CN217404233U

CN217404233U - Multifunctional air quality detection device

Info

Publication number: CN217404233U
Application number: CN202122972340.9U
Authority: CN
Inventors: 武斌; 申涛
Original assignee: Shenzhen Meisi Xianrui Electronic Co ltd
Current assignee: Shenzhen Meisi Xianrui Electronic Co ltd
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2022-09-09
Anticipated expiration: 2031-11-30

Abstract

The utility model discloses a multi-functional air quality detection device, place box body, particulate matter concentration detection module, carbon dioxide gas concentration detection module, temperature and humidity sensor, control module and the display of seting up the air inlet in including. The device of the utility model has rich functions, and can display the measured carbon dioxide gas concentration, the measured particulate matter concentration and the ambient temperature and humidity on the embedded display screen of the device in real time; and can set up carbon dioxide gas concentration and particulate matter concentration alarm threshold value and carry out audible and visual alarm, the utility model discloses device communication mode is abundant, and wireless communication agreements such as integrated wifi, bluetooth, 2.4G data pass module, NB-loT, loRa remain the wired interface of external equipment simultaneously, can carry out the linkage with external equipment such as air conditioner, air purifier, new trend system.

Description

Multifunctional air quality detection device

Technical Field

The utility model belongs to the technical field of harmful substance detects, concretely relates to multi-functional air quality detection device.

Background

With the improvement of living standard and quality, people pay more and more attention to indoor air quality; the concentration content of carbon dioxide gas and the concentration of particulate matters in the air are of great concern. The size of the current device for detecting the concentration of carbon dioxide and the concentration of particulate matters is not standard packaging, and the sizes are different; and the existing device only detects and displays the concentration of carbon dioxide and particles in the air, can not communicate with external equipment, lacks the treatment measures after the concentration of carbon dioxide gas and particles is too high, and experiences and feels poor.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model discloses a main aim at provides a multi-functional air quality detection device, has solved the device size nonconformity of carbon dioxide concentration and particulate matter concentration among the prior art, independently detects carbon dioxide and particulate matter concentration size in the air, and there is not treatment after the concentration is too high, can not communicate the scheduling problem with external equipment.

In order to achieve the above purpose, the technical solution of the present invention is realized as follows: a multifunctional air quality detection device comprises a box body, a particulate matter concentration detection module, a carbon dioxide gas concentration detection module, a temperature and humidity sensor, a control module and a display, wherein the box body is internally provided with an air inlet; the signal output end of the control module is connected with the display, after air enters the box body through the air inlet and respectively contacts the particulate matter concentration detection module, the carbon dioxide gas concentration detection module and the temperature and humidity sensor, the particle concentration detection module detects the concentration content of particles in the air, the carbon dioxide gas concentration detection module detects the concentration content of carbon dioxide gas in the air, the temperature and humidity sensor detects the temperature and humidity of air, the control module triggers an alarm module integrated in the control module to alarm when the signals fed back by the particulate matter concentration detection module, the carbon dioxide gas concentration detection module and the temperature and humidity sensor exceed an alarm threshold value, and all the parameters are sent to a display for display, and the box body is also provided with a touch key connected with the control module for setting a concentration alarm value.

Preferably, particulate matter concentration detection module includes first upper cover body, air flue subassembly, signal processing circuit board, photodiode, laser module, miniature fan and lower lid, first upper cover body is connected with lower lid, from last air flue subassembly and the signal processing circuit board of connecting gradually down in it, a terminal surface of signal processing circuit board is provided with photodiode, another terminal surface of signal processing circuit board is provided with laser module, miniature fan.

Preferably, the air flue subassembly includes air flue entry, laser module casing, side hole, below hole, light trap, air flue export and air flue casing, the air flue entry sets up in one side of air flue casing, one side of air flue entry is provided with laser module casing, the light-emitting end of laser module casing is provided with light trap, the below of laser module casing is provided with the air flue export, the top that the air flue exported corresponds with micro-fan's position, the light-emitting end of laser module casing is provided with side hole and below hole, the side hole is used for laser module to shine the air that awaits measuring, produces the scattered light when meetting the particulate matter that awaits measuring in the air, the below hole is located photodiode's top, and the scattered light that sends when being used for laser module transmission laser to shine the particulate matter in the air reachs photodiode through the below hole, laser module is 650nm wavelength's red laser module, The green laser module with 520nm wavelength or the blue laser module with 450nm wavelength comprises a metal shell and a built-in laser collimating lens.

Preferably, carbon dioxide gas concentration detection module includes lid, bottom plate, bulb light source, infrared thermopile gas sensor and waterproof ventilated membrane on the second, lid, bottom plate cooperation are connected and are formed the air chamber that detects carbon dioxide gas concentration on the second, bulb light source and infrared thermopile gas sensor set up in the air chamber and with bottom plate fixed connection, waterproof ventilated membrane setting is used for avoiding outside atmosphere steam composition to get into the air chamber influence and detects carbon dioxide gas concentration on the top of lid on the second.

Preferably, infrared thermopile gas sensor includes filtering module, infrared thermopile module, NTC module, pin post and base, the upper end of locating the base is detained to the filtering module, infrared thermopile module sets up in the base, the NTC module is two-sided silver-plated, and on one side used silver thick liquid to be fixed in the base, the another side used gold thread and pin support connnection.

Preferably, the filtering module comprises an optical filter and a pipe cap, the optical filter is located on the pipe cap, the optical filter and the infrared thermopile chips are respectively arranged in at least one number, and the number of the optical filter is matched with the number of the infrared thermopile chips.

Preferably, the infrared thermopile module is an infrared thermopile chip; the NTC module is an NTC chip; the filter can filter out infrared rays with specific wavelengths.

Compared with the prior art, the device has rich functions, and can display the measured carbon dioxide gas concentration, the measured particulate matter concentration and the ambient temperature and humidity on the embedded display screen of the device in real time; and can set up carbon dioxide gas concentration and particulate matter concentration alarm threshold value and carry out audible and visual alarm, the utility model discloses device communication mode is abundant, and wireless communication agreements such as integrated wifi, bluetooth, 2.4G data pass module, NB-loT, loRa remain the wired interface of external equipment simultaneously, can carry out the linkage with external equipment such as air conditioner, air purifier, new trend system.

Drawings

Fig. 1 is a schematic perspective view of a multifunctional air quality detection device provided in embodiment 1 of the present invention;

fig. 2 is an exploded schematic view of a multifunctional air quality detection device provided in embodiment 1 of the present invention;

fig. 3 is a schematic structural diagram of a particulate matter concentration detection module in the multifunctional air quality detection apparatus provided in embodiment 1 of the present invention;

fig. 4 is a schematic structural diagram of an air passage assembly in the multifunctional air quality detection apparatus provided in embodiment 1 of the present invention;

fig. 5 is a schematic structural diagram of a laser module in the multifunctional air quality detection apparatus provided in embodiment 1 of the present invention;

fig. 6 is a schematic structural diagram of a carbon dioxide gas concentration detection module in the multifunctional air quality detection apparatus provided in embodiment 1 of the present invention;

fig. 7 is a schematic structural diagram of a dual-channel infrared thermopile gas sensor in the multifunctional air quality detection apparatus provided in embodiment 1 of the present invention;

fig. 8 is a schematic structural diagram of a single-channel infrared thermopile gas sensor in the multifunctional air quality detecting apparatus provided in embodiment 1 of the present invention;

fig. 9 is a schematic view of a working flow of the multifunctional air quality detection device provided in embodiment 1 of the present invention;

fig. 10 is a schematic view of a carbon dioxide gas concentration detection flow of the multifunctional air quality detection device provided in embodiment 1 of the present invention;

fig. 11 is a schematic view of a process of detecting a particle concentration of the multifunctional air quality detecting device provided in embodiment 1 of the present invention;

fig. 12 is a dual-channel signal processing circuit diagram of the multifunctional air quality detection device provided in embodiment 1 of the present invention;

fig. 13 is a schematic structural diagram of a micro fan driving circuit in the multifunctional air quality detection apparatus provided in embodiment 1 of the present invention;

fig. 14 is a signal filtering and amplifying circuit of a particulate matter concentration detection module in the multifunctional air quality detection apparatus provided in embodiment 1 of the present invention;

fig. 15 is a block flow diagram of a detection method of the multifunctional air quality detection device provided in embodiment 2 of the present invention;

fig. 16 is a schematic diagram of measuring CO2 gas concentration by using the photoacoustic optical principle provided by the embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, it should be clear that the terms "vertical", "horizontal", "longitudinal", "front", "rear", "left", "right", "up", "down", "horizontal", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description of the present invention, and do not mean that the device or element referred to must have a unique orientation or position, and thus, cannot be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The embodiment of the utility model provides a multi-functional air quality detection device, as shown in fig. 1-15, including built-in box body 1, particulate matter concentration detection module 2, carbon dioxide gas concentration detection module 7, temperature and humidity sensor 8, control module 3 and the display 5 that set up air inlet 11, particulate matter concentration detection module 2, carbon dioxide gas concentration detection module 7 and temperature and humidity sensor 8 are connected with control module 3 respectively; the signal output end of the control module 3 is connected with the display 5, when air enters the box body 1 through the air inlet 11 and contacts the particulate matter concentration detection module 2, the carbon dioxide gas concentration detection module 7 and the temperature and humidity sensor 8 respectively, the particulate matter concentration detection module 2 detects the concentration content of particulate matter in the air, the carbon dioxide gas concentration detection module 7 detects the concentration content of carbon dioxide gas in the air, the temperature and humidity sensor 8 detects the temperature and humidity of the air, the control module 3 triggers the alarm module integrated in the control module 3 to alarm and sends each parameter to the display 5 to display according to the condition that signals fed back by the particulate matter concentration detection module 2, the carbon dioxide gas concentration detection module 7 and the temperature and humidity sensor 8 exceed an alarm threshold value, the box body 1 is further provided with a touch key 6 connected with the control module 3 and used for setting a concentration alarm value, according to the alarm value, the indoor air can be purified by linkage with external equipment such as an air conditioner, an air purifier, a fresh air system and the like.

After adopting above-mentioned scheme, through set up particulate matter concentration detection module 2, control module 3 in box body 1, realized measuring indoor particulate matter concentration.

As shown in fig. 1 and 2, a display 5 is further disposed on the box body 1, and the display 5 is connected to the control module 3 for displaying the current particulate matter concentration content value detected by the particulate matter concentration detection module 2.

Like this, through integrateing alarm module in control module 3 to couple together display 5 and control module 3, effectual realized reminding whether normal and the real-time purpose that shows indoor particulate matter concentration of indoor particulate matter concentration, and then promoted the market competitiveness and the quality of whole device.

As shown in fig. 3, the particulate matter concentration detection module 2 includes a first upper cover body 21, an air channel assembly 22, a signal processing circuit board 23, a photodiode 24, a laser module 25, a micro fan 26 and a lower cover body 27, the first upper cover body 21 is connected with the lower cover body 27, the air channel assembly 22 and the signal processing circuit board 23 are sequentially connected from top to bottom in the first upper cover body 21, the photodiode 24 is arranged on one end face of the signal processing circuit board 23, and the laser module 25 and the micro fan 26 are arranged on the other end face of the signal processing circuit board 23.

As shown in fig. 4, the air duct assembly 22 includes an air duct inlet 221, a laser module housing 222, a light trap 225, an air duct outlet 227 and an air duct housing 228, the air duct inlet 221 is disposed on one side of the air duct housing 228, the laser module housing 222 is disposed on one side of the air duct inlet 221, the light outlet end of the laser module housing 222 is disposed with the light trap 225, the air duct outlet 227 is disposed below the laser module housing 222, and the position above the air duct outlet 227 corresponds to the position of the micro fan 26.

As shown in fig. 4, the light-emitting end of the laser module housing 222 is provided with a lateral hole 223 and a lower hole 224, the lateral hole 223 is used for the laser module 25 to irradiate the air to be measured and generate scattered light when encountering particles in the air to be measured, the lower hole 224 is located above the photodiode 24 and is used for the scattered light emitted when the laser module 25 emits laser light to irradiate the particles in the air to reach the photodiode through the lower hole 224;

as shown in fig. 5, the laser module 25 is a red laser module with a wavelength of 650nm, a green laser module with a wavelength of 520nm, or a blue laser module with a wavelength of 450nm, and includes a metal housing 2221 and a built-in laser collimating lens 2222.

As shown in fig. 13 and 14, a driving circuit for driving the micro fan and a signal filtering and amplifying circuit are integrated on the signal processing circuit board 23, the micro fan driving circuit provides a stable voltage for the micro fan through a voltage stabilizing chip U5, and the signal filtering and amplifying circuit includes an operational amplifier U2, which performs two-stage amplification on a weak electrical signal output by the photodiode 24, so as to facilitate subsequent signal processing.

After the module is initialized, the laser module 25 enters a modulation state, namely, on for 0.5s and off for 0.5 s; within 0.5s of laser lighting, the photodiode 24 continuously receives scattered light generated by laser irradiation on the particulate matters and generates an electric signal, and after the time of 0.5s is over, the microprocessor reads a pulse count value and sends out a calculated particulate matter concentration value; and when the 1s period is timed out, the module repeats the measurement operation. It should be noted that the settling time of the micro fan 26 should not be less than 30s to avoid the inaccuracy of the measurement result due to the difference of the wind speeds of the micro fans.

As shown in fig. 11, air to be measured enters the air passage detection cavity in the air passage structure through the air inlet on the shell under the action of the micro fan, the laser module emits laser beams to irradiate the air in the detection cavity, scattered light is generated under the action of particles, the photodiode absorbs the scattered light to generate an electric signal, and the concentration of the particles in the air can be obtained after the electric signal is filtered and amplified and is processed by an algorithm based on the mie scattering theory.

Further, the box body 1 is also provided with a touch key 6 connected with the control module 3 for setting a particulate matter concentration alarm value.

Air is extracted and sent into the designed air channel component 2 through the built-in micro fan 26, light emitted by the laser module 25 irradiates the air to be detected through the side square hole 223, when particulate matters exist in the air, the laser module 25 irradiates the particulate matters to generate scattering, the photodiode 223 is used for receiving scattered light, an output signal of the photodiode 223 is in direct proportion to the intensity of the scattered light, and the equivalent particle size of the particulate matters and the number of the particulate matters with different particle sizes in unit volume are obtained by utilizing a Mie theory-based algorithm; the measured data is sent to the embedded display 5 of the device for real-time display, and a wireless communication protocol and a wired communication interface are integrated in the device and can be linked with external equipment to perform ventilation and other operations.

As shown in fig. 1, 2, 6, and 7, after carbon dioxide gas enters the cartridge 1 through the vent 11 and contacts the carbon dioxide gas concentration detection module 7, the carbon dioxide gas concentration detection module 7 detects the content of the currently specified gas concentration, and sends the detected gas concentration content to the control module 3, and the control module 3 sends a display signal to the display 5 for data display, and triggers the alarm module integrated in the control module 3 to alarm when the detected gas concentration exceeds the alarm threshold.

After adopting above-mentioned scheme, through set up carbon dioxide gas concentration detection module 7, control module 3 in box body 1, not only realized utilizing NDIR detection technique to measure indoor carbon dioxide gas concentration, prolonged the purpose of adjusting carbon dioxide gas concentration adjusting device's life moreover.

Further, as shown in fig. 6, the carbon dioxide gas concentration detecting module 7 includes a second upper cover 71, a bottom plate 72, a bulb light source 73, an infrared thermopile gas sensor 74, and a waterproof permeable membrane 75, the second upper cover 71 and the bottom plate 72 are cooperatively connected to form a gas chamber for detecting carbon dioxide gas concentration, the bulb light source 73 and the infrared thermopile gas sensor 74 are disposed in the gas chamber and fixedly connected to the bottom plate 72, and the waterproof permeable membrane 75 is disposed above the second upper cover 71 for preventing external atmospheric moisture components from entering the gas chamber to affect the detection of carbon dioxide gas concentration.

Further, the waterproof breathable film 75 is formed by pressing a polypropylene fabric, a high-molecular breathable film, a network reinforcing rib and the polypropylene fabric through a hot melt adhesive layer, so that the influence of external atmospheric water vapor components entering the air chamber on the detection of the carbon dioxide gas concentration can be effectively avoided.

Further, as shown in fig. 7 and 8, the infrared thermopile gas sensor 74 includes a filter module 741, an infrared thermopile module 742, an NTC module 743, a pin post 744, and a base 745, where the filter module 741 is fastened to an upper end of the base 745, the infrared thermopile module 742 is disposed on the base 745, the NTC module 743 is double-sided silver-plated, one side of the NTC module 743 is fixed on the base 745 by silver paste, and the other side of the NTC module is connected to the pin post 744 by gold wire;

the infrared thermopile module 742 is an infrared thermopile chip; the NTC module 743 is an NTC chip; the filter 7411 may filter out infrared rays of a specific wavelength.

In the above process, the NTC chip is used to detect the ambient temperature of the sensor, and can compensate the output voltage of the sensor.

Specifically, moisture, carbon dioxide, etc. in the atmosphere have a strong absorption effect on infrared light with a specific wavelength, and if infrared radiation in the whole wavelength range emitted by an object is allowed to pass through the sensor optical window, the radiation energy received by the thermopile sensor is easily interfered by the concentration of atmospheric components, so that the output result of the sensor is affected. The silicon-based infrared filter loaded on the optical window of the sensor can selectively transmit infrared light in a specific wavelength range, and by designing the transmission-cut-off wavelength parameters of the filter, an atmospheric absorption waveband causing interference can be shielded outside the sensor, so that the radiation energy received by the thermopile sensor is only related to the surface temperature of a measured object and is not interfered by the concentration of atmospheric components.

Further, at least one filter 7411 and at least one infrared thermopile chip 742 are provided, and the number of the filters 7411 matches the number of the infrared thermopile chips 742.

In a specific embodiment, when the filter 7411 and the infrared thermopile chip 742 are provided as one, the infrared thermopile infrared sensor formed thereby is a single-channel infrared thermopile gas sensor, as shown in fig. 8; when the filter 7411 and the infrared thermopile chip 742 are provided in two, the infrared thermopile infrared sensor formed by the filter is a dual-channel infrared thermopile gas sensor, as shown in fig. 7.

The carbon dioxide gas detection process is as shown in fig. 10, air to be detected enters a specially designed air chamber made of ABS material with high reflection property through an air hole of the air chamber structure with a waterproof breathable film 75 attached thereto, and infrared radiation within 5um emitted by a bulb light source 73 needs to be reflected for multiple times in the air chamber, so that the carbon dioxide gas can fully absorb infrared radiation with a wavelength of 4.26 um; the residual infrared radiation reaches the dual-channel infrared thermopile gas sensor, the sensor carries infrared narrow-band filters with the wavelengths of 3.95um and 4.26um, wherein the infrared narrow-band filter corresponding to 3.95um is used as a reference channel and is not influenced by the concentration of carbon dioxide gas, the infrared narrow-band filter corresponding to 4.26um is used as a working channel, and the output voltage is in inverse proportion to the concentration of the carbon dioxide gas; the electric signal is processed by an algorithm based on the beer-Lambert gas absorption law, and then the concentration of the carbon dioxide gas can be obtained.

The bulb light source adopts tungsten filaments as light-emitting elements, the tungsten filaments are packaged in the vacuum glass tube and can emit infrared light within 5um, and carbon dioxide gas has an absorption peak at the wavelength of 4.26um, so that the use requirement is met; meanwhile, the bulb light source can be replaced by an MEMS light source, and an MEMS light source chip in the MEMS light source is subjected to blackening treatment; when the infrared-light-emitting device works, the chip film is heated, and infrared light with the wavelength of 1-25 um is uniformly radiated outwards.

The infrared thermopile chip converts absorbed infrared radiation into a voltage signal by utilizing a Seebeck thermoelectric effect and outputs the voltage signal, and the carbon dioxide gas concentration can be obtained after the voltage signal is subjected to filtering amplification, analog-to-digital conversion and algorithm processing.

The wavelength of the infrared narrowband filter 7411 is 3.95um and 4.26um respectively, and the narrowband filter can shield the influence of the concentration of other components in the atmosphere on the measurement precision. The interference-causing atmosphere absorption waveband can be shielded outside the sensor, and the radiation energy received by the thermopile sensor is only related to the concentration of methane gas and is not interfered by the concentration of other atmospheric components. An infrared narrow-band filter with the wavelength of 3.95um is used as a reference channel, and aims to eliminate measurement errors caused by dust or radiation intensity change; the infrared narrowband filter with the wavelength of 4.26um is a working channel, and aims to detect the attenuation degree of infrared light with the wavelength of 4.26um after the carbon dioxide gas absorbs infrared radiation and measure the concentration of the carbon dioxide gas.

Example 2

The embodiment 2 of the utility model provides a detection method of multi-functional air quality detection device, as shown in fig. 15, this detection method includes following step:

s1, starting the multifunctional air quality detection device, and detecting the content of the current particulate matter concentration in real time by the particulate matter concentration detection module 2;

s2, judging whether the content of the current particulate matter concentration is within a particulate matter concentration threshold value of a preset value, if not, executing S3, and if so, continuing to execute the current process;

and S3, when the preset value is exceeded, the control module 3 triggers an alarm module integrated in the control module (3) to alarm, and the alarm signal is linked with external equipment through a wireless communication protocol and/or a wired communication interface arranged in the control module 3 to ventilate and transmit the gas concentration signal to the display 5 to display.

In summary, the device of the utility model has rich functions, and can display the measured carbon dioxide gas concentration, the measured particulate matter concentration and the ambient temperature and humidity on the embedded display screen of the device in real time; and can set up carbon dioxide gas concentration and particulate matter concentration alarm threshold value and carry out audible and visual alarm, the utility model discloses device communication mode is abundant, and wireless communication agreements such as integrated wifi, bluetooth, 2.4G data pass module, NB-loT, loRa remain the wired interface of external equipment simultaneously, can carry out the linkage with external equipment such as air conditioner, air purifier, new trend system.

The air quality index IAQI is divided into six grades, namely excellent, good, light pollution, moderate pollution, severe pollution and serious pollution. Judging that the air quality is excellent according to the air quality index IAQI numerical value of 0-50, wherein the corresponding concentration of the particulate matters is 0-35 ug/m 3; judging the air quality to be good by an air quality index IAQI numerical value of 50-100, wherein the concentration of the corresponding particulate matters is 35-75 ug/m 3; the air quality index IAQI value is 100-150, the air quality is judged to be light pollution, and the corresponding particulate matter concentration is 75-115 ug/m 3; the air quality index IAQI value is 150-200, the air quality is judged to be moderate pollution, and the corresponding particulate matter concentration is 115-150 ug/m 3; the air quality index IAQI value is 200-300, the air quality is judged to be severely polluted, and the corresponding particulate matter concentration is 150-250 ug/m 3; the air quality index IAQI value above 300 judges the air quality is serious pollution, and the corresponding particulate matter concentration is above 250ug/m 3.

The alarm module integrated in the control module 3 can also adopt a remote alarm assembly, the remote alarm assembly is embedded on the signal processing circuit board 23, the control module 3 sends an alarm signal and can alarm through the remote alarm assembly, and meanwhile, the remote alarm assembly can be sent to an external electronic device for alarming.

Like this, through setting up alarm module and remote alarm subassembly, wherein the remote alarm subassembly can with cell-phone direct communication, namely behind the special APP of user's cell-phone installation, can read alarm information and carbon dioxide gas and the particulate matter concentration information that control module sent.

The remote alarm component can be one or more of a low-power Bluetooth BLE module, a Wifi module, a ZigBee module, a Lora module, an NB-IOT module or a 4G-CAT1 module.

When the remote alarm component is a low-power consumption Bluetooth BLE module, a plurality of air quality detection devices form a network in a plane area with a certain area through a Bluetooth pass function, and a user can operate a special APP through a mobile phone and read data of any node in the network in the area of a local area network;

when the remote alarm subassembly is the Wifi module, in the plane area of certain area, the control module in a plurality of air quality detection device can pass through the Wifi module and connect wireless router, constitutes the LAN, perhaps connects the high in the clouds server through wireless router, regularly uploads data, perhaps reports alarm information in the proruption.

When the remote alarm subassembly is the zigBee module, can be in the plane area of certain area, many air quality detection device constitute a network, and all data gather to the zigBee main node after, upload to the high in the clouds by the main node.

When the remote alarm subassembly is the Lora module, can constitute the network in a three-dimensional region, in whole three-dimensional region, control module 3's data can be sent to the Lora server in real time among all air quality testing device to by the Lora server with data transmission to high in the clouds.

When the remote alarm component is an NB-IOT or 4G-CAT1 module, in a larger area, the data of the control module 3 in all the air quality detection devices can be connected with the communication base station through the NB-IOT module or the 4G-CAT1 module and directly sent to the cloud.

When the remote alarm subassembly is wireless module, constitutes the LAN, and the user can operate special APP in the cell-phone, directly reads the data of an arbitrary node in the LAN in the region of LAN, and the high in the clouds is also sent to the data simultaneously, and special APP in the user's operatable cell-phone visits the data of an arbitrary node in the high in the clouds in any place, sends emergency alarm information to the high in the clouds back, and the high in the clouds can direct propelling movement report to the police to user's cell-phone.

When the remote alarm component power carrier module is arranged in a three-dimensional area, a power carrier main node is arranged in a power control room or a monitoring room, and the main node can be directly connected with each air quality detection device in the three-dimensional area through a 220V live wire.

In the above, the temperature and humidity sensor may be composed of a temperature sensor and a humidity sensor, the temperature sensor is a temperature sensitive element, a thermosensitive resistance value is inversely proportional to a temperature, and a resistance value of the temperature sensor can be detected by using a voltage dividing circuit; the current environmental temperature value can be obtained by inquiring the resistance and temperature corresponding table by the resistance value; the humidity sensor is a humidity sensitive element, the humidity sensitive resistance value is in inverse proportion to the humidity, and the resistance value of the humidity sensor can be detected by using a voltage division circuit; the current environmental humidity value can be obtained by inquiring the resistance and humidity corresponding table according to the resistance value.

In the above, the carbon dioxide gas concentration can be detected by measuring the carbon dioxide gas concentration by using an electrochemical principle.

The electrochemical principle is used for measuring the concentration of carbon dioxide, a solid electrochemical carbon dioxide sensor is used as a core element, when the element is exposed to a carbon dioxide environment, an electrochemical reaction is generated, and an electromotive force is generated, and the applied Winst equation is as follows:

EMF＝E _c -(RT)/(2F)1n(P _co2 )

in the formula:

pco2 is the partial pressure of carbon dioxide,

ec is a constant value and is a constant value,

r is a gas constant, and R is a gas constant,

t is a temperature value in units of K,

f is the Faraday constant.

The method comprises the steps of monitoring an electric potential value EMF generated between two electrodes of a pin of an electrochemical sensor, processing the monitored electric potential value by using an operational amplifier with high input impedance and low bias current and a high-order digital-to-analog converter, and carrying out algorithm processing on the acquired electric signal through a Statt equation, so that the concentration of the carbon dioxide gas is measured.

The alternative scheme of the electrochemical principle has the advantages of linear output, low power consumption, good resolution and the like, but has the defects of short service life, serious interference and the like.

In the above, the carbon dioxide gas concentration may be detected by measuring the carbon dioxide gas concentration using the photoacoustic optical principle, and the measuring principle is shown in fig. 16.

The photoacoustic optical measurement device comprises an MEMS light source, an infrared narrowband filter, a temperature sensor, an atmospheric pressure sensor and a silicon microphone, wherein the MEMS light source is modulated and then emits 1-25 um spectrum infrared light outwards periodically, the infrared light with the wavelength of 4.26um is radiated outwards periodically after being filtered by the 4.26um infrared narrowband filter, air to be measured enters a detection cavity through an air inlet hole attached with a waterproof breathable film, carbon dioxide in the air absorbs infrared radiation with the wavelength of 4.26um and is converted into heat energy, so that thermal expansion and contraction are caused, and pressure change exists; the silicon microphone processes the detected pressure change to obtain the concentration of the carbon dioxide gas.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered by the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A multifunctional air quality detection device is characterized by comprising a box body (1) which is internally provided with an air inlet (11), a particulate matter concentration detection module (2), a carbon dioxide gas concentration detection module (7), a temperature and humidity sensor (8), a control module (3) and a display (5), wherein the particulate matter concentration detection module (2), the carbon dioxide gas concentration detection module (7) and the temperature and humidity sensor (8) are respectively connected with the control module (3); and the signal output end of the control module (3) is connected with a display (5).

2. The multifunctional air quality detection device according to claim 1, wherein the particulate matter concentration detection module (2) comprises a first upper cover body (21), an air passage component (22), a signal processing circuit board (23), a photodiode (24), a laser module (25), a micro fan (26) and a lower cover body (27), the first upper cover body (21) is connected with the lower cover body (27), the air passage component (22) and the signal processing circuit board (23) are sequentially connected with each other from top to bottom, the photodiode (24) is arranged on one end face of the signal processing circuit board (23), and the laser module (25) and the micro fan (26) are arranged on the other end face of the signal processing circuit board (23).

3. The multifunctional air quality detection device according to claim 2, wherein the air passage assembly (22) comprises an air passage inlet (221), a laser module housing (222), a side hole (223), a lower hole (224), a light trap (225), an air passage outlet (227) and an air passage housing (228), the air passage inlet (221) is arranged on one side of the air passage housing (228), the laser module housing (222) is arranged on one side of the air passage inlet (221), the light outlet end of the laser module housing (222) is provided with the light trap (225), the air passage outlet (227) is arranged below the laser module housing (222), the position of the air passage outlet (227) corresponds to the position of the micro fan (26), the light outlet end of the laser module housing (222) is provided with the side hole (223) and the lower hole (224), and the side hole (223) is used for irradiating the air to be detected by the laser module (25), the laser module (25) is a red laser module with the wavelength of 650nm, a green laser module with the wavelength of 520nm or a blue laser module with the wavelength of 450nm, and comprises a metal shell (2221) and a built-in laser collimating lens (2222).

4. The multifunctional air quality detection device according to any one of claims 1 to 3, wherein the carbon dioxide gas concentration detection module (7) comprises a second upper cover body (71), a bottom plate (72), a bulb light source (73), an infrared thermopile gas sensor (74) and a waterproof breathable film (75), the second upper cover body (71) and the bottom plate (72) are connected in a matching manner to form an air chamber for detecting the carbon dioxide gas concentration, the bulb light source (73) and the infrared thermopile gas sensor (74) are arranged in the air chamber and fixedly connected with the bottom plate (72), and the waterproof breathable film (75) is arranged above the second upper cover body (71) and used for preventing external atmospheric moisture components from entering the air chamber to influence the detection of the carbon dioxide gas concentration.

5. The multifunctional air quality detection device of claim 4, wherein the infrared thermopile gas sensor (74) comprises a filter module (741), an infrared thermopile module (742), an NTC module (743), a pin post (744) and a base (745), the filter module (741) is fastened to the upper end of the base (745), the infrared thermopile module (742) is disposed on the base (745), the NTC module (743) is double-sided silver-plated, one side of the NTC module is fixed on the base (745) by silver paste, and the other side of the NTC module is connected to the pin post (744) by gold wire.

6. The multifunctional air quality detection device according to claim 5, wherein the filtering module (741) comprises a filter (7411) and a cap (7412), and the filter (7411) is located on the cap (7412).

7. The multifunctional air quality detection device according to claim 6, wherein at least one filter (7411) and at least one infrared thermopile module (742) are provided, and the number of the filters (7411) is matched with the number of the infrared thermopile modules (742).

8. The multifunctional air quality detection device of claim 7, wherein the infrared thermopile module (742) is an infrared thermopile chip; the NTC module (743) is an NTC chip; the filter (7411) may filter infrared light.