Spis treści:
- 1 Main sources of air pollution
- 2 Clean air sensor - analysis of the amount of particulate matter
- 3 Air purity sensor - principle of operation
- 4 Additional information about sensors that measure the presence of particulate matter in the air
- 5 Other parameters of air quality sensors
- 6 Ways to connect air quality sensors and compatibility information
- 7 Battery-powered air quality sensor - a turnkey solution
- 8 Why install an air purity sensor?
The problem of polluted air affects both residents of large urban areas and rural areas, especially in the south of the country. Poor air quality has a direct impact on health by increasing the risk of developing respiratory diseases. Air quality sensors are advanced devices that analyze the air for the presence of pollutants, including PM10 and PM2.5 particulate matter.
With this information, it is possible to adjust activities outside the home and so minimize the impact of smog on health.
What else is worth knowing about these sensors?
Main sources of air pollution
Among the most harmful air pollutants are nitrogen oxides, sulfur dioxides and carbon dioxides. The pollutants are mainly emitted from household stoves, local boiler plants and combustion cars. On windless days, there is a high risk of so-called low emissions, which is the fact that many small sources emit small amounts of pollutants into the atmosphere, which accumulate to form smog. Particulate matter is the main component of smog and poses a serious health risk to people of all ages.
Clean air sensor - analysis of the amount of particulate matter
Air quality sensors are devices used to analyze the air for the presence of pollutants, mainly PM10 and PM2.5 particulate matter. They measure not only the presence, but also the amount of particulate matter. The diameter of PM10 particles does not exceed 10 micrometers.
In contrast, the diameter of PM2.5 particles is less than 2.5 micrometers.
The latter are particularly dangerous, as they can penetrate the bloodstream through the lungs and cause various diseases. Sensors report when safe levels of pollutants are exceeded, allowing action to be taken to protect health.
Air purity sensor - principle of operation
The air quality sensor examines the air flowing through it, assessing the level of pollution. If it detects an exceedance of the established standards for certain substances (e.g., PM10 and PM2.5 particulate matter), the device signals visually, acoustically or by sending a signal to the smart home system’s control panel. This type of operation avoids exposure to adverse atmospheric conditions, especially during periods of intense smog. The sensor can also inform about the need to run a purifier equipped, for example, with a carbon filter that cleans the air of PM10 and PM2.5 dust.
Additional information about sensors that measure the presence of particulate matter in the air
Air quality monitoring sensors can be part of home stations that determine pollution levels, humidity, atmospheric pressure, temperatures and other environmental parameters. Modern models of sensors, in addition to PM10 and PM2.5, also allow monitoring of PM1.0 concentrations. Selected devices are even capable of detecting cigarette smoke.
The advantage of modern air quality sensors is the low power consumption of, for example, 100 mA. Individual models differ from each other, among other things power supply voltage range (e.g. 4.5 V to 5.5 V), particle measurement range, e.g. from 0.3 µm to 1.0 µm, from 1.0 µm to 2.5 µm and 2.5 µm to 10 µm. Another parameter is sensitivity, e.g. 50% for 0.3 µm particles, 98% for 0.5 µm and larger particles. Sensors can also differ in the way they communicate. Some of them use the UART interface.
Other parameters of air quality sensors
The sensor that monitors the degree of concentration of particulate matter in the air guarantees a short response time. Selected models signal detected pollution in less than 10 seconds. Another advantage is the operating temperature range.
Some devices are designed for indoor use only, while others can be safely used outdoors. The standard temperature range of air quality sensors for outdoor use is between -20°C and +50°C. They are small devices with dimensions of 50 × 38 × 21 mm, for example.
Ways to connect air quality sensors and compatibility information
The airborne particulate matter sensor is an important component in many electronic projects, including smart home systems. Selected devices are compatible with microcontrollers such as Arduino, which are the control panel of home automation systems. On the sensor there are pins most often described as VCC (power supply), device ground, Reset, PWM, a pin that changes communication from UART to I2C and vice versa, SET pin and others.
Battery-powered air quality sensor - a turnkey solution
Battery-operated mobile air quality detectors are used to measure concentrations of, among other things. PM1, PM2.5 and PM10 particles with an accuracy of up to 1 ug/m3. Communication with devices of this type takes place via an integrated Bluetooth BLE module providing connectivity to smartphones, for example. In addition, manufacturers of selected sensors provide an application that allows reading and remote management of the sensor.
Some sensors use a laser module to generate an extremely precise beam of light, which is then directed into the medium being tested (such as air). As the laser light penetrates the air, the built-in microprocessor in the sensor carefully analyzes their amount and type. Such measurement involves a detailed analysis of changes in light scattering over a specified period of time.
This makes it possible to accurately determine the concentration of particulates in the air. Sensors of this type take into account not only the number of particles through which the laser beam penetrates, but also their diameter.
Why install an air purity sensor?
The use of an air quality sensor in homes and apartments is intended to provide information about the current concentration of dangerous particulates in the air. During the smog phenomenon, staying outside is particularly dangerous for the elderly, children and people with lung diseases. With the sensor, staying outdoors can be reduced or completely eliminated especially when the concentration of PM1, PM2.5 or PM10 particles is high.
