A measuring method of a detection system and a detection device

Abstract

The application discloses a kind of measurement methods of air quality detection system, it is related to gas detection field.It includes single-chip microcomputer, temperature and humidity sensor, gas sensor, the single-chip microcomputer connects temperature and humidity sensor, gas sensor, the temperature and humidity sensor is used to obtain temperature and humidity information, the gas sensor is used to obtain the VOC concentration of air, the single-chip microcomputer obtains the temperature and humidity information and VOC concentration, according to the temperature and humidity information compensation calibration air VOC concentration;The application is based on the temperature and humidity information and gas VOC concentration obtained by single-chip microcomputer, further according to the existing defect: moisture content influences the measurement of VOC concentration, so that the single-chip microcomputer further based on temperature and humidity information makes the compensation operation to the gas VOC concentration, so that the single-chip microcomputer obtains more accurate gas VOC concentration value after operation, improves the accuracy of system result;The application also discloses a kind of detection device.

Description

Technical Field

[0001] This invention relates to the field of gas detection, and more specifically, to a measurement method and detection device for a detection system. Background Technology

[0002] The resistance of the gas-sensitive material in a gas sensor changes with the VOC content (concentration) in the mixed gas at high temperatures. The VOC content (concentration) can be indirectly obtained by measuring the resistance of the gas-sensitive material (gas-sensitive resistor). However, in practical applications, the gas-sensitive resistor is also affected by the moisture content in the mixed gas. Summary of the Invention

[0003] The present invention aims to overcome at least one of the defects (deficiencies) of the prior art and provide a measurement method and detection device for a detection system, enabling the microcontroller to obtain more accurate gas VOC concentration.

[0004] The technical solution adopted in this invention is,

[0005] A measurement method for an air quality detection system includes a microcontroller, a temperature and humidity sensor, and a gas sensor. The microcontroller is connected to the temperature and humidity sensor and the gas sensor. The temperature and humidity sensor is used to acquire temperature and humidity information, and the gas sensor is used to acquire the VOC concentration in the air. After acquiring the temperature and humidity information and the VOC concentration, the microcontroller compensates and calibrates the VOC concentration in the air based on the temperature and humidity information. The gas sensor includes a gas-sensitive resistor Rs and a heating resistor R. HEAT ;

[0006] Methods for measuring the Rs of a gas-sensitive resistor include:

[0007] Based on the characteristic curve of the gas-sensitive resistor Rs:

[0008] R X =R0*EXP(-K*C X In the formula, K is the sensitivity coefficient, and C X R is the gas concentration, R0 is the clean air gas-sensitive resistor Rs value, R X VOC is C X The Rs value of the gas-sensitive resistor at the specified concentration;

[0009] The following measurement formula is derived to obtain the resistance value of the gas-sensitive resistor Rs:

[0010] C x Use y = 1 / (A) within 1 ppm x *K x ) Fit, where K x =R x / R1, when 0.1ppm = 1 / 10, that is, A 0.1 *(R0.1 / R1) = 10; then A 0.1 = 10 / K 0.1 ;

[0011] When R X > R 0.1 That is, for the range y where the gas concentration is below 0.1 ppm, the calculation is as follows:

[0012] y = 1 / (A 0.1 * K x );

[0013] When R1 < R X < R 0.1 That is, for the range y where the gas concentration is between 0.1 ppm and 1 ppm, the calculation is as follows:

[0014] y = 1 / (A x * K x ); where A x = 1 + (A 0.1 - 1)*(R x - R1) / (R 0.1 - R1);

[0015] When R X < R1 That is, for the range y where the gas concentration is between 1 ppm and 10 ppm, the calculation is as follows:

[0016] y = 1 + 9*(R1 - R x ) / (R1 - R 10 );

[0017] Where, R 0.1 is the resistance value at the concentration C 0.1 = 0.1 ppm, R1 is the resistance value at the concentration C1 = 1 ppm, R 10 is the resistance value at the concentration C 10 = 10 ppm, and A is the adjustment factor coefficient.

[0018] In this invention, through the characteristic curve of the gas-sensitive resistor Rs for simplification, only the calibration of R1 and R10 (i.e., 1 ppm and 10 ppm) is required to deduce R0.1, so as to calculate the VOC concentration within the range of 0 - 10 ppm; adopting this algorithm can greatly improve the production efficiency of the sensor and provide good support for the user's zero-point self-calibration; based on the microcontroller obtaining the temperature and humidity information and the gas VOC concentration, further according to the existing defect: the moisture content affects the measurement of the VOC concentration, the microcontroller further makes a compensation operation for the gas VOC concentration based on the temperature and humidity information, so that the microcontroller obtains a more accurate gas VOC concentration value after the operation, improving the accuracy of the system result.

[0019] As an optional implementation, the heating resistor R HEAT The microcontroller includes an I / O interface, which is connected to the heating resistor R. HEAT , used for heating resistor R HEAT The current is adjusted; the microcontroller includes an ADC interface, which is connected to the gas-sensitive resistor Rs, and the microcontroller obtains the resistance change of the gas-sensitive resistor Rs through the ADC interface.

[0020] As an optional implementation, a resistor R3 is also included, one end of which is connected to the IO interface, and the other end is connected in series with the heating resistor R. HEAT The microcontroller controls the heating resistor R through the I / O interface. HEAT The current; or, the resistance value of the resistor R3 is 200 to 500 Ω, preferably, the resistance value of the resistor R3 is 300 Ω.

[0021] This invention modifies the heating resistor R by setting up the microcontroller's I / O port and controlling the high and low levels of the I / O port. HEAT The current is used to accelerate the preheating of the sensor, providing a suitable high-temperature environment for the gas-sensitive resistor Rs. Simultaneously, controlling the level at the I / O interface also achieves rapid preheating, improving system efficiency. However, due to the limitations of the microcontroller's operating requirements, the current in the circuit is restricted; therefore, resistor R3 is added to adjust the heating resistor R. HEAT The current accelerates the preheating process.

[0022] As an optional implementation, the heating resistor R of the gas sensor HEAT A resistor R4 is also connected, one end of which is grounded; or, the gas sensor has a grounded end; or, the resistance of the resistor R4 is 50–100Ω, preferably 68Ω, and R4 serves as a heating resistor. HEAT Main fixed current.

[0023] In this invention, resistors R4 and R3 are both related to the heating resistor R. HEAT The circuit is connected in series, where resistor R4 is part of the heating circuit and is adapted to the heating resistor R. HEAT .

[0024] As an optional implementation, the gas-sensitive resistor Rs is connected in series with a voltage divider resistor R1.

[0025] As an optional implementation, the resistance of the voltage divider resistor R1 is 50KΩ to 150KΩ, preferably 100KΩ.

[0026] In this invention, the voltage divider resistor R1 and the gas-sensitive resistor Rs constitute a voltage divider circuit. The ADC interface is connected to the voltage divider circuit to sample the voltage of the gas-sensitive resistor Rs, thereby obtaining the voltage signal and resistance change of the gas-sensitive resistor Rs. The VOC concentration can be measured by the relationship between the gas-sensitive resistor Rs and the VOC concentration.

[0027] As an optional implementation, a power supply data interface is provided, which is used to input 5V power to the microcontroller.

[0028] As an optional implementation, the power supply data interface is connected in parallel with resistors R5 and R6, the resistance values ​​of which are in the range of 5kΩ to 15kΩ; preferably, resistors R5 and R6 with a resistance value of 10kΩ are selected.

[0029] The purpose of these two resistors in this invention is to ensure that there are defined high and low voltage levels during IIC communication, making the communication more stable and matching the requirements of the IIC protocol bus.

[0030] As an optional implementation, the power supply data interface is connected to an IIC bus, which uses the standard IIC protocol for communication. The IIC bus is used to connect external devices, and the external devices read the microcontroller data through the IIC bus and the standard IIC protocol.

[0031] As an optional implementation, the power supply data interface includes an LDO linear regulator, and the power supply voltage after passing through the LDO linear regulator is 3.0V. The power supply is input to the temperature and humidity sensor and the gas sensor.

[0032] As an optional implementation, the LDO linear regulator is connected in parallel with a filter capacitor to provide a smoother voltage.

[0033] As an optional implementation, one end of the filter capacitor is connected in parallel with the LDO linear regulator, and the other end is grounded.

[0034] As an optional implementation, the filter capacitor includes a first capacitor, a second capacitor, and a third capacitor.

[0035] As an optional implementation, the microcontroller includes an IIC interface, which is connected to the temperature and humidity sensor. The microcontroller acquires the temperature and humidity data measured by the temperature and humidity sensor through the IIC interface.

[0036] As an optional implementation, the temperature and humidity sensor communicates with the microcontroller using the IIC communication protocol, or pull-up resistors R8 and R9 are provided between the temperature and humidity sensor and the IIC interface.

[0037] As an optional implementation, the resistance values ​​of the pull-up resistors R8 and R9 are 1kΩ to 15kΩ; preferably, the resistance values ​​of R8 and R9 are 10kΩ.

[0038] In this invention, the addition of pull-up resistors ensures a defined voltage level during IIC bus communication, thus stabilizing IIC communication when the microcontroller connects to or reads data from the temperature and humidity sensor.

[0039] As an optional implementation, a PCB board is included, in which the gas sensor, the temperature and humidity sensor, and the microcontroller are integrated. The PCB board includes at least one isolation island, and through holes are provided around the isolation island. The gas sensor or the temperature and humidity sensor is disposed on the isolation island.

[0040] As an optional implementation, the through hole has a C-shaped structure, and the opening of the through hole is configured to connect to the PCB board to form the isolation island.

[0041] As an optional implementation, the PCB board has two isolation islands, with the openings of the two isolation islands facing opposite directions at both ends of the PCB board.

[0042] A temperature and humidity compensation method is provided for compensating the gas-sensitive resistor Rs in the aforementioned detection system. The microcontroller employs the following algorithm to implement temperature and humidity compensation.

[0043]

[0044] In the formula, TVOC is the original VOC concentration without temperature and humidity compensation, TVOCx is the VOC concentration after temperature and humidity compensation, RH is the relative humidity, and T is the temperature.

[0045] A detection device that uses the aforementioned measurement method and / or the aforementioned temperature and humidity compensation method to detect air quality.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] In this invention, the VOC gas sensor requires heating, which generates heat and significantly affects the temperature and humidity sensor's measurements. Therefore, the PCB layout design needs to take this into account. This PCB layout uses isolation islands to change the heat source conduction path, thereby greatly reducing the impact of the heat source on the temperature and humidity sensor within a limited size. Preferably, a method to minimize the impact is to use two isolation island structures. This structure has an annular C-shaped through-hole structure, which can minimize the contact area with the PCB board, thus reducing the contact area between the heating resistor R in the gas sensor and the PCB board. HEATThe heat transferred has minimal impact on the board; a better solution is to set up two isolation island structures to house the gas sensor and the temperature and humidity sensor respectively, further reducing the impact of sensor measurements on the PCB board and preventing them from interfering with each other's measurements; a less desirable solution is to set up only one isolation island to house the gas sensor. Attached Figure Description

[0048] Figure 1 This is an overall structural diagram of the present invention.

[0049] Figure 2 This is a schematic diagram of the PCB board of the present invention.

[0050] In the diagram, the temperature and humidity sensor is 100, the gas sensor is 200, and the power supply and data interface is 300. Detailed Implementation

[0051] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the invention. To better illustrate the following embodiments, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions; it is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0052] Example 1

[0053] like Figure 1 As shown, a measurement method for an air quality detection system includes a microcontroller, a temperature and humidity sensor 100, and a gas sensor 200. The microcontroller is connected to the temperature and humidity sensor 100 and the gas sensor 200. The temperature and humidity sensor 100 is used to acquire temperature and humidity information, and the gas sensor 200 is used to acquire the VOC concentration in the air. After acquiring the temperature and humidity information and the VOC concentration, the microcontroller compensates and calibrates the VOC concentration in the air based on the temperature and humidity information. The gas sensor 200 includes a gas-sensitive resistor Rs and a heating resistor R. HEAT , .

[0054] Based on the acquisition of temperature and humidity information and gas VOC concentration by a microcontroller, this invention further addresses the existing deficiency that moisture content affects VOC concentration measurement. By enabling the microcontroller to perform compensation calculations on the gas VOC concentration based on temperature and humidity information, the microcontroller obtains a more accurate gas VOC concentration value after the calculation, thus improving the accuracy of the system results.

[0055] As an optional implementation, the microcontroller includes an I / O interface, which is connected to the heating resistor R. HEAT , used for heating resistor R HEATThe current is adjusted; the microcontroller includes an ADC interface, which is connected to the gas-sensitive resistor Rs, and the microcontroller obtains the resistance change of the gas-sensitive resistor Rs through the ADC interface.

[0056] As an optional implementation, a resistor R3 is also included, one end of which is connected to the IO interface, and the other end is connected in series with the heating resistor R. HEAT The microcontroller controls the heating resistor R through the I / O interface. HEAT The current; or, the resistance value of the resistor R3 is 200 to 500 Ω, preferably, the resistance value of the resistor R3 is 300 Ω.

[0057] This invention modifies the heating resistor R by setting up the microcontroller's I / O port and controlling the high and low levels of the I / O port. HEAT The current is used to accelerate the preheating of the sensor, providing a suitable high-temperature environment for the gas-sensitive resistor Rs. Simultaneously, controlling the level at the I / O interface also achieves rapid preheating, improving system efficiency. However, due to the limitations of the microcontroller's operating requirements, the current in the circuit is restricted; therefore, resistor R3 is added to adjust the heating resistor R. HEAT The current accelerates the preheating process.

[0058] As an optional implementation, the gas sensor 200 is further connected to a resistor R4, one end of which is grounded; or, the gas sensor 200 has a grounded end; or, the resistance of the resistor R4 is 50–100Ω, preferably 68Ω, and R4 serves as a heating resistor R. HEAT Main fixed current.

[0059] In this invention, resistors R4 and R3 are both related to the heating resistor R. HEAT The circuit is connected in series, where resistor R4 is part of the heating circuit and is adapted to the heating resistor R. HEAT .

[0060] As an optional implementation, the gas-sensitive resistor Rs is connected in series with a voltage divider resistor R1.

[0061] As an optional implementation, the resistance of the voltage divider resistor R1 is 10KΩ to 150KΩ, preferably 100KΩ.

[0062] In this invention, the voltage divider resistor R1 and the gas-sensitive resistor Rs constitute a voltage divider circuit. The ADC interface is connected to the voltage divider circuit to sample the voltage of the gas-sensitive resistor Rs, thereby obtaining the voltage signal and resistance change of the gas-sensitive resistor Rs. The VOC concentration can be measured by the relationship between the gas-sensitive resistor Rs and the VOC concentration.

[0063] As an optional implementation, a power supply data interface 300 is provided, which is used to input 5V power to the microcontroller.

[0064] As an optional implementation, the power supply data interface 300 is connected in parallel with resistors R5 and R6, the resistance values ​​of which are in the range of 1kΩ to 15kΩ; preferably, resistors R5 and R6 with a resistance value of 10kΩ are selected.

[0065] The purpose of these two resistors in this invention is to ensure that there are defined high and low voltage levels during IIC communication, making the communication more stable and matching the requirements of the IIC protocol bus.

[0066] As an optional implementation, the power supply data interface 300 is connected to an IIC bus. The IIC bus uses the standard IIC protocol for communication and is used to connect external devices. The external devices read the microcontroller data through the IIC bus and the standard IIC protocol.

[0067] As an optional implementation, the power supply data interface 300 is equipped with an LDO linear regulator, and the power supply voltage after passing through the LDO linear regulator is 3.0V. The power supply is input to the temperature and humidity sensor 100 and the gas sensor 200.

[0068] As an optional implementation, the LDO linear regulator is connected in parallel with a filter capacitor to provide a smoother voltage.

[0069] As an optional implementation, one end of the filter capacitor is connected in parallel with the LDO linear regulator, and the other end is grounded.

[0070] As an optional implementation, the filter capacitor includes a first capacitor, a second capacitor, and a third capacitor.

[0071] As an optional implementation, the microcontroller includes an IIC interface, which is connected to the temperature and humidity sensor 100. The microcontroller acquires the temperature and humidity data measured by the temperature and humidity sensor 100 through the IIC interface.

[0072] As an optional implementation, the temperature and humidity sensor 100 communicates with the microcontroller using the IIC communication protocol, or pull-up resistors R8 and R9 are provided between the temperature and humidity sensor 100 and the IIC interface.

[0073] As an optional implementation, the resistance values ​​of the pull-up resistors R8 and R9 are 1kΩ to 15kΩ; preferably, the resistance values ​​of R8 and R9 are 10kΩ.

[0074] In this invention, the addition of pull-up resistors ensures a defined voltage level during IIC bus communication, thus stabilizing IIC communication when the microcontroller connects to or reads data from the temperature and humidity sensor 100.

[0075] As an optional implementation method, such as Figure 2 As shown, the device includes a PCB board, on which the gas sensor 200, the temperature and humidity sensor 100, and the microcontroller are integrated. The PCB board includes at least one isolation island, and through holes are provided around the isolation island. The gas sensor 200 or the temperature and humidity sensor 100 is disposed on the isolation island.

[0076] As an optional implementation, the through hole has a C-shaped structure, and the opening of the through hole is configured to connect to the PCB board to form the isolation island.

[0077] As an optional implementation, the PCB board has two isolation islands, with the openings of the two isolation islands facing opposite directions at both ends of the PCB board.

[0078] A measurement method for measuring the gas-sensitive resistor Rs in the aforementioned detection system, based on the characteristic curve of the gas-sensitive resistor Rs:

[0079] R X =R0*EXP(-K*C X In the formula, K is the sensitivity coefficient, and C X R is the gas concentration, R0 is the clean air gas-sensitive resistor Rs, R X VOC is C X The Rs value of the gas-sensitive resistor at the specified concentration;

[0080] The following measurement formula is derived to obtain the resistance value of the gas-sensitive resistor Rs:

[0081] C x Use y = 1 / (A) within 1 ppm x *K x ) Fit, where K x =R x / R1, when 0.1ppm = 1 / 10, that is, A 0.1 *(R 0.1 / R1)=10; then A 0.1 =10 / K 0.1 ;

[0082] When R X >R 0.1 The range for gas concentrations below 0.1 ppm is calculated as follows:

[0083] y = 1 / (A 0.1 *Kx )

[0084] When R1 < R X < R 0.1 That is, the gas concentration in the range of 0.1 ppm to 1 ppm is calculated as follows:

[0085] y = 1 / (A x * K x ); where A x = 1 + (A 0.1 - 1) * (R x - R1) / (R 0.1 - R1).

[0086] When R X < R1, that is, the gas concentration in the range of 1 ppm to 10 ppm is calculated as follows:

[0087] y = 1 + 9 * (R1 - R x ) / (R1 - R 10 );

[0088] Among them, R 0.1 is the resistance value at a concentration C 0.1 ​​​​​​​​​​​​​​​​​​​​​​​​​Based on experiments and relevant theories, the Rs characteristic model of the gas-sensitive resistor conforms to an exponential relationship and can be fitted using NTC characteristics.

[0096] R X =R0*EXP(-K*C X )

[0097] Where K is the sensitivity coefficient, and C X R is the gas concentration, R0 is the clean air gas-sensitive resistor Rs, R X C for VOCs X Gas-sensitive resistor Rs at concentration.

[0098] R 0.1 =R0*EXP(-K*C 0.1 )

[0099] R1 = R0 * EXP(-K * C1)

[0100] R 10 =R0*EXP(-K*C 10 )

[0101] In the formula R 0.1 For concentration C 0.1 The resistance is given at a concentration of C1 = 0.1 ppm, and R1 is the resistance given at a concentration of C1 = 1 ppm. 10 For concentration C 10 Resistance at 10ppm

[0102] achievable

[0103] LOG(R 0.1 / R0) / LOG(R1 / R0)=C 0.1 / C1=LOG(R1 / R0) / LOG(R 10 / R0)=C1 / C 10

[0104] Therefore there is

[0105] (LOG(R1 / R0)) 2 =LOG(R) 0.1 / R0)*LOG(R 10 / R0)

[0106] When high precision is not required, it can be simplified to

[0107] (R1 / R 0.1 ) 2 =(R 10 / R 0.1 )

[0108] Let K = R 10 / R1, further simplified to R1 / R0.1 = K, which is the key point,

[0109] When Cx is within 1 ppm, it is fitted with y = 1 / (Ax * Kx), where Kx = R x / R1. When 0.1 ppm = 1 / 10, that is, A 0.1 *(R 0.1 / R1) = 10; then A 0.1 = 10 / K 0.1 ;

[0110] When R X > R 0.1 That is, the range calculation for gas concentration below 0.1 ppm is as follows:

[0111] y = 1 / (A 0.1 * Kx);

[0112] When R1 < R X < R 0.1 That is, the range calculation for gas concentration between 0.1 ppm and 1 ppm is as follows:

[0113] y = 1 / (Ax * Kx); where A x = 1 + (A 0.1 - 1)*(R x - R1) / (R 0.1 - R1).

[0114] When R X < R1, that is, the range calculation for gas concentration between 1 ppm and 10 ppm is as follows:

[0115] y = 1 + 9*(R1 - R x ) / (R1 - R 10 );

[0116] Among them, R 0.1 is the resistance value at a concentration C0.1 = 0.1 ppm, R1 is the resistance value at a concentration C1 = 1 ppm, R10 is the resistance value at a concentration C10 = 10 ppm, and A is the adjustment factor coefficient.

[0117] In this invention, since the VOC gas sensor 200 needs to be heated and generates heat, which has a serious impact on the measurement of the temperature and humidity sensor 100, the PCB layout design needs to be considered. This PCB layout changes the heat source conduction path through the isolation island method; thus, within a limited size, the impact of the heat source on the temperature and humidity sensor 100 is greatly reduced. Preferably, a way to minimize the impact is to set up two isolation island structures. This structure has an annular C-shaped through-hole structure, which can minimize the contact area with the PCB board, making the heating resistor R in the gas sensor 200 HEATThe heat transferred has minimal impact on the board; a better solution is to set up two isolation island structures to house the gas sensor 200 and the temperature and humidity sensor 100 respectively, further reducing the impact of the sensors on the PCB board during measurement and preventing them from interfering with each other's measurements; a less desirable solution is to set up only one isolation island to house the gas sensor 200.

[0118] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A measurement method of an air quality detection system, the air quality detection system comprising: a single-chip microcomputer, a temperature and humidity sensor, and a gas sensor, the single-chip microcomputer being connected to the temperature and humidity sensor and the gas sensor, the temperature and humidity sensor being configured to acquire temperature and humidity information, and the gas sensor being configured to acquire VOC concentration of air, the measurement method being configured to measure the gas-sensitive resistor Rs, and comprising: obtaining a characteristic curve of the gas-sensitive resistor Rs; and deriving a measurement formula for obtaining the resistance value of the gas-sensitive resistor Rs based on the characteristic curve of the gas-sensitive resistor Rs. The PCB comprises at least one isolation island, and the gas sensor or the temperature and humidity sensor is arranged on the isolation island. The single-chip microcomputer acquires the temperature and humidity information and VOC concentration, compensates and calibrates the VOC concentration of air according to the temperature and humidity information, and the gas sensor comprises a gas-sensitive resistor Rs and a heating resistor R HEAT , The through hole is in a C-shaped structure, and an opening of the through hole is provided with a communication hole of the PCB for forming the isolation island. The PCB is provided with two isolation islands, and the two isolation islands are oppositely arranged at two ends of the PCB. R X = R0*EXP(-K*C X ), where K is a sensitivity coefficient, C X is the gas concentration, R0 is the value of the gas sensitive resistance Rs with clean air, and R X is the value of the gas sensitive resistance Rs with VOC concentration C X . The gas-sensitive resistor Rs is connected in series with a voltage dividing resistor R1. C x Within 1 ppm, y = 1 / (A x *K x ) is fitted, where K x = R x / R1, when 0.1 ppm = 1 / 10, i.e. A 0.1 * (R 0.1 / R1) = 10; then A 0.1 = 10 / K 0.1 ; When R X R 0.1 The range of gas concentration below 0.1 ppm is calculated as follows: y = 1 / (A 0.1 K x ); When R1 < R X When R1 < R 0.1 That is, the gas concentration in the range of 0.1 ppm to 1 ppm is calculated as follows: y = 1 / (A x * K x ) ; wherein A x = 1 + (A 0.1 - 1) * (R x - R1) / (R 0.1 - R1) ; When R X The gas concentration in the range of 1 ppm to 10 ppm is calculated as follows: y = 1 + 9 * (R1 - R x ) / (R1 - R 10 ) ; wherein R 0.1 is the resistance at a concentration C 0.1 = 0.1 ppm, R1is the resistance at a concentration C1= 1 ppm, R 10 is the resistance at a concentration C 10 = 10 ppm, and A is an adjustment factor coefficient.

2. The measurement method of an air quality detection system according to claim 1, wherein, The gas sensor is further connected with a resistor R4, one end of the resistor R4 is connected to the gas sensor, and the other end of the resistor R4 is grounded.

3. The measurement method of an air quality detection system according to claim 2, wherein, The measurement method is used for air quality detection.

4. The measurement method of an air quality detection system according to claim 3, wherein, ​ 5. The measurement method of an air quality detection system according to claim 1, wherein, The single-chip microcomputer comprises an IO interface connected to the heating resistor R HEAT for regulating the current of the heating resistor R HEAT ; the single-chip microcomputer further comprises an ADC interface connected to the gas-sensitive resistor Rs, and the single-chip microcomputer acquires the resistance value change of the gas-sensitive resistor Rs through the ADC interface.

6. The measurement method of an air quality detection system according to claim 5, wherein, Also include resistance R3, one end of the resistance R3 is connected to the IO interface, and the other end in series with the heating resistance R HEAT , the single-chip microcomputer controls the current of the heating resistance R HEAT by controlling the IO interface.

7. The measurement method of an air quality detection system according to claim 2, wherein, ​ 8. The measurement method of an air quality detection system according to claim 6, wherein, ​ 9. The measurement method of an air quality detection system according to claim 6, wherein, ​ 10. A detection device, characterized in that ​

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