Launched in 2006, the ACE system (Automated Soil CO2 Exchange System) is designed for long-term, unattended monitoring of soil gas exchange. The automated design means that during analysis cycles, the soil can be exposed to ambient conditions before the chamber closes to take measurements. This means the ACE will continue to collect data without any human intervention for as long as permitted by its battery life. This makes the ACE an ideal research instrument for continuous assessment of below-ground respiration and carbon stores in on-going experiments into the quantitative nature of the carbon cycle.