With frequent fog and haze weather in northern China, people pay more attention to the quality of the air. Mobile terminal weather information column to join the fog and haze data, even the central broadcast of the weather forecast has also joined the fog and haze information. PM2.5 as the main component of the haze began to be widely concerned, and for the PM2.5 in the air detection instruments are emerging, then the problem of what PM2.5 detector good?

在当前粉尘颗粒PM2.5检测领域中，PM2.5检测仪主要采用两种粉尘传感器：红外粉尘传感器和激光（Laser diode）粉尘传感器。

In the current field of PM2.5 detection of dust particles, PM2.5 detector mainly uses two kinds of dust sensors: infrared dust sensor and laser (diode Laser) dust sensor.

结构和原理红外原理粉尘传感器的结构和电路比较简单。其光源为红外LED光源，气流进出风口主要靠电阻发热以获得热气流流动，有颗粒通过即输出高电平。输出信号只有PWM型号。激光传感器的结构和电路相对复杂。其光源为激光二极管。采样空气通过风扇或鼓风机推动，通过复杂设计的风道，进行检测。当空气中的细颗粒物进入激光束所在区域时，将使激光发生散射;散射光在空间360°都有辐射，我们在适当位置放置光电探测器，使之只接收散射光，然后经过光电探测器的光电效应产生电流信号，经电路放大及处理后，即可得到细颗粒物浓度值。输出信号一般为串口输出。

Structure and principle of the infrared principle dust sensor structure and the circuit is relatively simple. The light source is an infrared LED light source, and the air inlet and the air outlet mainly rely on the resistance to heat to obtain the hot gas flow. The output signal is only PWM model. The structure and circuit of the laser sensor are relatively complex. Its light source is laser diode. The sampling air is driven by a fan or a blower, and is tested by means of a complex design of the duct. When air fine particles entering the laser beam region, the laser scattering; light scattering 360 degrees in the space radiation, we in the appropriate position placed photoelectric detector, which only receives light scattering, and then through the photoelectric effect photoelectric detector produces a current signal, after amplification circuit and processing can be obtained fine particulate matter concentration values. The output signal is generally the serial port output.

价格与成本红外原理粉尘传感器在业内已成熟应用多年，市场价位大约在二十多元。而激光粉尘传感器在业内刚刚兴起，价格在200元左右。两者的成本差距，主要是因为后者的物料成本中增加了激光发生器和风机等机构且需要复杂电路结构，并有较高的技术门槛。

Price and cost infrared principle dust sensor in the industry has been mature for many years, the market price of about twenty yuan. And laser dust sensor in the industry has just emerged, the price of 200 yuan. The cost difference between the two, mainly because of the cost of the material in the latter increased the laser generator and fan and other institutions and the need for complex circuit structure, and a high technical threshold.

测量精度红外原理粉尘传感器只能检测到1微米以上的颗粒，测量精度不足。因为红外LED光散射的颗粒信号较弱，只对大于1微米的大颗粒有响应，而且又仅用加热电阻来推动采样气流，采样数较少，数据计算完全交由上位机进行。而激光传感器可以检测到0.3微米以上的颗粒。因为自带高性能CPU，采用风扇或鼓风机采集大量数据，经由专业颗粒计数算法分析;综上，在采样数、数据源、算法三方面都比红外粉尘传感器更有优势。

Measurement precision infrared principle dust sensor can only detect particles of more than 1 microns, the measurement accuracy is insufficient. Because the infrared LED light scattering particle signal is weak, only to 1 micron particles greater than a response, and only with resistance heating to promote air sampling, small data samples, data calculation completely by the host computer. The laser sensor can detect particles of more than 0.3 microns. Because that comes with high performance CPU, a lot of data collected by a fan or blower, through analysis of professional particle counting algorithm. To sum up, the sampling number, the data source and the algorithm has more advantages than infrared dust sensor.

应用场合由于精度不足，红外原理传感器主要用于工矿扬尘，检测对象为大粒径、高浓度粉尘，检测级别是mg/m3，无法准确测量PM2.5的浓度。而激光原理传感器主要应用在PM2.5检测领域，以精度量化PM2.5质量。可嵌入到家用(车载、手持)空气检测仪、空气净化器中。此外，激光原理传感器在物联网数据采集、环境质量检测等领域亦有应用。

Application occasions due to lack of accuracy, the infrared principle sensor is mainly used for industrial and mining dust, detection of large particle size, high concentration of dust, the detection level is mg/m3, can not accurately measure the concentration of PM2.5. And the principle of laser sensor is mainly used in the field of PM2.5 detection, in order to quantify the quality of PM2.5. Can be embedded into the household (car, hand-held) air detector, air purifier. In addition, the principle of laser sensor in the Internet of things data collection, environmental quality testing and other fields also have applications.

发展趋势在激光原理传感器进入民用领域之前，空气净化器中大量采用了红外原理传感器。但随着空气净化行业的发展，激光原理传感器的造价在逐步降低，终端客户对精准测量空气质量的要求也越来越高。采用激光原理传感器、精准量化PM2.5质量已是业内公认的趋势。今年已有部分空气净化器采用了激光原理传感器。

Development trend in the laser sensor before entering the field of civil, air purifier in a large number of the use of infrared sensors. But with the development of the air purification industry, the cost of laser principle sensor is gradually reduced, the end customer demand for accurate measurement of air quality is also getting higher and higher. The use of laser principle sensor, accurate quantification of PM2.5 quality is the industry's recognized trends. This year has been part of the air purifier using a laser sensor.