CO₂ sensors measure carbon dioxide concentrations in confined spaces such as engine rooms, accommodation areas, or cargo holds. By converting gas levels into digital signals, these sensors provide real-time air quality data to monitoring consoles and alarm systems. Integrated with ventilation controls, CO₂ sensors enable timely adjustments to airflow, maintain safe breathing conditions, and prevent hazardous build-up. Their use enhances crew safety, regulatory compliance, and environmental monitoring onboard vessels.