BACnet and Modbus Particulate Matter Sensors provide air quality measurement in room spaces. These multi-sensors measure PM1.0, PM2.5, PM4.0, PM10 mass concetration and number concentration. The PMR25 multi-sensors measure also temperature, humidity and VOC (volatile organic compounds) as standard. Additional occupancy and CO2 measurements can be added to the sensors. Modbus and BACnet communication back to BMS. The sensors have optional colour LCD and colour touchscreen. The colour touchscreen can be used as the user interface for the BMS for setpoints, fan speed, operating mode etc.