CN-121995008-A - Detection device and detection method for formaldehyde and total volatile organic compounds

Abstract

The application relates to the technical field of intelligent sensing systems, and discloses a formaldehyde and total volatile organic compound detection device and a detection method, wherein the detection device comprises a pretreatment filter screen, a detection device and a detection device, wherein the surface of the pretreatment filter screen is provided with a hydrolyzable hydrophilic coating; the device comprises a pretreatment filter screen, a differential pressure monitoring module, a reference gas supply module, a differential sensing module and a processor, wherein the pretreatment filter screen is used for filtering clean air, the differential pressure monitoring module is used for outputting a differential pressure monitoring value reflecting the permeability of the pretreatment filter screen, the reference gas supply module is used for continuously generating and conveying clean air, the differential sensing module is used for providing a background reference signal for the processor, and the processor is used for dynamically compensating the detection value of the gas sensor according to the physical blocking state of the pretreatment filter screen. According to the application, the hydration dust is actively captured and removed, the error is judged by analyzing the physical signal provided by the differential pressure monitoring module and the electrical signal provided by the differential sensing module, and finally the compensation coefficient is dynamically generated to correct the reading of the detection device in real time, so that the reliability of the detection result of the detection device is improved.

Inventors

• WANG YANG
• TIAN HAIBO

Assignees

• 东虹芯光(上海)高科技有限公司

Dates

Publication Date

20260508

Application Date

20260213

Claims (10)

1. 1. A formaldehyde and total volatile organic compound detection device comprising a housing, a gas sensor, and a processor, the device further comprising: The pretreatment filter screen is arranged on the air inlet path of the device, and the surface of the pretreatment filter screen is provided with a hydrolyzable hydrophilic coating which is used for hydrolysis reaction after moisture absorption and is partially dissolved to remove hydration dust attached to the surface of the hydrophilic coating; The pressure difference monitoring module is arranged at the downstream of the pretreatment filter screen and is used for outputting a pressure difference monitoring value reflecting the permeability of the pretreatment filter screen; A reference gas supply module for continuously generating and delivering clean air; the differential sensing module comprises a main sensing channel and a reference sensing channel, wherein the main sensing channel detects sampling gas from the air inlet path and provides detection signals for the processor, and the reference sensing channel continuously receives and detects clean air from the reference gas providing module and is used for providing a background reference signal updated in real time for the processor; The processor is configured to: determining a physical blockage state caused by hydration adhesion of dust on the surface of the pretreatment filter screen by continuously comparing the detection signal with the background reference signal and combining the pressure difference monitoring value; Based on the physical clogging state, the detection value of the gas sensor is dynamically compensated to correct measurement deviation due to physical clogging.
2. 2. The formaldehyde and total volatile organic compound detection apparatus of claim 1, wherein the processor is further configured to: and determining a physical blockage state by analyzing whether a preset cooperative change relation is met between the continuous rising of the differential pressure monitoring value and the continuous attenuation of the detection signal relative to a background reference signal.
3. 3. The formaldehyde and total volatile organic compound detection apparatus of claim 1, wherein the processor is configured to execute a plugging diagnostic model, the inputs of the model including at least differential pressure monitoring values and differential signal values over time, and output as a quantitative assessment of physical plugging status.
4. 4. A formaldehyde and total volatile organic compound detection apparatus according to claim 3, wherein said build-up of a plugging diagnostic model comprises: And continuously collecting the sequence data of the pressure difference monitoring value and the differential signal value which change along with time in the life cycle of the device or in a preset accelerated aging experiment, and carrying out association training on the sequence data and the physical blockage state truth value of the known and simulated dust hydration process.
5. 5. A formaldehyde and total volatile organic compound detection apparatus according to claim 3, wherein the method for dynamically compensating the detection value of the gas sensor comprises: Based on the quantitative evaluation result of the physical blockage state, generating a real-time compensation coefficient through a predefined mapping rule, and correcting the detection value of the gas sensor.
6. 6. The formaldehyde and total volatile organic compound detection apparatus according to claim 1, wherein the main sensing channel and the reference sensing channel in the differential sensing module have identical gas path structure, sensing elements and operating parameters except for the source of the intake air.
7. 7. The formaldehyde and total volatile organic compound detection apparatus of claim 1, wherein the reference gas supply module comprises a purification unit configured to reduce formaldehyde and total volatile organic compound concentrations in the input air to below the detection limit of the gas sensor by adsorption, catalysis, or sieving.
8. 8. The formaldehyde and total volatile organic compound detection apparatus of claim 1, wherein the hydrolyzable hydrophilic coating is at least one of polyvinyl alcohol, hydroxypropyl methylcellulose, or alginate.
9. 9. The formaldehyde and total volatile organic compound detection apparatus of claim 1, wherein said apparatus further comprises: and the state prompting module is used for outputting state information and maintenance instructions corresponding to different jam grades according to the determined physical jam state.
10. 10. A method for detecting formaldehyde and total volatile organic compounds, which is applied to the device for detecting formaldehyde and total volatile organic compounds according to any one of claims 1 to 8, and comprises the following steps: continuously acquiring a differential pressure monitoring value reflecting the permeability of the pretreatment filter screen, and detecting signals of a main sensing channel and background reference signals of a reference sensing channel generated by a differential sensing module; diagnosing a physical blocking state of the pretreatment filter screen caused by dust hydration adhesion according to the trend of the differential pressure monitoring value and the differential trend of the detection signal relative to the background reference signal; based on the diagnosed physical occlusion status, the raw readings of the gas sensor are dynamically compensated to output a corrected contaminant concentration value.

Description

Detection device and detection method for formaldehyde and total volatile organic compounds Technical Field The invention relates to the technical field of intelligent sensing systems, in particular to a formaldehyde and total volatile organic compound detection device and a detection method. Background In the process of home decoration, various artificial boards, adhesives, coatings and other materials can continuously release formaldehyde, benzene series and other total volatile organic compounds, so that in order to ensure living safety, users often use a formaldehyde and total volatile organic compound detection device to evaluate indoor pollution degree after decoration, and the entering time is determined according to the readings of the formaldehyde and the total volatile organic compound detection device. However, a frequently neglected fact is that the evaluation process itself may be disabled due to side effects of the decoration, for example, the decoration process often includes a fine decoration process of marble, artificial stone surface polishing and cutting on the kitchen cabinet, windowsill or floor, which generates a large amount of calcium carbonate dust of micron order although formaldehyde is not directly released, and when the decoration is completed, the user typically opens a window and puts into a detection device to continuously monitor the gas concentration, and since the calcium carbonate dust is not completely dispersed, it is inevitably attached to the gas inlet of the working detection device. The key point of the problem is that the dust is not common dust, when the indoor environment is changed drastically, for example, in a few days after polishing, the local weather is changed from dry sunny days to stormy weather, the indoor humidity can rise sharply, the high humidity environment can promote a large amount of water molecules to be adsorbed on the surface of the calcium carbonate dust attached to the air inlet of the detection device, and the dust particles are agglomerated and bonded through capillary force under the action of an adsorption water film, so that the physical properties of the dust particles are changed from loose particles to a compact and hardened physical blocking layer. The barrier formed by the blocking layer seriously prevents target gas molecules such as formaldehyde in the air from normally passing through and reaching the internal sensor unit, so that the device reading can be continuously and reasonably reduced due to gradual blocking after the peak value displayed at the initial stage, and finally, the device reading is stabilized in a lower theoretical safety numerical range, and a user can misjudge that pollution is eliminated and the device reading is caught. In practice, the sensing capability of the sensor is seriously weakened, and the sensor cannot respond to the real concentration exceeding standard, so that serious missing report risks are caused, and hidden danger exists in the personal health safety of the user. Disclosure of Invention In order to solve the problems, the invention provides the following technical scheme: In a first aspect, the invention discloses a formaldehyde and total volatile organic compound detection device, comprising a housing, a gas sensor and a processor, the device further comprising: The pretreatment filter screen is arranged on the air inlet path of the device, and the surface of the pretreatment filter screen is provided with a hydrolyzable hydrophilic coating which is used for hydrolysis reaction after moisture absorption and is partially dissolved to remove hydration dust attached to the surface of the hydrophilic coating; The pressure difference monitoring module is arranged at the downstream of the pretreatment filter screen and is used for outputting a pressure difference monitoring value reflecting the permeability of the pretreatment filter screen; A reference gas supply module for continuously generating and delivering clean air; the differential sensing module comprises a main sensing channel and a reference sensing channel, wherein the main sensing channel detects sampling gas from the air inlet path and provides detection signals for the processor, and the reference sensing channel continuously receives and detects clean air from the reference gas providing module and is used for providing a background reference signal updated in real time for the processor; The processor is configured to: determining a physical blockage state caused by hydration adhesion of dust on the surface of the pretreatment filter screen by continuously comparing the detection signal with the background reference signal and combining the pressure difference monitoring value; Based on the physical clogging state, the detection value of the gas sensor is dynamically compensated to correct measurement deviation due to physical clogging. Further, the processor is further configured to: and determining a physical blockage sta