An ACI CO2 sensor is an essential tool for measuring the concentration of carbon dioxide in air. It works by detecting minute differences in infrared energy that are given off by the gas. Depending on the type of ACI CO2 sensor you use, it can tell you when concentrations reach excessive levels that could be detrimental to humans or other organisms. It can also provide feedback to businesses so they can make informed decisions about their sustainability policies. This makes it a valuable tool in improving workplace conditions and protecting the environment.