Slide 1 Slide 2 Slide 3 Slide 4 Slide 5 Slide 6 Slide 7 Slide 8 Slide 9 Slide 10 Slide 11 Slide 12 Slide 13 Slide 14 Slide 15 Slide 16 Slide 17 Slide 18 Product List Associated Content
How Does a CO2 Sensor Work?

CO2 sensors are used to monitor carbon dioxide levels within a designated space. Carbon dioxide gas molecules absorb infrared light in accordance with the Beer-Lambert Law. Non-dispersive infrared (NDIR) sensor modules apply this principle per the schematic. An infrared source emits energy through a gas sample cell (waveguide). A tuned optical filter eliminates all but the target wavelength for the gas of interest (~4.3 for CO2) from interaction with the thermopile detector. The thermopile detector then converts the amount of filtered infrared energy to an electrical signal; the greater the gas concentration (CO2), the lower the infrared energy reaching the detector. A microprocessor evaluates the electrical signal from the detector in relation to sensor calibration constants and other parameters, providing a signal-conditioned gas concentration output in ppm.

PTM Published on: 2021-08-25