... , ammonia, hydrogen sulfide, sulfur dioxide and other harmful gases u Monitor temperature and relative humidity u Three-color (green/orange/red ... become an invisible killer of human life, especially to the infant, the pregnant and the old, it can also cause nerve ... 230VAC Wall mounting G02-VOC-B310A IAQ, temperature and humidity monitor/alarm Three-color backlit LCD, buzzer alarm. Modbus RS485 interface ...