Gas analysis system for vehicles and arrangement of such systems

A gas analysis system for a vehicle, comprising:

• a measurement chamber that comprises at least one sensor configured for measuring substances in at least one of exhalations from vehicle occupants and ambient air in a vehicle interior;
• at least one fan placed at a discharge opening for the system and configured to convey air through the measurement chamber;
• at least one filter located at an intake opening in the system and configured to prevent particles from contaminating the system;
• at least one first check valve, located between the measurement chamber and the fan, and configured to block a return-flow of the air out of the measurement chamber and/or ambient air from the vehicle interior into the measurement chamber;
• and
• a control unit configured to regulate and/or control the conveyance of air through the measurement chamber, wherein the control unit is configured to activate and deactivate the system and begin the measurement when a predefined carbon dioxide threshold value is reached in the measurement chamber.