CN110857928A - Semiconductor-type gas sensor, multi-sensor device, and method for identifying the same - Google Patents
Semiconductor-type gas sensor, multi-sensor device, and method for identifying the same Download PDFInfo
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- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
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Abstract
The present invention relates to a semiconductor-type gas sensor, a multi-sensor device, and a method for identifying the multi-sensor device. The semiconductor-type gas sensor includes: a substrate; an electrode formed on the upper surface of the substrate in a predetermined pattern; a gas detection film having a predetermined thickness and covering an outer exposed surface of the electrode; and a heater which is in close contact with the lower surface of the substrate and heats the gas detection film at a predetermined temperature, wherein the gas detection film is SnO having an amorphous layer formed thereon2The detection substance of (3) is a mixture of a predetermined amount of a thermosetting resin and a silane coupling agent as a binder. According to the semiconductor-type gas sensor having the above-described configuration, the heating temperature of the semiconductor-type gas sensor is significantly reduced, so that the power consumption and maintenance cost for operation can be reduced, the manufacturing cost can be reduced, the measurement sensitivity can be improved, the measurement variability due to the change in the ambient temperature and humidity can be reduced, and the gas can be accurately detected.
Description
Technical Field
The invention relates to a semiconductor type gas sensor, a multiple sensing device and an identification method thereof. Specifically, in the semiconductor-type gas sensor, the heating temperature for operating the semiconductor-type gas sensor is significantly reduced, so that the power consumption for operating the gas sensor and the maintenance cost can be reduced, the manufacturing cost can be reduced, the measurement sensitivity can be improved, and the measurement variability due to the change in the temperature and humidity around the gas sensor can be reduced, thereby enabling accurate gas detection.
Background
With the rapid development of modern society and automobile industry, the problem of air pollution caused by toxic gases such as carbon monoxide, carbon dioxide, hydrogen sulfide, and nitrogen dioxide, which are by-products thereof, is becoming more prominent, and under the actual situation that the risk of gas explosion or gas poisoning is increasing, research into a gas sensor capable of measuring a gas that cannot be visually recognized is actively ongoing.
Among the conventional gas sensors, the semiconductor type gas sensor is a metal oxide semiconductor SnO2、ZnO、In2O3Etc. by measuring the presence and concentration of a specific gas in the air by a change in resistance. Such a semiconductor-type gas sensor is mainly used for gas leakage alarm and gas concentration measurement after commercialization in 1968 by Figaro (Figaro) of Japan. The semiconductor-type gas sensor is suitable for the evolution of respective detection gases and purposes by improving the material of the gas sensor and the detection equipment using the gas sensor, and is commercialized, thereby being applied to the fields of industry, medical treatment and actual life.
Semiconductors are classified into n-type semiconductors and p-type semiconductors, SnO, according to their conduction mechanism2Belonging to the n-type semiconductor, since the number of negative ions (O) is smaller in number than that of positive ions (Sn), surplus electrons are generated, which contribute to the electrical conductivity. Such SnO2There is a tendency that oxygen species are insufficiently adsorbed from the atmosphere so that imbalance in the number ratio of positive/negative ions is alleviated, and since the adsorbed oxygen species are negatively charged, electrons that have a conductive action in the semiconductor become confined to the surface of the adsorbed oxygen, at which point conductivity is lost. In this state, if the surface is exposed to a reducing gas such as carbon monoxide or ammonia, the adsorbed oxygen on the surface reacts with the exposed gas species, and the adsorbed oxygen on the surface is desorbed again. At the moment, is surrounded by oxygenThe trapped electrons are recaptured to affect the conductivity, which will vary depending on the target gas to be detected, from which the presence and concentration of leaking gas species can be known.
As shown in fig. 1, the conventional semiconductor-type gas sensor for detecting peripheral gas by such a process is provided with an electrode for detecting SnO accompanying a detection agent on a substrate2The gas detection film of (4) has a detection agent SnO formed in a predetermined thickness around the periphery of the electrode2The gas detection film of (1) is provided with a heater on the lower surface of the substrate, and the gas detection film is activated by heating the gas detection film to 300 to 400 ℃ through the substrate placed on the upper surface of the heater by operating the heater.
As described above, in the conventional semiconductor-type gas sensor, since it is necessary to perform the heater at a temperature of at least 300 ℃ at the minimum in order to activate the gas detection film and to maintain the activation temperature, it is not possible to use a general PCB substrate using epoxy resin or the like, and an expensive heat-resistant substrate such as a ceramic substrate is mainly used, which leads to an increase in production cost and power consumption. In order to improve the sensitivity to the peripheral leaked gas, the conventional gas sensing film needs to be additionally added with a catalyst such as Pt, and the gas detection degree changes along with the change of the temperature and the humidity around the gas sensing film, so that the gas is difficult to be accurately detected.
Disclosure of Invention
The present invention has been made to solve the above problems, and it is an object of the present invention to provide a semiconductor-type gas sensor that includes a gas sensitive film that can operate even in a state where an activation temperature is significantly low, can significantly reduce a heating temperature required for operating the semiconductor-type gas sensor, can save power consumption for operating the gas sensor and maintenance costs, and can reduce the manufacturing costs of the gas sensor by manufacturing the semiconductor-type gas sensor using an inexpensive general PCB substrate without using an expensive heat-resistant substrate.
Further, the present invention can provide a semiconductor-type gas sensor capable of improving the measurement sensitivity of the gas sensitive film and reducing measurement variability due to changes in temperature and humidity around the gas sensor, thereby accurately detecting a gas.
In addition, the present invention also provides a multi-sensor apparatus using an identification circuit and an identification method of the multi-sensor apparatus, which can ensure flexibility of different indoor environments, energy sources, and safety-related measurement factors.
In order to solve the above problem, the present invention provides a semiconductor-type gas sensor including: a substrate; an electrode formed in a predetermined pattern on an upper surface of the substrate; a gas detection film having a predetermined thickness and covering the electrode; and a heater provided on a lower surface of the substrate and configured to heat the gas detection film at a predetermined temperature, wherein the gas detection film is formed of SnO having an amorphous layer formed thereon2The detection substance of (3) is a mixture of a predetermined amount of a thermosetting resin and a silane coupling agent as a binder.
In addition, the present invention also provides a multiple sensing apparatus, comprising: a sensor module unit including at least one semiconductor-type gas sensor as described above and outputting a sensor measurement signal for measuring any one of the measurement objects related to environment, energy, and safety and a sensor identification signal for identifying the measurement object; a sensor base portion for attaching or detaching the sensor module portion; and a sensor data generation unit that recognizes the sensor module unit and generates sensor data when the sensor module unit is attached to the sensor base unit.
Further, the present invention provides a method of identifying a multiple sensing apparatus including at least one semiconductor-type gas sensor as described above, the method being performed in the multiple sensing apparatus, the method including: scanning an input pin of the PWM signal; a step of storing PWM signal information under the condition that the PWM signal exists; calculating the duty ratio by utilizing the PWM signal information and storing the duty ratio; and recognizing a sensor module part corresponding to the calculated duty ratio and generating a sensor recognition value after the scanning of the PWM signal input pin is completed.
Effects of the invention
The semiconductor type gas sensor of the present invention can reduce the heating temperature required for activation by significantly reducing the activation temperature of the gas sensitive film for operating the gas sensor, and reduce the power consumption and maintenance cost required for operating the heater, and can also manufacture the semiconductor type gas sensor using a general PCB substrate which is inexpensive, thereby significantly saving the manufacturing cost of the gas sensor.
In addition, the semiconductor type gas sensor of the present invention has high measurement sensitivity by the gas sensitive film having improved conductivity, and reduces measurement variability caused by changes in ambient temperature and humidity of the gas sensor, thereby being free from the influence of the ambient environment and being capable of accurately detecting gas.
Drawings
Fig. 1 is a cross-sectional view of a conventional semiconductor-type gas sensor.
Fig. 2 is a cross-sectional view of a semiconductor-type gas sensor of the present invention.
Fig. 3 is a schematic cross-sectional view of a detection substance for forming a gas sensitive film in the semiconductor-type gas sensor of the present invention.
Fig. 4 is a graph of the composition distribution of the detection substance for forming a gas sensitive film in the semiconductor-type gas sensor of the present invention.
Fig. 5 is a graph comparing the change of the resistance value with time of the semiconductor-type gas sensor of the present invention and the conventional semiconductor-type gas sensor at a heating temperature of 150 ℃.
Fig. 6 is a schematic diagram for explaining an embodiment of a multiple sensing device management system using an identification circuit according to the present invention.
Fig. 7 is a schematic diagram for explaining an embodiment of a multiple sensing apparatus using an identification circuit according to the present invention.
Fig. 8 and 9 are schematic views for explaining a sensor module according to the present invention.
Fig. 10 is a schematic diagram for explaining an oscillation circuit according to the present invention.
Fig. 11 is a schematic diagram for explaining a sensor identifying section according to the present invention.
Fig. 12 to 14 are flowcharts for explaining an identification method of a multi-sensor device using an identification circuit according to the present invention.
Detailed Description
The following description is made with reference to the accompanying drawings of embodiments of the present invention in which the above objects can be specifically achieved. In the description of the present embodiment, the same names and reference numerals are used for the same constituents, and additional description thereof will be omitted hereinafter.
Fig. 2 is a cross-sectional view of a semiconductor-type gas sensor according to the present invention, fig. 3 is a schematic cross-sectional view of a detection substance for forming a gas sensitive film in the semiconductor-type gas sensor according to the present invention, fig. 4 is a graph of a component distribution of the detection substance for forming a gas sensitive film in the semiconductor-type gas sensor according to the present invention, and fig. 5 is a graph comparing a change in resistance value with time of the semiconductor-type gas sensor according to the present invention and a conventional semiconductor-type gas sensor at a heating temperature of 150 ℃.
As shown in fig. 2, the semiconductor-type gas sensor according to the present invention roughly includes: a substrate formed to have a predetermined thickness; an electrode formed in a predetermined pattern on an upper surface of the substrate; a gas-sensitive film having a predetermined thickness so as to cover one side periphery of the electrode; and a heater which is in close contact with the lower surface of the substrate, heats the gas sensitive film at a predetermined temperature through the substrate, and activates the gas sensitive film.
As shown in fig. 2, the substrate is formed in a plate shape having a predetermined thickness, and the electrode and the gas sensing film are provided on the upper side so that the heating amount of the heater located on the lower surface is transmitted to the electrode and the gas sensing film.
As shown in fig. 2 to 4, the gas sensing film is formed on an outer exposed surface of the electrode to cover an upper side of the substrate and is formed of a detection material in which SnO2 is located at an inner center and SnO located at the inner center2Around the surface, Sn, SnO and SnO are irregularly dispersed2To form an amorphous layer。
As shown in fig. 2, the heater is closely attached to the lower surface of the substrate, and the gas sensitive film is heated at a predetermined activation temperature by the substrate located on the upper surface. When the operating temperature of the heater is lower than 110 ℃, the gas sensor cannot be normally operated because the gas sensing film cannot be activated, and when the operating temperature is higher than 170 ℃, it is difficult to use a general synthetic resin substrate such as epoxy resin or phenolic resin, and therefore, it is preferable to set the operating temperature of the heater to 110 to 170 ℃ and use it.
Although the prior art is made solely of SnO2The formed detection substance is added with catalysts such as gold, platinum, silver and the like to improve the conductivity of the gas-sensitive film, but the semiconductor type gas sensor of the invention adopts SnO2Sn, SnO and SnO are formed at the center and are irregularly dispersed at the periphery2The amorphous layer can obviously improve the conductivity of the gas sensitive film, can omit the addition of a catalyst for improving the conductivity, particularly, the metallic Sn positioned at the periphery of the amorphous layer also reacts with the peripheral gas at a low activation temperature, changes the conductivity and can obviously reduce the operation heating temperature of a heater positioned on the lower surface of the substrate.
Since the activation temperature of the gas sensitive film is lowered, power consumption for heating a heater and operation and maintenance costs of the gas sensor can be reduced, and in the prior art, in order to heat the gas sensitive film at a high activation temperature of 300 to 400 ℃, an expensive heat-resistant substrate such as a ceramic substrate is used, but the semiconductor-type gas sensor of the present invention can activate the gas sensitive film even at a low temperature of 110 to 170 ℃, and a general phenol resin or epoxy resin substrate which is inexpensive can be used, so that the manufacturing costs of the semiconductor-type gas sensor can be significantly reduced.
In the detection substance, SnO2At the center of the interior, and at the periphery, Sn, SnO and SnO are irregularly dispersed2Thus forming an amorphous layer, a preferred fabrication method for forming the detection substance is as follows: first, in tin dioxide (SnO)2) Mixing a prescribed amount of carbon powder such as charcoal in the powder, and homogenizing the mixed powder by stirring operation; feeding the homogenized mixed powder to a high temperatureAfter the inside of the energy beam irradiation device is sealed from the outside, nitrogen gas is injected into the sealed high-energy beam irradiation device, and in the state of injecting the nitrogen gas, high-energy beams such as electron beams, ion beams or microwaves are injected for a predetermined time to heat the mixed powder, so that the heated carbon powder is gasified, a part of tin dioxide is reduced to Sn or SnO, and the Sn or SnO generated by reduction and the part of SnO not reduced are reduced2Tin dioxide is centrally deposited around it to form an amorphous layer. And, nitrogen gas was passed through SnO where an amorphous layer was formed2Nitrogen is doped, and the conductivity is improved.
FIG. 4 is a graph showing the composition analysis of the detection substance formed in this manner, and it is understood that Sn, SnO and SnO are dispersed around tin dioxide, together with the portions N and C2Form (b) forming an amorphous layer.
Preferably, SnO layer formed with amorphous layer2The detection substance according to (1), wherein a predetermined amount of a thermosetting resin and a Silane Coupling agent (Silane Coupling agent) as a binder are mixed, and the mixture is applied to the outside of the electrode to a predetermined thickness to form the gas sensing film, thereby forming the SnO layer having an amorphous layer formed thereon2The detection substance of (a) is excellently adhered to the outer side surface of the electrode, and the mixed thermosetting resin and silane coupling agent are used as a protective film of the detection substance, so that the change of the conductivity of the gas sensitive film according to the change of the ambient temperature and humidity of the gas sensor is minimized, and the gas can be detected relatively accurately.
Fig. 5 is a graph comparing the change of the resistance value with time of the semiconductor-type gas sensor of the present invention and the conventional semiconductor-type gas sensor at the heating temperature of 150 ℃, and it can be confirmed that the semiconductor-type gas sensor of the present invention causes the change of the resistance of the detection film (change of the conductivity) due to the presence of nitrogen dioxide even at the heating temperature of 150 ℃, but the conventional semiconductor-type gas sensor does not cause the change of the resistance (change of the conductivity) due to the leakage of nitrogen dioxide because the heating temperature (150 ℃) is significantly low and does not reach the activation temperature (300 to 400 ℃) of the conventional gas sensing film.
The semiconductor type gas sensor of the present invention can reduce the heating temperature required for activation due to the remarkably low activation temperature required for operating the gas sensitive film of the gas sensor, save the power consumption and maintenance cost required for operating the heater, and can manufacture the semiconductor type gas sensor by using the cheap common synthetic resin PCB substrate, thereby greatly reducing the manufacturing cost of the gas sensor.
In addition, the gas sensitive film with improved conductivity improves the measurement sensitivity of the gas sensor, reduces the measurement variability caused by the change of the ambient temperature and humidity of the gas sensor, is not influenced by the change of the ambient environment, and can accurately detect gas.
Hereinafter, embodiments to which the present invention is applied will be described in detail with reference to the accompanying drawings.
Fig. 6 is a schematic diagram for explaining an embodiment of a multiple sensing device management system using an identification circuit according to the present invention.
As shown in fig. 6, the multiple sensing device management system using an identification circuit according to the present invention includes: a multi-sensor apparatus 100; a sensor management device 200; and, a mobile device 300.
The multiple sensing apparatus 100 measures at least two of environment, energy, and security management objects of a specific space and generates sensor data. The measurement target related to the environment, energy, and safety may be at least one of temperature, humidity, fine dust, carbon dioxide (CO2), carbon monoxide (CO), Volatile Organic Compounds (VOCs), ozone, formaldehyde, noise, power consumption, and motion. A multisensing apparatus 100 comprising: and the sensor data generation module comprises a plurality of sensor modules and is used for identifying each sensor module and generating a plurality of sensor data. Here, at least one of the plurality of sensor modules is constituted by the semiconductor-type gas sensor according to the present invention. The multiple sensing apparatus 100 includes: a communication module for transmitting the generated sensor data to the sensor management apparatus 200 and the mobile device 300. The communication module can be a wireless communication module such as bluetooth or a wireless local area network, and the mobile device can be an input/output device such as a smart phone, a tablet computer, a wearable device, etc. which uses the sensor module to realize monitoring and control of related devices. The multiple sensing device 100 can include: the general-purpose firmware is in the form of an embedded system, and can provide an environment in which various sensors related to a management target substance defined in advance can be used as targets and identification and measurement can be performed. The multiple sensing device 100 can include: the sensor board ensures the flexibility of measurable sensor components by designing a common protocol that can be connected to various sensors and thereby provide a standardized means of communication and power.
The sensor management device 200 receives and stores sensor data regarding a plurality of measurement objects generated in the multiple sensing device 100. The sensor management device 200 expands the functions of collecting, processing, and storing data so as to provide a user with measurement information defined in advance, and determines and analyzes a measurement substance based on real-time collected information transmitted from the multiple sensor device 100 having a plurality of sensor combinations. The sensor management apparatus 200 can output the analysis result or send a report to the mobile device 300. The sensor management device 200 can include: the general middleware processes a measuring device environment in which a plurality of types of sensors are mounted into a single platform, and provides an environment in which various applications can be driven in the single platform as described above.
The mobile device 300 outputs sensor data relating to a plurality of measurement objects generated in the multiple sensing apparatus 100. The mobile device 300 can generate a control signal for switching or controlling the operation of the multiple sensing apparatus 100 based on the output sensor data. Further, the mobile device 300 can drive a control algorithm that controls the relevant improving device based on the sensor data.
Fig. 7 is a schematic diagram for explaining an embodiment of a multiple sensing apparatus using an identification circuit according to the present invention.
As shown in fig. 7, the multiple sensing apparatus 100 to which the present invention is applied includes: a sensor module section 110; a sensor base portion 120; and a sensor data generation unit 130.
The sensor module unit 110 outputs a sensor measurement signal for measuring any one of the measurement objects related to the environment, energy, and safety and a sensor identification signal for identifying the measurement object. The sensor module unit 110 will be described in more detail with reference to fig. 8 to 10.
The sensor base portion 120 is used to attach or detach the sensor module portion 110. The sensor base portion 120 can include: and a slot for mounting or dismounting the sensor module part 110.
When the sensor module unit 110 is mounted on the sensor base portion 120, the sensor data generating unit 130 receives the PWM signal from the sensor module unit 110, calculates the duty ratio of the received PWM signal, and identifies the measurement target measured by the mounted sensor module unit 110.
Further, the sensor data generation unit 130 receives the sensor measurement signal from the sensor module unit 110, and generates sensor data related to the identified measurement object. The sensor data generation unit 130 can transmit the generated sensor data to at least one of the sensor management device 200 and the mobile device 300 by wireless communication. The sensor data generating unit 130 will be described in more detail with reference to fig. 10.
Fig. 8 and 9 are schematic views for explaining a sensor module according to the present invention.
As shown in fig. 8 and 9, the sensor module portion 110 includes: a sensor portion 112; and an oscillation circuit section 114.
The sensor unit 112 measures any one of the measurement objects related to the environment, energy, and safety, and generates a sensor measurement signal.
The oscillation circuit unit 114 continuously generates a PWM (Pulse Width Modulation) signal, which is a sensor identification signal for identifying any one of the measurement objects related to the environment, energy, and safety.
The sensor module unit 110 may have a 4-pin or 5-pin configuration as an input/output terminal. When the sensor module portion 110 employs an input-output terminal composed of 4 pins, input-output pins for the power supply Vcc, the ground GND, the sensor identification signal, and the sensor measurement signal can be included. The sensor module unit 110 may also employ an input/output terminal composed of 5 pins, including input/output pins for a power supply Vcc, a ground GND, a sensor identification signal, a 1 st sensor measurement signal, and a 2 nd sensor measurement signal.
Fig. 10 is a schematic diagram for explaining an oscillation circuit according to the present invention.
As shown in fig. 10, the oscillation circuit section 114 can be formed of an IC (integrated circuit) including 8 input/output pins, and the input voltage thereof can be in a range of 4 to 15V, for example, 5V. In the oscillation circuit section 114, the No. 8 pin is connected to the power supply, the No. 1 pin is connected to GND, the No. 4 reset (reset) pin is connected to the power supply, and the PWM signal can be output through the No. 3 pin. The oscillator circuit unit 114 can be formed by modifying a ne555 circuit, for example.
The oscillation circuit unit 114 continuously generates a PWM (Pulse width modulation) signal having the same period. The oscillation circuit unit 114 is configured to be able to change the periods of the high signal and the low signal of the PWM signal in accordance with the relative proportion of the 1 st resistance value (R1) and the 2 nd resistance value (R2), thereby realizing the duty ratio as shown in the following formula 1.
[ equation 1]
Duty Ratio (Duty Ratio) ═ R1+ R2)/(R1+2R2)
Where R1 is the 1 st resistance value (R1) between the No. 7 and No. 8 pins in the oscillation circuit section, and R2 is the 2 nd resistance value (R2) between the No. 6 and No. 7 pins in the oscillation circuit section.
Fig. 11 is a schematic diagram for explaining a sensor identifying section according to the present invention. As shown in fig. 11, the sensor data generation unit 130 includes: a sensor recognition section 132; a sensor data forming unit 134; a power supply section 136; and a communication unit 138.
The sensor identification portion 132 generates a sensor identification value using a sensor identification signal received from the sensor module portion 110 mounted in the sensor base portion 120. The sensor identification section 132 receives a PWM signal from the sensor module section 110 mounted in the sensor base section 120, and calculates the duty ratio of the received PWM signal. The sensor recognition unit 132 can calculate the duty ratio of the received PWM signal by the following equation (2) using a timer.
[ formula 2]
Duty Ratio (Duty Ratio) (T1)/(T1+ T2)
Where T1 is the time width of the High (High) interval of the PWM signal, and T2 is the signal width of the Low (Low) interval of the PWM signal.
The sensor identification unit 132 compares the calculated duty ratio of the PWM signal with a duty ratio range of each sensor stored in advance, thereby identifying the sensor and generating a sensor identification value.
The sensor data composing part 134 composes sensor data using the sensor measurement signal received from the sensor module part 110 mounted in the sensor base part 120 and the generated sensor identification value. When the sensor identification value is, for example, temperature, humidity, fine dust, carbon dioxide (CO2), carbon monoxide (CO), Volatile Organic Compounds (VOCs), ozone, formaldehyde, noise, power consumption, and fine dust in motion, and the sensor measurement value is 0.02ppm, the sensor data generating section 134 can generate sensor data corresponding to 0.02ppm of fine dust.
The power supply section 134 supplies necessary electric power to the sensor module section 110 and the sensor data generation section 130 mounted in the sensor base section 120.
The communication unit 136 can transmit the generated sensor data to at least one of the sensor management apparatus 200 and the mobile device 300 by wireless communication.
Fig. 12 to 14 are flowcharts for explaining an identification method of a multi-sensor device using an identification circuit according to the present invention.
As shown in fig. 12, in the identification method of the multi-sensor device using the identification circuit according to the embodiment of the present invention, in step S710, the multi-sensor device receives the PWM signal.
In step S720, the duty ratio of the received PWM signal is calculated by the multiple sensing device. In step S730, the sensor is identified by the multiple sensing device sensor by comparing the calculated duty ratio with a duty ratio saved in advance and a sensor identification value is generated.
As shown in fig. 13, in the identification method of the multiple sensing device using the identification circuit according to another embodiment of the present invention, in step S810, the input pin of the PWM signal is scanned by the multiple sensing device.
In step S820, the multiple sensing device determines whether there is a PWM signal.
In step S830, if the PWM signal is present, the multiple sensing device stores the PWM signal information.
In step S840, the multiple sensing device calculates the duty ratio using the PWM signal information and stores the duty ratio. The multiple sensing means can calculate the duty ratio of the PWM signal using equation 2 as described above.
As shown in fig. 14, the duty ratio of the sensor module can be adjusted by adjusting the resistance value of the circuit for generating the PWM signal, for example, the temperature sensor can be adjusted to 48 to 53, the fine dust sensor can be adjusted to 56 to 62, carbon monoxide can be adjusted to 63 to 69, carbon dioxide can be adjusted to 73 to 77, the volatile organic compound can be adjusted to 78 to 82, and the amount of power consumption can be adjusted to 83 to 86.
In step S850, the multiple sensing device determines whether the scanning of the PWM signal input pin is completed.
In step S860, when the scanning of the PWM signal input pin is completed, the sensor module part corresponding to the calculated duty ratio is recognized by the multi-sensor device and a sensor recognition value is generated.
In step S870, the sensor measurement value input from the identified sensor module unit is read by the multiple sensor device and stored.
In step S880, it is determined by the multiple sensor device whether or not the sensor measurement values of all the mounted sensor module sections have been read.
In step S890, the multiple sensor device generates sensor data using the generated sensor identification value and sensor measurement value.
The embodiments to which the present invention is applied as described above can be implemented by various means. For example, embodiments to which the present invention is applied can be implemented by hardware, firmware, software, or a combination thereof. When implemented in hardware, methods consistent with embodiments of the invention may be implemented in one or more of asics (application Specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays), processors, controllers, microcontrollers, microprocessors, etc. When implemented in firmware or software, the method according to the embodiments of the present invention can be implemented in the form of a module, a procedure, a function, or the like for executing the functions or actions described in the above. The computer program such as the pole routing software code can be stored in a computer-readable recording medium or a memory unit and driven by a processor. The memory unit is located inside or outside the processor and can perform data interaction with the processor through various well-known means. In addition, each block in the block diagrams attached in the present invention and each combination of steps in the flowchart can be executed by a computer program instruction. Because the computer program instructions described above can be loaded onto an encoding processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, the instructions that execute via the encoding processor of the computer or other programmable data processing apparatus create means for implementing the functions specified in the block diagrams' individual blocks or steps in the flowchart. Because the computer program instructions may also be stored in a computer-usable or computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such instructions stored in the computer-usable or computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the block diagrams or flowchart block or blocks. Because the computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the block diagrams and flowchart block or blocks and step or steps. Also, each block or step can be a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). Furthermore, it should be noted that several alternative embodiments are also possible with an adjustment of the functional sequence mentioned in the individual blocks or individual steps. For example, two blocks or steps shown in succession may be executed substantially concurrently, or the blocks or steps may be executed in the reverse order depending upon the functionality involved.
While several embodiments have been illustrated and described, it will be apparent to those skilled in the art that the present invention may be embodied in various other forms without departing from the spirit or scope of the invention.
Therefore, the present invention is not limited to the above-described embodiments, and all embodiments within the scope of the appended claims and equivalents thereof are included in the scope of the present invention.
Claims (12)
1. A semiconductor-type gas sensor, comprising:
a substrate;
an electrode formed in a predetermined pattern on an upper surface of the substrate;
a gas detection film having a predetermined thickness and covering the electrode; and
a heater provided on a lower surface of the substrate and configured to heat the gas detection film at a predetermined temperature,
the gas detection membrane is in the form ofSnO having amorphous layer2The detection substance of (3) is a mixture of a predetermined amount of a thermosetting resin and a silane coupling agent as a binder.
2. The semiconductor-type gas sensor according to claim 1,
the substrate is made of epoxy resin or phenolic resin;
and operating the heater to heat the gas detection film at 110-170 ℃.
3. The semiconductor-type gas sensor according to claim 1,
of the above-mentioned detection substances, SnO2SnO located at inner center, SnO located at said inner center2Around the surface, Sn, SnO and SnO are irregularly dispersed2Thereby forming an amorphous layer.
4. A multisensing apparatus, comprising:
a sensor module unit including at least one semiconductor-type gas sensor according to any one of claims 1 to 3, and capable of outputting a sensor measurement signal for measuring any one of the measurement objects related to environment, energy, and safety and a sensor identification signal for identifying the measurement object;
a sensor base portion for attaching or detaching the sensor module portion; and
and a sensor data generation unit that recognizes the sensor module unit and generates sensor data when the sensor module unit is attached to the sensor base unit.
5. The multisensing apparatus of claim 4,
the sensor module unit includes:
a sensor unit that measures any one of measurement objects related to environment, energy, and safety, and generates a sensor measurement signal; and
the oscillation circuit unit generates a sensor identification signal for identifying any one of the measurement objects related to the environment, the energy, and the safety.
6. The multisensing apparatus of claim 5,
the oscillation circuit unit continuously generates a PWM signal.
7. The multisensing apparatus of claim 4,
the sensor data generation unit includes:
a sensor identification unit configured to generate a sensor identification value using a sensor identification signal received from the sensor module unit attached to the sensor base unit; and
and a sensor data composing unit that composes sensor data from the sensor measurement signal received from the sensor module unit and the generated sensor identification value.
8. The multisensing apparatus of claim 7,
the sensor identification unit receives the PWM signal from the sensor module unit, calculates a duty ratio of the received PWM signal, and compares the calculated duty ratio of the PWM signal with a duty ratio range of each sensor stored in advance to identify the sensor and generate a sensor identification value.
9. The multisensing apparatus of claim 7,
the sensor module unit further includes a power supply unit configured to supply necessary power to the sensor module unit and the sensor data generation unit.
10. A method of identifying a multiple sensing device including at least one semiconductor-type gas sensor according to any one of claims 1 to 3, performed in the multiple sensing device, the method comprising:
scanning an input pin of the PWM signal;
a step of storing PWM signal information under the condition that the PWM signal exists;
calculating the duty ratio by utilizing the PWM signal information and storing the duty ratio; and the number of the first and second groups,
and recognizing the sensor module part corresponding to the calculated duty ratio and generating a sensor recognition value after the scanning of the PWM signal input pin is completed.
11. The method for identifying multiple sensing devices of claim 10,
the duty ratio is adjusted by adjusting the resistance value of the circuit for generating the PWM signal.
12. The method for identifying multiple sensing devices of claim 10, further comprising:
reading and storing the sensor measurement value input from the recognized sensor module unit; and the number of the first and second groups,
and generating sensor data using the generated sensor identification value and the sensor measurement value.
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