Most of us know that CO₂ is a colorless, odorless gas that’s soluble in water and often seen as the bubbles in fizzy drinks. But it’s also a greenhouse gas, a by-product that’s released when we burn materials containing carbon, as well as a gas formed in the respiratory and metabolic processes of living organisms, which can also be considered slow burning reactions. As CO₂ is always a result of a burning reaction, it is non-combustible and inert. At temperatures below -79 °C (-110 °F) CO₂ becomes solid, and then it’s known as dry ice, which is typically used in transportation or cargo of frozen goods. All of the above characteristics have an impact on the benefits of measuring CO₂.
CO₂ in indoor air
To keep the CO₂ concentration at the recommended level of below 1000 ppm inside places like office buildings, hospitals, and schools, it’s important to control it, which can be done with a building automation system. In colder climates controlling CO₂ levels saves energy and helps to maintain optimal air quality, which has a direct impact on the wellbeing and efficiency of employees occupying the space.
CO₂ in greenhouses
In some applications it’s desirable to keep the CO₂ concentration at a higher level than the ambient concentration of about 400 ppm CO₂. In greenhouses, for example, CO₂ is used as a fertilizer for the plants. To optimize yield, it’s important to maintain optimal levels of CO₂: it’s expensive to use as a fertilizer and excessive use increases costs, but not the harvest.
CO₂ in incubators
CO₂ incubators, or the growth or storage chambers for biological samples, are critical applications, where the CO₂ levels are kept elevated, often at 5 %CO₂, which together with elevated temperature and high humidity ensure optimal growth conditions for the specimens. These both are typical measurement and control applications for CO₂ as it’s not possible to cultivate cells if the CO₂ levels are inaccurate.
In addition to the examples discussed above, CO₂ measurement is often needed for safety reasons in any location where CO₂ is produced, used, or stored. Vaisala has a wide range of dedicated CO₂ measurement instruments ideal for specific applications without frequent calibration needs.