By visualizing invisible gases such as CO₂, methane, ethane, ethanol, toluene, etc., one could detect and quantify leakages from pipes, exhalation flow, or characterize bare air flow using CO₂; gas as an inexpensive tracer.

A particular concern when visualizing CO₂ is that it is generally difficult to distinguish from water vapor.
On the other hand, CO₂ cameras can discriminate gases by spectrally filtering infrared absorption at specific wavelengths.
In the 4.3 micron wavelength band, CO₂ is much more absorptive than water vapor, so this concern can be overcome.

CO₂ cameras are equipped with a cooled sensor which has unparalleled sensitivity.
It can detect small gas leaks from several meters away, large gas leaks from several hundred meters away, and gas leaks from moving transport vehicles such as tanker trucks, cargo ships, and freight trains.