On-line peculiar smell monitoring equipment based on gas sensor array

Abstract

The invention provides on-line peculiar smell monitoring equipment based on a gas sensor array, and the equipment comprises a case which is provided with a gas inlet and a gas outlet; the sampling device is arranged at the gas inlet and is used for collecting sample gas; the hybrid sensor array is arranged in the case and is provided with a gas inlet pipeline and a gas outlet pipeline, the gas inlet pipeline is communicated with the output end of the sampling device, one end of the gas outlet pipeline is arranged at the gas outlet, and the hybrid sensor array is used for detecting and analyzing the sample gas to obtain voltage data of various odorous gases, converting the voltage data into voltage signals and outputting the voltage signals; a circuit board with a heating module and a resistance adjusting module is configured in the hybrid sensor array; the display module is arranged on the case; the communication module is arranged in the case; the power supply module is arranged in the case; and the control module is arranged in the case and used for controlling opening and closing. The device has the beneficial effects that the structure can be simplified, the cost can be reduced, various odorous gases can be detected, and the real-time optimization and accurate regulation and control of the sensor performance can be realized.

Description

Technical Field

[0001] This invention relates to the technical field of air pollution monitoring equipment, and more specifically, to an online odor monitoring device based on a gas sensor array. Background Technology

[0002] With the acceleration of industrialization and urbanization, the emission of odorous gases has become an increasingly prominent concern. Odorous gases not only affect environmental quality but may also harm human health and ecosystems. Traditional gas detection methods typically rely on single sensors or simple sensor combinations, making it difficult to comprehensively cover the detection needs of various odorous gases. Existing gas sensors generally suffer from baseline drift and response value drift during long-term use, leading to decreased detection accuracy and increased risk of misjudgment.

[0003] In addition, existing odor monitoring devices are usually complex in structure, expensive, and lack effective sensor performance regulation mechanisms, making them difficult to adapt to complex and ever-changing field environments. These problems limit the promotion and use of existing technologies in practical applications. Therefore, there is an urgent need for an online odor monitoring device that is simple in structure, low in cost, and capable of detecting a variety of odor gases and achieving real-time optimization and precise regulation of sensor performance. Summary of the Invention

[0004] The technical problem to be solved by this invention is how to simplify the structure, reduce the cost, detect various odor gases, and achieve real-time optimization and precise control of sensor performance. In order to overcome the defects of the above-mentioned prior art (or related technology), this invention provides an online odor monitoring device based on a gas sensor array.

[0005] This invention provides an online odor monitoring device based on a gas sensor array, comprising: A chassis, wherein an air inlet and an air outlet are provided on the chassis; A sampling device is installed at the air inlet for continuously collecting sample gas from the environment surrounding the chassis; A hybrid sensor array is disposed inside the chassis. The hybrid sensor array is provided with an air inlet pipe and an air outlet pipe. The air inlet pipe is connected to the output terminal of the sampling device, and one end of the air outlet pipe is placed at the air outlet. The hybrid sensor array is used to detect and analyze the sample gas to obtain voltage data of various odor gases, and convert the voltage data into voltage signals for output. The hybrid sensor array is equipped with a circuit board with a heating module and a resistance adjustment module for adjusting the heating temperature and the load resistance matching adjustment. A display module is mounted on the chassis; A communication module, located inside the chassis, is electrically connected to the hybrid sensor array and the display module, respectively, and is used to output the voltage signal to the display module for visualization of the voltage data; A power supply module is located inside the chassis; A control module, located inside the chassis, is electrically connected to the sampling device, the gas sensor array module, the display module, the communication module, and the power supply module, respectively, and is used to control the opening and closing of the sampling device, the gas sensor array module, the display module, and the communication module.

[0006] Compared with existing technologies, the odor online monitoring device based on a gas sensor array proposed in this application has the following advantages: This application only configures a few functional modules: a sampling device, a hybrid sensor array, a display module, a communication module, a power supply module, and a control module. This eliminates the need for complex gas analysis devices, simplifies the structure, and reduces costs. The sampling device collects sample gas, the hybrid sensor array analyzes the sample gas to obtain voltage data for various odor gases, the display module displays the data, the communication module transmits data, the power supply module provides power, and the control module controls the on / off operation of each component. This enables the detection of multiple odor gases. Furthermore, the circuit board provides adaptive heating and load resistance adjustment functions to optimize the sensor's operating state. Heating keeps the sensor at its optimal operating temperature, and the sensor load resistance can be automatically adjusted according to site conditions, ensuring high accuracy and stability in monitoring and enabling real-time optimization and precise control of sensor performance.

[0007] In one possible implementation, the sampling device is a miniature diaphragm air pump.

[0008] Compared with existing technologies, the above technical solution utilizes the low power consumption and low noise characteristics of the micro diaphragm air pump to enable long-term continuous operation while ensuring the stability and continuity of gas sampling.

[0009] In one possible implementation, the air intake pipe is made of polytetrafluoroethylene (PTFE).

[0010] Compared with existing technologies, the above technical solution can reduce the adsorption of VOCs components in the sample gas and ensure the representativeness of the sample gas.

[0011] In one possible implementation, the hybrid sensor array includes an 8-channel MEMS gas sensor array, four semiconductor gas sensors, four electrochemical gas sensors, one photoionization gas sensor, a MEMS sensor test box, a semiconductor sensor test box, and an electrochemical sensor test box. The MEMS gas sensor array is fixedly installed inside the MEMS sensor test box, the four semiconductor gas sensors are fixedly installed inside the semiconductor sensor test box, and the four electrochemical gas sensors are fixedly installed inside the electrochemical sensor test box. The semiconductor sensor test box is connected to the electrochemical sensor test box via a first gas pipe, the electrochemical sensor test box is connected to the photoionization gas sensor via a second gas pipe, and the photoionization gas sensor is connected to the MEMS sensor test box via a third gas channel.

[0012] Compared with existing technologies, the above technical solution enables multiple types of sensors to work together to form a wide-spectrum detection capability, which can identify a variety of odor gases. The graded test box design enables the classification and management of sensors, and the separate detection of sensors with different principles can reduce mutual interference.

[0013] In one possible implementation, a first test chamber is provided inside the MEMS sensor test box, and the MEMS gas sensor array is fixedly installed inside the first test chamber. Two first vent holes are provided on the inner wall of the first test chamber, and the two first vent holes are respectively connected to the third gas pipe and the gas outlet pipe.

[0014] Compared with existing technologies, the above technical solution can form a unidirectional airflow path through the dual vent design of the first test chamber, ensuring full contact between the MEMS sensor array and the sample gas.

[0015] In one possible implementation, the semiconductor sensor test box has two second test chambers and two third test chambers arranged in a 2x2 array, with the two second test chambers and the two third test chambers arranged diagonally in the array, and the four semiconductor gas sensors are respectively fixedly installed in the two second test chambers and the two third test chambers.

[0016] In one possible implementation, the electrochemical sensor test box has four fourth test chambers arranged in a 2x2 array, and the four electrochemical gas sensors are respectively fixedly installed in the four fourth test chambers.

[0017] In one possible implementation, the MEMS gas sensor array includes eight sensing units fabricated using metal oxide semiconductor gas-sensitive materials, and the eight sensing units are arranged laterally in the first test cavity.

[0018] Compared with existing technologies, the above technical solution can utilize the high sensitivity and fast response characteristics of metal oxide semiconductor materials, and the collaborative work of multiple sensing units can improve the accuracy of characteristic gas identification.

[0019] In one possible implementation, two second vent holes are respectively formed on the inner walls of the two second test chambers and the two third test chambers. The two second vent holes of one second test chamber are respectively connected to the first gas pipeline and one of the second vent holes of one of the third test chambers. The two second vent holes of the other second test chamber are respectively connected to the other second vent hole of one of the third test chambers and one of the second vent holes of the other third test chamber. The other second vent hole of the other third test chamber is connected to the second gas pipeline.

[0020] Compared with existing technologies, the above technical solution can extend the residence time of sample gas through a cross-vent layout.

[0021] In one possible implementation, the electrochemical sensor test box has an internal gas path, one end of which is connected to the second gas pipe and the other end of which is connected to the third gas pipe. The bottom of each of the four fourth test chambers has a third vent hole, and each third vent hole is connected to the internal gas path.

[0022] Compared with existing technologies, the above technical solution can achieve uniform distribution of sample gas through the internal gas path, and the bottom ventilation design of the fourth test chamber can ensure that the electrochemical sensor is in full contact with the sample gas. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the MEMS sensor test box of the present invention; Figure 3 This is a schematic diagram of the semiconductor sensor test box of the present invention; Figure 4 This is a schematic diagram of the electrochemical sensor test box of the present invention; Figure 5 This is a schematic diagram of the internal gas path of the electrochemical sensor test box of the present invention; Figure 6This is a schematic diagram showing the distribution of the hybrid sensor array of the present invention; Figure 7 This is a schematic diagram illustrating the process of adjusting the heating temperature and matching load resistance according to the present invention; Figure 8 This is a schematic diagram of the sensor response of the present invention; Figure 9 The radar images of different gases obtained by the sensor of this invention; Figure 10 This is a scatter plot of the quantitative analysis results of gas concentration in this invention. Explanation of reference numerals in the attached drawings: 1. Sampling device; 2. Hybrid sensor array; 3. Display module; 4. Communication module; 5. Power supply module; 6. Control module; 7. MEMS sensor test box; 8. Semiconductor sensor test box; 9. Electrochemical sensor test box; 10. First test chamber; 11. First vent; 12. Second test chamber; 13. Third test chamber; 14. Fourth test chamber; 15. Second vent; 16. Internal gas path; 17. Third vent. Detailed Implementation

[0024] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of this application and are not intended to limit the scope of protection of the embodiments of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0025] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0026] See Figure 1 This application discloses an online odor monitoring device based on a gas sensor array. To overcome the shortcomings of existing odor gas monitoring devices, such as insufficient accuracy and signal drift, a modular design is adopted, integrating functions such as gas acquisition, sensing detection, signal processing, data transmission, and data display. The aim is to achieve real-time, efficient, and accurate monitoring of various odor gases. The device includes a sampling device 1, a hybrid sensor array 2, a display module 3, a communication module 4, a power module 5, and a control module 6. The sampling device 1 is located at the air inlet on the chassis and is used to continuously collect sample gas from the surrounding environment. The hybrid sensor array 2 is located inside the chassis and integrates an air inlet pipe and an air outlet pipe. The air inlet pipe is connected to the output end of the sampling device 1, and one end of the air outlet pipe is placed at the air outlet of the chassis. This outlet pipe is used to detect and analyze the sample gas to obtain corresponding voltage data and convert the voltage data into a voltage signal for output. Figure 7As shown, the hybrid sensor array 2 is equipped with a circuit board containing a heating module and a resistance adjustment module for heating the sensor channels and adjusting the load resistance. The display module 3 is located on the chassis. The communication module 4 is located inside the chassis and is electrically connected to the hybrid sensor array 2 and the display module 3, respectively, for outputting voltage signals to the display module 3 for visual display of voltage data. The power supply module 5 is located inside the chassis. The control module 6 is located inside the chassis and is electrically connected to the sampling device 1, the gas sensor array module, the display module 3, the communication module 4, and the power supply module 5, respectively, for controlling the opening and closing of the sampling device 1, the gas sensor array module, the display module 3, and the communication module 4.

[0027] In the embodiments of this application, see Figure 6 The hybrid sensor array 2 includes an 8-channel MEMS gas sensor array, four semiconductor gas sensors, four electrochemical gas sensors, one photoionization gas sensor, a MEMS sensor test box 7, a semiconductor sensor test box 8, and an electrochemical sensor test box 9. The MEMS gas sensor array is fixedly installed inside the MEMS sensor test box 7, the four semiconductor gas sensors are fixedly installed inside the semiconductor sensor test box 8, and the four electrochemical gas sensors are fixedly installed inside the electrochemical sensor test box 9. The semiconductor sensor test box 8 is connected to the electrochemical sensor test box 9 through a first gas pipe, the electrochemical sensor test box 9 is connected to the photoionization gas sensor through a second gas pipe, and the photoionization gas sensor is connected to the MEMS sensor test box 7 through a third gas channel.

[0028] In this embodiment, the circuit board in the hybrid sensor array 2 has an adaptive heating function and a matching load resistance adjustment function. Through pulse heating and adjustable heating voltage waveform frequency, the sensor is kept at the optimal operating temperature. At the same time, the load resistance can be automatically adjusted according to the site conditions to optimize sensor signal acquisition and ensure high accuracy and stability of monitoring.

[0029] In this embodiment, the sampling device 1 mainly consists of a miniature diaphragm air pump, an inlet pipe, and an outlet pipe, used to collect sample gas and transport it to the hybrid sensor array 2. The inlet pipe and outlet pipe are made of polytetrafluoroethylene, which helps to reduce the adsorption of VOCs components in the sample gas and improve the stability of the device.

[0030] In this embodiment, the communication module 4 has dual functions: first, it transmits the voltage signal from the sensor to the local display module 3 to realize real-time data display; second, it transmits the voltage signal to the cloud server database through the 4G DTU to facilitate remote storage and management, and to provide support for subsequent data analysis.

[0031] In this embodiment, the power module 5 is adaptable to multiple power supply methods, including mains power and solar power, providing the required operating voltage for each component of the monitoring equipment and ensuring stable operation of the equipment in different application scenarios.

[0032] In this embodiment, the operating voltage of the 4G DTU and the micro diaphragm air pump can be 12 V, 18 V, 24 V, etc.; the operating voltage and heating voltage of the sensor can be 3 V, 4 V, 5 V, etc.

[0033] In this embodiment, the display module 3 is an electronic screen with display and local storage functions. It can display and store the voltage data of various gas sensors in real time. Its built-in dedicated software system can synchronously present the original voltage signal and environmental parameters such as temperature, humidity, wind speed and direction, and GPS positioning. Multiple monitoring devices can form a monitoring network based on GPS positioning function to realize regional linkage monitoring. After the voltage data of the sensors is processed and inverted in the cloud, the gas type and concentration are determined. The results are transmitted back to the device and presented intuitively on the display module 3.

[0034] In this embodiment, the semiconductor gas sensor can be the Figaro TGS series, Cubic Sensor and Instrument Co., Ltd. ATRS series, or the DirectIndustry China platform Cubic Sensor series, etc.; the electrochemical gas sensor can be the Honeywell CLE series, DDS Scientific DceL series, or the Shenzhen Sandate Technology Co., Ltd. GS+ series, etc.; and the photoionization gas sensor can be the Ion Science MiniPID 2 series, MOCON BASELINE piD-TECH series, or the Inshaw Instruments PID-A1 series, etc.

[0035] In this embodiment, the heating voltage range of each sensor channel can be 0-1.8 V, 0-1.2 V, or 0-3.3 V, etc.; the load resistor matched to each sensor channel can be 1kΩ, 10kΩ, 50kΩ, 100kΩ, 200kΩ, etc.

[0036] See Figure 2 The MEMS sensor test box 7 has a first test chamber 10. The MEMS gas sensor array is fixedly installed in the first test chamber 10. The inner wall of the first test chamber 10 has two first vent holes 11. The two first vent holes 11 are connected to the third gas pipe and the gas outlet pipe, respectively. The MEMS gas sensor array includes eight sensing units made of metal oxide semiconductor gas-sensitive material. The eight sensing units are arranged horizontally in the first test chamber 10.

[0037] In this embodiment, the MEMS gas sensor array is constructed by arranging eight sensing units made of specific metal oxide semiconductor gas-sensitive materials laterally in a ceramic tube shell, i.e., the first test cavity 10, using precision deposition technology.

[0038] See Figure 3 The semiconductor sensor test box 8 has two second test chambers 12 and two third test chambers 13 arranged in a 2x2 array. The two second test chambers 12 and the two third test chambers 13 are diagonally arranged in the array. Four semiconductor gas sensors are fixedly installed in the two second test chambers 12 and the two third test chambers 13 respectively. Two second vent holes 15 are opened on the inner walls of the two second test chambers 12 and the two third test chambers 13 respectively. The two second vent holes 15 of one second test chamber 12 are connected to a first gas pipe and one of the second vent holes 15 of one of the third test chambers 13 respectively. The two second vent holes 15 of the other second test chamber 12 are connected to the other second vent hole 15 of one of the third test chambers 13 and one of the second vent holes 15 of the other third test chamber 13 respectively. The other second vent hole 15 of the other third test chamber 13 is connected to a second gas pipe.

[0039] See Figure 4 and Figure 5 The electrochemical sensor test box 9 has four fourth test chambers 14 arranged in a 2x2 array. Four electrochemical gas sensors are fixedly installed in the four fourth test chambers 14 respectively. An internal gas passage 16 is opened in the electrochemical sensor test box 9. One end of the internal gas passage 16 is connected to the second gas pipe, and the other end of the internal gas passage 16 is connected to the third gas pipe. A third vent hole 17 is opened at the bottom of each of the four fourth test chambers 14, and each third vent hole 17 is connected to the internal gas passage 16.

[0040] In this embodiment, the MEMS sensor test box 7, semiconductor sensor test box 8, and electrochemical sensor test box 9 adopt a conformal gas chamber design, which has good applicability, can be compatible with various types of sensors, and can meet the sensor replacement requirements. They are designed and customized according to different circuit boards and sensor combinations, providing independent gas chambers and reaction spaces for various sensors to ensure that the sample gas and the sensor are in full contact and reaction. At the same time, by setting grooves and placing sealing rings on the outer edge of the test chamber, the airtightness of the test chamber is effectively ensured, gas leakage is prevented, and the accuracy of data is guaranteed.

[0041] In this embodiment, the MEMS sensor array is installed entirely within the first test chamber 10, while the semiconductor gas sensor and the electrochemical gas sensor are embedded in their respective independent second test chamber 12, third test chamber 13, and fourth test chamber 14.

[0042] In this embodiment, the odor online monitoring device is used as follows: Connect the device to an external power source and turn it on. Press the start button on the control module 6. The control module 6 will send activation signals to each module, and the device will enter the initialization state. Each module will start self-testing and prepare to run. Then, the micro diaphragm gas pump will start. The sample gas will be drawn in from the inlet of the device under the suction action of the micro diaphragm gas pump and will flow sequentially through the semiconductor sensor test box 8, the electrochemical sensor test box 9, the photoionization gas sensor, and the MEMS sensor test box 7 along the polytetrafluoroethylene gas pipeline. In each test box, the sample gas will fully contact the corresponding gas sensor and undergo a chemical reaction. Finally, the sample gas will be discharged from the device through the outlet. After the voltage signal is collected, it will be transmitted to the cloud server database through the 4G DTU in the communication module 4. At the same time, the voltage data of each gas sensor will be displayed in real time on the display module 3 of the device. After the voltage data is processed by the cloud, the inverted gas type and concentration results will be transmitted back to the device and displayed on the display module 3. The device can run continuously and monitor the ambient gas without interruption until the device is manually turned off.

[0043] In this embodiment, when the sample gas enters each sensor test box and comes into contact with the gas sensor, the gas sensor starts to work. The MEMS gas sensor array uses pulse heating, and the frequency of the heating voltage waveform can be adjusted according to the actual situation. During pulse heating, the heating voltage changes continuously or gradually within a certain range, causing the nanomaterials on the surface of the gas sensor to react chemically with the gas, resulting in a change in resistance. At the same time, the load resistor matched to each gas sensor channel can be automatically adjusted according to the field conditions to ensure that the collected gas sensor voltage signal is within a reasonable range. In addition, when collecting the voltage signal, the resistance value of the matched load resistor can be further fine-tuned according to the real-time response of the gas sensor to optimize the voltage signal acquisition effect.

[0044] See Figure 8 The diagram shows the responses of different sensors. It can be seen that the hybrid sensor array 2, which uses gas sensors based on three principles—semiconductor, electrochemical, and photoionization—can produce different responses to the target gas.

[0045] See Figure 9 The radar diagrams of the hybrid sensor array 2 of the present invention for different gases show that the response modes of the sensor array to each gas are significantly different, and each sensor exhibits a unique selectivity that is different from other sensors.

[0046] See Figure 10The scatter plot shows the concentration prediction results of the data monitored by the hybrid sensor array 2. It can be seen that the coefficient of determination (R²) of the response data reaches 0.99 and the root mean square error (RMSE) is only 16 ppb, indicating that the odor online monitoring device in this application has high monitoring accuracy.

[0047] The odor online monitoring device provided in this embodiment has the following advantages: 1. High detection accuracy and stability: Through adaptive heating and matching load resistance adjustment, the sensor's working state is optimized, effectively solving the problems of sensor baseline drift and response value drift, improving the accuracy and stability of gas detection, ensuring the reliability of monitoring data, and providing strong support for the accurate monitoring of odorous gases; 2. Strong environmental adaptability: The unique array test box design ensures that the equipment can still work normally under complex environmental conditions, making it more adaptable and broadening the application range of the equipment, enabling it to operate stably in a variety of industrial and urban environments; 3. Modular design and simple structure: The modular design approach makes the equipment structure simple and compact, which is easy to install, maintain and upgrade. At the same time, it reduces the cost of the equipment, improves the cost-effectiveness of the equipment, and is conducive to the widespread promotion and application of the equipment.

[0048] In the description of this application, the references to terms such as "an embodiment," "some embodiments," "in this embodiment," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0049] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An online odor monitoring device based on a gas sensor array, characterized in that, include: A chassis, wherein an air inlet and an air outlet are provided on the chassis; A sampling device is installed at the air inlet for continuously collecting sample gas from the environment surrounding the chassis; A hybrid sensor array is disposed inside the chassis. The hybrid sensor array is provided with an air inlet pipe and an air outlet pipe. The air inlet pipe is connected to the output terminal of the sampling device, and one end of the air outlet pipe is placed at the air outlet. The hybrid sensor array is used to detect and analyze the sample gas to obtain voltage data of various odor gases, and convert the voltage data into voltage signals for output. The hybrid sensor array is equipped with a circuit board with a heating module and a resistance adjustment module for adjusting the heating temperature and the load resistance matching adjustment. A display module is mounted on the chassis; A communication module, located inside the chassis, is electrically connected to the hybrid sensor array and the display module, respectively, and is used to output the voltage signal to the display module for visualization of the voltage data; A power supply module is located inside the chassis; A control module, located inside the chassis, is electrically connected to the sampling device, the gas sensor array module, the display module, the communication module, and the power supply module, respectively, and is used to control the opening and closing of the sampling device, the gas sensor array module, the display module, and the communication module.

2. The odor online monitoring device according to claim 1, characterized in that, The sampling device is a miniature diaphragm air pump.

3. The odor online monitoring device according to claim 1, characterized in that, The air intake pipe is made of polytetrafluoroethylene.

4. The odor online monitoring device according to claim 1, characterized in that, The hybrid sensor array includes an 8-channel MEMS gas sensor array, four semiconductor gas sensors, four electrochemical gas sensors, one photoionization gas sensor, a MEMS sensor test box, a semiconductor sensor test box, and an electrochemical sensor test box. The MEMS gas sensor array is fixedly installed inside the MEMS sensor test box, the four semiconductor gas sensors are fixedly installed inside the semiconductor sensor test box, and the four electrochemical gas sensors are fixedly installed inside the electrochemical sensor test box. The semiconductor sensor test box is connected to the electrochemical sensor test box through a first gas pipe, the electrochemical sensor test box is connected to the photoionization gas sensor through a second gas pipe, and the photoionization gas sensor is connected to the MEMS sensor test box through a third gas channel.

5. The odor online monitoring device according to claim 4, characterized in that, The MEMS sensor test box has a first test chamber, and the MEMS gas sensor array is fixedly installed in the first test chamber. The inner wall of the first test chamber has two first vent holes, which are respectively connected to the third gas pipe and the gas outlet pipe.

6. The odor online monitoring device according to claim 4, characterized in that, The semiconductor sensor test box has two second test chambers and two third test chambers arranged in a 2x2 array. The two second test chambers are diagonally arranged in the array, and the two third test chambers are diagonally arranged in the array. The four semiconductor gas sensors are respectively fixedly installed in the two second test chambers and the two third test chambers.

7. The odor online monitoring device according to claim 4, characterized in that, The electrochemical sensor test box has four fourth test chambers arranged in a 2x2 array, and the four electrochemical gas sensors are respectively fixedly installed in the four fourth test chambers.

8. The odor online monitoring device according to claim 5, characterized in that, The MEMS gas sensor array includes eight sensing units made of metal oxide semiconductor gas-sensitive material, and the eight sensing units are arranged horizontally in sequence in the first test cavity.

9. The odor online monitoring device according to claim 6, characterized in that, Two second vent holes are respectively opened on the inner walls of the two second test chambers and the two third test chambers. The two second vent holes of one second test chamber are respectively connected to the first gas pipeline and one of the second vent holes of one of the third test chambers. The two second vent holes of the other second test chamber are respectively connected to the other second vent hole of one of the third test chambers and one of the second vent holes of the other third test chamber. The other second vent hole of the other third test chamber is connected to the second gas pipeline.

10. The odor online monitoring device according to claim 7, characterized in that, An internal gas path is provided inside the electrochemical sensor test box. One end of the internal gas path is connected to the second gas pipeline, and the other end of the internal gas path is connected to the third gas pipeline. A third vent is provided at the bottom of each of the four fourth test chambers, and each third vent is connected to the internal gas path.

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