Maintaining a healthy CO2 level within the incubator is important as CO2 interacts with the buffering system of the cell culture media to determine the media’s pH. A key choice to make for CO2 control is what type of CO2 sensor the incubator will have. While many incubators use either the more traditional thermal conductivity (TC) sensor, the newer type of infrared (IR) sensor is often more effective as it is not as sensitive to fluctuations caused by door openings.