Haze detectors, also known as haze meters, are measured by their ability to accurately detect PM2.5 concentrations, which depends on the type of dust sensor and detection principle they use. Currently, haze detectors on the market utilize two types of PM2.5 sensors: infrared dust sensors and laser PM2.5 sensors.

Infrared dust sensors are widely used in air purifiers and lower-priced haze detectors (currently, less than 10% of purification devices on the market are equipped with more accurate laser sensors). Their accuracy is lower, making it difficult to distinguish between PM10 and PM2.5.

With the growth of the air purification industry, end-users have higher demands for precise air quality measurement. Furthermore, as the impact of haze intensifies—with PM2.5 being its primary component—using laser principle sensors for precise PM2.5 quantification has become a recognized industry trend.

Although there are many haze detectors on the market, the quality is mixed. If they do not use the laser particle scattering principle for detection, these products have zero accuracy for haze detection. Since the cost of an infrared sensor is roughly half that of a laser sensor, they can be roughly distinguished by price.

The state does not yet have specific measurement standards for haze detector products. In April this year, the General Administration of Quality Supervision, Inspection and Quarantine conducted a sample survey of haze meters, increasing the crackdown on non-compliant products, which significantly improved the market environment.