CO₂ sensor

A CO₂ sensor measures carbon-dioxide concentration in air and can help indicate ventilation conditions in occupied spaces. The value is a partial indicator, not a complete indoor-air-quality measure or direct proof of infection risk. Accuracy depends on sensing technology, calibration, placement, height, airflow, occupancy and maintenance. Positioning beside a person, window or supply vent can distort readings. A deployment should define purpose, interval, recording, alerts, owner and intended response using criteria applicable to the building and activity. Comparing devices without checking calibration can drive poor decisions. Validation includes a reference, response to occupancy changes and communication failures. A green dashboard does not prove that the sensor is correctly placed or measuring accurately.