Update: 2019-11-19 16:23 Source: LUFTMY
Haze is a kind of weather phenomenon that a large number of small dust particles, smoke particles or salt particles suspended in the atmosphere make the air turbid and reduce the horizontal visibility to below 10km. Because of the continuous occurrence of "haze weather", air pollution has also seriously harmed our health, followed by the continuous marketing of air purification products, the most typical is air Air purifier.
Air purifier with built-in dust sensor
There are many kinds of air purifiers, which can be simply divided into physical purification and chemical purification. Physical purification is adsorption, such as HEPA filter, activated carbon adsorption, chemical purification is decomposition, mainly for harmful gases. The principle of technology is high energy particle oxidation. Of course, the sensors used in their front signal acquisition and detection are basically the same, generally using air quality sensor and PM2.5 dust sensor.
The progress of "sensor technology" is closely related to people's understanding of "air quality" and the development of the times' needs In the field of smart home, people want to pursue quality life, one of the requirements is that all kinds of smart home products have a certain degree of comfort. And the design of humanized details is the embodiment of a smart home brand's pursuit of excellence and consideration for customers. At present, there are three kinds of air purifiers in the market: temperature and humidity sensor, dust sensor and odor sensor.
The dust sensor (also known as PM2.5 sensor) targets particles larger than the odorant. Its detection uses optical method. "When the light hits the air, if there is dust in the air, the light will scatter. And the dust sensor is to detect the dust by measuring the reflected light. At present, the sensor measures not only the amount, but also the size of dust based on a certain threshold. According to the current recognition method, if the amount of light reflected by dust passing through becomes larger, the particles will be larger and smaller, and the particles will be smaller. " In this way, by the mid-1990s, air purifiers had been able to detect air quality in terms of smell and dust.
The function of the humidity sensor is to manage the operation of the "humidifier" necessary for air purifiers today. Check room humidity (dry condition). According to this data, the humidification amount is controlled to maintain the most comfortable humidity.
In the 1980s, the main function of the air purifier was to "remove the smell of smoke". Among the sensors, the air purifier is first equipped with an "odor sensor". The function of odor sensor is to detect the concentration of "odor" substances floating in the air. When the surface of the sensor made of metal oxide semiconductor adsorbs the odor molecule, the electrical conductivity will increase and the resistance will decrease. The sensor can judge the concentration of odorant by detecting the generation of resistance value.
At present, it is very difficult to measure indoor air quality accurately no matter whose sensor it is. On the one hand, the accuracy of the sensor itself is a problem. On the other hand, due to the uneven distribution of air mobility and pollutants, it is difficult to determine the PM2.5 and TVOC values of air in a certain space by a single sensor.
On the market, most air purifier manufacturers only make qualitative judgment on air quality and determine the level of air quality, which is the basis of machine operation. This involves complex algorithm design, because of the existence of the above problems. Even when used to measure air quality levels, these machines can make false judgements.
Air purifier mobile phone remote control APP
In the near future, the air purifier will become more and more intelligent. For example, add the app with remote control, connect the air purifier with the mobile phone, receive the data of indoor sensors in a short distance, check the indoor air quality, and adjust the air volume, various modes, humidification, etc. directly and remotely through the mobile phone. The realization of this function will greatly facilitate people's life. Office workers and people who often go out can master and control the home environment at any time.
LUFTMY PM particulate matter sensor HPD05 uses the principle of optical scattering to measure the dust concentration within the detection range through the conversion of optical path and circuit. The air flow sensor module hpd05 has the characteristics of small volume, high precision, low power consumption, short response time, stable operation under high dust concentration, etc. it can be used in air purifier, air conditioner with purification function, PM2.5 detector, etc.