This Air Quality Sensor is a high-accuracy particulate matter monitoring device designed to measure PM1.0, PM2.5, and PM10 concentrations from 0–1000 µg/m³. It features a Modbus RS485 interface with soft configuration, allowing easy integration with PLC, SCADA, BMS, EMS, and industrial automation systems. The unit includes a 4-digit 7-segment display with a cyclic viewing mode, enabling real-time on-site visibility of PM levels without external equipment. Powered by a 12–24V DC input supply, the sensor is suitable for indoor air-quality monitoring, pollution measurement, smart buildings, industrial environments, and HVAC applications.