What Type of CO2 Sensor Does Airmonitor Plus Use?

Modified on Mon, Jan 22 at 1:14 PM

Accurate CO2 monitoring has never been more crucial, particularly in the context of COVID-19. Humans exhale CO2, and individuals infected with the virus emit aerosols containing SARS-CoV-2. By precisely monitoring CO2 levels, we gain insights into the indoor aerosol transmission risk for COVID-19 and other respiratory diseases.


Beyond the pandemic, elevated CO2 levels can impact cognitive function and overall comfort, leading to symptoms like drowsiness, headaches, loss of concentration, increased heart rate, and nausea.


While many air quality monitors use less accurate Metal Oxide Semiconductor (MOS) or Electrochemical sensors, the Airmonitor Plus sets itself apart by employing a highly precise Non-Dispersive Infra-Red (NDIR) sensor. This advanced technology involves passing infrared light through a tube containing a sample of air. At one end, there's an optical filter and a detector that precisely measures the amount of light passing through the filter, ensuring unparalleled accuracy in CO2 level monitoring



The sensor contained in Airmonitor Plus utilizes infra-red light with a wavelength close to the unique 4.26-micron absorption band of CO2. As this light travels through the tube, CO2 molecules selectively absorb this specific wavelength while allowing other wavelengths to pass through to the optical filter. The filter, in turn, absorbs all wavelengths of light except those absorbed by the CO2 molecules in the air sample.


The detector then precisely measures the remaining light that was not absorbed, calculating the difference between this and the emitted light. This measured light absorption is converted into an electrical output, providing an accurate parts per million (ppm) measurement.


In simpler terms, the greater the light absorbed, the more target gas molecules present, resulting in a lower output signal and, inversely, a higher reported CO2 concentration. This sophisticated process ensures that the Airmonitor Plus delivers precise and reliable measurements of CO2 levels, contributing to a comprehensive understanding of your indoor air quality.


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