CO2 sensors and transmitters measure the concentration of carbon dioxide (CO2) in the ambient air. These measuring instruments are placed in confined spaces that require constant monitoring of the CO2 level in the indoor air.

They are also available in portable versions, which HVAC technicians can use for inspection, monitoring and verification of ventilation systems and indoor air quality in buildings. Other mobile versions are also available as stand-alone data loggers for simplified long-term monitoring campaigns at various locations in a building.

The most reliable CO2 measuring instruments are equipped with a NDIR (non-dispersive infrared) sensor and are based on the absorption rate of the infrared spectrum.

CO2 Transmitters: Essential for indoor air quality control  

To ensure healthy indoor air, it is important to monitor the air quality by using CO2 sensors to adjust the indoor air change rate according to the measured CO2 levels. This prevents excessive concentrations of harmful substances in the indoor air, such as exhaust fumes, cigarette smoke, cleaning chemicals, pollens, volatile organic compounds (VOCs), bacteria and viruses. Excessive CO2 levels can also affect the health of occupants by themselves, causing headaches, fatigue and drowsiness.  
  
It is therefore recommended to maintain indoor air CO2 levels between 800 and 1000 ppm to ensure that the air is sufficiently renewed with fresh filtered air within a building, which will mechanically reduce the concentration of harmful substances in the ambient air.  
 
To learn more about the role of CO2 measuring instruments and their relation with the indoor air change rate (ACR), several articles provide a lot of information in our INsights blog, in order to prevent contamination and poisoning of any kind:Â