Waste gas monitoring and collecting system

Abstract

The utility model relates to a waste gas monitoring and collecting system, which comprises a monitoring sensor pre-amplification circuit, which is used for carrying out preliminary amplification processing on waste gas related signals collected by a monitoring sensor; the pre-amplification circuit of the monitoring sensor comprises an integrated electrode EC, the integrated electrode EC comprises a working electrode WE, a reference electrode RE and a counter electrode CE, a constant potential circuit is connected between the working electrode WE and the reference electrode RE, the working electrode WE is further connected with a signal conditioning circuit, the output end of the signal conditioning circuit is electrically connected with an analog-to-digital conversion module, and the analog-to-digital conversion module is electrically connected with the counter electrode CE. The output end of the analog-to-digital conversion module is electrically connected with a master control MCU. By adopting the pre-amplification circuit of the monitoring sensor, the strength and the stability of waste gas related signals acquired by the monitoring sensor can be effectively improved.

Description

Technical Field

[0001] This application relates to the field of sensor monitoring technology, and in particular to an exhaust gas monitoring and collection system. Background Technology

[0002] In recent years, to protect air quality, the state has formulated and promulgated a series of laws, regulations, and standards, and various industries have been vigorously promoting the control of air pollution, effectively preventing the further deterioration of air pollution problems. However, existing waste gas collection devices do not have waste gas collection monitoring systems or units, and therefore cannot automatically acquire data and provide users with waste gas collection data, which is detrimental to further improving the results of waste gas pollution control.

[0003] Chinese patent CN215525671U discloses an exhaust gas collection and monitoring system and an exhaust gas collection and monitoring unit. The exhaust gas collection and monitoring system includes an exhaust gas collection and monitoring unit, which comprises: a first sensing component for acquiring first combined exhaust gas data; and a second sensing component for acquiring second combined exhaust gas data. The first and second sensing components are located at different positions near the exhaust gas source. The exhaust gas collection and monitoring system, including the first and second sensing components, can use the first and second combined exhaust gas data acquired by the first and second sensing components to calculate exhaust gas collection data, thereby providing a basis for the supervision and evaluation of exhaust gas collection. While this solution addresses the issues of limited exhaust gas collection points and insufficient data dimensions to some extent, the performance of the sensors may drift due to environmental factors (such as temperature, humidity, and dust) during long-term operation. For example, in complex industrial environments, the composition of exhaust gases is complex and the concentration varies widely. Sensors may have difficulty accurately measuring the concentration of various exhaust gas components, especially in low concentration ranges or when multiple components interfere with each other. The measurement error may be further increased, thus affecting the accuracy of the final exhaust gas collection data and failing to provide a completely reliable basis for exhaust gas pollution control.

[0004] Therefore, we propose an exhaust gas monitoring and collection system. Utility Model Content

[0005] The main objective of this application is to provide an exhaust gas monitoring and collection system, which aims to solve the problem that in the existing exhaust gas collection and monitoring system, the sensor performance is easily affected by environmental factors and drifts during long-term operation, resulting in increased measurement errors and ultimately insufficient accuracy of exhaust gas collection data, which cannot provide a completely reliable basis for exhaust gas pollution control.

[0006] To achieve the above objectives, this application provides an exhaust gas monitoring and collection system, including: a monitoring sensor preamplifier circuit, which is used to perform preliminary amplification processing on the exhaust gas-related signals collected by the monitoring sensor;

[0007] The monitoring sensor preamplifier circuit includes an integrated electrode EC, which includes a working electrode WE, a reference electrode RE, and a counter electrode CE. A constant potential circuit is connected between the working electrode WE and the reference electrode RE. The working electrode WE is also connected to a signal conditioning circuit. The output of the signal conditioning circuit is electrically connected to an analog-to-digital converter module. The output of the analog-to-digital converter module is electrically connected to a main control MCU.

[0008] Preferably, the constant potential circuit includes: a MOSFET Q1, the gate of the MOSFET Q1 is connected to a 3.3V signal terminal, the source of the MOSFET Q1 is connected to a signal conditioning circuit through a resistor R4, and the drain of the MOSFET Q1 is connected to the working electrode WE.

[0009] The working electrode WE is connected to the inverting input terminal of the operational amplifier U1 through resistors R1 and R5. The non-inverting input terminal of the operational amplifier U1 is connected to resistor R6, and capacitor C4 is connected between its non-inverting input terminal and the inverting input terminal. Resistor R6 is connected to the reference voltage VR. The output terminal of the operational amplifier U1 is connected to the counter electrode CE through a filter circuit consisting of feedback resistor R2 and capacitor C1.

[0010] More preferably, resistor R6 is connected in parallel with resistors R7 and R8, resistor R8 is grounded, resistor R7 is connected to the reference voltage VR, the reference voltage VR is grounded through capacitor C6, resistor R7 is also connected to the anode pin of Schottky diode IC1, the cathode pin of Schottky diode IC1 is grounded, and the control pin of Schottky diode IC1 is connected in parallel with resistors R9 and R10, resistor R9 is grounded, and resistor R10 is connected to the 3.3V signal terminal.

[0011] Preferably, the signal conditioning circuit includes: an operational amplifier U2, the working electrode WE being connected to the inverting input terminal of the operational amplifier U2 via resistors R4 and R13, a capacitor C7 being connected between the inverting input terminal and the non-inverting input terminal of the operational amplifier U2, a resistor R14 being connected to the non-inverting input terminal of the operational amplifier U2, a voltage source VS being connected to the resistor R14, the output terminal of the operational amplifier U2 being connected to the inverting input terminal via a filter circuit consisting of resistor R15 and capacitor C9, and the output terminal of the operational amplifier U2 being connected to the input terminal of the analog-to-digital converter via a filter circuit consisting of resistor R15 and capacitor C9.

[0012] Preferably, the voltage source VS and the reference voltage source VR are two different independent voltage sources.

[0013] Preferably, a common-emitter amplifier circuit is connected between the input terminal of the analog-to-digital converter and the output terminal of the operational amplifier U2.

[0014] More preferably, the common-emitter amplifier circuit includes: a transistor Q2, the base of which is connected to the output of an operational amplifier U2; a resistor R17 and a resistor R19 are connected in parallel between the output of the operational amplifier U2 and the base of the transistor Q2; the resistor R17 is grounded; the resistor R19 is connected to the input of an analog-to-digital converter; a resistor R21 is connected between the input of the analog-to-digital converter and the resistor R19; the resistor R21 is connected to the collector of the transistor Q2; the emitter of the transistor Q2 is grounded through a resistor R18; a power supply filter network is formed between the collector and emitter of the transistor Q2 through a capacitor C10 and a load resistor R20 to provide a stable static operating point for the transistor; and a bypass capacitor C11 is also connected in parallel to the emitter of the transistor Q2.

[0015] Preferably, the main control MCU is also connected to an external display device and alarm device via a communication interface.

[0016] The beneficial effects of this utility model's technical solution are as follows:

[0017] By employing a preamplifier circuit for the monitoring sensor, the intensity and stability of the exhaust gas-related signals acquired by the monitoring sensor can be effectively improved. The integrated electrode EC, consisting of the working electrode WE, reference electrode RE, and counter electrode CE, combined with a constant potential circuit, signal conditioning circuit, analog-to-digital converter module, and main control MCU, enables precise acquisition, preliminary amplification, stabilization processing, analog-to-digital conversion, and subsequent data processing and analysis of exhaust gas-related signals.

[0018] The constant potential circuit, through the design of components such as the MOSFET Q1, provides a stable potential environment for the working electrode WE, reducing measurement errors caused by potential fluctuations. The operational amplifier U1 and its peripheral circuits constitute a precise signal conditioning circuit. Through reasonable resistor and capacitor configurations and coordination with the reference voltage source VR, the signal from the working electrode WE is further amplified, filtered, and stabilized, ensuring the accuracy and reliability of the signal.

[0019] Operational amplifier U2 in the signal conditioning circuit further optimizes the pre-processed signal, improving signal quality and stability through fine adjustments of components such as resistors and capacitors. The addition of a common-emitter amplifier circuit provides extra amplification gain to the entire signal conditioning process, resulting in a stronger and clearer signal output to the analog-to-digital converter.

[0020] The analog-to-digital converter (ADC) transforms analog signals into digital signals, facilitating subsequent data processing and analysis by the main control MCU. Simultaneously, the connection between the main control MCU and the display and alarm devices allows real-time exhaust gas monitoring data to be displayed on the screen, enabling on-site personnel to intuitively observe and understand the exhaust gas emission situation. Furthermore, when the concentration of certain harmful components in the exhaust gas exceeds a preset safety threshold, the main control MCU immediately sends a command to the alarm device, triggering an audible and visual alarm signal to remind personnel to take timely measures to prevent environmental pollution accidents. Attached Figure Description

[0021] Figure 1 This is a partial circuit diagram of the monitoring sensor preamplifier circuit in one embodiment of this application;

[0022] Figure 2 This is a partial circuit diagram of the monitoring sensor preamplifier circuit in another embodiment of this application;

[0023] Figure 3 This is a schematic diagram of the circuit structure of the signal conditioning circuit in one embodiment of this application;

[0024] Figure 4 This is a schematic diagram of the common-emitter amplifier circuit in one embodiment of this application;

[0025] Figure 5 This is a schematic diagram of the circuit structure of the monitoring sensor preamplifier circuit in one embodiment of this application.

[0026] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0027] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0028] Furthermore, descriptions using terms such as "first" and "second" in this application are for descriptive purposes only (e.g., to distinguish identical or similar elements) and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, technical solutions from different embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, such a combination should be considered nonexistent and not within the scope of protection claimed in this application.

[0029] See Figures 1-3 This utility model proposes an exhaust gas monitoring and collection system, including: a monitoring sensor preamplifier circuit, which is used to perform preliminary amplification processing on the exhaust gas-related signals collected by the monitoring sensor.

[0030] The monitoring sensor preamplifier circuit includes an integrated electrode EC, which comprises a working electrode WE, a reference electrode RE, and a counter electrode CE. A constant potential circuit is connected between the working electrode WE and the reference electrode RE. The constant potential circuit controls the potential of the working electrode WE relative to the reference electrode RE and measures the current response on the working electrode WE. The working electrode WE is also connected to a signal conditioning circuit, which amplifies and filters the electrical signal generated on the working electrode WE to remove noise and enhance signal strength. The output of the signal conditioning circuit is electrically connected to an analog-to-digital converter (ADC), which converts the analog exhaust gas related signal output by the monitoring sensor into a digital signal. The output of the ADC is electrically connected to a main control MCU, which receives and processes the digital signal from the ADC. The main control MCU is also connected to an external display device and alarm device via a communication interface.

[0031] In this embodiment, the potential of the working electrode WE is precisely controlled within a specific range by setting a constant potential circuit, ensuring the stability and repeatability of the electrochemical reaction, reducing measurement errors caused by potential fluctuations, and guaranteeing the accuracy of the monitoring sensor in detecting the components of the exhaust gas. The signal conditioning circuit amplifies and filters the electrical signal generated on the working electrode WE, effectively improving signal quality and ensuring that the electrical signal is enhanced to a level sufficient for accurate identification and processing by the subsequent analog-to-digital conversion module. This avoids the signal being ignored or misjudged due to its weakness, and removes noise and interference components from the signal, enabling it to more accurately reflect the actual concentration of the exhaust gas components when converted into a digital signal.

[0032] Furthermore, the connection between the main control MCU and the display device and alarm device allows real-time exhaust gas monitoring data to be displayed on the display device, enabling on-site personnel to intuitively observe and understand the exhaust gas emission situation. On the other hand, when the concentration of certain harmful components in the exhaust gas exceeds the preset safety threshold, the main control MCU will immediately send a command to the alarm device to trigger an audible and visual alarm signal, reminding personnel to take timely measures to avoid environmental pollution accidents.

[0033] In one embodiment, the constant potential circuit includes: a MOSFET Q1, the gate of which is connected to a 3.3V signal terminal, the source of which is connected to a signal conditioning circuit through a resistor R4, and the drain of which is connected to the working electrode WE.

[0034] The working electrode WE is connected to the inverting input terminal of the operational amplifier U1 through resistors R1 and R5. The non-inverting input terminal of the operational amplifier U1 is connected to resistor R6, and capacitor C4 is connected between its non-inverting input terminal and the inverting input terminal. Resistor R6 is connected to the reference voltage VR. The output terminal of the operational amplifier U1 is connected to the counter electrode CE through a filter circuit consisting of feedback resistor R2 and capacitor C1.

[0035] In this embodiment, under the control of the 3.3V signal terminal, the MOSFET Q1 adjusts its conduction level according to the actual potential of the working electrode WE, thereby controlling the current flowing through the working electrode WE. When the potential of the working electrode WE deviates from the set value, the potential deviation information is transmitted to the operational amplifier U1 through the feedback network composed of resistors R1, R5, and R6 and capacitor C4. The operational amplifier U1 amplifies and processes the deviation information and transmits its output to the subsequent circuit to adjust the conduction state of the MOSFET Q1, so that the potential of the working electrode WE returns to the set value.

[0036] In another embodiment, resistor R6 is connected in parallel with resistors R7 and R8, resistor R8 is grounded, resistor R7 is connected to a reference voltage VR, the reference voltage VR is grounded through capacitor C6, resistor R7 is also connected to the anode pin of Schottky diode IC1, the cathode pin of Schottky diode IC1 is grounded, and the control pin of Schottky diode IC1 is connected in parallel with resistors R9 and R10, resistor R9 is grounded, and resistor R10 is connected to a 3.3V signal terminal.

[0037] In this embodiment, a low-pass filter is formed by a voltage divider network of resistors R7 and R8 and capacitor C6 to generate a low-noise reference voltage. The reference value can be flexibly set by adjusting the ratio of resistors R7 and R8 to adapt to different detection requirements.

[0038] Furthermore, when the reference voltage VR exceeds the safety threshold due to unexpected interference, the Schottky diode IC1 clamps VR within the safe range by forward conduction or reverse breakdown, thus preventing overvoltage damage to the operational amplifier U1.

[0039] Specifically, when the voltage of the reference electrode RE is less than the reference voltage VR, the voltage of the counter electrode CE rises synchronously, which yields: ,in, The voltage at the counter electrode CE. The voltage of the reference electrode RE, The reference voltage is VR; at this time, since the potential at the inverting input terminal of operational amplifier U1 is higher than that at the non-inverting input terminal, operational amplifier U1 will output a high-level signal.

[0040] Simultaneously, the aforementioned high-level signal drives the subsequent circuit connected to the output of operational amplifier U1, controlling the potential difference between the working electrode WE and the counter electrode CE to reduce the voltage on the counter electrode CE. This causes the potential difference between the working electrode WE and the counter electrode CE to approach the reference voltage VR. Therefore: .

[0041] Due to the presence of Schottky diode IC1, when the reference voltage VR exceeds the safety threshold (e.g., 3.3V plus the forward voltage drop of the Schottky diode of 0.3V, i.e., 3.6V) due to unexpected interference, Schottky diode IC1 will conduct. Its anode pin is connected to the reference voltage VR through resistor R7, its cathode pin is grounded, and its control pin is grounded through resistor R9 and connected to the 3.3V signal terminal through resistor R10. When the reference voltage VR exceeds 3.6V, Schottky diode IC1 will conduct forward, clamping the excess voltage to ground, thus protecting operational amplifier U1 from excessive voltage surges.

[0042] In one embodiment, the signal conditioning circuit includes: an operational amplifier U2, the working electrode WE being connected to the inverting input terminal of the operational amplifier U2 via resistors R4 and R13, a capacitor C7 being connected between the inverting input terminal and the non-inverting input terminal of the operational amplifier U2, a resistor R14 being connected to the non-inverting input terminal of the operational amplifier U2, a voltage source VS being connected to the resistor R14, the output terminal of the operational amplifier U2 being connected to the inverting input terminal via a filter circuit consisting of resistor R15 and capacitor C9, and the output terminal of the operational amplifier U2 being connected to the input terminal of the analog-to-digital converter via a filter circuit consisting of resistor R15 and capacitor C9.

[0043] In this embodiment, the working electrode WE is connected to the inverting input terminal of the operational amplifier U2 through resistors R4 and R13, forming an inverting proportional amplifier structure, thereby accurately amplifying the signal input to the working electrode WE, and using capacitor C7 to achieve frequency filtering to remove any possible high-frequency noise.

[0044] Meanwhile, its non-inverting input is connected to the voltage source VS through resistor R14, providing a stable reference voltage for operational amplifier U2 to improve the common-mode rejection ratio (CMRR) of the entire circuit and reduce errors caused by power supply fluctuations or other common-mode interference. The output of operational amplifier U2 is fed back to the inverting input through a filter network consisting of resistor R15 and capacitor C9, forming a negative feedback loop that stabilizes the gain of operational amplifier U2, optimizes frequency response characteristics, and ensures signal stability and accuracy. Furthermore, the output of operational amplifier U2 is connected to the input of the analog-to-digital converter (ADC) through the same R15 and C9 filter network, ensuring that the analog signal is adequately preprocessed before conversion to a digital signal, thereby improving the accuracy and resolution of the analog-to-digital conversion.

[0045] In another embodiment, the voltage source VS and the reference voltage source VR are two different independent voltage sources.

[0046] Specifically, the working electrode WE is connected to the inverting input of operational amplifier U2 through resistors R4 and R13. Then, according to the characteristics of an inverting proportional amplifier, its output voltage is inversely proportional to the input voltage, i.e., the voltage across the working electrode WE. Therefore, we can obtain:

[0047]

[0048] in, The voltage of the working electrode WE. This is the output voltage of operational amplifier U2;

[0049] Furthermore, the output of operational amplifier U2 is fed back to the inverting input through a filter network consisting of resistor R15 and capacitor C9, forming a negative feedback loop. This negative feedback loop stabilizes the gain of the operational amplifier and optimizes its frequency response characteristics. Under steady-state conditions, we can approximate that the output voltage VO is mainly determined by the input voltage (amplified by resistors R4 and R13) and the reference voltage VS, therefore:

[0050]

[0051] Then, the reference voltage source VR is treated as an additional voltage source superimposed on the inverting input;

[0052] At this time, the output voltage VO of operational amplifier U2 can be expressed as:

[0053]

[0054] in, The change in voltage at the inverting input is due to the reference voltage VR. Furthermore, since the reference voltage VR is adjusted proportionally by resistors R7 and R8, then... It can be represented as:

[0055]

[0056] Therefore, the relationship between the final output voltage VO and the voltage source VS and the reference voltage source VR can be expressed as:

[0057]

[0058] In this embodiment, by precisely controlling the voltage source VS and the reference voltage source VR, a highly linear relationship between the output voltage VO and the input voltage can be ensured, reducing nonlinear distortion and thus improving the accuracy of signal conditioning. The voltage source VS provides a stable reference voltage for the operational amplifier U2. Combined with the inverting proportional amplifier circuit composed of resistors R4 and R13 and the negative feedback loop (composed of resistor R15 and capacitor C9), the output voltage VO can accurately reflect changes in the input voltage. Furthermore, by superimposing the voltage adjusted proportionally by the reference voltage source VR through resistors R7 and R8, the adjustment dimensions of the output voltage are further enriched.

[0059] In one embodiment, a common-emitter amplifier circuit is connected between the input terminal of the analog-to-digital converter and the output terminal of the operational amplifier U2.

[0060] Specifically, the common-emitter amplifier circuit includes: a transistor Q2, the base of which is connected to the output of operational amplifier U2; resistors R17 and R19 are connected in parallel between the output of operational amplifier U2 and the base of transistor Q2; resistor R17 is grounded; resistor R19 is connected to the input of an analog-to-digital converter; resistor R21 is connected between the input of the analog-to-digital converter and resistor R19; resistor R21 is connected to the collector of transistor Q2; the emitter of transistor Q2 is grounded through resistor R18; a power supply filter network is formed between the collector and emitter of transistor Q2 through capacitor C10 and load resistor R20 to provide a stable static operating point for the transistor; and a bypass capacitor C11 is also connected in parallel with the emitter of transistor Q2.

[0061] In this embodiment, the current amplification characteristics of the common-emitter amplifier circuit effectively enhance the driving capability of the operational amplifier output signal, amplifying weak signals to the optimal input range of the analog-to-digital converter (ADC) and improving quantization accuracy. Resistors R17 (base pull-down) and R19 (pull-up) form a voltage divider network to precisely set the base bias voltage of transistor Q2. Combined with R21 (collector load resistor), this achieves input / output impedance matching, reducing high-frequency distortion caused by signal reflection.

[0062] The RC filter network composed of capacitor C10 and resistor R20 can suppress the influence of power supply ripple on the static operating point of the transistor, and achieve temperature drift compensation through the negative feedback of the emitter resistor R18, ensuring stable operation of the circuit over a wide temperature range. The bypass capacitor C11 absorbs the emitter AC component through a low-impedance path, eliminating common-mode interference signals. Combined with the power supply decoupling effect of C10, this improves the circuit's signal-to-noise ratio by approximately 20dB (typical value), making it particularly suitable for microvolt-level acquisition scenarios such as bioelectrical signals.

[0063] Furthermore, by reasonably setting the resistance ratio of R19 / R21 and the capacitance value of C11, the -3dB bandwidth of the circuit can be extended to over 500kHz. At the same time, by utilizing the leading phase characteristic formed by the internal junction capacitance of the transistor, the potential oscillation risk of the operational amplifier U2 can be effectively offset.

[0064] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, apparatus, article, or exhaust gas monitoring and collection system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, apparatus, article, or exhaust gas monitoring and collection system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or exhaust gas monitoring and collection system that includes that element.

[0065] The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made based on the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. An exhaust monitoring collection system, characterized by, The utility model relates to a kind of exhaust gas monitoring system, including: Monitoring sensor preamplifier circuit is used to preliminary amplification process to the exhaust gas related signal collected by monitoring sensor; The monitoring sensor preamplifier circuit includes: integrated electrode EC, the integrated electrode EC includes: working electrode WE, reference electrode RE and counter electrode CE, constant potential circuit is connected between the working electrode WE and reference electrode RE, the working electrode WE is also connected signal conditioning circuit, the output of the signal conditioning circuit is electrically connected with analog-digital conversion module, the output of the analog-digital conversion module is electrically connected with main control MCU.

2. An exhaust monitoring collection system according to claim 1, wherein, The constant potential circuit includes: MOS tube Q1, the gate of the MOS tube Q1 is connected with 3.3V signal end, the source of MOS tube Q1 is connected with signal conditioning circuit through resistance R4, the drain of MOS tube Q1 is connected to working electrode WE; The working electrode WE is connected to the inverting input of operational amplifier U1 through resistance R1 and resistance R5, the same-phase input of the operational amplifier U1 is connected with resistance R6, and capacitor C4 is connected between the same-phase input and the inverting input of the operational amplifier U1, the resistance R6 is connected with reference voltage VR, the output of the operational amplifier U1 is connected to counter electrode CE through filter circuit composed of feedback resistance R2 and capacitor C1.

3. An exhaust monitoring collection system according to claim 2, wherein, The resistance R6 is connected with resistance R7 and resistance R8 in parallel, the resistance R8 is grounded, the resistance R7 is connected with reference voltage VR, the reference voltage VR is grounded through capacitor C6, the resistance R7 is also connected to the anode pin of Schottky diode IC1, the cathode pin of the Schottky diode IC1 is grounded, the control electrode pin of the Schottky diode IC1 is connected with resistance R9 and resistance R10 in parallel, the resistance R9 is grounded, the resistance R10 is connected with 3.3V signal end.

4. The exhaust monitoring collection system of claim 1, wherein, The signal conditioning circuit includes: operational amplifier U2, the working electrode WE is connected to the inverting input of operational amplifier U2 through resistance R4 and resistance R13, the inverting input and the same-phase input of the operational amplifier U2 are connected with capacitor C7, the same-phase input of the operational amplifier U2 is connected with resistance R14, the resistance R14 is connected with voltage source VS, the output of the operational amplifier U2 is connected to the inverting input through filter circuit composed of resistance R15 and capacitor C9, the output of the operational amplifier U2 is also connected to the input of analog-digital converter through filter circuit composed of resistance R15 and capacitor C9.

5. An exhaust monitoring collection system according to claim 4, wherein, The voltage source VS and reference voltage source VR are two different independent voltage sources.

6. An exhaust monitoring collection system according to claim 4, wherein, Common-emitter amplification circuit is connected between the input of the analog-digital converter and the output of the operational amplifier U2.

7. An exhaust monitoring collection system according to claim 6, wherein, The common-emitter amplification circuit comprises a transistor Q2, the base of the transistor Q2 is connected to the output of an operational amplifier U2, the output of the operational amplifier U2 and the base of the transistor Q2 are connected in parallel with a resistor R17 and a resistor R19, the resistor R17 is grounded, the resistor R19 is connected to an analog-to-digital converter input, the analog-to-digital converter input and the resistor R19 are connected with a resistor R21, the resistor R21 is connected to the collector of the transistor Q2, the emitter of the transistor Q2 is grounded through a resistor R18, the collector and the emitter of the transistor Q2 are connected through a capacitor C10 and a load resistor R20 to form a power filter network, so as to provide a stable static working point for the transistor, and the emitter of the transistor Q2 is also connected in parallel with a bypass capacitor C11.

8. The exhaust monitoring collection system of claim 1, wherein, The master MCU is also connected with external display devices and alarm devices through the communication interface.

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