Novel temperature, humidity and carbon dioxide detection sensor and control method thereof

Abstract

The invention relates to the technical field of temperature, humidity and carbon dioxide detection, and discloses a novel temperature, humidity and carbon dioxide detection sensor and a control method thereof.The novel temperature, humidity and carbon dioxide detection sensor comprises a bottom shell, an upper cover, a control circuit board, a temperature sensor, a humidity sensor, a carbon dioxide sensor, a displayer and a ventilation mechanism; a device cavity is defined by the bottom shell and the upper cover, a control circuit board, a temperature sensor, a humidity sensor and a carbon dioxide sensor are arranged in the device cavity, the ventilation mechanism is installed on the bottom shell and used for communicating the external environment with the environment in the device cavity, and the displayer is installed on the upper cover. The control end of the display, the control end of the temperature sensor, the control end of the humidity sensor and the control end of the carbon dioxide sensor are electrically connected with the control end of the control circuit board. The sensor can realize integration of temperature, humidity and carbon dioxide detection control, saves resources, saves space, reduces cost and the like, and is also convenient for overall observation of the environment condition of the greenhouse.

Description

Technical Field

[0001] This invention relates to the field of temperature, humidity and carbon dioxide detection technology, and specifically to a novel temperature, humidity and carbon dioxide detection sensor and its control method. Background Technology

[0002] A greenhouse, also known as a heated room, is a facility that allows light to pass through while maintaining (or heating) heat for cultivating plants. During seasons unsuitable for plant growth, it provides a growing period and increases yield, and is primarily used for cultivating or raising seedlings of warm-season vegetables, flowers, and trees. Greenhouses come in many types, categorized by their roof frame materials, lighting materials, shape, and heating conditions. Types of greenhouses include planting greenhouses, livestock greenhouses, exhibition greenhouses, experimental greenhouses, catering greenhouses, and entertainment greenhouses. Greenhouse systems include heating, insulation, cooling, ventilation, control, and irrigation systems. A simple plastic film greenhouse (or simply a shed) has fewer internal facilities and lower requirements than a greenhouse. Therefore, strictly speaking, greenhouses require more sophisticated equipment and may necessitate more advanced instruments for precise temperature control.

[0003] Besides temperature control, greenhouses also require control of humidity and air volume. However, commercially available testing for these aspects is often done separately. Some monitor temperature control separately, some monitor humidity control separately, some monitor carbon dioxide control separately, or they monitor and control temperature and humidity together. This necessitates the introduction of additional monitoring devices within the greenhouse, such as placing a separate temperature and humidity sensor and a separate carbon dioxide sensor. This takes up extra space, wastes resources, and increases costs.

[0004] Therefore, existing temperature, humidity, and carbon dioxide detection technologies need further design. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of existing temperature, humidity, and carbon dioxide detection technologies being separate and not integrated, resulting in inconvenience, space occupation, resource waste, and increased costs. By rationally designing the temperature, humidity, and carbon dioxide detection technologies and adopting a bottom shell, top cover, control circuit board, temperature sensor, humidity sensor, carbon dioxide sensor, display, and ventilation mechanism, integrated temperature, humidity, and carbon dioxide detection and control can be achieved, saving resources, space, and reducing costs, while also facilitating overall observation of the greenhouse environment.

[0006] The specific technical solution of the present invention is as follows:

[0007] A novel temperature, humidity, and carbon dioxide detection sensor includes: a bottom shell, a top cover, a control circuit board, a temperature sensor, a humidity sensor, a carbon dioxide sensor, a display, and a ventilation mechanism. The top cover is mounted on the bottom shell, and the bottom shell and the top cover form a cavity. The control circuit board, temperature sensor, humidity sensor, and carbon dioxide sensor are disposed within the cavity. The ventilation mechanism is mounted on the bottom shell and is used to connect the external environment with the environment inside the cavity. The display is mounted on the top cover, and the control terminals of the display, temperature sensor, humidity sensor, and carbon dioxide sensor are electrically connected to the control terminals of the control circuit board.

[0008] Among them, a graphene-based carbon dioxide sensor was selected.

[0009] Furthermore, both the bottom shell and the top cover are made of plastic.

[0010] Furthermore, the bottom shell and the top cover are connected by snap-fit ​​or screw thread connection.

[0011] Furthermore, the detection sensor also includes a hook, which is mounted on the upper part of the bottom shell.

[0012] Furthermore, the detection sensor also includes a power data interface, the output of which is electrically connected to the input of the control circuit board, and the input of which is connected to external electrical appliances, etc.

[0013] Furthermore, the detection sensor also includes an inner solid shell, a heater, and a waterproof sleeve. The inner solid shell is disposed inside the bottom shell and the top cover. The control circuit board, humidity sensor, and carbon dioxide sensor are disposed inside the inner solid shell. The waterproof sleeve is disposed on the outer surface of the inner solid shell. The heater is disposed on the waterproof sleeve. The control terminal of the heater is electrically connected to the control terminal of the control circuit board.

[0014] Furthermore, the heater includes a resistance wire heater and a spring steel wire heat transfer device. The control terminal of the resistance wire heater is electrically connected to the control terminal of the control circuit board. The resistance wire heater is connected to the spring steel wire heat transfer device, and the spring steel wire heat transfer device is spirally wound on the waterproof sleeve.

[0015] Furthermore, the waterproof sleeve is selected from silicone or rubber materials.

[0016] Furthermore, the ventilation mechanism includes a ventilation inlet, a ventilation outlet, a fan, and a ventilation valve. The ventilation inlet, ventilation outlet, fan, and ventilation valve are respectively disposed on the bottom shell. The fan is disposed near the ventilation inlet, and the ventilation valve is disposed near the ventilation outlet. The ventilation inlet and ventilation outlet are respectively connected to the cavity. The control terminal of the fan is electrically connected to the control terminal of the control circuit board.

[0017] Furthermore, the vent valve is selected as an electromagnetic vent valve.

[0018] Furthermore, the vent valve includes an electromagnet and a push plug. The push plug is installed at the vent outlet and is used to open and close the vent outlet. The control terminal of the electromagnet is electrically connected to the control terminal of the control circuit board and is used to attract and release the push plug.

[0019] Furthermore, the ventilation inlet is equipped with a filter screen, which has the functions of preventing dust and particulate matter.

[0020] Furthermore, the temperature sensor is selected as a thermistor sensor.

[0021] Furthermore, the display is selected as a digital display tube type display.

[0022] Furthermore, a novel method for controlling temperature, humidity, and carbon dioxide detection sensors is provided, comprising the following steps:

[0023] Step 1: Fabrication of the carbon dioxide sensor

[0024] A graphene substrate was selected, and a zinc oxide film was deposited on the graphene substrate using magnetron sputtering technology. Then, a water bath solution was prepared, which included 15-20 parts of copper acetate, 35-40 parts of zinc nitrate, 5-10 parts of silver nitrate, and 30-45 parts of ammonia. The graphene substrate with zinc oxide deposited was placed in the water bath solution according to the weight parts, and heated at a constant temperature of 90℃ for 3 hours. After heating, silver / zinc oxide / copper oxide nanoparticles were deposited on the zinc oxide. The graphene substrate was removed, rinsed with deionized water, and then naturally dried and cooled to room temperature. Using metallic silver as electrodes, the first metallic silver was connected to the zinc oxide film, and the second metallic silver was connected to the silver / zinc oxide / copper oxide nanoparticles to complete the fabrication of the carbon dioxide sensor.

[0025] Step 2: Sensor Assembly

[0026] Using the carbon dioxide sensor from step 1, the following components are selected: a thermistor sensor, a filter, an electromagnet, a pusher, an air inlet, an air outlet, a fan, a silicone waterproof sleeve, a resistance wire heater, a spring steel wire heat transfer device, an inner solid shell, a bottom shell, a top cover, a control circuit board, a humidity sensor, and a display. The top cover is mounted on the bottom shell, and the bottom shell and top cover form a cavity. Inside the cavity are the resistance wire heater and the spring steel wire heat transfer device. A silicone waterproof sleeve is located inside the spring steel wire heat transfer device. The resistance wire heater is connected to the spring steel wire heat transfer device, which is spirally wound around the waterproof sleeve. Inside the silicone waterproof sleeve is the inner solid shell, and a control circuit board is located within the inner solid shell. The device includes a circuit board, a humidity sensor, and a carbon dioxide sensor. Inside the cavity, there is also a thermistor sensor, an air inlet, an air outlet, and a fan. A filter is installed at the air inlet, and a thermistor sensor is located inside the filter. A fan is located inside the thermistor sensor. An electromagnet and a push plug are located at the air outlet. A display is mounted on the top cover. The control terminals of the display, the thermistor sensor, the humidity sensor, the carbon dioxide sensor, the fan, the resistance wire heater, and the electromagnet are electrically connected to the control terminals of the control circuit board. The sensor is then assembled.

[0027] Step 3: Sensor Control

[0028] Select the sensor from step 2 and place it inside the greenhouse. Power on the control circuit board and activate it. The control board then controls the fan to draw air from the greenhouse into the intake. The air is first filtered through a filter, then passes to a thermistor sensor for temperature measurement, which feeds the signal back to the control circuit board. The air then enters a humidity sensor for humidity measurement, which also feeds the signal back to the control circuit board. Because the greenhouse air has varying humidity and temperature, the air is first heated to ensure balanced temperature and humidity. Then, the air enters a carbon dioxide sensor for carbon dioxide content measurement, which feeds the signal back to the control circuit board. The control circuit board processes and integrates the temperature, humidity, and carbon dioxide signals, displaying them on a monitor. Finally, the control circuit board controls an electromagnet to push a stopper, releasing internal air. The control circuit board continuously controls the electromagnet to push the stopper, ensuring the necessary air conditions.

[0029] Beneficial effects

[0030] This invention, through the rational design of temperature, humidity, and carbon dioxide detection technologies, integrates temperature, humidity, and carbon dioxide detection and control into a single unit. This design utilizes a base shell, top cover, control circuit board, temperature sensor, humidity sensor, carbon dioxide sensor, display, and ventilation mechanism, saving resources, space, and costs, while also facilitating overall observation of the greenhouse environment. The fan configuration aids air circulation; the heater configuration ensures constant temperature and humidity levels after detection; the carbon dioxide sensor collects the carbon dioxide content in the air for more accurate data; and the combination of an electromagnet and a pusher allows for timely replenishment and expulsion of air. The use of a graphene-based carbon dioxide sensor improves the detection sensitivity. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of a novel temperature, humidity and carbon dioxide detection sensor according to the present invention.

[0032] Figure 2 This is a schematic diagram of the heating section of a novel temperature, humidity, and carbon dioxide detection sensor according to the present invention.

[0033] Figure 3 This is a schematic diagram of the inner solid shell portion of a novel temperature, humidity, and carbon dioxide detection sensor according to the present invention.

[0034] Figure 4 This is a schematic diagram of the display section of a novel temperature, humidity, and carbon dioxide detection sensor according to the present invention.

[0035] Figure 5 This is a schematic diagram of the internal structure of a novel temperature, humidity, and carbon dioxide detection sensor according to the present invention.

[0036] Figure 6 This is a SEM image of the zinc oxide thin film of the carbon dioxide sensor of a novel temperature, humidity and carbon dioxide detection sensor of the present invention.

[0037] Figure 7 This is a SEM image of a silver / zinc oxide / copper oxide thin film of a novel temperature, humidity and carbon dioxide detection sensor according to the present invention.

[0038] Reference numerals: 01. Hanging ear; 02. Power data interface; 03. Bottom shell; 04. Top cover; 05. Filter screen; 06. Heater; 07. Temperature sensor; 08. Waterproof sleeve; 09. Inner solid shell; 10. Display; 11. Control circuit board; 12. Carbon dioxide sensor; 13. Humidity sensor; 14. Ventilation inlet; 15. Push plug; 16. Electromagnet; 17. Fan. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0040] See Figures 1-5 As shown, this invention provides a novel temperature, humidity, and carbon dioxide detection sensor and its control method. The sensor includes: a bottom shell 03, a top cover 04, a control circuit board 11, a temperature sensor 07, a humidity sensor 13, a carbon dioxide sensor 12, a display 10, and a ventilation mechanism. The bottom shell 03 and the top cover 04 are both made of plastic. The temperature sensor 07 is a thermistor sensor. The display 10 is a digital display tube type display. The humidity sensor is an SHT31 humidity sensor. The carbon dioxide sensor is a graphene-type carbon dioxide sensor.

[0041] The upper cover 04 is mounted on the lower shell 03, and the lower shell 03 and upper cover 04 are connected by screw threads. The lower shell 03 and upper cover 04 form a cavity, which is ventilated by a ventilation mechanism (ribbed track) on the inner side of the lower shell and upper cover, as well as an inner solid shell and a waterproof sleeve. A control circuit board 11, a temperature sensor 07, a humidity sensor 13, and a carbon dioxide sensor 12 are installed inside the cavity. The ventilation mechanism is mounted on the lower shell 03 and is used to connect the external environment with the environment inside the cavity. A display 10 is mounted on the upper cover 04, and the control terminals of the display 10, temperature sensor 07, humidity sensor 13, and carbon dioxide sensor 12 are electrically connected to the control terminals of the control circuit board 11. The sensor also includes a hook 01, which is installed on the lower shell 03 and the upper cover. The sensor also includes a power and data interface 02. The output of the source data interface 02 is electrically connected to the input of the control circuit board 11, and the input of the power data interface 02 is connected to external electrical appliances, etc. The detection sensor also includes an inner solid shell 09, a heater 06, and a waterproof sleeve 08. The inner solid shell 09 is located inside the bottom shell 03 and the top cover 04. The control circuit board 11, the humidity sensor 13, and the carbon dioxide sensor 12 are located inside the inner solid shell 09. The outer surface of the inner solid shell 09 is provided with a waterproof sleeve 08. The heater 06 is provided on the waterproof sleeve 08. The control terminal of the heater 06 is electrically connected to the control terminal of the control circuit board 11. The heater 06 includes a resistance wire heater 06 and a spring steel wire heat transfer device. The control terminal of the resistance wire heater 06 is electrically connected to the control terminal of the control circuit board 11. The resistance wire heater 06 is connected to the spring steel wire heat transfer device, which is spirally wound on the waterproof sleeve 08. The waterproof sleeve 08 is made of silicone material.

[0042] The ventilation mechanism includes a ventilation inlet 14, a ventilation outlet, a fan 17, and a ventilation valve. The ventilation inlet 14, ventilation outlet, fan 17, and ventilation valve are respectively mounted on the bottom shell 03. The fan 17 is positioned near the ventilation inlet 14, and the ventilation valve is positioned near the ventilation outlet. The ventilation inlet 14 and ventilation outlet are respectively connected to the cavity. The control terminal of the fan 17 is electrically connected to the control terminal of the control circuit board 11. The ventilation valve is an electromagnetic type, comprising an electromagnet 16 and a push plug 15. The push plug 15 is installed at the ventilation outlet and is used to open and close the ventilation outlet. The control terminal of the electromagnet 16 is electrically connected to the control terminal of the control circuit board 11 and is used to perform suction and release operations on the push plug 15. The ventilation inlet 14 is equipped with a filter screen 05.

[0043] The specific implementation of this invention is as follows: After assembling the sensor, it is suspended inside a greenhouse. Controlled by the control circuit board, a fan is turned on, drawing air from inside the greenhouse into the sensor cavity. The outside air first passes through a filter, then enters a temperature sensor for temperature measurement, followed by a humidity sensor for humidity measurement, and then passes through a heater to maintain constant conditions before entering a carbon dioxide sensor for carbon dioxide measurement. The data collected by these three sensors is displayed on a monitor. Then, an electromagnet and a pusher cooperate to release the gas to the outside, completing the detection and control of temperature, humidity, and carbon dioxide. For ease of detection, the centers of the temperature sensor, humidity sensor, carbon dioxide sensor, fan, electromagnet, and pusher are aligned in a straight line.

[0044] One of the methods for controlling a novel temperature, humidity, and carbon dioxide detection sensor includes the following steps:

[0045] Step 1: Fabrication of the carbon dioxide sensor

[0046] A graphene substrate was selected, and a zinc oxide film was deposited on the graphene substrate using magnetron sputtering technology. Then, a water bath solution was prepared, which included 15-20 parts of copper acetate, 35-40 parts of zinc nitrate, 5-10 parts of silver nitrate, and 30-45 parts of ammonia. The graphene substrate with zinc oxide deposited was placed in the water bath solution according to the weight parts, and heated at a constant temperature of 90℃ for 3 hours. After heating, silver / zinc oxide / copper oxide nanoparticles were deposited on the zinc oxide. The graphene substrate was removed, rinsed with deionized water, and then naturally dried and cooled to room temperature. Using metallic silver as electrodes, the first metallic silver was connected to the zinc oxide film, and the second metallic silver was connected to the silver / zinc oxide / copper oxide nanoparticles to complete the fabrication of the carbon dioxide sensor.

[0047] Step 2: Sensor Assembly

[0048] Using the carbon dioxide sensor from step 1, the following components are selected: a thermistor sensor, a filter, an electromagnet, a pusher, an air inlet, an air outlet, a fan, a silicone waterproof sleeve, a resistance wire heater, a spring steel wire heat transfer device, an inner solid shell, a bottom shell, a top cover, a control circuit board, a humidity sensor, and a display. The top cover is mounted on the bottom shell, and the bottom shell and top cover form a cavity. Inside the cavity are the resistance wire heater and the spring steel wire heat transfer device. A silicone waterproof sleeve is located inside the spring steel wire heat transfer device. The resistance wire heater is connected to the spring steel wire heat transfer device, which is spirally wound around the waterproof sleeve. Inside the silicone waterproof sleeve is the inner solid shell, and a control circuit board is located within the inner solid shell. The device includes a circuit board, a humidity sensor, and a carbon dioxide sensor. Inside the cavity, there is also a thermistor sensor, an air inlet, an air outlet, and a fan. A filter is installed at the air inlet, and a thermistor sensor is located inside the filter. A fan is located inside the thermistor sensor. An electromagnet and a push plug are located at the air outlet. A display is mounted on the top cover. The control terminals of the display, the thermistor sensor, the humidity sensor, the carbon dioxide sensor, the fan, the resistance wire heater, and the electromagnet are electrically connected to the control terminals of the control circuit board. The sensor is then assembled.

[0049] Step 3: Sensor Control

[0050] Select the sensor from step 2 and place it inside the greenhouse. Power on the control circuit board and activate it. The control board then controls the fan to draw air from the greenhouse into the intake. The air is first filtered through a filter, then passes to a thermistor sensor for temperature measurement, which feeds the signal back to the control circuit board. The air then enters a humidity sensor for humidity measurement, which also feeds the signal back to the control circuit board. Because the greenhouse air has varying humidity and temperature, the air is first heated to ensure balanced temperature and humidity. Then, the air enters a carbon dioxide sensor for carbon dioxide content measurement, which feeds the signal back to the control circuit board. The control circuit board processes and integrates the temperature, humidity, and carbon dioxide signals, displaying them on a monitor. Finally, the control circuit board controls an electromagnet to push a stopper, releasing internal air. The control circuit board continuously controls the electromagnet to push the stopper, ensuring the necessary air conditions.

[0051] Specifically, the experiment for step 1 is as follows:

[0052] A graphene substrate was selected, and a 200 nm thick zinc oxide film was deposited on the graphene substrate using magnetron sputtering. Then, a water bath solution was prepared, which included 20 parts of copper acetate, 40 parts of zinc nitrate, 10 parts of silver nitrate, and 30 parts of ammonia. The graphene substrate with zinc oxide deposited was placed in the water bath solution according to the weight parts, and heated at a constant temperature of 90℃ for 3 hours. After heating, silver / zinc oxide / copper oxide nanoparticles were deposited on the zinc oxide. The graphene substrate was removed, rinsed with deionized water, and then naturally dried and cooled to room temperature. Using metallic silver as electrodes, the first metallic silver was connected to the zinc oxide film, and the second metallic silver was connected to the silver / zinc oxide / copper oxide nanoparticles to complete the fabrication of the carbon dioxide sensor.

[0053] The above experiments were then tested, and the surface morphology of the zinc oxide film and the silver / zinc oxide / copper oxide surfaces were observed using a scanning electron microscope. It can be seen that: Figure 6 This is a SEM image of the zinc oxide thin film of the carbon dioxide sensor of a novel temperature, humidity and carbon dioxide detection sensor of the present invention. It can be seen that the zinc oxide thin film is uniform and the particle size is about 25nm. Figure 7 This is a SEM image of the silver / zinc oxide / copper oxide thin film of a novel temperature, humidity and carbon dioxide detection sensor of the present invention. It can be seen that the silver / zinc oxide / copper oxide forms flower-like nanoparticles on the zinc oxide surface. The nanoparticles are evenly distributed on the zinc oxide thin film and are firmly bonded to the zinc oxide thin film. Their particle size is about 1 μm.

[0054] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A new type of temperature, humidity and carbon dioxide detection sensor, characterized in that: The detection sensor comprises: a bottom shell, an upper cover, a control circuit board, a temperature sensor, a humidity sensor, a carbon dioxide sensor, a display and a ventilation mechanism, wherein the upper cover is mounted on the bottom shell, the bottom shell and the upper cover enclose a cavity, the control circuit board, the temperature sensor, the humidity sensor and the carbon dioxide sensor are arranged in the cavity, the ventilation mechanism is mounted on the bottom shell, the ventilation mechanism is used to connect the external environment with the environment in the cavity, the display is mounted on the upper cover, and the control end of the display, the control end of the temperature sensor, the control end of the humidity sensor and the control end of the carbon dioxide sensor are electrically connected to the control end of the control circuit board respectively; Among them, the carbon dioxide sensor selects a graphene carbon dioxide sensor.

2. A new type of temperature, humidity and carbon dioxide detection sensor according to claim 1, characterized in that: The detection sensor also includes an inner solid shell, a heater and a waterproof cover. The inner solid shell is arranged on the inner side of the bottom shell and the upper cover. The control circuit board, the humidity sensor and the carbon dioxide sensor are arranged on the inner side of the inner solid shell. The outer surface of the inner solid shell is provided with the waterproof cover. The heater is provided on the waterproof cover. The control end of the heater is electrically connected to the control end of the control circuit board.

3. A new type of temperature, humidity and carbon dioxide detection sensor according to claim 2, characterized in that: The heater comprises a resistance wire heater and a spring steel wire heat transfer device, the control end of the resistance wire heater is electrically connected to the control end of the control circuit board, the resistance wire heater is connected to the spring steel wire heat transfer device, and the spring steel wire heat transfer device is spirally wound on the waterproof cover.

4. A new type of temperature, humidity and carbon dioxide detection sensor according to claim 3, characterized in that: The waterproof cover is made of silicone or rubber.

5. A new type of temperature, humidity and carbon dioxide detection sensor according to claim 1, characterized in that: The ventilation mechanism includes a ventilation inlet, a ventilation outlet, a fan and a ventilation valve, which are respectively arranged on the bottom shell, the fan is arranged near the ventilation inlet, and the ventilation valve is arranged near the ventilation outlet. The ventilation inlet and the ventilation outlet are respectively communicated with the device cavity, and the control end of the fan is electrically connected to the control end of the control circuit board.

6. A new type of temperature, humidity and carbon dioxide detection sensor according to claim 5, characterized in that: The vent valve is an electromagnetic vent valve.

7. A new type of temperature, humidity and carbon dioxide detection sensor according to claim 6, characterized in that: The vent valve includes an electromagnet and a push plug, wherein the push plug is installed at the vent outlet and is used to open and close the vent outlet. The control end of the electromagnet is electrically connected to the control end of the control circuit board, and the electromagnet is used to suck and release the push plug.

8. A new type of temperature, humidity and carbon dioxide detection sensor according to claim 5, characterized in that: The ventilation inlet is provided with a filter screen.

9. A novel temperature, humidity and carbon dioxide detection sensor according to claim 1, characterized in that: The temperature sensor is a thermistor sensor.

10. A novel method for controlling a temperature, humidity and carbon dioxide detection sensor, characterized in that: The control method steps are as follows: Step 1: Making a CO2 Sensor A graphene substrate is selected, and a zinc oxide film is deposited on the graphene substrate by magnetron sputtering technology, and then a water bath solution is prepared, wherein the water bath solution includes 15-20 parts of copper acetate, 35-40 parts of zinc nitrate, 5-10 parts of silver nitrate and 30-45 parts of ammonia water, and the graphene substrate with zinc oxide deposited is placed in the water bath solution and heated at a constant temperature for 3 hours, and the temperature is kept constant at 90° C. After the heating is completed, silver / zinc oxide / copper oxide nano-objects are deposited on the zinc oxide, and the graphene substrate is taken out, and then rinsed with deionized water, and naturally dried and cooled to room temperature, and metallic silver is used as an electrode, and the first metallic silver is connected to the zinc oxide film, and the second metallic silver is connected to the silver / zinc oxide / copper oxide nano-object, and the production of the carbon dioxide sensor is completed; Step 2: Assembly of the Sensor The carbon dioxide sensor of step 1 is adopted, and a thermistor sensor, a filter, an electromagnet, a push plug, a ventilation inlet, a ventilation outlet, a fan, a silicone waterproof cover, a resistance wire heater, a spring steel wire heat transfer device, an inner solid shell, a bottom shell, an upper cover, a control circuit board, a humidity sensor and a display are selected. The upper cover is installed on the bottom shell, and the bottom shell and the upper cover form a device cavity. A resistance wire heater and a spring steel wire heat transfer device are arranged in the device cavity, a silicone waterproof cover is arranged in the spring steel wire heat transfer device, the resistance wire heater is connected to the spring steel wire heat transfer device, the spring steel wire heat transfer device is spirally wound on the waterproof cover, an inner solid shell is arranged in the silicone waterproof cover, and a control circuit board is arranged in the inner solid shell. A circuit board, a humidity sensor and a carbon dioxide sensor are provided in the chamber. A thermistor sensor, a ventilation inlet, a ventilation outlet and a fan are also provided. A filter is provided at the ventilation inlet, a thermistor sensor is provided inside the filter, a fan is provided inside the thermistor sensor, an electromagnet and a push plug are provided at the ventilation outlet. A display is installed on the upper cover. The control end of the display, the control end of the thermistor sensor, the control end of the humidity sensor, the control end of the carbon dioxide sensor, the control end of the fan, the control end of the resistance wire heater and the control end of the electromagnet are electrically connected to the control end of the control circuit board respectively, and the sensor is assembled. Step 3: Sensor Control Select the sensor of step 2, put it into the greenhouse, connect the power supply to the control circuit board, start the control circuit board, the control circuit board controls the fan operation, and inhales the air of the greenhouse into the fan. The air of the greenhouse is first filtered through the filter, and then goes to the thermistor sensor for temperature collection, and the temperature signal is fed back to the control circuit board. The air of the greenhouse continues to enter the humidity sensor for humidity collection, and the humidity signal is fed back to the control circuit board. Since the air in the greenhouse has different humidity and temperature, the factors change too much, the air of the greenhouse is first heated to ensure the temperature and humidity balance, and then enters the carbon dioxide sensor to collect the carbon dioxide content, and the carbon dioxide signal is fed back to the control circuit board. The control circuit board processes and integrates the temperature, humidity and carbon dioxide signals and displays them to the outside through the display. Then the control circuit board controls the electromagnet to push the plug to release the internal air. The control circuit board shell here controls the electromagnet to push the plug at any time to ensure the required air conditions.

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