is completed, the solenoid valve 19 is further opened to guide the generated zero-point gas to the ozone generator 20 to generate a span standard gas of a preset concentration. The response calibration coefficient is automatically calculated and updated by comparing the measured value of the span standard gas by the detection component with the preset concentration value stored internally. Application of calibration results: After calibration is completed, the control gas path returns to measurement mode, and in subsequent concentration calculations, the updated zero-point baseline and the response calibration coefficient are automatically invoked.

[0033] Specifically, an ozone detection system is installed on circuit board 6. This ozone detection system includes: a main control unit, a measuring gas path control module, a self-calibrating gas path control module, and a data processing and calculation module.

[0034] The main control unit is used to control the operation of the measurement gas path control module and the self-calibration gas path control module according to a preset program, user instructions, or remote instructions, so that the entire detector can switch between standard measurement mode, zero-point calibration mode, and span calibration mode. The main control unit is also responsible for coordinating the data processing and calculation module to perform data acquisition and calculation.

[0035] In standard measurement mode, the main control unit drives the measurement gas path control module to open solenoid valve 13 while keeping solenoid valve 14 closed. The gas to be measured is drawn in by the suction pump 26 through the intake pipe 10, passes through the filter 11 and the guide pipe 12 in sequence, enters the opened solenoid valve 13, and then enters the confluence block 22 through the flow pipe 15.

[0036] After flowing out of the confluence block 22, the gas enters the mass flow controller 23, where its flow rate is stabilized at a preset value. Subsequently, the gas with a stable flow rate enters the ultraviolet absorption cell 24. In the ultraviolet absorption cell 24, ultraviolet light of a specific wavelength, such as 253.7 nm, passes through the gas. The data processing and calculation module collects and records the light intensity signal after passing through the gas. After the measurement is completed, the gas flows through the outflow pipe 25 and the intake pump 26, and is finally discharged into the chassis 1 through the exhaust pipe 27, and diffuses into the external environment through the heat dissipation hole 2.

[0037] The data processing and calculation module calculates ozone concentration based on Lambert-Beer's Law. The calculation formula is as follows: ; in, The calculated ozone concentration is expressed in ppb. This is the instrument calibration coefficient, with an initial value of 1; The absorption coefficient of ozone at a specific wavelength and under standard conditions is a constant. The optical path length of the ultraviolet absorption cell 24 is a constant; The absolute temperature inside the ultraviolet absorption cell 24 is measured by an internal temperature sensor. The standard operating temperature is 273.15 K. The absolute pressure inside the ultraviolet absorption cell 24 is measured by an internal pressure sensor. The standard pressure is 101.325 kPa. The transmitted light intensity signal of the zero-point gas sample gas, which does not contain ozone, when it passes through the ultraviolet absorption cell for 24 hours. This is the transmitted light intensity signal of the sample gas as it passes through the ultraviolet absorption cell for 24 hours.

[0038] When a self-calibration procedure is required, the main control unit drives the self-calibration gas path control module to perform zero-point calibration and span calibration.

[0039] During the zero-point calibration step, the main control unit controls solenoid valve 13 to close and simultaneously controls solenoid valve 14 to open. After the external sample gas enters through inlet pipe 10, the flow path switches to flow pipe 16 and enters the ozone remover 17 in the calibration assembly. Inside the ozone remover 17, the ozone in the sample gas is completely decomposed, generating zero-point gas. This zero-point gas enters the confluence block 22 through a transport pipe 18 and subsequently enters the ultraviolet absorption cell 24. The data processing and calculation module acquires the light intensity signal at this time and stores it as a new zero-point light intensity reference value. .

[0040] During the span calibration step, the main control unit, while keeping solenoid valve 2 14 open, further controls solenoid valve 3 19 to open. At this time, the zero-point gas flowing out of ozone scrubber 17 is guided into ozone generator 20 through another transport pipe 1 18 and the opened solenoid valve 3 19. Ozone generator 20 irradiates the zero-point gas with ultraviolet light to generate a standard ozone gas of a preset concentration. This standard ozone gas enters the confluence block 22 via transport pipe 2 21 and subsequently enters the ultraviolet absorption cell 24.

[0041] The data processing and calculation module d uses the currently stored zero-point reference value. and the light intensity signal measured at this time Calculate a measured concentration value Subsequently, the measured concentration value was... Compared with the standard concentration preset value stored in the system The comparisons were made, and the new instrument calibration coefficients were calculated. The calculation formula is: ; The data processing and computing module will do this Update and store the value.

[0042] After the calibration procedure is completed, the main control unit closes solenoid valves 14 and 19 and reopens solenoid valve 13, returning the detector to standard measurement mode. In all subsequent measurements, the data processing and calculation module will automatically retrieve the latest stored zero-point light intensity reference value. and instrument calibration coefficient Concentration calculations were performed to ensure the accuracy of the output data.

[0043] Working principle: In the process of using a UV photolysis ozone detector with self-calibration function, the gas to be detected is first injected into the device through the inlet pipe 10. Then, the device is started by operating the display screen 3 to start detecting the gas. After the gas is filtered through the filter 11, it enters the gas guide pipe 12. At this time, the solenoid valve 13 opens and the gas flows into the confluence block through the flow pipe 15. After that, the mass flow controller 23 controls its speed to enter the UV absorption cell 24 for detection. The detected gas flows out from the tail end of the UV absorption cell 24 and enters the outlet pipe 25. It is discharged from the tail end of the exhaust pipe 27 through the isolation layer 5 and flows into the casing 1. Finally, it flows into the outside air through the heat dissipation hole 2. During the entire detection process, the suction pump 26 provides power for the inflowing gas. An isolation plate 9 exists inside the entire isolation layer 5 to separate the electrical control area from the gas path, preventing ozone leakage from the gas path area from corroding the main circuit board 6 inside the electrical control area and causing damage to the equipment. When the main circuit board 6 generates heat due to prolonged operation, the fan 7 inside the isolation layer 5 starts, drawing away the heat generated by the main circuit board 6 and directing it to the surface of the heat conduction plate 8. The heat conduction plate 8 then conducts the heat to the outside of the chassis 1 and dissipates it into the outside air. The instrument periodically or automatically performs a three-step calibration process upon receiving a remote command: The first step is to enter zero-point calibration mode, control solenoid valve 14 to open, guide the external sample gas through ozone remover 17, and then send it into the ultraviolet absorption cell 24. Theoretically, the ozone concentration should be zero at this time. If the instrument reading is not zero, the system will define the current measurement signal value as the new zero-point baseline and automatically perform zero-point compensation. The second step is to enter the span calibration mode and control the solenoid valve 19 to guide the zero gas that has passed through the ozone scrubber 17 into the ozone generator 20 to generate standard ozone gas with a known concentration. Then, the gas is sent into the ultraviolet absorption cell 24. The system calculates the concentration according to the Lambert-Beer law and compares it with the standard concentration value stored inside. If there is a deviation, the system will automatically calculate and update the calibration coefficient. The third step involves returning to measurement mode. Solenoid valves 14 and 19 are switched back to the closed state, allowing external sample gas to directly enter the ultraviolet absorption cell 24 for measurement. The instrument uses the new zero point and new calibration coefficients to calculate and output a highly accurate ozone concentration value.

Claims

1. A UV photolysis ozone detector with self-calibration function, characterized in that, include: The chassis (1) and the isolation layer (5) are provided with multiple heat dissipation holes (2) on both sides of the chassis (1), a display screen (3) is electrically connected to one side of the chassis (1), a handle (4) is fixedly connected to the top of the chassis (1), the bottom of the isolation layer (5) is fixedly connected to the inside of the chassis (1), a main circuit board (6) is fixedly connected inside the isolation layer (5), the main circuit board (6) has an ozone detection system built in it, a heat dissipation component is fixedly connected inside the isolation layer (5), and an isolation plate (9) is fixedly connected inside the isolation layer (5). An air guide pipe (12) is fixedly connected inside the isolation layer (5). An air intake component is provided at one end of the air guide pipe (12). Solenoid valve one (13) and solenoid valve two (14) are fixedly connected at the other two ends of the air guide pipe (12). A flow pipe one (15) is fixedly connected at the bottom end of solenoid valve one (13). A flow pipe two (16) is fixedly connected at the bottom end of solenoid valve two (14). A calibration component is provided at one end of the flow pipe two (16). A merging block (22) is fixedly connected at one end of the flow pipe one (15). A detection component is provided on one side of the merging block (22). An exhaust component is provided on one side of the inner wall of the isolation layer (5).

2. The ultraviolet photolysis ozone detector with self-calibration function according to claim 1, characterized in that, The heat dissipation assembly includes a fan (7) and a heat-conducting plate (8). The outer wall of the fan (7) is fixedly connected to the inside of the isolation layer (5). The outer wall of the heat-conducting plate (8) passes through one side of the isolation layer (5). One side of the fan (7) is located on one side of the main circuit board (6).

3. The ultraviolet photolysis ozone detector with self-calibration function according to claim 1, characterized in that, The air intake assembly includes an air intake pipe (10) and a filter (11). One end of the air intake pipe (10) is fixedly connected to one end of the air guide pipe (12). The inner wall of the filter (11) is fixedly connected to the inside of the air intake pipe (10). The outer wall of the air intake pipe (10) passes through the inside of the filter (11).

4. The ultraviolet photolysis ozone detector with self-calibration function according to claim 1, characterized in that, The calibration assembly includes an ozone remover (17) and an ozone generator (20). One end of the ozone remover (17) is fixedly connected to one end of the flow pipe (2) (16). The output end of the ozone remover (17) is fixedly connected to multiple transport pipes (18). One of the transport pipes (18) is fixedly connected to a solenoid valve (3) (19). The other transport pipe (18) is fixedly connected to one side of the confluence block (22). The bottom of the ozone generator (20) is fixedly connected to the inside of the isolation layer (5). The output end of the ozone generator (20) is fixedly connected to a transport pipe (21). One end of the transport pipe (21) is fixedly connected to the top of the confluence block (22).

5. The ultraviolet photolysis ozone detector with self-calibration function according to claim 1, characterized in that, The detection component includes a mass flow controller (23) and an ultraviolet absorption cell (24). The input end of the mass flow controller (23) is fixedly connected to one side of the confluence block (22), and the output end of the mass flow controller (23) is fixedly connected to the input end of the ultraviolet absorption cell (24). The bottom of the ultraviolet absorption cell (24) is fixedly connected inside the isolation layer (5), and the output end of the ultraviolet absorption cell (24) is fixedly connected to an outflow pipe (25).

6. The ultraviolet photolysis ozone detector with self-calibration function according to claim 1, characterized in that, The exhaust assembly includes an intake pump (26) and an exhaust pipe (27). The input end of the intake pump (26) is fixedly connected to one end of the outlet pipe (25), and one end of the exhaust pipe (27) is fixedly connected to the output end of the intake pump (26). The exhaust pipe (27) passes through the interior of the isolation layer (5).

7. The ultraviolet photolysis ozone detector with self-calibration function according to claim 1, characterized in that, The solenoid valve one (13) and solenoid valve two (14) are arranged in a symmetrical array on the inner wall of the isolation layer (5). One side of the solenoid valve one (13) is fixedly connected to the inner wall of the isolation layer (5), and one side of the solenoid valve two (14) is fixedly connected to the inner wall of the isolation layer (5).

8. The ultraviolet photolysis ozone detector with self-calibration function according to claim 4, characterized in that, The ozone generator (20) and the mass flow controller (23) are arranged in a parallel array on one side of the isolation plate (9), and the ozone remover (17) and the mass flow controller (23) are arranged in a parallel array on one side of the isolation plate (9).

9. The ultraviolet photolysis ozone detector with self-calibration function according to claim 1, characterized in that, The ozone detection system includes: The main control unit is set on the main circuit board (6) and is used to control the detector to switch between measurement mode, zero-point calibration mode and span calibration mode, and is responsible for processing data and executing algorithms. The measuring gas path is controlled by the main control unit. In the measurement mode, the sample gas from the gas inlet assembly is sequentially guided through the flow pipe (15), the confluence block (22), and the detection assembly consisting of the mass flow controller (23) and the ultraviolet absorption cell (24) by opening the solenoid valve (13). The self-calibrating gas path, controlled by the main control unit, guides the sample gas to the calibration component by opening solenoid valve two (14) in calibration mode. The calibration component selectively performs one of the following two operations according to the instructions of the main control unit: Zero-point gas is generated by an ozone remover (17) and delivered to the confluence block (22). The zero-point gas generated by the ozone scrubber (17) is further guided to the ozone generator (20) to generate the span standard gas and delivered to the confluence block (22). The main control unit is further configured to: receive and process signals from the detection component, calculate ozone concentration according to Beer-Lambert law, and after performing self-calibration, use the updated zero-point baseline and calibration coefficient to perform subsequent concentration calculations, and finally display the results on the display screen (3).

10. The ultraviolet photolysis ozone detector with self-calibration function according to claim 1, characterized in that, The main control unit is further configured to perform the following operations in the calibration mode: Perform zero-point calibration: control the opening of the second solenoid valve (14) to connect the self-calibration gas path, guide the sample gas through the ozone remover (17) to generate zero-point gas, and automatically update and store the zero-point baseline according to the measurement signal of the zero-point gas by the detection component; Perform span calibration: After the zero-point calibration is completed, the solenoid valve three (19) is further controlled to open, and the zero-point gas generated above is guided to the ozone generator (20) to generate a span standard gas of preset concentration. The response calibration coefficient is automatically calculated and updated according to the measurement value of the span standard gas by the detection component and the preset concentration value stored in the internal storage. Application of calibration results: After calibration is completed, the control gas path returns to measurement mode, and in subsequent concentration calculations, the updated zero-point baseline and the response calibration coefficient are automatically invoked.

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