Application of Gas Sensors in the Field of IoT Intelligent Environment
1. Hazardous Gas Detection for Newly Renovated Houses
More than 90% of newly decorated rooms have seriously excessive hazardous gases. Taking formaldehyde as an example, its concentration in newly decorated houses is often above 2.5 ppm, and some even reach more than ten or dozens of ppm (the GB/T 18883-2002 Indoor Air Quality Standard stipulates that the maximum formaldehyde content shall not exceed 0.1 mg/m³, equivalent to 0.0746 ppm).
Decoration materials are the main source of harmful gases, such as wood-based panels, sandwich panels, glues, paints, coatings, adhesives, granite, ceramic tiles, gypsum, etc. These materials contain varying degrees of pollutants including formaldehyde, benzene, ammonia, and radon. There are no zero-pollution decoration materials.
The traditional practice is to leave the newly renovated house vacant for half a year with continuous ventilation to volatilize harmful gases before occupancy. However, this method is time-consuming and labor-intensive; it only reduces hazards and avoids the period with the highest risks from formaldehyde and other pollutants, but cannot eliminate dangers completely.
Applying gas sensors to domestic living environments—either by developing independent gas detection products targeting volatile organic compounds (VOCs) such as formaldehyde, benzene, and toluene, or integrating gas sensors with air conditioners, air fresheners, air purifiers, etc.—achieves the combination of indoor pollution detection and treatment. This greatly protects vulnerable groups such as the elderly, the weak, women, and children who stay at home for a long time, and also reassures family members working hard outside.
The growing popularity of smart home products is driven not only by comfort but also by family care. In terms of home applications, semiconductor gas sensors stand out for their fast response and recovery, wide detection range, and long service life, while electrochemical gas sensors are favored for their high sensitivity and good linearity.
2. PM2.5 Dust Detection for Indoor Air
Indoor PM2.5 mainly comes from smoking, cooking fumes, and incomplete combustion of gas, which easily cause various discomforts. It is especially harmful to the elderly, children, infants, and people with respiratory or cardiovascular diseases. The traditional methods—opening windows for ventilation and using range hoods during cooking—cannot guarantee clean indoor air.
PM2.5 dust sensors count airborne particles by the scattering of infrared light on dust particles, sensitively detecting particles larger than 1 μm. The built-in heater enables automatic air suction to reduce measurement errors. They are compact and easy to install and use.
3. Air Quality Detection for New Cars
According to surveys, 93.6% of new cars suffer from severe indoor air pollution. Pollution sources mainly come from the vehicle body and decorative materials, among which toxic substances such as formaldehyde, xylene, and benzene are the most harmful and may induce cancer.
Another frequently reported in-vehicle hazardous gas is carbon monoxide, known as the "silent killer". It mainly comes from car engines and exhaust, especially when the air conditioner is on while parking. Once accumulated inside the car, occupants may unknowingly inhale this colorless and odorless toxic gas and die from poisoning.
By adopting appropriate gas sensors, it is possible to monitor not only VOCs such as formaldehyde, xylene, and benzene in the car, but also the concentration of carbon monoxide, providing timely early warnings and reminding car owners to take effective improvement measures to prevent tragedies.
In these applications,
gas sensors reliably complete detection tasks and provide users with accurate data references. Furthermore, linkage control based on these data represents the future development trend. For example:
When excessive formaldehyde or PM2.5 is detected indoors, the exhaust system or negative oxygen ion equipment can be activated in time to improve indoor air quality.
When a household gas leak is detected, the valve is closed immediately, the exhaust system is turned on, and an alarm is sent to users and the control center.
When pollutants are detected in the car, the air conditioning and ventilation system is activated to eliminate hazards.
