This document describes the properties of carbon dioxide (CO2) and presents ideal gas law, unit conversion and gas dilution theory to support gas sampling issues in CO2 measurements.
What is CO2?
Carbon dioxide (CO2) is a colorless gas consisting of one carbon and two oxygen atoms. CO2 exists in gas state above -78.5°C and in solid state (dry ice) below -78.5°C. CO2 changes from solid to gas by sublimation In nature, plants use CO2 in photosynthesis, where CO2 and water are combined using sun light as energy to produce sugars (and oxygen). The reaction can be written in a general form as shown in Figure 1.