The self-developed BA series ETCO2 Sensor with high integration level is designed on the basis of the dual waveband, non-dispersive infrared technology combined with the latest microprocessor and digital signal processing technique. The proven concentration algorithm is used to draw real-time curve of CO2 and deduct the parameters, such as ETCO2, inCO2 and RR. The sampling flow rate of BA series CO2 Sensor can be set to a minimum of 50ml/min and could be setup according to different patient groups, such as babies, children and adults. The standard RS232 or TTL communication interface of the system can be quickly integrated into the monitor or other medical systems involved with the need to monitor the CO2.